Unity Biotechnology, Inc.
Annual Report 2018

Plain-text annual report

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 10-K (Mark One)☒ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the fiscal year ended December 31, 2018OR☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIODFROM TO Commission File Number 001-38470 Unity Biotechnology, Inc.(Exact name of Registrant as specified in its Charter) Delaware26-4726035( State or other jurisdiction ofincorporation or organization)(I.R.S. EmployerIdentification No.)3280 Bayshore Blvd. Suite 100Brisbane, CA94005(Address of principal executive offices)(Zip Code)Registrant’s telephone number, including area code: (650) 416-1192 Title of each class Name of each exchange on which registered Common stock, par value $0.0001 The Nasdaq Global Select Market Securities registered pursuant to Section 12(g) of the Act: NoneIndicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YES ☐ NO ☒Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. YES ☐ NO ☒Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. YES ☒ NO ☐Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 ofthis chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). YES ☒ NO ☐Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405) is not contained herein, and will not be contained, to the best ofRegistrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ☐Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company.See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer ☐ Accelerated filer ☐ Non-accelerated filer ☒ Smaller reporting company ☐ Emerging growth company ☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financialaccounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YES ☐ NO ☒The aggregate market value of the voting and non-voting common equity held by non-affiliates of the Registrant, based on the closing price of the shares of common stock on TheNASDAQ Global Select Market on June 29, 2018, was $423,352,473.The number of shares of Registrant’s Common Stock outstanding as of March 1, 2019 was 42,856,993.DOCUMENTS INCORPORATED BY REFERENCEPortions of the Registrant’s Definitive Proxy Statement relating to the 2019 Annual Meeting of Shareholders, scheduled to be held on June 20, 2019, are incorporated by reference intoPart III of this Report. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the end of the fiscal year covered by this Annual Report onForm 10-K. Table of Contents PagePART I Item 1.Business4Item 1A.Risk Factors42Item 1B.Unresolved Staff Comments82Item 2.Properties82Item 3.Legal Proceedings82Item 4.Mine Safety Disclosures82 PART II Item 5.Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities83Item 6.Selected Financial Data85Item 7.Management’s Discussion and Analysis of Financial Condition and Results of Operations86Item 7A.Quantitative and Qualitative Disclosures About Market Risk98Item 8.Financial Statements and Supplementary Data99Item 9.Changes in and Disagreements With Accountants on Accounting and Financial Disclosure131Item 9A.Controls and Procedures131Item 9B.Other Information131 PART III Item 10.Directors, Executive Officers and Corporate Governance132Item 11.Executive Compensation132Item 12.Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters132Item 13.Certain Relationships and Related Transactions, and Director Independence132Item 14.Principal Accounting Fees and Services132 PART IV Item 15.Exhibits, Financial Statement Schedules133Item 16.Form 10-K Summary136 Signatures137 i Forward-Looking StatementsThis Annual Report on Form 10-K contains “forward-looking statements” within the meaning of Section 21E of the Securities Exchange Act of1934, as amended (the “Exchange Act”). All statements other than statements of historical facts contained in this Annual Report on Form 10-K are statementsthat could be deemed forward-looking statements reflecting the current beliefs and expectations of management with respect to future events or to our futurefinancial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievementsto be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. These statementsare often identified by the use of words such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “due,” “estimate,” “expect,”“goal,” “if,” “intend,” “may,” “objective,” “plan,” “predict,” “potential,” “positioned,” “seek,” “should,” “target,” “will,” “would,” “until” and similarexpressions or variations. Forward-looking statements contained in this Annual Report on Form 10-K include, but are not limited to, statements about: •our expectations regarding the potential benefits, activity, effectiveness and safety of our drug candidates; •our expectations with regard to the results of our clinical studies, preclinical studies and research and development programs, including the timingand availability of data from such studies; •our preclinical, clinical and regulatory development plans for our drug candidates, including the timing or likelihood of regulatory filings andapprovals for our drug candidates; •our expectations with regard to our ability to acquire, discover and develop additional drug candidates and advance such drug candidates into, andsuccessfully complete, clinical studies; •our expectations regarding the potential market size and size of the potential patient populations for our drug candidates, if approved forcommercial use; •our intentions and our ability to establish collaborations and/or partnerships; •the timing and amount of any milestone payments we are obligated to make pursuant to our existing license agreements and any future license orcollaboration agreements that we may enter into; •our commercialization, marketing, and manufacturing capabilities and expectations; •our intentions with respect to the commercialization of our drug candidates; •the pricing and reimbursement of our drug candidates, if approved; •the implementation of our business model and strategic plans for our business and drug candidates, including additional indications for which wemay pursue; •the scope of protection we are able to establish and maintain for intellectual property rights covering our drug candidates, including the projectedterms of patent protection; •estimates of our expenses, future revenue, capital requirements, our needs for additional financing, and our ability to obtain additional capital; •our anticipated use of proceeds from our initial public offering; •our future financial performance; •developments and projections relating to our competitors and our industry, including competing therapies; and •other risks and uncertainties, including those listed under the caption “Risk Factors.”We caution you that the foregoing list may not contain all of the forward-looking statements made in this Annual Report on Form 10-K.Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance orachievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Wediscuss these risks in greater detail in “Risk Factors” and elsewhere in this Annual Report on Form 10-K. Given these uncertainties, you should not placeundue reliance on these forward-looking statements. Also, forward-looking statements represent our management’s beliefs and2 assumptions only as of the date of this Annual Report on Form 10-K. Except as required by law, we assume no obligation to update these forward-lookingstatements publicly, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if newinformation becomes available in the future.This Annual Report on Form 10-K also contains estimates, projections and other information concerning our industry, our business and the marketsfor certain drugs, including data regarding the estimated size of those markets, their projected growth rates and the incidence of certain medical conditions.Information that is based on estimates, forecasts, projections or similar methodologies is inherently subject to uncertainties, and actual events orcircumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry,business, market and other data from reports, research surveys, studies and similar data prepared by third parties, industry, medical and general publications,government data and similar sources. In some cases, we do not expressly refer to the sources from which this data is derived. In that regard, when we refer toone or more sources of this type of data in any paragraph, you should assume that other data of this type appearing in the same paragraph is derived from thesame sources, unless otherwise expressly stated or the context otherwise requires.TrademarksThis Annual Report on Form 10-K includes trademarks, service marks and trade names owned by us or other companies. All trademarks, servicemarks and trade names included in this Annual Report on Form 10-K are the property of their respective owners.3 PART IItem 1. Business.Overview Our mission is to extend human healthspan. We define healthspan, or healthy longevity, as the period of one’s life unburdened by thediseases of aging. Enabled by foundational scientific insights, we have devoted over seven years to identifying multiple mechanisms that we believe to beroot causes of age-related disease. We are utilizing these insights to develop a broad portfolio of drug candidates to treat these diseases of aging, and weinitiated our first clinical study of our lead drug candidate in the second quarter of 2018. We believe our team of scientific, clinical, and business leaders, andour strong culture of collaboration with external scientists make us uniquely qualified to accomplish our ambitious mission.Age-related diseases such as arthritis, vision loss, and cognitive decline cause considerable economic, personal, and societal burden. As individualsage, the prevalence of chronic disease increases, with 80% of older Americans having at least one chronic disease and 50% having two or more. Age-relateddiseases negatively impact quality of life, are typically chronic, and progress from the time of onset until death. It is estimated that providing healthcare forpeople over the age of 65 costs four to five times more than for younger individuals. According to the Centers for Disease Control and Prevention, this elderlypopulation of Americans is expected to nearly double by 2050, increasing the economic burden of aging dramatically. Any success increasing longevitywithout treating underlying diseases of aging would only serve to increase this burden.We have developed a portfolio of programs targeting specific biological mechanisms implicated in diseases of aging and a pipeline of drugcandidates to attack specific age-related diseases, beginning with musculoskeletal, ophthalmologic, and pulmonary indications.Cellular SenescenceWe believe that the accumulation of senescent cells is a fundamental mechanism of aging and a major driver of many common age-related diseases.Cellular senescence is a natural biological state in which a cell permanently halts division. These cells are referred to as senescent. As senescent cellsaccumulate with age, they begin secreting large quantities of more than 100 proteins, including inflammatory factors, proteases, fibrotic factors, and growthfactors, that disturb the tissue micro-environment. This collection of secreted proteins is referred to as the Senescence Associated Secretory Phenotype, orSASP. In addition to its effects on tissue function, the SASP contains factors that induce senescence in neighboring cells, setting off a cascade of events thatculminates in the formation of the functionally aged and/or diseased tissue that underlies a variety of age-related diseases.Senolytic medicines selectively eliminate senescent cells and stop the production of the SASP at its source, which we believe addresses a rootcause of diseases of aging. Many existing therapeutics, such as antibodies, target single SASP factors, but fail to remove the cells that continually producemultiple SASP factors. By stopping the production of the SASP at it source, we believe senolytic medicines could have a more durable impact on disease andcould slow, halt, or reverse particular diseases of aging, and shift the treatment paradigm from chronic to intermittent dosing. Less frequent dosing may alsoimprove drug tolerability and patient adherence. We are developing a number of molecules that we refer to as senolytic medicines.Our PipelineWe are developing a portfolio of programs targeting specific biological mechanisms implicated in diseases of aging. Our core therapeutic approachtargets cellular senescence, and we are currently advancing senescence programs in musculoskeletal, ophthalmologic, and pulmonary disorders. Our clinicaldevelopment strategy is initially focused on the development of senolytic medicines designed to be administered locally into diseased tissue. Afterdemonstrating efficacy in indications amenable to localized therapy, we plan to pursue the development of senolytic medicines that could be administeredsystemically to treat additional age-related diseases such as kidney disease, liver disease and neurological disorders. In addition to our efforts to eliminatesenescent cells, we are also advancing other programs that have the potential to extend human healthspan, including the administration of circulating youthfactors and the enhancement of mitochondrial function.4 Our current pipeline of programs is illustrated below:Within our cellular senescence programs, our lead senolytic molecules, UBX0101 and UBX1967, designed for local treatment for the removal ofaccumulated senescent cells, are described below:Musculoskeletal/Osteoarthritis ProgramsUBX0101 is our lead drug candidate for musculoskeletal disease with an initial focus on osteoarthritis, or OA, of the knee. It is a potent senolyticsmall molecule inhibitor of the MDM2/p53 interaction. Disruption of this protein-protein interaction can trigger the elimination of senescent cells. Weinitiated a Phase 1 clinical study in OA of the knee in the second quarter of 2018 and we expect initial results from this Phase 1 clinical study in the secondquarter of 2019. We own, co-own or have exclusively licensed worldwide rights for the use of UBX0101 for the treatment of OA. See “—IntellectualProperty.”Ophthalmology ProgramUBX1967 is our most advanced lead drug candidate for age-related diseases of the eye, including age-related macular degeneration, diabeticmacular edema and proliferative diabetic retinopathy. This drug candidate is a potent senolytic small molecule inhibitor of specific members of the Bcl-2family of apoptosis regulatory proteins. UBX1967 inhibits the function of proteins that senescent cells rely on for survival. In our preclinical studies, wehave demonstrated that by targeting this pathway UBX1967 preferentially eliminates senescent cells while sparing non-senescent cells. We plan to submit anIND application for UBX1967 in early 2020 that, if accepted, would enable us to pursue multiple age-related eye indications in clinical trials. Under alicense agreement with Ascentage Pharma Group Corp Limited, we have exclusive worldwide development and commercialization rights and non-exclusivemanufacturing rights to UBX1967 outside of Greater China (China, Hong Kong, Macau and Taiwan) in all non-oncology indications Inside Greater China,we will be obligated to develop, manufacture and commercialize UBX1967 through a joint venture with Ascentage. See “—Licenses and Collaborations.”Our StrategyTo achieve our objective of building Unity into a leading healthspan company, we focus on two parallel efforts. First, we are committed todeveloping senolytic medicines that slow, halt, or reverse specific diseases of aging. Second, we dedicate significant resources and effort to better understandfundamental aging mechanisms and translating these insights into human medicines. This pioneering work is supported by valuable collaborations withleading academics. By investing early in the science of aging, we believe we are positioned to transition the field of5 aging biology from fundamental scientific insights to the development and commercialization of medicines. Our core strategies to achieve this objectiveinclude: •Demonstrate in our clinical studies that local treatment with senolytic medicines can alter the course of age-related diseases. We believe thatlocal treatment with senolytic medicines has the potential to slow, halt, or reverse aspects of aging. If we prove this concept in a localized setting,we will be well-positioned to expand upon that success with numerous additional applications. •Continue research into the development of systemic senolytic medicines. We believe that harnessing the full potential of senolysis, or theselective elimination of senescent cells, to alter many diseases of aging will require systemic senolytic medicines. We intend to explore thedevelopment of systemic senolytic medicines using multiple modalities, including small molecules and biologics. •Target aging mechanisms beyond cellular senescence. While cellular senescence and senolysis have been shown to affect the course of multiplediseases of aging, we believe achieving our broader goal of extending human healthspan will require intervention in additional aging mechanismsbeyond cellular senescence. We will continue to conduct fundamental research into these other aging mechanisms, including loss of circulatingyouth factors and mitochondrial dysfunction. We will also continue to partner with the most forward-thinking aging researchers in the world tofoster a collaborative environment to bring their insights, innovation, and technologies into our powerful research and drug developmentinfrastructure. •Leverage our core science and biotechnology experience. We strive to attract, retain, and incentivize a unique team with significant strengthsand experience in basic science, biotechnology, medicinal chemistry, and clinical development. Over the last seven years, our team has identifiedmultiple mechanisms that can selectively eliminate senescent cells, created potent senolytic molecules, and developed proprietary animal modelsto monitor senescent cell clearance. We have developed significant insight into the relationship between the accumulation of senescent cells andhuman disease. Further, our management team has extensive biotechnology and pharmaceutical experience, and has played a leadership role in thecreation of numerous FDA-approved medicines. •Opportunistically expand our product portfolio. Our internal research has identified multiple biological pathways that are potential targets fordiseases of aging. We will search for opportunities to in-license novel medicines that can rapid enter clinical development. We expect that ourcurrent leadership in the biology of cellular senescence will serve as a foundation for us to develop numerous products to treat human disease. •Continue to build a robust and defensible patent portfolio. We are an innovative biotechnology company focused on developing novel insightsinto the biology and diseases of aging. Our current patent portfolio consists, on a worldwide basis, of 30 issued and allowed patents and more than100 additional pending patent applications which we own, co-own or have exclusively licensed. We intend to continue to aggressively develop,file, and pursue additional patent protection for our innovative technologies and products.Healthspan and Diseases of AgingAge-related diseases such as arthritis, vision loss, and cognitive decline cause considerable economic, personal and societal burden. As individualsage, the prevalence of chronic disease increases, with 80% of older Americans having at least one chronic disease and 50% having two or more. Thisdeterioration of health negatively impacts quality of life, and age-related diseases are typically chronic and persist from the time of onset until death.Diseases of aging drive significant healthcare spending. It is estimated that providing healthcare for people over the age of 65 costs four to fivetimes more than for younger individuals. The Centers for Medicare and Medicaid Services expect health spending in the United States, or U.S., to exceed$5.2 trillion by 2025, which is equal to approximately 20% of the projected U.S. gross national product for the same year. According to the Centers forDisease Control and Prevention, the population of Americans aged 65 years or older is expected to nearly double by 2050, dramatically increasing theeconomic burden of aging. Moreover, diseases associated with aging have a detrimental impact on quality of life and older adults are often less optimisticabout their future. Of the 34 million6 family caregivers in the U.S. who support aging relatives, many experience a deterioration in their own health and well-being as a result.We believe that by creating medicines that target fundamental aging mechanisms, we can reduce the economic, personal, and societal burden ofaging and enhance quality of life. Our Approach to Extending Human HealthspanCauses of Cellular SenescenceCellular senescence is a natural biological state in which a cell permanently halts division. Cells become senescent when they experience someform of unresolvable cellular stress. To date, six stress mechanisms have been identified that can cause a cell to become senescent, including (i) extensive celldivision and telomere shortening, (ii) DNA damage, (iii) oxidative stress, (iv) high concentration glucose, (v) mitochondrial dysfunction, and (vi) activationof a cancer-causing gene.These cellular stress events result in the activation of the tumor suppressor protein p53, which drives the production of two cell-cycle dependentkinase inhibitors, or CDK inhibitors, p21 and p16. These two molecules are required for the establishment and subsequent maintenance of the senescent cellstate. The first CDK inhibitor to be produced is p21, which works through subsequent pathways to block the production of numerous proteins that cells needto divide. The initial p21-driven signal is an acute response to cell damage and eventually decreases. In contrast, p16 permanently locks the cell into a non-dividing state and the production of p16 continues as long as the cell lives. Given that p16 production, in most cases, continues indefinitely and is believedto be produced almost exclusively in senescent cells, it is a widely used marker to identify and quantify senescent cells.The process through which stress mechanisms can induce cells to become senescent is illustrated in the figure below. How Senescent Cells Drive Diseases of Aging: The SASPOnce cells become senescent, they begin secreting large quantities of more than 100 proteins, including pro-inflammatory factors that recruit theimmune system, proteases that remodel the extra-cellular matrix, pro-fibrotic factors that drive the formation of dysfunctional matrix, and growth factors thatperturb the function of the tissue7 micro-environment. This collection of secreted proteins is referred to as the Senescence Associated Secretory Phenotype, or SASP. In addition to its effects ontissue function, the SASP contains factors that induce senescence in neighboring cells, setting off a cascade of events that ultimately culminates in theformation of a functionally aged and/or diseased tissue that underlies a variety of age-related diseases. This process is illustrated in the figure below. Numerous SASP factors have been implicated as potentially contributing to human disease and it is now believed that the SASP is the primarymeans by which senescent cells drive specific diseases of aging. For example, a variety of single SASP factors (TNF-α and VEGF-A) have been demonstratedto drive human diseases by themselves and have been the target of well-known antibody therapeutics, including HUMIRA® and EYLEA®. While theseantibodies are able to modify human disease by removing the activity of a single SASP factor, we believe the clearance of senescent cells will remove thesource of numerous SASP factors, providing improvement in both efficacy and duration-of-effect. Our Therapeutic ParadigmWe were founded on the principle that the selective elimination of senescent cells and their accompanying SASP has the potential to slow, halt, orreverse diseases of aging. Our insights into senescent cell biology allow us to8 identify senescence-driven diseases, target the senescent cells driving a particular disease, and selectively eliminate these cells. The figure below illustratesthis process. In developing this approach, we have acquired significant expertise with respect to senescent cell survival pathways, which are the signalingsystems that senescent cells rely on for survival. When these pathways are inhibited with specifically designed molecules, senescent cells undergoprogrammed cell death. Through our research, we have identified several of these mechanistically distinct survival pathways, which differ depending on celltype and the tissue in which the senescent cells reside.Using small molecules, we have cataloged these survival pathways on a cell-type-by-cell-type basis into a database we refer to as the ATLAS. Thedatabase indicates the survival pathways on which specific senescent cell types depend thereby elucidating vulnerabilities in those cells that can beexploited by the administration of senolytic molecules to trigger the selective elimination of these cells. The ATLAS provides us with a map of chemicalstarting points for the creation of senolytic medicines. Advantages of Our ApproachWe believe that senolytic medicines—medicines that selectively eliminate senescent cells from diseased tissues—may have four advantages overother efforts to treat age-related diseases: •Senolytic medicines target a root cause of diseases of aging. We believe that the accumulation of senescent cells is a root cause of many diseasesof aging. Unlike treatments that inhibit the activity of a single factor (such as antibodies targeting single pro-inflammatory proteins), we believe asenolytic medicine that selectively eliminates accumulated senescent cells and consequently also their associated SASP, could blunt the activityof numerous factors contributing to disease. As a result, senolytic medicines could have improved efficacy because they target diseases at theirsource and therefore may be able to normalize tissue levels of numerous disease-causing factors simultaneously. •Senolytic medicines can be dosed intermittently. The administration of senolytic medicines would remove senescent cells from diseased tissue.As new senescent cells may take months or even years to re-accumulate, senolytic medicines could potentially be dosed infrequently. We believethat intermittent dosing (rather than ongoing chronic dosing) could restore normal tissue function such that further drug administration would notbe required until senescent cells have re-accumulated. Intermittent dosing may also improve drug tolerability and patient adherence whencompared to chronic therapies. •Senescent cells accumulate at sites of disease, simplifying multiple aspects of clinical development. We believe senescent cells accumulate atsites of disease and drive disease through their accompanying SASP.9 Our ability to quantify senescent cells and accompanying SASP factors in sites of disease may simplify clinical development in a number of ways.First, we can simplify indication selection to pursue the development of senolytic medicines for diseases in which we observe the localaccumulation of senescent cells. Second, it is possible to identify patients that may better respond to senolytic medicines based on p16 expressionand other biomarkers of senescence. Third, we can potentially monitor patients for response to therapy by tracking the reduction of senescence-associated biomarkers. •Senolytic medicines restore tissues to a healthy state. We believe senescent cells generally do not accumulate in young individuals and that theaccumulation of senescent cells is unnecessary for normal tissue function. Our goal for the administration of senolytic medicines is to restore tissueto a functionally younger state.Our Discovery and Development StrategyWe believe that each of our senolytic programs has the potential to address a root cause of an age-related disease. Our clinical developmentstrategy is initially to develop senolytic medicines designed to be administered locally into diseased tissue (either by injection or inhalation), which reducessystemic toxicological risks by limiting drug exposure largely to the treated tissue. After demonstrating safety and efficacy in indications amenable tolocalized therapy, we plan to pursue the development of senolytic medicines that could be administered systemically, initially acting on specific tissues forwhich direct local administration is challenging. Ultimately, we envision the potential for systemic administration of senolytic medicines to selectivelyeliminate senescent cells throughout the body to treat diseases of aging that are not amenable to local treatment, such as kidney, liver, and heart disease. Weare also developing medicines that act on aging mechanisms beyond cellular senescence, such as those that address the loss of circulating youth factors andenhance mitochondrial health. By targeting specific biological mechanisms that are implicated in diseases of aging, our vision is to address the body as awhole, reducing age-related diseases and extending human healthspan.Cellular Senescence Biology ProgramMusculoskeletal/Osteoarthritis ProgramsUnmet Need and Therapeutic RationaleDiseases of the musculoskeletal system represent one of the leading causes of disability in the world, particularly among the aging population.According to the 2015 World Health Organization World Report on Ageing and Health, musculoskeletal diseases account for the most time those over age 50in the developed world spend living with a disability. To date, senescence has been linked with osteoarthritis of the knee, hip, and intervertebral (spine) facetjoints, degeneration of intervertebral discs, and loss of bone density.Osteoarthritis, or OA, is a degenerative disease that negatively impacts subchondral bone and the synovial tissue surrounding the joint, causingpain and physical impairment. The effect of tissue degeneration causes the normally smooth joint layers to become fragmented and pitted, the synovial tissueto become inflamed and thickened, and the bone to develop abnormal morphology, all of which lead to a decrease in joint function and mobility, pain, andphysical impairment. OA is a highly prevalent disease, symptomatically affecting as many as 10% to 15% of the world’s population over age 60, and resultsin a decline in quality of life. The most common joint affected by OA is the knee, followed by the hip, ankle, and shoulder. Importantly, the current standardof care begins with symptomatic treatment that temporarily addresses joint inflammation or pain control. The natural progression of treatment often results injoint replacement surgery. Based on data from the Agency for Healthcare Research and Quality (a division of the U.S. Department of Health and HumanServices) for 2009, the aggregate cost of knee and hip replacements in the United States was $42.3 billion. The overall cost of OA is estimated to be greaterthan $150 billion per year in the United States.OA of the knee is believed to be a heterogeneous and multifactorial disease. We believe that the accumulation of senescent cells and associatedSASP are significant contributing factors in OA disease. A number of SASP factors are secreted by senescent cells into the tissue and/or synovial fluidsurrounding an affected joint, including (i) cytokines and chemokines which may cause inflammation, such as the interleukins IL-1ß and IL-6; (ii) proteasesand protease inhibitors, which may cause tissue degradation, such as MMP-1, MMP-3 and MMP-13; and (iii) growth10 factors and adhesion molecules, which may lead to tissue remodeling, such as VEGFC and ICAM-1. The presence and concentrations of these SASP factorsmay vary based on the tissue and fluid type, however we believe these SASP factors lead to cartilage loss, inflammation of the synovial membrane,abnormalities to bone, degeneration of the joint cartilage, and pain.Evidence for Cellular Senescence Burden in Human Disease and Human Biomarker DiscoveryTo evaluate the link between cellular senescence, SASP accumulation and OA disease, we conducted a non-interventional biomarker study in 30patients with primary OA of the knee. The enrolled patients displayed a range of OA disease between grades 1 and 4 based on an X-ray scoring system calledthe Kellgren-Lawrence, or KL, grade. The KL grade is a common tool used to classify extent of OA with scores ranging from 0, referring to no disease, tograde 4, referring to severe disease. During the study, patients underwent knee MRI imaging with contrast enhancement and arthroscopy, a fiber opticsurgical device inserted into the knee joint, for biopsy of synovial membrane and non-weight bearing cartilage. They also provided blood and urine, andunderwent pain scoring, as measured by the WOMAC-A sub-scale, a commonly used standardized questionnaire, to evaluate their OA disease status and itsrelationship to senescent cell burden.Immunohistochemistry, or IHC, of the sampled tissue demonstrated p16-positive cells affecting a number of cell types within the synovialmembrane. The degree of senescence was quantified in these samples by measuring the percentage of p16 positive cells relative to the total cell number in thespecimen.Several significant findings were identified by assessing the relationship between the percent of p16-positive cells and other measures in thisstudy. First, the extent of senescence was significantly correlated with the concentration of IL-6, a well-established inflammatory marker associated with OA.(Figure 1A). Second, the extent of senescence in the synovial membrane from each patient showed statistically significant correlation to the amount of paineach of those patients experienced at the start of the study, based on the WOMAC-A pain sub-scale (Figure 1B). Third, the extent of senescence in thesynovial membrane, including examining specific individual areas within the knee, showed statistically significantly correlation with the MRI-basedsynovitis score that evaluates 11 different regions within the knee (Figure 1C). Finally, a relationship trend was identified when assessing the correlationbetween the extent of senescence and the grade of disease based on the KL grade. When evaluating the relationship in patients with mild to moderatelysevere disease (KL grades 1-3), this relationship was statistically significant (Figure 1D). 11 Figure 1A. Relationship between concentration of IL-6 and percent of p16 positive cells within the synovial membrane. Regression adjusted partial R, rank = 0.5888, p-value = 0.0137. The regression adjusted partial R is the correlation after adjustment for body mass index (BMI), age, and KL grade.Figure 1B. Relationship between WOMAC-A Score and percent of p16 positive cells within the synovial membrane. Regression adjusted partial R, rank = 0.4554, p-value =0.0147. Figure 1C. Relationship between MRI synovitis score and percent of p16 positive cells within the synovial membrane; p-value overall = 0.0008; Score 0 vs 2, p = 0.0043;Score 1 vs 2, p = 0.0656.Figure 1D. Relationship between KL grade and percent of p16 positive cells within the synovial membrane. Trend observed across all grades; across grades 1-3, p=0.005 inan unadjusted regression model.Mechanism of Action of UBX0101UBX0101 is a small molecule inhibitor of the MDM2/p53 protein-protein interaction. The tumor suppressor p53 is a transcription factor thatregulates a broad set of genes that control cellular functions including cell cycle arrest, cell death (or apoptosis), and senescence. MDM2 is a protein-ubiquitin ligase that marks proteins for destruction. UBX0101 binds to MDM2, raising p53 levels and causing senescent cells to undergo apoptosis.Preclinical Studies with UBX0101We conducted in vitro experiments to study the potency of UBX0101 and its ability to eliminate senescent cells. In vitro studies demonstrate thatUBX0101 is a potent inducer of p53 expression and senescent cell apoptosis. This confirmed that UBX0101 elevates p53 and eliminates senescent cells. Inparticular, treatment of irradiated human fetal lung fibroblasts, or IMR90, and irradiated human primary synovial fibroblasts exhibited a dose-dependentpotent reduction of senescent cell survival. IMR90 cells have been the cell line used to study senescence biology for the past 30 years. These cells are used tostudy senescence in vitro because they are normal cells without acquired mutations that could drive resistance to drug-induced apoptosis. We use IMR90 andsynovial fibroblast cells as our primary screens and complement these two cell types with disease-relevant primary cell cultures to confirm that mechanismsof senescence translate to the relevant cell type.We next studied the in vivo efficacy of UBX0101 in a mouse model of OA. We used the mouse anterior cruciate ligament, or ACL, transectionmodel in which the ACL is transected in a surgical procedure after which the mouse is allowed to recover for 14 days. This model induces an aggressive formof OA characterized by inflammation, cartilage degeneration, and pain. We selected this model as it has demonstrated the accumulation of senescent cells.Intra-articular, or IA, dosing of our clinical candidate, UBX0101, led to a dose-dependent reduction of senescent cells as measured by lowering the expressionof p16 (Figure 2A) and a reduced expression of SASP factors, including IL-1ß (Figure 2B) and MMP-13 (Figure 2C), each in whole knee homogenate.Although attempts to replicate these findings in different animal models of OA proved to be challenging, as it is difficult to mimic a disease like OA, which12 develops over a long period of time in humans, in short-term animal models, these mouse model data further support our hypothesis that elimination ofsenescent cells with UBX0101 leads to changes in accompanying SASP. Figures 2A, 2B and 2C. IA dosing of UBX0101 reduces p16 expression (*p<0.05) and OA-relevant SASP factors, including IL-1ß and MMP-13 expression levels inthe ACLT murine model.We also conducted an ex vivo study in which cartilage (chondrocytes) from active OA lesions was obtained from human knees following total kneereplacement surgery and then placed in culture and treated with UBX0101. The regions of high OA disease tissue burden correlated well with higher p16 andMMP-13 biomarker levels, which we believe is a key indicator of cellular senescence-driven disease within cartilage. When treated with UBX0101, thenumber of p16 positive cells and cells expressing MMP-13 were greatly reduced. In addition, the expression of two key proteins, type 2 collagen andaggrecan, were significantly upregulated (n=4; *p≤0.05)). These two proteins are among the most abundant components of cartilage. These data suggest thatchondrocytes from patients with end-stage OA are capable of synthesizing new cartilage once accumulated senescent cells are removed. As a result, webelieve that intervening in vivo in humans could not only slow the progression of OA, but could also induce a reparative state in which more functionaltissue is restored.The potential for local toxicity was assessed in GLP-compliant studies after a single-dose intra-articular injection in both rabbits (doses of 0.1, 0.3and 0.6 mg/joint) and canines (doses of 0.1, 0.3 and 1.0 mg/joint). Findings from these rabbit and canine studies showed that a single intra-articularadministration of UBX0101 was well tolerated at doses up to 0.6 mg/joint in the rabbit and 1 mg/joint in the canine, the highest doses tested in the GLPtoxicity studies. UBX0101-related histopathological findings after a single intra-articular injection were limited to fibrinoid degeneration and mixed cellinflammation of the synovium in canines. Neither the degeneration nor the inflammation was considered adverse at any dose level due to the minimalseverity of the changes. There was no evidence of systemic toxicity in the canines following intra-articular injection. Although histopathological findingswere noted in earlier exploratory rabbit studies performed at high doses (up to 9 mg/joint), no UBX0101-related findings in the joint or evidence of systemictoxicity were noted in the 2017 GLP toxicity study conducted in rabbits.The potential systemic toxicity was evaluated in GLP-compliant toxicity studies after a single oral administration in both rats (doses of 30, 300 and600 mg/kg) and canines (doses of 30, 100 and 300 mg/kg). In these studies, the no-observed-adverse-effect level (NOAEL) was 300 mg/kg in rats and100 mg/kg in canines. At doses of 100 mg/kg and above, adverse effects after oral dosing consisted of transient, reversible and monitorable clinical signs incanines (300 mg/kg), decrease in body weight in canines (100 and 300 mg/kg) and rats (600 mg/kg) and clinical pathology changes (decrease inhematopoietic populations and increase in hepatic parameters) in both canines (100 and 300 mg/kg) and rats (300 and 600 mg/kg). At pathologicalexamination, changes in hematopoietic organs were noted in both rats (600 mg/kg) and dogs (100 and 300 mg/kg) whereas non-adverse liver-related changeswere observed in rats only (300 and 600 mg/kg). These effects were observed at systemic exposures that are greater than 800-fold the anticipated maximumexposure in patient after a single intra articular injection.The potential genotoxicity of UBX0101 was evaluated in the following GLP studies: (i) a bacterial reverse mutation assay (in vitro) atconcentrations up to 5000 µg/plate, (ii) a chromosome aberration assay (in vitro) at concentrations ranging from 0.25 µg/ml to 300 µg/ml, and (iii) a ratmicronucleus assay (oral/once) at doses of 500,13 1000 and 2000 mg/kg. In these studies, UBX0101 was non-mutagenic in bacterial species up to a concentration of 5000 ug/plate and it was weakly positivein vitro for inducing chromosomal aberrations, which is consistent with the pharmacological activity of UBX0101. It was negative for inducing polyploidyand endoreduplication in cultured human lymphocytes and negative in the in vivo rat micronucleus at oral doses up to 2000 mg/kg, the maximumrecommended dose based on regulatory guidelines.We also conducted the following safety pharmacology studies: (i) hERG channel in mammalian cells (in vitro) at concentrations of 1, 3, 10 and30 µM, (ii) central nervous system in rat (oral/once) at doses of 30, 300 and 600 mg/kg, (iii) cardiovascular in canine (oral/once) at doses of 10, 30 and100 mg/kg, and (iv) respiratory in rat at doses of 30, 300 and 600 mg/kg. These studies indicated that the risk for significant hERG inhibition in vivo isminimal. UBX0101 demonstrated a low potential for cardiovascular effects in canines (NOAEL of 30 mg/kg) and did not produce any effect on ventilatoryfunction or neurobehavioral effects in rats at doses up to 30 mg/kg (the no-observed-effect-level, or NOEL) when given as a single oral administration.The nonclinical exploratory and GLP studies have demonstrated that findings related to the proposed clinical intra-articular route of administrationare generally non-adverse and likely to be reversible. There was no systemic toxicity noted after intra-articular injection in safety assessment studies at anydose level tested. Estimated UBX0101 knee concentrations at the NOAEL from the safety studies were 38-fold higher than the exposures required to achievethe EC50 concentration in the in vitro OA knee efficacy model. Based on the findings of our preclinical studies, we believe the safety pharmacology andtoxicology studies support the evaluation of UBX0101 in the Phase 1 clinical program.UBX0101 Development PlanIn the second quarter of 2018, we initiated a Phase 1 clinical study in patients with moderate to severe OA of the knee. This Phase 1 study is arandomized, double-blind, placebo-controlled study to investigate the safety and tolerability of single, ascending intra-articular doses of UBX0101. In theinitial phase, or Part A, of the study, 48 patients were randomly assigned to receive UBX0101 or placebo in 3:1 randomization by dose level cohort. Primaryendpoints are safety and tolerability. Secondary and exploratory endpoints include plasma pharmacokinetics, synovitis as measured by MRI, pain, and SASPfactors in synovial fluid and plasma. Patients will be followed for a total of 12 weeks following treatment administration, at which time key endpoints will beassessed.In the first quarter of 2019, we expanded the study to include a second phase, or Part B, with an additional cohort of at least 24 patients with thehighest safe and tolerated dose level evaluated during Part A of the study (4 mg). Part B is intended to supplement Part A by further evaluating the impact ofUBX0101 on SASP factors. In Part B, patients will be randomized to receive UBX0101 or placebo in a 2:1 randomization. Primary endpoints are safety andtolerability. Secondary endpoints include SASP factors in synovial fluid and plasma, pain, and drug exposure. Synovial fluid samples will be obtained pre-treatment and at four weeks. Key endpoints will be assessed at four weeks and patients will be followed for a total of six weeks following treatmentadministration. We expect top-line results from both Part A and Part B in the second quarter of 2019.OA of the knee is believed to be a heterogeneous and multifactorial disease where multiple SASP factors are implicated in pathogenesis. Whileevidence suggests that individual SASP factors contribute to OA disease pathology, it is our belief that suppression of multiple factors is likely needed for ameaningful clinical benefit to be observed. The Phase 1 study will evaluate the impact of UBX0101 on SASP factors (24 in synovial fluid and 8 plasma)believed to play a role in human OA. The factors were selected based on our Ph 0 OA biomarker study, pre-clinical data, and an extensive literature review.These factors, which include cytokines and chemokines, proteases and protease inhibitors, and growth factors and adhesion molecules, will be measured forchange from baseline to 12 weeks in Part A and from baseline to 4 weeks in Part B (Figure 3).14 Figure 3: SASP factors for Phase 1 measurement.At the conclusion of Parts A and B of this study, if the results are positive, we expect to have the option to use the safety, tolerability, andpharmacodynamic data from Parts A and B, to support the further expansion of selected cohorts to sufficiently power a proof-of-concept study for theassessment of pain and inflammation. Additionally, we may also conduct a repeated dose study to optimize the dosing regimen for future trials.Ophthalmology ProgramsUnmet Need and Therapeutic RationaleThe majority of significant eye diseases are age related, with the prevalence of vision-threatening disease increasing significantly over the age of75. Of the 285 million individuals worldwide living with visual impairment, 65% are over the age of 50. The individual diseases that are associated withthese figures include age-related macular degeneration, diabetic eye diseases and glaucoma, all of which have a high prevalence and significant unmet needin either prevention or therapeutic options. The diseases we are evaluating as initial target indications for local administration of senolytic therapy in the eyeare age-related macular degeneration, diabetic macular edema, diabetic retinopathy, and primary open angle glaucoma.Age-Related Macular DegenerationAge-related macular degeneration, or AMD, is the leading cause of irreversible vision loss in people over the age of 65 in the United States, wherethere are an estimated 2.1 million people with AMD. This number is projected to more than double by 2050, reaching 5.4 million. The prevalence of AMDincreases significantly with advancing age, with a prevalence of 2.8% in those aged 65 to 74 years, increasing to 8.7% in those over 75 years. AMD affectscentral vision, impairing functions such as reading, driving, and facial recognition, and has a major impact on quality of life and the ability to liveindependently. AMD is defined in three stages: (i) “early,” in which visual function is affected in the presence of signs of age-related changes in the retinasuch as drusen and pigmentary changes, (ii) “intermediate,” in which increasing degrees of macular lipid deposition and structural changes are noted, and (iii)“late,” in which central vision is severely compromised due to abnormal blood vessel growth (known as “wet” AMD) or advanced atrophy of the retina(known as “dry” AMD). It is a heterogenous, complex, multifactorial disease, with inflammatory, degenerative, genetic, and vascular factors all contributingto its development and progression. The15 potential role of senescent cells and the associated SASP in driving the two main presentations of the disease, both wet and dry forms, could prove a unifyingmechanism across this complex disorder.Standard of care for AMD is limited to anti-vascular endothelial growth factor, or anti-VEGF, drugs which control aspects of the wet form of thedisease only. Therapeutic options for dry AMD have proven challenging with no currently approved therapies available to slow progression or reversedisease. Wet AMD has been significantly impacted by anti-VEGF therapy but that approach is limited by the need for frequent, long-term eye injections, asignificant percentage of patients not completing or being non-responsive or poorly-responsive to anti-VEGF therapy, and the contribution of multiple othermechanisms at play in the disease beyond VEGF. Thus, there is considerable potential for a senolytic approach to impact disease progression and achievestabilization in AMD via modulation of senescent cell burden and the accompanying SASP. SASP factors in AMD include molecules that promote abnormalblood vessel growth, inflammation, and fibrosis, all of which have been implicated in various stages of the disease. It is our hypothesis that a senolyticmedicine could have a meaningful and prolonged impact on the AMD disease state and help restore the cellular microenvironment to a more normal, pre-senescent state.Diabetic Macular EdemaThe prevalence of diabetic macular edema, or DME, in the U.S. ranges from approximately 4.0 to 6.8% of people with diabetes who are 40 years ofage or older. There is a high burden of DME among non-Hispanic blacks and robust associations with higher hemoglobin A1c and longer duration ofunderlying diabetes.Because the prevalence of DME increases with increasing duration of hyperglycemia, retinopathy is more likely to be found in eyes of patientswho have a longer interval between the onset of diabetes and its discovery. Lower frequencies of DME would be expected in asymptomatic people who arediscovered to have diabetes by testing during population-based studies. These people are probably closer to the time of “onset” of their diabetes thansymptomatic patients who are discovered to have Type 2 diabetes by their physicians.Despite the success achieved with anti-VEGF treatment for retinal disease like AMD that involve the proliferation of abnormal blood vessels, orneovascularization, in DME, the impact of this therapeutic approach has been limited. This is due to poor patient compliance with the regimen (monthly andor bimonthly IVT injections), the number of cases that are refractory to anti-VEGF treatment (50% of DME patients), and the long-term complication ofincreased ischemia and retinal fibrosis associated with long-term treatment with anti-VEGF injections. As a result there is an unmet need in this group ofpatients. Although VEGF has been identified as a primary biomarker for neovascular disease, other biomarkers, which we believe are SASP factors, are presentin DME (including IL-1ß, TNF-a, IL-6, and TGF-ß, among others). Due to the multifactorial nature of the disease, a significant opportunity exists to develop amore comprehensive approach to the treatment of DME that targets the root cause of the disease.Diabetic RetinopathyDiabetic retinopathy, or DR, is estimated to affect over 90 million people globally and approximately 28 million have vision-threatening stages ofdisease. It is a leading cause of vision loss in middle-aged and elderly people and impacts 8% of the U.S. population over age 65. Due to the increasingdiabetic population arising from lifestyle changes in developing countries, the disease incidence is predicted to climb.Diabetic retinopathy is a complex multifactorial disease, characterized by progression through a series of stages of increasing severity. Highglucose levels incite a variety of inflammatory and a number of metabolic stress-induced events leading to proliferation of neovascularization, withsubsequent bleeding and swelling causing visual loss. The risk of developing diabetic retinopathy and its severity increase with the duration of underlyingdiabetes. It is also associated with poor glycemic control and the presence of additional coexistent diseases, such as high blood pressure, high cholesterollevels, and impaired kidney function.Current standard of care for diabetic retinopathy, which includes blood sugar control, anti-VEGF drugs, and laser therapy, is modestly effective.Limitations of existing therapy include general challenges with achieving diabetes control, the need for frequent intra-vitreal injections for theadministration of anti-VEGF therapy, a significant percentage of patients not completing or being non-responsive to anti-VEGF therapy, and tissuedestruction with16 permanent side effects from laser therapy. This presents a significant opportunity to design and develop a treatment paradigm that treats a root cause of thedisease.Evidence suggests that diabetic retinopathy is driven by the accumulation of senescent cells that are a direct result of elevated glucose levels inpatients with diabetes. These senescent cells are triggered by local stresses in the retina and their accumulation drives the production of the accompanyingocular SASP factors, VEGF and PDGF. Overproduction of VEGF and IL-6 leads to ocular inflammation and abnormal blood vessel growth, key signatures ofthe causes of diabetic retinopathy. Thus, a senolytic approach could target multiple aspects of the underlying causes of diabetic retinopathy and ideally leadto greater therapeutic coverage in a wider range of patients. By eliminating senescent cell accumulation and accompanying SASP factors, one could limitfurther disease progression, reduce vessel leakage and inflammation, and prevent vision loss.Primary Open-Angle GlaucomaGlaucoma is the leading cause of irreversible blindness in the world, with an estimated 60 million cases worldwide. There are approximately2.7 million people in the United States with glaucoma, with up to 50% of cases undetected as the result of the disease typically being asymptomatic untilvery late in the course of its progression. This number is projected to reach 6.3 million by 2050 and age is one of the strongest risk factors for thedevelopment of the disease. Prevalence in general increases with age, with 2.5% prevalence between the ages of 55 and 64, 5.7% between 65 and 74 and10.3% over the age of 75.Primary open-angle glaucoma, or POAG, is a degeneration of nerve cells in the retina characterized by a progressive loss of retinal nerve function.This occurs due to abnormalities in the outflow channels, which are referred to as the trabecular meshwork, or TM, of the front portion of the eye such thatremoval of aqueous humor, or AH fluid, no longer balances AH production. As a result, intra-ocular pressure, or IOP, increases. Before vision loss becomesprominent, POAG is an asymptomatic disease making screening examinations critical for early detection. There are no available therapies that restore lostvisual function. With advancing disease, more central vision is lost and, if left untreated, total blindness can occur. There are no curative therapies forglaucoma. Treatment is lifelong and aimed at slowing progression of disease. Even with maximal therapy a proportion of patients will continue to progress,highlighting the significant unmet need in glaucoma treatment.Current POAG management primarily includes strategies to lower IOP by medical and/or surgical means in an attempt to slow disease progression.IOP is a modifiable risk factor in glaucoma and therefore a target for therapy, yet it is known that IOP is but one of many factors in the complexpathophysiology of POAG. Topical therapeutic options to reduce IOP include prostaglandin analogues, cholinergic agonists, and ß-blockers. The majorchallenge in topical therapy is non-adherence with regimens that require at least daily dosing and are associated with significant tolerability profiles.Adherence rates with topical regimens at one year following prescription were reported to be between 10% and 40%. Compounding this problem is a greaterthan 40% incidence rate of intolerability issues and that 40% of patients require more than one medication to control IOP to their individual target range.Surgical options to control IOP include laser therapy, surgery to open the outflow channels, and micro-incisional glaucoma surgery. Surgical interventionsare associated with greater risks and are in general reserved for more advanced cases.Thus, POAG remains a high unmet medical need with significant opportunity for a sustained and durable IOP lowering therapy. We believe thatPOAG is driven by the accumulation of senescent cells and secretion of the SASP in the TM as a result of cellular stress and injury leading to decreasedoutflow of AH. A reduction in cellularity leading to changes in TM architecture has been described in glaucoma and supports our belief that a senolyticcould have prolonged effect on IOP lowering through the clearance of senescent cells and reduction in SASP.Evidence for Senescence Burden in Human Disease and Human Biomarker Discovery: AMD, DME and DRWe evaluated the presence of senescent cells in retinal donor tissue from normal and AMD subject samples by IHC staining for p16. We believethat data supported our hypothesis that the accumulation of senescent cells is linked to AMD and is seen at the juncture between normal retina and AMDaffected retina. 17 We have also evaluated the link between senescence in human retinal microvascular endothelial cells, or HRMEC, and human DME/DR patientsby evaluating the gene expression of several disease-relevant factors. Quantitative polymerase chain reaction, or PCR, demonstrated elevations in VEGF,PDGF, IL-1ß, and TNF in senescent HRMEC, relative to non-senescent cells. These disease-relevant mediators have been reported to be elevated in DME/DRpatients. We believe this data is consistent with our hypothesis that senescent cell accumulation and SASP factors play a central role in both DME and DR.We further investigated this hypothesis by evaluating one of our proprietary senolytic molecules in an animal model of DR.With recently optimized methods, we are now focused on quantifying the senescence burden in samples from normal donors verses donors withAMD and DME/DR. We intend to use this method to identify the cell types that stain positive for p16, and the localization of disease-relevant factors whichwill assist in the development of AMD and DR models in cells and animal models. Figure 4. Disease-relevant mediators are elevated in senescent HRMECEvidence for Senescence Burden in Human Disease and Human Biomarker Discovery: POAGWe evaluated the presence of senescent cells in the trabecular meshwork, or TM, by quantifying the detection of p16 positive cells in TM fromcontrol verses POAG patients. We are currently focused on utilizing optimized methods for the detection of p16-positive cells and co-localization withdisease-relevant factors in human donor globes. In addition, we will have the opportunity to look for p16-positive senescent cells in POAG patient retinas.Mechanism of Action of UBX1967 (Inhibitors of the Bcl-2 Family)The most advanced senolytic drug candidate in our ophthalmology program, UBX1967, is a potent small molecule inhibitor of specific subtypeswithin the Bcl-2 family of regulator proteins. The B-cell lymphoma 2, or Bcl-2, gene family encodes more than 20 proteins that regulate the intrinsicapoptosis pathway and are fundamental to the balance between cell survival and cell death. Inhibition of certain Bcl-2 family proteins results in cell death.Targeting this pathway has been extensively studied in connection with the search for new oncology medicines. In vitro and in vivo Pharmacology Studies with UBX1967We conducted an in vitro assessment of binding and efficacy to determine the potency of senolytic molecules for the Bcl-2 family protein targetsand their potency at eliminating senescent cells. Biochemical assays for Bcl-2, Bcl-xL, and Bcl-w yielded binding affinities in the sub-nM range. In order toassess the activity of UBX1967 on senescent cells, we used a cell-based assay with radiation-induced senescence. Senescent cells were then exposed toincreasing concentrations of UBX1967 for 72 hours. In this study, UBX1967 showed potent, dose-dependent senolytic activity against IMR90, human retinalpigmented epithelial cells, and HRMEC as measured by reduction of senescent cell survival. UBX1967 demonstrated selectivity for elimination of senescentHRMEC over non-senescent HRMEC which is observed as decreased potency in non-senescent cells (Figure 5).18 Figure 5. Dose dependent induction of apoptosis in HRMEC cellsWe next studied the efficacy of UBX1967 in the eye in an in vivo model. We employed the mouse oxygen-induced retinopathy, or OIR, model,which provides an in vivo model of retinopathy of prematurity, or ROP, and DR. In this model, UBX1967 showed statistically significant improvement in thedegree of neovascularization at all dose levels along with a reduction in the number of p16-positive senescent cells. We also identified a dosing formulationof UBX1967 that is compatible with clinical development, a polysorbate-80 (PS-80)-based solution formulation, which has demonstrated the same activity inthis OIR model (Figure 6). Figure 6. Intravitreal injection of UBX1967 reduced retinal neovascularization in the mouse OIR model19 Based on these results in this key OIR model, we believe a single ocular injection of UBX1967 can functionally inhibit pathogenic angiogenesisand promote vascular repair (Figure 7). Figure 7. Representative images from mouse OIR illustrate the reduction in neovascularization and vaso-obliteration after treatment with UBX1967We believe that efficacy of UBX1967 in the OIR model is due to elimination of senescent cells and accompanying SASP that propagatessenescence in retinal cells and promotes neovascularization of retinal vessels.We then studied in vivo efficacy in a mouse streptozotocin model to understand the effects of UBX1967 in a diabetic retina, which showsphenotypes similar to the human diseased condition. In this model, UBX1967 demonstrated changes in the electroretinogram, or ERG, as a measure ofretinal/photoreceptor function, vascular leakage, and production of several disease-relevant cytokines. UBX1967 showed a dose dependent reduction (1 –100 µM) in IL-1ß and TNF mRNA (p<0.05 v. vehicle control) in the diabetic retina. Evans Blue dye permeation was measured as an indication of vascularleakage in the eye. Administration of UBX1967 significantly reversed leakage in the DMSO-based formulation (p<0.01) and demonstrated dose-dependentreversal in the PS-80-based formulation, although not statistically significant. Finally, at doses of 1 – 100 µM delivered per eye, UBX1967 led to significantincrease in the amplitude of both the A- and B-waves (p<0.05 and p<0.001, respectively) of the ERG when compared20 to the vehicle control group. The UBX1967-treated groups were not significantly different from the non-diabetic control animals. Figure 8. Streptozotocin-induced diabetic mice have increased cytokine expression (8A), increased retinal vascular leakage (8B) and decreased A-wave amplitude in ERG(8C). Administration of UBX1967 attenuated each of these disease-relevant endpoints.We have also studied the in vivo efficacy of UBX1967 in a mouse model of elevated IOP, which is relevant to glaucoma. An experimental increasein IOP was induced in one eye of a mouse cohort by injection of bleomycin, a DNA damage agent known to cause fibrosis. Within the study design, the lefteye of a single animal was used as a vehicle control (no insult and no treatment) while the right eye was subjected to insult and treatment with UBX1967.During the study we measured the level of p16 expression and intraocular pressure. We experienced some procedural challenges with this version of theelevated IOP model and we have recently employed a more refined technique to administer bleomycin and UBX1967. Using these new refinements, we willnow extend the study duration in order to measure neuron loss in the retina after administration of UBX1967. Preliminary studies with a reference standardmolecule indicate a decrease in bleomycin-induced IOP elevation and preservation of retinal ganglion cells.We completed non-GLP non-clinical safety assessment, tolerability and drug metabolism and pharmacokinetics, or DMPK, studies with UBX1967in two non-clinical species. In December 2018, we nominated UBX1967 as a development candidate to progress into GLP safety assessment studies to enablethe filing of an IND.21 Ophthalmology Development PlanOne of the properties of UBX1967 is a sustained exposure in ocular tissues of interest after intravitreal injection. After engaging regulatoryauthorities regarding the design of IND-enabling studies, we have determined that the duration of these non-clinical studies will be longer than originallyanticipated due to the pharmacokinetic profile. As a result, we expect to file our IND for UBX1967 in early 2020 that, if accepted, would enable us to pursuemultiple age-related diseases of the eye in clinical trials, such as AMD, DME and DR.As part of our continued commitment to our ophthalmology indications, we have also designed a number of alternative senolytic molecules withdiffering mechanisms of action. We are also focused on the physiochemical properties of our small molecules and are developing approaches to optimizesolubility, permeability, and PK parameters to create favorable ocular absorption, distribution, metabolism, and residency profiles.Pulmonary ProgramsUnmet Need and Therapeutic RationaleData from the World Health Organization from 2015 shows that respiratory diseases make up three of the top five causes of death worldwide,several of which are prevalent in the elderly. In addition, the National Heart, Lung, and Blood Institute of the U.S. National Institutes of Health published awhite paper in 2017 highlighting the association of age with lung disease, including idiopathic pulmonary fibrosis, or IPF, and chronic obstructivepulmonary disease, or COPD, and underscoring the potential for understanding and developing therapeutics related to aging biology.Historically, therapies for these diseases have been non-specific in their mode of action, whether anti-inflammatory (e.g., corticosteroids), orimmunosuppressive (e.g., cyclophosphamide), or purely supportive in nature (e.g., supplemental oxygen). Increasingly, new therapies have been developedthat are more targeted to specific pathogenic factors, such as anti-IL-5 antibody (mepolizumab) in COPD and tyrosine kinase inhibitor (nintedanib) in IPF. Incontrast, the goal of senolytics is not just to interrupt specific pathogenic pathways but specifically to target senescent cells and thereby inhibit multiplepathogenic pathways.We initiated an active discovery and development program in IPF based on a series of observations including the aggressive nature of the diseaseand data suggesting a potentially strong association between IPF and senescence.IPF is a severely debilitating fibrotic disease of the lung that primarily affects older adults and often leads to a progressive worsening of lungfunction, eventually leading to respiratory failure or lung transplantation. Increasing organ fibrosis causes a restriction of ventilation that symptomatically isperceived as a constant state of suffocation. While the course of the disease is variable, the prognosis is uniformly poor with a median survival of about threeto four years after diagnosis. In the United States, it is estimated to affect up to 90,000 people, with approximately 40,000 people dying each year. While theoverall prevalence is not high, it increases substantially in people over the age of 65. The hypoxemia resulting from IPF ultimately necessitates the use ofsupplemental oxygen. Supplemental oxygen relieves dyspnea and improves functional status and may play a role in ameliorating associated comorbiditiessuch as secondary pulmonary hypertension. However, the use of supplemental oxygen requires equipment for administration that can place significantburden on patients, limiting their mobility and profoundly reducing quality of life.Beyond the use of oxygen, there are two marketed products available for the treatment of IPF, nintedanib and pirfenidone, that are recommendedby the American Thoracic Society. In clinical studies, these anti-fibrotic agents slowed the rate of decline in lung function over 52 weeks but did not show asignificant effect on survival or disease exacerbations. IPF remains a fatal disease for which additional effective therapies that treat the underlying lungfibrosis to improve quality of life and survival are needed.Resident cell types within the lung, including epithelial cells and macrophages, have been shown to become senescent. Accumulation of thesesenescent cells followed by SASP secretion may drive IPF disease exacerbation and progression. In the case of senescent lung cells, we believe that the SASPis characterized in part by pro-fibrotic factors such as connective tissue growth factor CTGF and TGF-β. We believe that excessive and prolonged exposure tothese factors leads to remodeling of the lung, expansion of lung matrix, and fibrosis, all of which deteriorate function and22 ultimately result in death. Furthermore, these factors may also play a role in suppressing the endogenous capacity of the lung to demonstrate regenerativecapacity that has been shown in patients after removal of diseased lung tissue, as well as during recuperation of those patients who survive Acute RespiratoryDistress Syndrome, an injury that severely damages the lung.Evidence for Cellular Senescence Burden in Human Disease and Human Biomarker DiscoveryOur exploratory work in IPF resulted in the identification of senescent cells associated with areas of active disease in lung tissue taken frompatients with IPF. Immunohistochemistry staining for p16 in human IPF lung tissue demonstrated the presence of senescent cells. These cells werepredominantly epithelial in origin and located in areas of fibrosis and at the leading edge of the disease. These sites are likely amendable to access byinhalation therapeutics.Importantly, the number of p16 positive cells was greater across all levels of fibrosis relative to that of normal tissue (p<0.0001 for group differenceamong means by one-way ANOVA). Additionally, there was a strong relationship between the extent of disease in a given area and the percentage ofsenescent cells present in those areas. At its peak, approximately 30% of the total cellularity in an affected region is comprised of senescent cells. These datasupport the hypothesis that elimination of senescent cells and its associated SASP could halt progressive fibrosis and potentially allow for restoration ofpulmonary function. This further supports our hypothesis that IPF is related to SASP proliferation and suggests that treatment with senolytic molecules hasthe potential to treat the root cause of disease. We further studied our hypothesis regarding cellular senescence accumulation and their accompanying SASPby investigating the cellular senescence signature in a key animal model of lung fibrosis.Preclinical Disease Model of Lung FibrosisPreclinical studies were conducted to understand the involvement of senescent cells in in vivo models of lung fibrosis. Based on initial resultsdemonstrating a modest increase in whole lung senescence (p16 mRNA) following23 local delivery of bleomycin, we validated an in vivo bleomycin-induced PD model focusing on enriched epithelial cells from mouse lungs and demonstrateda reduction in p16 mRNA following local senolytic treatment. Figure 9. Epithelial cells enriched from mouse lungs treated with bleomycin exhibited an increase in p16 mRNA, which was significantly reduced following local senolytictreatmentWhile preliminary results from the bleomycin model of lung fibrosis in the mouse were compelling, we are exploring alternative models that betterrepresent senescence and fibrotic lung disease. We are also conducting studies that explore how the observed senolysis translates to a reduction in lungfibrosis. Development Plan in Pulmonary DiseasesWe intend to advance our lead development candidate, an inhaled administration senolytic molecule for pulmonary indications, into IND-enablingstudies and, subject to the acceptance by the FDA of an IND for such candidate, into human clinical trials. While IPF is currently our lead indication, we arealso exploring inhaled administration opportunities in other lung diseases, such as systemic sclerosis with pulmonary manifestations and hypersensitivitypneumonitis, and in obstructive diseases such as COPD.We expect our integrated pulmonary development plan will utilize patient safety data and pharmacological dose responses from the initial clinicalstudy to accelerate the design of next-generation clinical studies in other pulmonary diseases. We expect that any Phase 1 program in any of these diseaseswould closely parallel our work in IPF and would take advantage of any learnings regarding pharmacokinetics following inhaled administration as well asbiomarker and imaging responses. This approach should allow us to lay additional groundwork for a broader range of pulmonary diseases once wedemonstrate the safety, tolerability, and pharmacodynamics of inhaled senolytic administration.Research and Discovery – Other Anti-Aging ProgramsWe have secured our lead position in the discovery and development of senolytic medicines through our commitment to fundamental biologicalresearch and translational science. We have partnered with key academics and thought leaders to pursue areas of emerging aging science. We continue torecruit top-tier scientists with the desire and drive to understand, uncover, and invent. We invest a significant proportion of our resources and effort inemerging fields of aging science in order to transition fundamental scientific observations to the design and development of new therapeutics. We believethat we have built the internal research capabilities and scientific network to continue to be at the forefront of extending human healthspan.24 Strategy for Systemically Administered Senolytic MedicinesIn addition to our discovery and development of locally administered senolytic medicines for the treatment of local disease, we are similarlyinvestigating the systemic administration of senolytic medicines for the treatment of senescent cell-driven disease within specific organs, tissues, and celltypes.Our first approach to systemic administration is to create a senolytic medicine that is designed to target a specific organ or even specific tissuewithin that organ. Such a senolytic medicine would selectively eliminate senescent cells within a tissue and reduce the SASP within that tissue. Inconsidering therapeutic areas with unmet need and where there is strong evidence for the role of senescent cells driving disease, we are evaluating liver andkidney disease as well as neurological disorders.Our long-term goal is to use the principles that we establish for the design of systemically administered, targeted senolytic medicines to produce apipeline of clinical candidates to eliminate senescent cells throughout the body. This could draw on ideas from immunology, senolytic viruses, vaccines,CAR-T type approaches or antibody drug conjugates.Circulating Youth Factors (α-Klotho Protein)We are also evaluating the administration of circulating youth factors in age-related diseases. Our lead discovery effort in circulating youth factorsis focused on the α-Klotho protein. First discovered in 1997, the klotho gene was identified in mice as an “aging-suppressor” that accelerates aging whendisrupted and extends lifespan when overexpressed. The α-Klotho protein is a circulating hormone primarily produced in the kidneys and choroid plexus ofthe brain and was recently discovered to delay and suppress the deleterious effects of aging on multiple organs, including the brain. Circulating levels of α-Klotho protein gradually decline with age and are implicated in chronic stress, cognitive impairment, and neurodegenerative disease.A small percentage of the population possesses naturally elevated α-Klotho levels as a result of the α-Klotho-VS heterozygous genetic variation. α-Klotho-VS heterozygosity is associated with extended healthspan, enhanced cognition, and less age-related cognitive decline. Elevated α-Klotho levels arealso associated with greater dorsolateral prefrontal cortex volume and improved connectivity between cortical regions, which in turn correlates with betterexecutive function in normal aging humans. As this brain region is especially susceptible to shrinkage with age and vulnerable in several psychiatric andneurological disorders, its protection may provide clinical benefit in both normal aging and disease.In 2014, Dena Dubal, of the University of California, San Francisco, and one of our scientific collaborators, first demonstrated that geneticallyelevated α-Klotho levels significantly enhance cognitive performance and neural resilience independent of age in normal and human amyloid precursorprotein mouse models of neurodegenerative disease related to Alzheimer’s Disease. α-Klotho is hypothesized to optimize synaptic neurotransmission ofNMDA receptors in the brain, effectively combatting the cognitive and synaptic deficits, despite high levels of pathogenic Ab, tau, and phosphorylated tauproteins associated with Alzheimer’s Disease.We are exploring the utility of α-Klotho protein in a variety of preclinical animal models, with the intention of identifying a drug candidate.ManufacturingOur success as a company will depend on our ability to deliver reliable, high-quality preclinical and clinical drug supply. As we mature as acompany and approach commercial stage operations, securing reliable high-quality commercial drug supply will be critical. We do not currently own oroperate facilities for product manufacturing, storage and distribution, or testing. We contract with third parties for the manufacture of our drug candidates.Because we rely on contract manufacturers, we employ personnel with extensive technical, manufacturing, analytical, and quality experience. Our staff hasstrong project management discipline to oversee contract manufacturing and testing activities, and to compile manufacturing and quality information for ourregulatory submissions.25 Manufacturing is subject to extensive regulation that imposes various procedural and documentation requirements and that governs recordkeeping, manufacturing processes and controls, personnel, quality control and quality assurance, and more. Our systems and our contractors are required to bein compliance with these regulations, and compliance is assessed regularly through monitoring of performance and a formal audit program.Our current supply chains for our lead drug candidates involve several manufacturers that specialize in specific operations of the manufacturingprocess, specifically, raw materials manufacturing, drug substance manufacturing, and drug product manufacturing. We currently operate under purchaseorder programs for our drug candidates with Material Service Agreements in place, and we intend to establish long-term supply agreements in the future. Webelieve our current manufacturers have the scale, the systems, and the experience to supply all planned clinical studies.We do not currently require commercial manufacturing capabilities. Should our needs change, we will likely need to scale up our manufacturingprocesses to enable commercial launch. To ensure continuity in our supply chain, we plan to establish supply arrangements with alternative larger scalesuppliers for certain portions of our supply chain, as appropriate.Commercialization PlanWe do not currently have, nor do we expect to have in the near term, any FDA-approved drugs in our portfolio. Therefore, we have not yet built aninfrastructure for sales, marketing, or commercial distribution.Should any of our drug candidates be approved for commercialization, we intend to develop a plan to commercialize them in the U.S. and otherkey markets, through an internal infrastructure or external partnerships.CompetitionThe biotechnology and pharmaceutical industries, including the field of research in aging, are typically rife with rapid technologicaldevelopments, bold competition, and dependence on intellectual property. Like any biotechnology company, we face competition from multiple sources,including large or established pharmaceutical, biotechnology, and wellness companies, academic research institutions, government agencies, and privateinstitutions. We believe our drug candidates will prevail amid the competitive landscape through their efficacy, safety, administration methods andconvenience, cost, public and institutional demand, intellectual property portfolio, and treatment of the root cause of many age-related diseases.We are aware of other companies seeking to develop treatments to prevent or treat aging-associated diseases through various biological pathways,including Calico, resTORbio and several other earlier-stage companies exploring cellular senescence. Calico has not yet disclosed any pipeline candidates ormechanisms of interest, and resTORbio is developing candidates targeting TORC1. Hence, we believe that we currently have the most advanced programaddressing cellular senescence.Our drug candidates are likely to compete against current therapies from a wide range of companies and technologies, including therapies for ourlead indications: •Musculoskeletal diseases, including osteoarthritis: current standard of care treatments (though not disease-modifying and focused on symptommanagement) include anti-inflammatory drugs (Ibruprofen, Diclofenac, Celecoxib), analgesic pain relief (Acetaminophen), or narcotic pain relief(Tramadol). •Ophthalmology diseases, including diabetic retinopathy: potentially disease-modifying therapeutics are being sold and developed by severalpharmaceutical and biotechnology companies, including Roche/Genentech and Regeneron. •Pulmonary disease, including idiopathic pulmonary fibrosis: therapeutics are being sold and developed by several pharmaceutical andbiotechnology companies and academic institutions, including Genentech, Boehringer-Ingelheim, Cytokinetics and Mallinckrodt, and are invarious stages of clinical studies.26 Many of our competitors, either alone or with strategic partners, have substantially greater financial, technical, and human resources than we do.Accordingly, our competitors may be more successful in obtaining approval for treatments and achieving widespread market acceptance, rendering ourtreatments obsolete or non-competitive. Accelerated merger and acquisition activity in the biotechnology and biopharmaceutical industries may result ineven more resources concentrated among a smaller number of our competitors. These companies also compete with us in recruiting and retaining qualifiedscientific and management personnel, establishing clinical study sites, patient registration for clinical studies, and acquiring technologies complementary to,or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborativearrangements with large and established companies. Our commercial opportunity could be substantially limited in the event that our competitors developand commercialize products that are more effective, safer, more tolerable, more convenient, or less expensive than our comparable products. In geographiesthat are critical to our commercial success, competitors may also obtain regulatory approvals before us, resulting in our competitors building a strong marketposition in advance of our products’ entry. We believe the factors determining the success of our programs will be the efficacy, safety, and convenience of ourdrug candidates.Intellectual PropertyOur success depends in large part upon our ability to obtain and maintain proprietary protection for our products and technologies and to operatewithout infringing the proprietary rights of others. Our policy is to protect our proprietary position by, among other methods, filing U.S. and foreign patentapplications that relate to our proprietary technologies, inventions and improvements that are important to the development and implementation of ourbusiness. We also rely on trademarks, trade secrets, know-how, continuing technological innovation and licensing opportunities to develop and maintain ourproprietary position.Patent PortfolioOur patent portfolio consists of a combination of issued and allowed patents and pending patent applications that are owned or co-owned by usand/or licensed or optioned to us from third parties. The majority of these patents and applications cover our cellular senescence program, and others pertainto our programs that target aging mechanisms beyond cellular senescence, including the administration of circulating youth factors and enhancement ofmitochondrial health. As of March 2019, we own, co-own, or have an exclusive license or exclusive option to license in certain fields of use to more than100 patents and pending applications in the United States and foreign jurisdictions. This portfolio includes 27 issued U.S. patents, 33 pending U.S.applications (including 13 provisional applications), and over 30 granted or pending applications in foreign jurisdictions.Our cellular senescence patent portfolio includes patents and patent applications that are directed to our senolytic agents and programs, includingour lead molecules UBX0101 and UBX1967, related molecules, and other compounds. We also have licensed the issued patents and patent applicationscovering the composition of matter and process manufacturing of UBX1967 under a license agreement with Ascentage Pharma Group Corp. Ltd., orAscentage, as further described below. Our cellular senescence patent portfolio includes patents and patent applications directed to compositions of matter,use for treating age-related conditions, and methods of manufacture.Our patent portfolio, including patents and applications that we have exclusively optioned, as well as those we own, co-own or have exclusivelylicensed, directed to our programs that target aging mechanisms beyond cellular senescence, including the administration of circulating youth factors andenhancement of mitochondrial health, includes four pending U.S. patent applications and six pending patent applications in foreign jurisdictions.In general, patents have a term of 20 years from the earliest claimed non-provisional priority date. Several of our issued U.S. and foreign patentsthat relate to UBX0101 and UBX1967 are scheduled to expire between approximately 2032 and 2037. The patent term may be extendible by up to five yearsin certain countries by means of patent term extension, depending on the regulatory pathway and the remaining term upon marketing approval. Certain otherpatents and patent applications directed to our cellular senescence patent portfolio, if they were to issue, may have later expiration dates.27 Osteoarthritis ProgramWe co-own a patent family directed to the treatment of senescence-related diseases, including osteoarthritis, by removal of senescent cells in oraround the site of the disease. The other co-owners of this patent family are the Buck Institute for Research on Aging, or the Buck Institute, the Johns HopkinsUniversity, and Mayo Clinic, each of which has granted us an exclusive license which extends to the treatment of senescence-related diseases in therapeuticareas. This patent family includes four issued U.S. patents and one foreign patent directed toward the use of UBX0101 for the treatment of osteoarthritis. Oneof these issued U.S. patents covers a unit dose of a pharmaceutical composition as a composition of matter, and the other three cover methods of treatment.Applications are also pending in the following 14 foreign jurisdictions: Australia, Brazil, Canada, China, Europe, Hong Kong, Israel, Japan, Korea, Mexico,New Zealand, Russia and Singapore, and South Africa. Patents that issue from this family are expected to expire in 2035, excluding any patent termadjustments or extensions.We also own a patent family directed to a scalable method of chiral synthesis of UBX0101, which includes one issued U.S. and one pending U.S.patent application and one international application filed under the patent cooperation treaty, or PCT. Future U.S. and foreign patents issued from this familyare expected to expire in 2037, excluding any patent term adjustments and patent term extensions.We additionally own 10 patent applications directed to alternative drug candidates for osteoarthritis, 10 pending provisional U.S. applications(which also cover aspects of our ophthalmology and pulmonary programs), and two pending international applications. Future U.S. and foreign patentsissued from these patent families are expected to expire between 2035, 2038, and 2039, excluding any patent term adjustments and patent term extensions.Ophthalmology ProgramWe have entered into a license with Ascentage to a family of issued composition of matter patents and pending manufacturing patent applicationsdirected to chemical entities including our lead drug candidate, UBX1967. This license grants us exclusive development and commercialization rights andnon-exclusive manufacturing rights to UBX1967 for all non-oncology indications outside of Greater China (China, Hong Kong, Macau and Taiwan). InsideGreater China, we will be obligated to develop, manufacture and commercialize UBX1967 through the joint venture with Ascentage. Patents in this familyhave been granted in the U.S., Korea, New Zealand, and South Africa, and are pending in Australia, Canada, China, Europe, India, Japan, and Singapore.Future U.S. and foreign patents issued from this family are expected to expire in 2032, excluding any patent term adjustments or extensions.We co-own two families of pending patent applications directed to the use of Bcl-2 inhibitors, including UBX1967 and related chemical entitiesfor the treatment of eye disease, including diabetic retinopathy, age-related macular degeneration, and glaucoma (which also cover aspects of ourosteoarthritis and/or pulmonary programs). One of these patent families is co-owned by the Buck Institute and us. The patents within the other family that arerelevant for ophthalmology indications are co-owned by the Buck Institute, the Mayo Clinic and us. We have exclusive licenses from each of the BuckInstitute and the Mayo Clinic to these patent families in the field of senescence. Applications in both of these families are pending in the U.S., Australia,Canada, China, Europe, and Japan. Future U.S. and foreign patents issued from these families are expected to expire in 2035 and 2036, excluding any patentterm adjustments and patent term extensions.We also own eight patent applications directed to alternative drug candidates for the treatment of eye disease and 12 pending provisionalapplications (which also cover aspects of our osteoarthritis and pulmonary programs). Future U.S. and foreign patents issued from these patent families areexpected to expire between 2035 and 2039, excluding any patent term adjustments and patent term extensions.Pulmonary ProgramWe are currently testing a number of drug candidates for the treatment of pulmonary disease. One of these compounds is covered as composition ofmatter by the issued patents and pending applications that are included in the patent family we have licensed from Ascentage.28 We also co-own two families of pending patent applications directed to the use of these compounds and other Bcl inhibitors for the treatment ofpulmonary disease, including IPF and COPD (which also cover aspects of our osteoarthritis and/or ophthalmology programs). One of these patent families isco-owned by the Buck Institute and us. The patents within the other family that are relevant for pulmonary indications are co-owned by the Buck Institute,the Mayo Clinic and us. We have exclusive licenses from each of the Buck Institute and the Mayo Clinic to these patent families in the field of senescence.Patent applications in both these families are pending in the U.S., Australia, Canada, China, Europe, and Japan. Future U.S. and foreign patents issued fromthese families are expected to expire in 2035 and 2036, excluding any patent term adjustments and patent term extensions.We additionally own eight patent applications directed to the use of alternative drug candidates for the treatment of lung disease and 12 pendingprovisional applications (which also cover aspects of our osteoarthritis and ophthalmology programs). Future U.S. and foreign patents issued from thesepatent families are expected to expire between 2035 and 2039, excluding any patent term adjustments and patent term extensions.We also own a provisional patent application directed to the use of certain combinations of compounds for the treatment of various pulmonarydiseases, as well as other disease indications. Future U.S. and foreign patents issued from this application are expected to expire in 2039, excluding anypatent term adjustments and patent term extensions.Other Anti-Aging ProgramsWe have an option to enter into an exclusive license with The Regents of the University of California for a patent family directed to methods oftreatment and the use of klotho protein for the development of human therapeutics. Patent applications in this family are pending in the U.S. and six foreignjurisdictions. Future U.S. and foreign patents issued from this family are expected to expire in 2036, excluding any patent term adjustments and patent termextensions.We also own one pending PCT application and co-own one U.S. provisional application with the Buck Institute on the enhancement ofmitochondrial health. Future U.S. and foreign patents issued from these two patent families are expected to expire in 2038 and 2039, excluding any patentterm adjustments and patent term extensions.Other Intellectual PropertyOur continuing research and development, technical know-how, and contractual arrangements supplement our intellectual property protection tomaintain our competitive position. Our policy is to require inventors who are identified on any Company-owned patent applications to assign rights to us.We also have confidentiality agreements with our employees, consultants, and other advisors to protect our proprietary information. Our policy is to requirethird parties that receive material UNITY confidential information to enter into confidentiality agreements with us.We also protect our brand through procurement of trademark rights. As of March 1, 2019, the mark UNITY BIOTECHNOLOGY® and the UNITYBIOTECHNOLOGY® design logo are registered in both the United States and the European Union. The mark UNITY® is also registered in the EuropeanUnion. In order to supplement protection of our brand, we have also registered several internet domain names.Government RegulationGovernment authorities in the United States (including federal, state and local authorities) and in other countries, extensively regulate, amongother things, the manufacturing, research and clinical development, marketing, labeling and packaging, storage, distribution, post-approval monitoring andreporting, advertising and promotion, pricing, and export and import of pharmaceutical products, such as those we are developing. The process of obtainingregulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure ofsubstantial time and financial resources.29 U.S. Government RegulationIn the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act, or FDCA, and its implementing regulations, andbiologics under the FDCA and the Public Health Service Act, or PHSA, and its implementing regulations. FDA approval is required before any newunapproved drug or dosage form, including a new use of a previously approved drug, can be marketed in the United States. Drugs and biologics are alsosubject to other federal, state and local statutes and regulations. If we fail to comply with applicable FDA or other requirements at any time during the drugdevelopment process, clinical testing, the approval process or after approval, we may become subject to administrative or judicial sanctions. These sanctionscould include the FDA’s refusal to approve pending applications, license suspension or revocation, withdrawal of an approval, warning letters, productrecalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, civil penalties or criminal prosecution.The process required by the FDA before drug candidates may be marketed in the United States generally involves the following: •completion of extensive preclinical laboratory tests and preclinical animal studies, all performed in accordance with the Good LaboratoryPractices, or GLP, regulations; •submission to the FDA of an IND, which must become effective before human clinical studies may begin; •approval by an independent IRB or ethics committee representing each clinical site before each clinical study may be initiated; •performance of adequate and well-controlled human clinical studies to establish the safety and efficacy, or in the case of a biologic, the safety,purity and potency, of the drug candidate for each proposed indication; •preparation of and submission to the FDA of a new drug application, or NDA, or biologics license application, or BLA, after completion of allpivotal clinical studies; •review of the product application by an FDA advisory committee, where appropriate and if applicable; •a determination by the FDA within 60 days of its receipt of an NDA or BLA to file the application for review; •satisfactory completion of an FDA pre-approval inspection of the manufacturing facilities where the drug candidate is produced to assesscompliance with current Good Manufacturing Practices, or cGMP; and •FDA review and approval of an NDA or BLA prior to any commercial marketing or sale of the drug or biologic in the United States.An IND is a request for authorization from the FDA to administer an investigational new drug product to humans. The central focus of an INDsubmission is on the general investigational plan and the protocol(s) for human studies. The IND also includes results of animal and in vitro studies assessingthe toxicology, pharmacokinetics, pharmacology and pharmacodynamic characteristics of the product; chemistry, manufacturing and controls information;and any available human data or literature to support the use of the investigational new drug. An IND must become effective before human clinical studiesmay begin. An IND will automatically become effective 30 days after receipt by the FDA, unless before that time the FDA raises concerns or questions relatedto the proposed clinical studies. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstandingconcerns or questions before clinical studies can begin. Accordingly, submission of an IND may or may not result in the FDA allowing clinical studies tocommence.Clinical StudiesClinical studies involve the administration of the investigational new drug to human subjects under the supervision of qualified investigators inaccordance with Good Clinical Practice regulations, or GCPs, which include the requirement that all research subjects provide their informed consent for theirparticipation in any clinical study. Clinical studies are conducted under protocols detailing, among other things, the objectives of the study, the parametersto be used in monitoring safety and the efficacy criteria to be evaluated. A protocol for each clinical study and any subsequent protocol amendments must besubmitted to the FDA as part of the IND. Additionally, approval must also be obtained from each clinical study site’s IRB before the studies may be initiated,and the IRB must monitor30 the study until completed. There are also requirements governing the reporting of ongoing clinical studies and clinical study results to public registries.The clinical investigation of a drug or biologic is generally divided into three or four phases. Although the phases are usually conductedsequentially, they may overlap or be combined. •Phase 1. The drug or biologic is initially introduced into healthy human subjects or patients with the target disease or condition. These studiesare designed to evaluate the safety, dosage tolerance, metabolism and pharmacologic actions of the investigational new drug in humans, the sideeffects associated with increasing doses, and if possible, to gain early evidence on effectiveness. •Phase 2. The drug or biologic is administered to a limited patient population to evaluate dosage tolerance and optimal dosage, identify possibleadverse side effects and safety risks and preliminarily evaluate efficacy. •Phase 3. The drug or biologic is administered to an expanded patient population, generally at geographically dispersed clinical study sites togenerate enough data to statistically evaluate dosage, clinical effectiveness and safety, to establish the overall benefit-risk relationship of theinvestigational product and to provide an adequate basis for product approval. •Phase 4. In some cases, the FDA may condition approval of an NDA or BLA for a drug candidate on the sponsor’s agreement to conductadditional clinical studies after approval. In other cases, a sponsor may voluntarily conduct additional clinical studies after approval to gain moreinformation about the drug. Such post-approval studies are typically referred to as Phase 4 clinical studies.A pivotal study is a clinical study that adequately meets regulatory agency requirements for the evaluation of a drug candidate’s efficacy andsafety such that it can be used to justify the approval of the product. Generally, pivotal studies are Phase 3 studies, but the FDA may accept results from Phase2 studies if the study design provides a well-controlled and reliable assessment of clinical benefit, particularly in situations where there is an unmet medicalneed and the results are sufficiently robust.The FDA, the IRB or the clinical study sponsor may suspend or terminate a clinical study at any time on various grounds, including a finding thatthe research subjects are being exposed to an unacceptable health risk. Additionally, some clinical studies are overseen by an independent group of qualifiedexperts organized by the clinical study sponsor, known as a data safety monitoring board or committee. This group provides authorization for whether or nota study may move forward at designated check points based on access to certain data from the study. We may also suspend or terminate a clinical study basedon evolving business objectives and/or competitive climate.Submission of an NDA or BLA to the FDAAssuming successful completion of all required testing in accordance with all applicable regulatory requirements, detailed investigational newdrug product information is submitted to the FDA in the form of an NDA or BLA requesting approval to market the product for one or more indications.Under federal law, the submission of most NDAs and BLAs is subject to a substantial application user fee. Applications for orphan drug products areexempted from the NDA and BLA application user fees.An NDA or BLA must include all relevant data available from pertinent preclinical and clinical studies, including negative or ambiguous results aswell as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls and proposed labeling, among otherthings. Data can come from company-sponsored clinical studies intended to test the safety and effectiveness of a use of a product, or from a number ofalternative sources, including studies initiated by investigators. To support marketing approval, the data submitted must be sufficient in quality and quantityto establish the safety and effectiveness of the investigational product to the satisfaction of the FDA.Once an NDA or BLA has been submitted, the FDA’s goal is to review the application within ten months after it accepts the application for filing,or, if the application relates to an unmet medical need in a serious or life-threatening indication, six months after the FDA accepts the application for filing.The review process is often significantly extended by FDA requests for additional information or clarification.31 Before approving an NDA or BLA, the FDA typically will inspect the facility or facilities where the product is manufactured. The FDA will notapprove an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assureconsistent production of the product within required specifications. Additionally, before approving an NDA or BLA, the FDA will typically inspect one ormore clinical sites to assure compliance with GCP.The FDA is required to refer an application for a novel drug or biologic to an advisory committee or explain why such referral was not made. Anadvisory committee is a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and provides arecommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisorycommittee, but it considers such recommendations carefully when making decisions and typically follows such recommendations.The FDA’s Decision on an NDA or BLAAfter the FDA evaluates the NDA or BLA and conducts inspections of manufacturing facilities, it may issue an approval letter or a CompleteResponse Letter. An approval letter authorizes commercial marketing of the drug or biologic with specific prescribing information for specific indications. AComplete Response Letter indicates that the review cycle of the application is complete and the application is not ready for approval. A Complete ResponseLetter may require additional clinical data and/or an additional pivotal Phase 3 clinical study(ies), and/or other significant, expensive and time-consumingrequirements related to clinical studies, preclinical studies or manufacturing. Even if such additional information is submitted, the FDA may ultimatelydecide that the NDA or BLA does not satisfy the criteria for approval. The FDA could also approve the NDA or BLA with a Risk Evaluation and MitigationStrategy, or REMS, to mitigate risks, which could include medication guides, physician communication plans or elements to assure safe use, such asrestricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes toproposed labeling, development of adequate controls and specifications or a commitment to conduct one or more post-market studies or clinical studies.Such post-market testing may include Phase 4 clinical studies and surveillance to further assess and monitor the product’s safety and effectiveness aftercommercialization. Also, new government requirements, including those resulting from new legislation, may be established, or the FDA’s policies maychange, which could delay or prevent regulatory approval of our products under development.Expedited Review and Accelerated Approval ProgramsThe FDA has various programs, including fast track designation, breakthrough therapy designation, accelerated approval, and priority review, thatare intended to expedite the development and approval of new drugs and biologics that address unmet medical needs in the treatment of serious or life-threatening diseases and conditions. To be eligible for a fast track designation, the FDA must determine, based on the request of a sponsor, that a product isintended to treat a serious or life-threatening disease or condition and demonstrates the potential to address an unmet medical need. The FDA may reviewsections of the NDA for a fast-track product on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for thesubmission of the sections of the NDA, the FDA agrees to accept sections of the NDA and determines that the schedule is acceptable, and the sponsor paysany required user fees upon submission of the first section of the NDA.The FDA may give a priority review designation to drugs that offer major advances in treatment, or provide a treatment where no adequate therapyexists. A priority review means that the goal for the FDA to review an application is six months, rather than the standard review of ten months under current.These six- and 10-month review periods are measured from the “filing” date rather than the receipt date for NDAs for new molecular entities, which typicallyadds approximately two months to the timeline for review and decision from the date of submission. Most products that are eligible for fast-track designationare also likely to be considered appropriate to receive a priority review.In addition, products studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningfultherapeutic benefit over existing treatments may be eligible for accelerated approval and may be approved on the basis of adequate and well-controlledclinical studies establishing that the product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinicalendpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity ormortality or other clinical benefit, taking into account the severity, rarity or prevalence of the condition32 and the availability or lack of alternative treatments. As a condition of approval, the FDA may require a sponsor of a drug receiving accelerated approval toperform post-marketing studies to verify and describe the predicted effect on irreversible morbidity or mortality or other clinical endpoint, and the drug maybe subject to accelerated withdrawal procedures.Moreover, under the provisions of the Food and Drug Administration Safety and Innovation Act, or FDASIA, passed in July 2012, a sponsor canrequest designation of a drug candidate as a “breakthrough therapy.” A breakthrough therapy is defined as a drug or biologic that is intended, alone or incombination with one or more other drugs or biologics, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicatesthat the product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantialtreatment effects observed early in clinical development. Drugs designated as breakthrough therapies are also eligible for the other expedited review andapproval programs, including accelerated approval, priority review, and fast-track designation. The FDA must take certain actions, such as holding timelymeetings and providing advice, intended to expedite the development and review of an application for approval of a breakthrough therapy.Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions forqualification or decide that the time period for FDA review or approval will not be shortened.Post-Approval RequirementsDrugs and biologics marketed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among otherthings, requirements relating to recordkeeping, periodic reporting, product sampling and distribution, advertising and promotion and reporting of adverseexperiences with the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims are subject toprior FDA review and approval. There also are continuing, annual user fee requirements.Manufacturers are subject to periodic unannounced inspections by the FDA and state agencies for compliance with cGMP requirements. Changesto the manufacturing process are strictly regulated and, depending on the significance of the change, may require prior FDA approval before beingimplemented. FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting and documentation requirementsupon us and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue to expend time, money and effort in the areaof production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance.Discovery of previously unknown problems with a product or the failure to comply with applicable requirements may result in restrictions on aproduct, manufacturer or holder of an approved NDA or BLA, including withdrawal or recall of the product from the market or other voluntary, FDA-initiatedor judicial action that could delay or prohibit further marketing. Also, new government requirements, including those resulting from new legislation, may beestablished, or the FDA’s policies may change, which could delay or prevent regulatory approval of our products under development.The FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the productreaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or withmanufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information;imposition of post-market studies or clinical studies to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMSprogram. Other potential consequences include, among other things: •restrictions on the marketing or manufacturing of the product; •complete withdrawal of the product from the market or product recalls; •fines, warning letters or holds on post-approval clinical studies;33 •refusal of the FDA to approve pending NDAs or BLAs or supplements to approved NDAs or BLAs, or suspension or revocation of product licensesor approvals; •product seizure or detention, or refusal to permit the import or export of products; or •injunctions or the imposition of civil or criminal penalties.The FDA strictly regulates marketing, labeling, advertising and promotion of products that are placed on the market. Drugs may be promoted onlyfor the approved indications and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws andregulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significantliability.Orphan Designation and ExclusivityUnder the Orphan Drug Act, the FDA may grant orphan designation to a drug or biologic intended to treat a rare disease or condition, defined as adisease or condition with a patient population of fewer than 200,000 individuals in the United States, or a patient population greater than 200,000individuals in the United States and when there is no reasonable expectation that the cost of developing and making available the drug or biologic in theUnited States will be recovered from sales in the United States for that drug or biologic. Orphan drug designation must be requested before submitting a BLAor NDA. After the FDA grants orphan drug designation, the generic identity of the therapeutic agent and its potential orphan use are disclosed publicly by theFDA.If a product that has orphan drug designation subsequently receives the first FDA approval for a particular active ingredient for the disease forwhich it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications,including a full BLA, to market the same biologic for the same indication for seven years, except in limited circumstances, such as a showing of clinicalsuperiority to the product with orphan drug exclusivity or if FDA finds that the holder of the orphan drug exclusivity has not shown that it can assure theavailability of sufficient quantities of the orphan drug to meet the needs of patients with the disease or condition for which the drug was designated. Orphandrug exclusivity does not prevent the FDA from approving a different drug or biologic for the same disease or condition, or the same drug or biologic for adifferent disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the BLA or NDAapplication user fee.A designated orphan drug many not receive orphan drug exclusivity if it is approved for a use that is broader than the indication for which itreceived orphan designation. In addition, orphan drug exclusive marketing rights in the United States may be lost if the FDA later determines that the requestfor designation was materially defective or, as noted above, if the second applicant demonstrates that its product is clinically superior to the approvedproduct with orphan exclusivity or the manufacturer of the approved product is unable to assure sufficient quantities of the product to meet the needs ofpatients with the rare disease or condition.Biosimilars and ExclusivityThe Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, or the Affordable Care Act,signed into law in 2010, includes a subtitle called the Biologics Price Competition and Innovation Act of 2009, or BPCIA, which created an abbreviatedapproval pathway for biological products that are biosimilar to or interchangeable with an FDA-licensed reference biological product. To date, only ahandful of biosimilars have been licensed under the BPCIA, although numerous biosimilars have been approved in Europe. The FDA has issued severalguidance documents outlining an approach to review and approval of biosimilars.Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in termsof safety, purity and potency, can be shown through analytical studies, animal studies and a clinical study or studies. Interchangeability requires that aproduct is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the referenceproduct in any given patient and, for products that are administered multiple times to an individual, the biologic and the reference biologic may be alternatedor switched after one has been previously administered without increasing safety34 risks or risks of diminished efficacy relative to exclusive use of the reference biologic. However, complexities associated with the larger, and often morecomplex, structures of biological products, as well as the processes by which such products are manufactured, pose significant hurdles to implementation ofthe abbreviated approval pathway that are still being worked out by the FDA.Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the referenceproduct was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date onwhich the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of thereference product if the FDA approves a full BLA for the competing product containing that applicant’s own preclinical data and data from adequate andwell-controlled clinical studies to demonstrate the safety, purity and potency of its product. The BPCIA also created certain exclusivity periods forbiosimilars approved as interchangeable products. At this juncture, it is unclear whether products deemed “interchangeable” by the FDA will, in fact, bereadily substituted by pharmacies, which are governed by state pharmacy law.A biological product can also obtain pediatric market exclusivity in the United States. Pediatric exclusivity, if granted, adds six months to existingexclusivity periods and patent terms. This six-month exclusivity, which runs from the end of other exclusivity protection or patent term, may be grantedbased on the voluntary completion of a pediatric study in accordance with an FDA-issued “Written Request” for such a study.The BPCIA is complex and continues to be interpreted and implemented by the FDA. In addition, recent government proposals have sought toreduce the 12-year reference product exclusivity period. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have alsobeen the subject of recent litigation. As a result, the ultimate impact, implementation, and impact of the BPCIA is subject to significant uncertainty.Hatch-Waxman Amendments and ExclusivitySection 505 of the FDCA describes three types of marketing applications that may be submitted to the FDA to request marketing authorization for anew drug. A Section 505(b)(1) NDA is an application that contains full reports of investigations of safety and efficacy. A 505(b)(2) NDA is an application thatcontains full reports of investigations of safety and efficacy but where at least some of the information required for approval comes from investigations thatwere not conducted by or for the applicant and for which the applicant has not obtained a right of reference or use from the person by or for whom theinvestigations were conducted. This regulatory pathway enables the applicant to rely, in part, on the FDA’s prior findings of safety and efficacy for anexisting product, or published literature, in support of its application. Section 505(j) establishes an abbreviated approval process for a generic version ofapproved drug products through the submission of an Abbreviated New Drug Application, or ANDA. An ANDA provides for marketing of a generic drugproduct that has the same active ingredients, dosage form, strength, route of administration, labeling, performance characteristics and intended use, amongother things, to a previously approved product. ANDAs are termed “abbreviated” because they are generally not required to include preclinical (animal) andclinical (human) data to establish safety and efficacy. Instead, generic applicants must scientifically demonstrate that their product is bioequivalent to, orperforms in the same manner as, the innovator drug through in vitro, in vivo or other testing. The generic version must deliver the same amount of activeingredients into a subject’s bloodstream in the same amount of time as the innovator drug and can often be substituted by pharmacists under prescriptionswritten for the reference listed drug. In seeking approval for a drug through an NDA, applicants are required to list with the FDA each patent with claims thatcover the applicant’s drug or a method of using the drug. Upon approval of a drug, each of the patents listed in the application for the drug is then publishedin the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. Drugs listed in the Orange Bookcan, in turn, be cited by potential competitors in support of approval of an ANDA or 505(b)(2) NDA.Upon submission of an ANDA or a 505(b)(2) NDA, an applicant must certify to the FDA that (1) no patent information on the drug product that isthe subject of the application has been submitted to the FDA; (2) such patent has expired; (3) the date on which such patent expires; or (4) such patent isinvalid or will not be infringed upon by the manufacture, use or sale of the drug product for which the application is submitted. Generally, the ANDA or505(b)(2) NDA cannot be approved until all listed patents have expired, except where the ANDA or 505(b)(2) NDA applicant challenges a listed patentthrough the last type of certification, also known as a paragraph IV certification. If the applicant does not challenge the listed patents, or indicates that it isnot seeking approval of a patented method35 of use, the ANDA or 505(b)(2) NDA application will not be approved until all of the listed patents claiming the referenced product have expired.If the ANDA or 505(b)(2) NDA applicant has provided a Paragraph IV certification to the FDA, the applicant must send notice of the Paragraph IVcertification to the NDA and patent holders once the application has been accepted for filing by the FDA. The NDA and patent holders may then initiate apatent infringement lawsuit in response to the notice of the paragraph IV certification. If the paragraph IV certification is challenged by an NDA holder or thepatent owner(s) asserts a patent challenge to the paragraph IV certification, the FDA may not approve that application until the earlier of 30 months from thereceipt of the notice of the paragraph IV certification, the expiration of the patent, when the infringement case concerning each such patent was favorablydecided in the applicant’s favor or settled, or such shorter or longer period as may be ordered by a court. This prohibition is generally referred to as the 30-month stay. In instances where an ANDA or 505(b)(2) NDA applicant files a paragraph IV certification, the NDA holder or patent owner(s) regularly takeaction to trigger the 30-month stay, recognizing that the related patent litigation may take many months or years to resolve.The FDA also cannot approve an ANDA or 505(b)(2) application until all applicable non-patent exclusivities listed in the Orange Book for thebranded reference drug have expired. For example, a pharmaceutical manufacturer may obtain five years of non-patent exclusivity upon NDA approval of anew chemical entity, or NCE, which is a drug containing an active moiety that has not been approved by FDA in any other NDA. An “active moiety” isdefined as the molecule responsible for the drug substance’s physiological or pharmacologic action. During that five-year exclusivity period, the FDA cannotaccept for filing (and therefore cannot approve) any ANDA seeking approval of a generic version of that drug or any 505(b)(2) NDA that relies on the FDA’sapproval of the drug, provided that that the FDA may accept an ANDA four years into the NCE exclusivity period if the ANDA applicant also files aParagraph IV certification.A drug, including one approved under Section 505(b)(2), may obtain a three-year period of exclusivity for a particular condition of approval, orchange to a marketed product, such as a new formulation for a previously approved product, if one or more new clinical studies (other than bioavailability orbioequivalence studies) was essential to the approval of the application and was conducted/sponsored by the applicant. Should this occur, the FDA would beprecluded from approving any ANDA or 505(b)(2) application for the protected modification until after that three-year exclusivity period has run. However,unlike NCE exclusivity, the FDA can accept an application and begin the review process during the exclusivity period.Other Healthcare Laws and Compliance RequirementsPharmaceutical companies are subject to additional healthcare regulation and enforcement by the federal government and by authorities in thestates and foreign jurisdictions in which they conduct their business. Such laws include, without limitation, state and federal anti-kickback, fraud and abuse,false claims, privacy and security and physician sunshine laws and regulations. If their operations are found to be in violation of any of such laws or any othergovernmental regulations that apply, they may be subject to penalties, including, without limitation, civil and criminal penalties, damages, fines, thecurtailment or restructuring of operations, exclusion from participation in federal and state healthcare programs and individual imprisonment.Coverage and ReimbursementSales of any product depend, in part, on the extent to which such product will be covered by third-party payors, such as federal, state and foreigngovernment healthcare programs, commercial insurance and managed healthcare organizations and the level of reimbursement for such product by third-party payors. Decisions regarding the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. These third-partypayors are increasingly reducing reimbursements for medical products, drugs and services. In addition, the U.S. government, state legislatures and foreigngovernments have continued implementing cost-containment programs, including price controls, restrictions on coverage and reimbursement andrequirements for substitution of generic products. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies injurisdictions with existing controls and measures, could further limit sales of any product. Decreases in third-party reimbursement for any product36 or a decision by a third-party payor not to cover a product could reduce physician usage and patient demand for the product and also have a material adverseeffect on sales.Healthcare ReformIn March 2010, former President Obama signed the Affordable Care Act, which substantially changed the way healthcare is financed by bothgovernmental and private insurers in the United States, and significantly affected the pharmaceutical industry. The Affordable Care Act contains a number ofprovisions, including those governing enrollment in federal healthcare programs, reimbursement adjustments and fraud and abuse changes. Additionally, theAffordable Care Act increases the minimum level of Medicaid rebates payable by manufacturers of brand name drugs from 15.1% to 23.1%; requirescollection of rebates for drugs paid by Medicaid managed care organizations; requires manufacturers to participate in a coverage gap discount program,under which they must agree to offer 50 percent point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during theircoverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D; and imposes a non-deductible annual fee onpharmaceutical manufacturers or importers who sell “branded prescription drugs” to specified federal government programs.Since its enactment, there have been judicial and Congressional challenges to certain aspects of the Affordable Care Act, and we expect there willbe additional challenges and amendments to the Affordable Care Act in the future. Other legislative changes have been proposed and adopted since theAffordable Care Act was enacted, including aggregate reductions of Medicare payments to providers of 2% per fiscal year and reduced payments to severaltypes of Medicare providers. Moreover, there has recently been heightened governmental scrutiny over the manner in which manufacturers set prices for theirmarketed products, which has resulted in several Congressional inquiries and proposed bills designed to, among other things, bring more transparency toproduct pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologiesfor drug products. Individual states in the United States have also become increasingly active in implementing regulations designed to controlpharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing costdisclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.Licenses and CollaborationsDescription of Ascentage AgreementsIn February 2016, we entered into several related agreements with Ascentage Pharma Group Corp Limited, or, Ascentage, based in Hong Kong,China. These agreements include (i) a compound library and option agreement, which includes a template form of license agreement, (ii) a license agreementcovering an initial compound, APG1252, and (iii) a research services agreement. In January 2019, we entered into another license agreement granting usdevelopment and commercialization rights to UBX1967 and the right to continue preclinical development efforts with another Ascentage-controlled Bcl-2inhibitor compound.Library Agreement and License TemplateThe compound library and option agreement, or library agreement, gives us access to Ascentage’s existing collection of Bcl-2 inhibitorcompounds, as well as any additional Bcl-2 inhibitor compounds developed during the term of the library agreement, in order to screen such compounds forsenolytic activity. The library agreement permits us to nominate up to 15 such compounds at any given time for further evaluation and subsequently to selectup to five of such selected compounds for preclinical development and an additional five as back-up compounds.. Prior to commencing IND-enablingtoxicology studies on an Ascentage compound of interest, we must formally designate the compound as a development candidate under the libraryagreement and enter into a separate license agreement with Ascentage covering that compound on the terms set forth in the template form of licenseagreement. The library agreement includes exclusivity provisions that (i) prohibit us from developing Ascentage Bcl-2 compounds for oncology indications,(ii) prohibit Ascentage from researching or developing certain Bcl-2 compounds for non-oncology indications under any circumstances, and (iii) prohibitAscentage from researching or developing certain other Bcl-2 compounds for a specified set of non-oncology indications under certain circumstances. Theterm of the37 library agreement is determined by a formula that is linked to the term of the research services agreement, with a maximum term of six years. The libraryagreement may be terminated by either party due to the other party’s uncured material breach of the library agreement.Under the terms of the template form of license agreement, Ascentage will grant us the following rights with respect to a selected Ascentagecompound for all non-oncology indications: (i) exclusive worldwide development rights, and (ii) exclusive commercialization rights outside of GreaterChina (China, Hong Kong, Macau and Taiwan). Inside Greater China, we will be obligated to commercialize the licensed Ascentage compound through ajoint venture with Ascentage. Ascentage will also have the right to manufacture at least 50% of our supply requirements of the licensed compound, providedthey achieve and maintain certain manufacturing quality standards. We will be obligated to make certain milestone payments in the form of shares of ourcommon stock, subject to the equity cap described below, and other milestone payments in in the form of cash, not to exceed $38 million per licensedproduct, based in each case, upon the achievement of certain clinical and commercial milestones. We will also be required to make low-single digit royaltypayments on net sales of the licensed product under the agreement. Our royalty payment obligations will expire on a country-by-country basis and licensedproduct-by-licensed product basis upon the later to occur of (a) the expiration of the last valid claim of a licensed patent covering such licensed product insuch country, (b) the expiration of regulatory exclusivity for such licensed product in such country, and (c) the tenth anniversary of the first commercial saleof such licensed product in any country. We have the right to credit certain royalty payments that we pay to third parties with respect to certain licensedproducts against our royalty obligation to Ascentage. Any license agreement may be terminated by either party due to the other party’s uncured materialbreach of the agreement.Under the library agreement, we issued 133,333 shares of our common stock as an upfront license fee. Of such shares, 80% were issued to Ascentageand 20% were issued to the University of Michigan in satisfaction of Ascentage’s obligation to pay a related sublicense fee to the University of Michigan. Inaddition to the shares issued pursuant to the APG1252 license agreement described below, we will also be obligated to issue an additional 133,333 shares ofour common stock as an upfront license fee to Ascentage and the University of Michigan for each of the next two license agreements. The aggregate numberof shares of our common stock we could be required to issue to Ascentage and the University of Michigan pursuant to the library agreement, the APG1252license agreement, and any additional license agreements we enter into pursuant to the library agreement is capped at 1,333,338 shares.APG1252 License AgreementIn conjunction with the library agreement, we entered into our first license agreement with Ascentage, which grants us the right to develop andcommercialize an Ascentage compound known as APG1252 on the template license terms described above, including up to $38.0 million of potential cashmilestone payments and low-single digit royalties. Under the APG1252 license agreement, Ascentage retains the right to manufacture APG1252 compoundsfor use in our licensed products. In connection with the APG1252 license agreement, we issued 533,335 shares of our common stock as an upfront license feeto Ascentage and the University of Michigan, in the proportion described above. The APG1252 license agreement may be terminated by either party due tothe other party’s uncured material breach of the APG1252 license agreement, and we may terminate for convenience on a licensed product-by-licensedproduct basis.Research AgreementIn conjunction with the library agreement we also entered into a research services agreement with Ascentage under which we provide $500,000 peryear in funding to Ascentage for the further development of Bcl-2 inhibitor compounds, which we retain the right to access under the library agreement. Theresearch agreement has a term of up to four years from the effective date of February 2, 2016, provided that the research agreement may be terminated by usfor convenience after the first year, by either party due to the other party’s uncured material breach, and by Ascentage if we fail to make the $500,000payment in any given year.UBX1967 License AgreementIn January 2019, we entered into our second license agreement with Ascentage granting rights to UBX1967 (which Ascentage calls APG1197) onthe template license terms described above, including up to $38.0 million of potential cash milestone payments and low-single digit royalties. Under theterms of this license agreement, Ascentage38 has granted us exclusive development and commercialization rights and non-exclusive manufacturing rights to UBX1967 for all non-oncology indicationsoutside of Greater China. Inside Greater China, we will be obligated to develop, manufacture and commercialize UBX1967 through a joint venture withAscentage. The UBX1967 license agreement also grants us the right to continue our preclinical development efforts with another Ascentage-controlled Bcl-2inhibitor compound. In the event we wish to pursue clinical development of the additional compound as well as UBX1967, we will be required to enter into aseparate license agreement with Ascentage on the template license terms described above. In connection with the UBX1967 license agreement, we will issue106,666 shares of common stock to Ascentage and 26,667 shares if common stock to the University of Michigan as an upfront license fee in early 2019. TheUBX1967 License Agreement may be terminated by either party due to an uncured material breach of the agreement but the other party, and we mayterminate for convenience on a licensed product-by-licensed product basis. Additional License AgreementsWe are party to three additional license agreements that support our senescence-related patent portfolio. These agreements are with The JohnHopkins University, or JHU, an entity affiliated with the Mayo Clinic, or Mayo, and the Buck Institute for Research on Aging, or Buck, and provide us with aworldwide, exclusive, sublicensable license under those counter-parties’ rights to a patent family that is co-owned by JHU, Buck, Mayo and us to developand commercialize licensed products, including for the treatment of senescence-related diseases in therapeutic areas including osteoarthritis, ophthalmology,and pulmonary disease.Under our November 2016 license with JHU, which relates to patents that are relevant only to osteoarthritis indications, we may be obligated tomake development and sales milestone payments to JHU in the form of equity (22,033 shares of our common stock) and cash (of up to $2.6 million in theaggregate), to pay JHU a low-single digit percentage of certain sublicensing revenue, and to pay JHU a running royalty payment of less than 1% on net sales,in all cases, with respect to licensed products for the treatment of osteoarthritis, which we refer to as Royalty Products. Our obligation to pay running royaltiesto JHU under the agreement is subject to a non-material minimum annual royalty, and may continue on a country-by-country basis until such time as neitherthe manufacture, sale, or use of such Royalty Product would infringe a valid claim of a licensed patent in the applicable country. Our agreement with JHUcontinues on a country-by-country basis until the expiration of the last to expire licensed patent in such country (or until twenty years after the effective dateif no licensed patent issues in such country). We may terminate the agreement for convenience (as a whole, with respect to a licensed product, or with respectto a particular licensed patent). Either party may terminate the agreement for the other party’s uncured material breach or bankruptcy or insolvency-relatedevents.Under our June 2013 license with Mayo, we may be obligated to make development and sales milestone payments to Mayo of up to $10.8 millionin the aggregate, to pay Mayo a percentage of certain sublicensing revenue that is between the high-single digits and the low-teens, and to pay Mayo runningroyalty payments ranging from less than 1% to low-single digit percentages on net sales of licensed products. Our obligation to pay running royalties toMayo under the agreement is subject to a non-material minimum annual royalty and could potentially extend until January 1, 2037. We also issued 677,966shares of our common stock to Mayo under this agreement. Our agreement with Mayo continues until the later of (i) the expiration of the last valid claimwithin the licensed patents and (ii) 13 years after first commercial sale of the first licensed product. We may terminate the agreement for convenience, andeither party may terminate the agreement for the other party’s uncured material breach.Under our January 2017 license with Buck, which includes similar rights to a second patent family that is co-owned only by Buck and us, we maybe obligated to make development and sales milestone payments to Buck of up to $5.4 million in the aggregate, to pay Buck a mid-single digit percentage ofcertain sublicensing revenue, and to pay Buck running royalty payments ranging from less than 1% to low-single digit percentages on net sales of licensedproducts. Our obligation to pay running royalties to Buck under the agreement is subject to a non-material minimum annual royalty and could potentiallyextend until January 1, 2037. We also issued 132,203 shares of our common stock to Buck under this agreement. The term of our license agreement withBuck continues until the expiration of all our payment obligations to Buck thereunder. We may terminate the agreement for convenience, and either partymay terminate the agreement for the other party’s uncured material breach.39 EmployeesAs of March 1, 2019, we had 106 employees, all of whom were full-time. Greater than 65% of our employees hold advanced degrees. The majorityof our employees work in our Brisbane, California, facility. None of our employees is represented by a labor union or a collective bargaining agreement.40 FacilitiesOur corporate headquarters are located in Brisbane, California, where we currently lease approximately 39,000 square feet of office and laboratoryspace pursuant to a lease dated May 13, 2016. Although this facility is sufficient for our current needs, we will require additional space by the end of 2019 toaccommodate our anticipated growth. Therefore, on February 28, 2019, we entered into a lease for a new facility which we anticipate will be ready foroccupancy during the fourth quarter of 2019. The new facility is located in South San Francisco, California, and is comprised of approximately 62,000square feet of office and laboratory space. The new lease has a term of 10 years from the lease commence date. Substantially all our employees work at ourcurrent facility and will also work at the new facility.Legal ProceedingsWe are not currently involved in any litigation or legal proceedings that, in management’s opinion, are likely to have any material adverse effecton our company. While we know of no imminent legal action in which we are likely to be involved, we may in the future become engaged in litigation orother legal proceedings. Regardless of the outcome, litigation can have an adverse impact due to defense fees, settlement costs, demands on managementattention, and other concerns.Financial Information About SegmentsWe view our operations and manage our business as one reportable segment. See Note 1 in the Notes to Financial Statements included in thisAnnual Report on Form 10 K. Additional information required by this item is incorporated herein by reference to Part II, Item 6, “Selected Financial Data.”About UnityWe were incorporated in the State of Delaware on March 30, 2009. Our registered trademarks include UNITY BIOTECHNOLOGY®. Other servicemarks, trademarks and trade names referred to in this document are the property of their respective owners.Available InformationWe are subject to the information requirements of the Securities Exchange Act of 1934, as amended, and we therefore file periodic reports, proxystatements and other information with the SEC relating to our business, financial statements and other matters. The SEC maintains an Internet site,www.sec.gov, that contains reports, proxy statements and other information regarding issuers such as Unity.For more information about Unity, including free access to our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports onForm 8-K and amendments to those reports, visit our website, www.unitybiotechnology.com. The information found on or accessible through our website isnot incorporated into, and does not form a part of, this Form 10-K.41 Item 1A. Risk Factors.This Annual Report on Form 10-K contains forward-looking information based on our current expectations. Because our business is subject tomany risks and our actual results may differ materially from any forward-looking statements made by or on behalf of us, this section includes a discussion ofimportant factors that could affect our business, operating results, financial condition and the trading price of our common stock. This discussion should beread in conjunction with the other information in this Annual Report on Form 10-K, including our condensed financial statements and the notesaccompanying those financial statements and “Management’s Discussion and Analysis of Financial Condition and Results of Operations”. The occurrenceof any of the events or developments described below could have a material adverse effect on our business, results of operations, financial condition,prospects and stock price. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also impair our business.Risks Related to Our Limited Operating History, Financial Condition, and Capital RequirementsWe are a clinical-stage biopharmaceutical company with a limited operating history and no products approved for commercial sale. We haveincurred significant losses since our inception, and we anticipate that we will continue to incur losses for the foreseeable future, which, together with ourlimited operating history, make it difficult to assess our future viability.We are a clinical-stage biopharmaceutical company with a limited operating history. Biopharmaceutical product development is a highlyspeculative undertaking and involves a substantial degree of risk. We have not yet sought approval for commercial sale of any products and therefore haveno products approved for commercial sale and have not generated any revenue from contracts with customers and have incurred losses in each year since ourinception in March 2009. We have only a limited operating history upon which you can evaluate our business and prospects. In addition, we have limitedexperience and have not yet demonstrated an ability to successfully overcome many of the risks and uncertainties frequently encountered by companies innew and rapidly evolving fields, particularly in the biopharmaceutical industry. We initiated a Phase 1 clinical study of UBX0101, a potent senolytic small-molecule inhibitor of the MDM2/p53 interaction, in osteoarthritic patients in the second quarter of 2018. We have not yet submitted an Investigational NewDrug, or IND, application or initiated a clinical study for any of our other drug candidates.We have had significant operating losses since our inception. Our net loss for the years ended December 31, 2018 and 2017, was approximately$76.4 million and $44.7 million, respectively. As of December 31, 2018, we had an accumulated deficit of $163.3 million. Substantially all of our losses haveresulted from expenses incurred in connection with our research and development programs and from general and administrative costs associated with ouroperations. We expect to continue to incur losses for the foreseeable future, and we anticipate these losses will increase as we continue to develop our drugcandidates, conduct clinical studies and pursue research and development activities. Even if we achieve profitability in the future, we may not be able tosustain profitability in subsequent periods. Our prior losses, combined with expected future losses, have had and will continue to have an adverse effect onour stockholders’ equity and working capital.We will require substantial additional financing to achieve our goals, and a failure to obtain this capital when needed on acceptable terms, or atall, could force us to delay, limit, reduce or terminate our product development, other operations or commercialization efforts.Since our inception, we have invested a significant portion of our efforts and financial resources in research and development activities. Preclinicalstudies and clinical studies for our drug candidates and additional research and development activities to discover and develop new drug candidates willrequire substantial funds to complete. As of December 31, 2018, we had capital resources consisting of cash, cash equivalents, and marketable securities of$171.1 million. In March and April 2018, we sold and issued an aggregate of 3,913,425 shares of our Series C convertible preferred stock at $15.3317 pershare for net cash proceeds to us of approximately $59.9 million. In May 2018, we completed our initial public offering, or IPO, and received net proceeds of$75.9 million, after deducting underwriting discounts, commissions and offering expenses payable by us. We believe that we will continue to expendsubstantial resources for the foreseeable future in connection with the preclinical and clinical development of our lead drug candidates, UBX0101 andUBX1967, and the discovery and/or development of any other drug candidates we may choose to pursue. These expenditures will include costs associatedwith conducting preclinical studies and clinical studies, obtaining regulatory approvals, and manufacturing and supply, as well as marketing and selling anyproducts42 approved for sale. In addition, other unanticipated costs may arise. Because the outcome of any preclinical study or clinical study is highly uncertain, wecannot reasonably estimate the actual amounts necessary to successfully complete the development and commercialization of our lead drug candidates orany future drug candidates.Based on our current operating plans, we expect our existing capital resources will fund our planned operating expenses into 2021. However, ouroperating plans may change as a result of many factors currently unknown to us, and we may need to seek additional funds sooner than planned, throughpublic or private equity or debt financings or other sources, such as strategic collaborations. Such financing may result in dilution to stockholders, theimposition of burdensome debt covenants and repayment obligations, or other restrictions that may affect our business. In addition, we may seek additionalcapital due to favorable market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans.Our future capital requirements depend on many factors, including: •the scope, progress, results and costs of researching and developing UBX0101, UBX1967 or any other drug candidates, and conductingpreclinical studies and clinical studies, including our ongoing Phase 1 clinical study of UBX0101, which was initiated in the second quarter of2018; •the timing of, and the costs involved in, obtaining regulatory approvals for our lead drug candidates or any future drug candidates; •the number and characteristics of any additional drug candidates we develop or acquire; •the timing and amount of any milestone payments we are required to make pursuant to our license agreements; •the cost of manufacturing our lead drug candidates or any future drug candidates and any products we successfully commercialize; •the cost of building a sales force in anticipation of product commercialization; •the cost of commercialization activities if our lead drug candidates or any future drug candidates are approved for sale, including marketing,sales and distribution costs; •our ability to maintain existing, and establish new, strategic collaborations, licensing or other arrangements and the financial terms of any suchagreements, including the timing and amount of any future milestone, royalty or other payments due under any such agreement; •any product liability or other lawsuits related to our products; •the expenses needed to attract, hire and retain skilled personnel; •the costs associated with being a public company; •the costs involved in preparing, filing, prosecuting, maintaining, defending and enforcing our intellectual property portfolio; and •the timing, receipt and amount of sales of any future approved products, if any.Additional funds may not be available when we need them, on terms that are acceptable to us, or at all. If adequate funds are not available to us ona timely basis, we may be required to: •delay, limit, reduce or terminate preclinical studies, clinical studies or other development activities for our lead drug candidates or any futuredrug candidate; •delay, limit, reduce or terminate our research and development activities; or •delay, limit, reduce or terminate our efforts to establish manufacturing and sales and marketing capabilities or other activities that may benecessary to commercialize our lead drug candidates or any future drug candidate, or reduce our flexibility in developing or maintaining oursales and marketing strategy.We also could choose or be required to seek funds through arrangements with collaborators or others that may require us to relinquish rights tosome of our technologies or drug candidates that we would otherwise pursue on our own. We do not expect to realize revenue from sales of products orroyalties from licensed products in the foreseeable future, if at all, and unless and until our drug candidates are clinically tested, approved forcommercialization and43 successfully marketed. To date, we have primarily financed our operations through the sale of debt and equity securities. We will be required to seekadditional funding in the future and currently intend to do so through collaborations, public or private equity offerings or debt financings, credit or loanfacilities or a combination of one or more of these funding sources. Our ability to raise additional funds will depend on financial, economic and other factors,many of which are beyond our control. Additional funds may not be available to us on acceptable terms or at all. If we raise additional funds by issuingequity securities, our stockholders will suffer dilution and the terms of any financing may adversely affect the rights of our stockholders. In addition, as acondition to providing additional funds to us, future investors may demand, and may be granted, rights superior to those of existing stockholders. Debtfinancing, if available, is likely to involve restrictive covenants limiting our flexibility in conducting future business activities, and, in the event ofinsolvency, debt holders would be repaid before holders of our equity securities received any distribution of our corporate assets.Due to the significant resources required for the development of our drug candidates, we must prioritize development of certain drug candidatesand/or certain disease indications. We may expend our limited resources on candidates or indications that do not yield a successful product and fail tocapitalize on drug candidates or indications that may be more profitable or for which there is a greater likelihood of success.We plan to continue to develop a pipeline of drug candidates to treat age-related diseases and extend human healthspan. Our clinical developmentstrategy is initially focused on the development of senolytic medicines designed to be administered locally into diseased tissue and we are currentlyadvancing programs in musculoskeletal, ophthalmologic, and pulmonary disorders. We are also in the early stages of developing senolytic medicines thatcould be administered systemically to treat additional age-related diseases, such as kidney disease, liver disease, and neurological disorders. In addition toour efforts to eliminate senescent cells, we are also advancing other programs with the potential to extend human healthspan, including the administration ofcirculating youth factors.We seek to maintain a process of prioritization and resource allocation among our programs to maintain a balance between aggressively advancinglead programs in identified indications and exploring additional indications and/or mechanisms related to diseases of aging. However, due to the significantresources required for the development of our drug candidates, we must focus on specific diseases and disease pathways and decide which drug candidates topursue and the amount of resources to allocate to each. Our near-term objective is to demonstrate in our clinical studies that local treatment with senolyticmolecules can alter the course of an age-related disease. To accomplish this goal, we initiated a Phase 1 clinical study of UBX0101 in osteoarthritic patientsin the second quarter of 2018. In addition, we plan to submit an ophthalmology IND application for UBX1967 in early 2020 that, if accepted, would enableus to pursue multiple indications in age-related eye diseases.Our decisions concerning the allocation of research, development, collaboration, management and financial resources toward particular drugcandidates or therapeutic areas may not lead to the development of any viable commercial product and may divert resources away from better opportunities.Similarly, our potential decisions to delay, terminate or collaborate with third parties in respect of certain programs may subsequently also prove to besuboptimal and could cause us to miss valuable opportunities. If we make incorrect determinations regarding the viability or market potential of any of ourprograms or drug candidates or misread trends in the biopharmaceutical industry, particularly those segments focused on aging and healthspan, our business,financial condition and results of operations could be materially adversely affected. As a result, we may fail to capitalize on viable commercial products orprofitable market opportunities, be required to forego or delay pursuit of opportunities with other drug candidates or other diseases and disease pathways thatmay later prove to have greater commercial potential than those we choose to pursue, or relinquish valuable rights to such drug candidates throughcollaboration, licensing or other royalty arrangements in cases where it may have been more advantageous for us to invest additional resources to retaindevelopment and commercialization rights.Our operating results may fluctuate significantly, which makes our future operating results difficult to predict and could cause our operatingresults to fall below expectations.44 Our quarterly and annual operating results may fluctuate significantly, making it difficult for us to predict our future operating results. Thesefluctuations may occur due to a variety of factors, many of which are outside of our control and may be difficult to predict, including: •the timing, cost and level of investment in research, development and, if approved, commercialization activities relating to our drug candidates,which may change from time to time; •the timing and status of enrollment for our clinical studies; •the cost of manufacturing our drug candidates, as well as building out our supply chain, which may vary depending on the quantity ofproduction and the terms of our agreements with manufacturers; •expenditures we may incur to acquire, develop or commercialize additional drug candidates and technologies; •timing and amount of any milestone, royalty or other payments due under any collaboration or license agreement; •future accounting pronouncements or changes in our accounting policies; •the timing and success or failure of preclinical studies and clinical studies for our drug candidates or competing drug candidates, or any otherchange in the competitive landscape of our industry, including consolidation among our competitors or partners; •the timing of receipt of approvals for our drug candidates from regulatory authorities in the United States, or U.S., and internationally; •coverage and reimbursement policies with respect to our drug candidates, if approved, and potential future drugs that compete with our products;and •the level of demand for our products, if approved, which may vary significantly over time.The cumulative effects of these factors could result in large fluctuations and unpredictability in our quarterly and annual operating results. As aresult, comparing our operating results on a period-to-period basis may not be meaningful. Investors should not rely on our past results as an indication of ourfuture performance.This variability and unpredictability could also result in our failing to meet the expectations of industry or financial analysts or investors for anyperiod. If our revenue or operating results fall below the expectations of analysts or investors or below any forecasts we may provide to the market, or if theforecasts we provide to the market are below the expectations of analysts or investors, the price of our common stock could decline substantially. Such astock price decline could occur even when we have met any previously publicly stated revenue or earnings guidance we may provide.Risks Related to Our BusinessOur core therapeutic approach to extending human healthspan is based on our understanding of cellular senescence. Utilizing senolyticmolecules to treat age-related diseases is a novel therapeutic approach, which exposes us to unforeseen risks and makes it difficult to predict the time andcost of drug development and potential for regulatory approval.We are developing a pipeline of drug candidates to treat age-related diseases and extend human healthspan. Our foundational science and leaddrug candidates are based on senescence biology. We believe that we can develop drug candidates capable of eliminating accumulated senescent cells andtheir associated Senescence Associated Secretory Phenotype, or SASP, when administered locally. We are also in the early stages of developing senolyticmedicines that could be administered systemically to treat additional other age-related diseases such as kidney disease, liver disease, and neurologicaldisorders. In our development efforts we intend to explore senolytic medicines that use multiple modalities. However, this approach to treating age-relateddiseases is novel and the scientific research that forms the basis of our efforts to develop senolytic medicines is ongoing. We currently have only limited data,and no conclusive evidence in humans, that the accumulation of senescent cells and resulting exposure to SASP factors is the underlying cause of tissuedamage and dysfunction associated with many age-related diseases. The indications we45 are currently pursuing, including osteoarthritis, or OA, of the knee, and several age-related eye diseases, are believed to be heterogeneous and multifactorialdiseases that are driven by multiple SASP factors. While evidence suggests that, in each case, individual SASP factors contribute to the disease, it is our beliefthat suppression of multiple factors is likely needed for a meaningful clinical benefit to be observed and we do not yet know which of the SASP factors willbe most important in each disease or whether we can measure them. We have only just begun testing our senolytic molecules in humans and our current datais largely limited to animal models and preclinical cell lines, the results of which may not translate into humans. As such, there can be no assurances that evenif we are able to develop senolytic medicines capable of eliminating senescent cells and their associated SASP, that such medicines would safely andeffectively treat age-related diseases.Further, while cellular senescence is a natural occurring biological process, the administration of senolytic medicines to eliminate accumulatedsenescent cells and their associated SASP in humans is untested and may potentially harm healthy tissue or result in unforeseen safety events. We may alsoultimately discover that our senolytic molecules do not possess certain properties required for therapeutic effectiveness, or that even if found to be effectivein one type of tissue, that such molecules will be effective in other tissues. In addition, given the novel nature of this therapeutic approach, designingpreclinical and clinical studies to demonstrate the effect of senolytic medicines is complex and exposes us to unforeseen risks. For example, our attempts toreplicate early in vivo findings in different animal models proved to be challenging, particularly with respect to our efforts to mimic a disease like OA, whichdevelops over a long period of time in humans. In addition, the scientific evidence to support the feasibility of developing systemic senolytic medicines isboth preliminary and limited. We may spend substantial funds attempting to develop these drug candidates and never succeed in doing so.No regulatory authority has granted approval for a senolytic medicine. As such, we believe the U.S. Food and Drug Administration, or the FDA, haslimited experience with biological senescence, which may increase the complexity, uncertainty and length of the clinical development and regulatoryapproval process for our drug candidates. We may never receive approval to market and commercialize any drug candidate. Even if we obtain regulatoryapproval, the approval may be for targets, disease indications or patient populations that are not as broad as we intended or desired or may require labelingthat includes significant use or distribution restrictions or safety warnings. We may be required to perform additional or unanticipated clinical studies toobtain approval or be subject to post-marketing testing requirements to maintain regulatory approval. If our senolytic molecules prove to be ineffective,unsafe or commercially unviable, our entire senolytic platform and pipeline would have little, if any, value, which would have a material and adverse effecton our business, financial condition, results of operations and prospects.Our business is dependent on the successful development, regulatory approval, and commercialization of our drug candidates, all of which are inearly stages of development and none of which have been tested in a human subject.We have no products approved for sale and all of our drug candidates are in early stages of development. Our first lead drug candidate, UBX0101,is currently being evaluated in a Phase 1 clinical study and we will commence IND-enabling studies with our other lead drug candidate, UBX1967 in the firstquarter of 2019. UBX0101 is the only drug candidate that we have administered to humans, and as such, we face significant translational risk with our drugcandidates. We may also be required by the FDA or similar foreign regulatory agencies to conduct additional preclinical studies beyond those planned tosupport the commencement of clinical trials. For example, one of the properties of UBX1967 is a sustained exposure in ocular tissues of interest afterintravitreal injection. After engaging the FDA regarding the design of IND-enabling studies for UBX1967, we determined that the duration of these non-clinical studies will be longer than originally anticipated due to the pharmacokinetic profile, which will delay the filing of our IND until early 2020.The success of our business, including our ability to finance our company and generate any revenue in the future, will primarily depend on thesuccessful development, regulatory approval and commercialization of drug candidates from our senolytic medicine pipeline. However, given our early stageof development, it may be many years, if we succeed at all, before we have demonstrated the safety and efficacy of a drug candidate sufficient to warrantapproval for commercialization.46 In the future, we may also become dependent on other drug candidates that we may develop or acquire. The clinical and commercial success of ourdrug candidates and future drug candidates will depend on a number of factors, including the following: •our ability to raise any additional required capital on acceptable terms, or at all; •our ability to complete IND-enabling studies and successfully submit IND or comparable applications; •timely completion of our preclinical studies and clinical studies, which may be significantly slower or cost more than we currently anticipate andwill depend substantially upon the performance of third-party contractors; •whether we are required by the FDA or similar foreign regulatory agencies to conduct additional clinical studies or other studies beyond thoseplanned to support the approval and commercialization of our drug candidates or any future drug candidates; •acceptance of our proposed indications and primary endpoint assessments relating to the proposed indications of our drug candidates by theFDA and similar foreign regulatory authorities; •our ability to demonstrate to the satisfaction of the FDA and similar foreign regulatory authorities the safety, efficacy and acceptable risk tobenefit profile of our lead drug candidates or any future drug candidates; •the prevalence, duration and severity of potential side effects or other safety issues experienced with our drug candidates or future approvedproducts, if any; •the timely receipt of necessary marketing approvals from the FDA and similar foreign regulatory authorities; •achieving and maintaining, and, where applicable, ensuring that our third-party contractors achieve and maintain compliance with ourcontractual obligations and with all regulatory requirements applicable to our lead drug candidates or any future drug candidates or approvedproducts, if any; •the willingness of physicians, operators of clinics and patients to utilize or adopt any of our future drug candidates to treat age-related diseases; •the ability of third parties with whom we contract to manufacture adequate clinical study and commercial supplies of our lead drug candidates orany future drug candidates, to remain in good standing with regulatory agencies and develop, validate and maintain commercially viablemanufacturing processes that are compliant with current good manufacturing practices, or cGMP; •our ability to successfully develop a commercial strategy and thereafter commercialize our drug candidates or any future drug candidates in theU.S., and internationally, if approved for marketing, reimbursement, sale and distribution in such countries and territories, whether alone or incollaboration with others; •the convenience of our treatment or dosing regimen; •acceptance by physicians, payors and patients of the benefits, safety and efficacy of our drug candidates or any future drug candidates, ifapproved, including relative to alternative and competing treatments; •patient demand for our drug candidates, if approved; •our ability to establish and enforce intellectual property rights in and to our drug candidates or any future drug candidates; and •our ability to avoid third-party patent interference, intellectual property challenges or intellectual property infringement claims.These factors, many of which are beyond our control, could cause us to experience significant delays or be unable to obtain regulatory approvals orcommercialize our drug candidates. Even if regulatory approvals are obtained, we may never achieve success in commercializing any of our drug candidates.Accordingly, we cannot provide assurances that we will be able to generate sufficient revenue through the sale of our drug candidates or any future drugcandidates to continue our business or achieve profitability.47 We may be unable to obtain regulatory approval for our drug candidates under applicable regulatory requirements. The denial or delay of anysuch approval would delay commercialization of our drug candidates and adversely impact our potential to generate revenue, our business and our resultsof operations.To gain approval to market our drug candidates, we must provide the FDA and foreign regulatory authorities with clinical data that adequatelydemonstrate the safety and efficacy of the drug candidate for the intended indication applied for in the applicable regulatory filing. For our senolyticmedicines, we must also demonstrate that eliminating senescent cells and the associated SASP will lead to the improvement of well-defined and measurableendpoints.We have not previously submitted a new drug application, or NDA, or biologics license application, or BLA, to the FDA, or similar approval filingsto comparable foreign regulatory authorities. An NDA, BLA or other relevant regulatory filing must include extensive preclinical and clinical data andsupporting information to establish that the drug candidate is safe, pure and potent for each desired indication. The NDA, BLA or other relevant regulatoryfiling must also include significant information regarding the chemistry, manufacturing and controls for the product.The research, testing, manufacturing, labeling, approval, sale, marketing and distribution of drug and biologic products are subject to extensiveregulation by the FDA and other regulatory authorities in the U.S. and other countries, and such regulations differ from country to country. We are notpermitted to market our drug candidates in the U.S. or in any foreign countries until they receive the requisite approval from the applicable regulatoryauthorities of such jurisdictions.The FDA or any foreign regulatory bodies can delay, limit or deny approval of our drug candidates for many reasons, including: •our inability to demonstrate to the satisfaction of the FDA or the applicable foreign regulatory body that any of our drug candidates is safe andeffective for the requested indication; •the FDA’s or the applicable foreign regulatory agency’s disagreement with our trial protocol or the interpretation of data from preclinical studiesor clinical studies; •our inability to demonstrate that the clinical and other benefits of any of our drug candidates outweigh any safety or other perceived risks; •the FDA’s or the applicable foreign regulatory agency’s requirement for additional preclinical studies or clinical studies; •the FDA’s or the applicable foreign regulatory agency’s failure to approve the formulation, labeling or specifications of UBX0101, UBX1967, orany of our future drug candidates; •the FDA’s or the applicable foreign regulatory agency’s failure to approve the manufacturing processes or facilities of third-party manufacturersupon which we rely; or •the potential for approval policies or regulations of the FDA or the applicable foreign regulatory agencies to significantly change in a mannerthat renders our clinical data insufficient for approval.Of the large number of biopharmaceutical and pharmaceutical products in development, only a small percentage successfully complete the FDA orother regulatory approval processes and are commercialized.In addition, disruptions at the FDA and other regulatory agencies that are unrelated to our company or our products could also cause delays to theregulatory approval process for our products. For example, over the last several years, including in December 2018 and January 2019, the U.S. governmenthas shut down several times and certain regulatory agencies, including the FDA, have had to furlough critical employees and stop critical activities. If aprolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions.Even if we eventually complete clinical testing and receive approval from the FDA or applicable foreign agencies for any of our drug candidates,the FDA or the applicable foreign regulatory agency may grant approval contingent on the performance of costly additional clinical studies which may berequired after approval. The FDA or the applicable foreign regulatory agency also may approve our lead drug candidates for a more limited indication or a48 narrower patient population than we originally requested, and the FDA, or applicable foreign regulatory agency, may not approve our drug candidates withthe labeling that we believe is necessary or desirable for the successful commercialization of such drug candidates.Any delay in obtaining, or inability to obtain, applicable regulatory approval would delay or prevent commercialization of our drug candidatesand would materially adversely impact our business and prospects.Clinical development involves a lengthy and expensive process with an uncertain outcome, and results of earlier studies and trials may not bepredictive of future trial results.Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure or delay can occur at any timeduring the clinical study process. Success in preclinical studies and early clinical studies does not ensure that later clinical studies will be successful. Anumber of companies in the biotechnology, and pharmaceutical industries have suffered significant setbacks in clinical studies, even after positive results inearlier preclinical studies or clinical studies. These setbacks have been caused by, among other things, preclinical findings made while clinical studies wereunderway and safety or efficacy observations made in clinical studies, including previously unreported adverse events. The results of our preclinical animalstudies or studies in ex vivo human tissues may not be predictive of the results of outcomes in human clinical studies. For example, our senolytic moleculesmay demonstrate different chemical and pharmacological properties in patients than they do in laboratory studies or may interact with human biologicalsystems in unforeseen or harmful ways. Additionally, with respect to our initial clinical trials for our senolytic drug candidates. we may be unable toaccurately predict whether or in what manner we will be able to measure the impact of a drug candidate on relevant SASP factors. The indications we arecurrently pursuing, including OA of the knee and several age-related eye diseases, are believed to be heterogeneous and multifactorial diseases that aredriven by multiple SASP factors. While evidence suggests that, in each case, individual SASP factors contribute to the disease, it is our belief that suppressionof multiple factors is likely needed for a meaningful clinical benefit to be observed and we do not yet know which of the SASP factors will be most importantin each disease or whether we can measure them. For example, in the initial phase, or Part A, of our Phase 1 clinical of UBX0101 in patients with osteoarthritisof the knees, we sought to collect synovial fluid via simple aspiration; however, a number of patients had an insufficient amount of fluid for sampling. Thisled us to expand the study to include a second phase, or Part B, with an additional cohort of patients to provide an increased sample size for SASP assessmentby allowing saline lavage in those patients who do not have adequate fluid to collect via simple aspiration.Drug candidates in later stages of clinical studies may fail to show the desired pharmacological properties or safety and efficacy traits despitehaving progressed through preclinical studies and initial clinical studies. Notwithstanding any promising results in earlier studies, we cannot be certain thatwe will not face similar setbacks. Even if we are able to initiate and complete clinical studies, the results may not be sufficient to obtain regulatory approvalfor our drug candidates.Although we initiated our Phase 1 clinical study of UBX0101 in osteoarthritis in the second quarter of 2018, we may experience delays inobtaining the FDA’s authorization to initiate further clinical studies under the IND for UBX0101, completing ongoing studies of our other drug candidatesand initiating our planned studies and trials. Additionally, we cannot be certain that studies or trials for our drug candidates will begin on time, not requireredesign, enroll an adequate number of subjects on time or be completed on schedule, if at all. Clinical studies can be prolonged, delayed or terminated for avariety of reasons, including: •the FDA or comparable foreign regulatory authorities disagreeing with or requiring changes to the design or implementation of our clinicalstudies; •delays in obtaining regulatory approval to commence or continue a trial; •reaching agreement on acceptable terms with prospective contract research organizations, or CROs, and clinical study sites, the terms of whichcan be subject to extensive negotiation and may vary significantly among different CROs and trial sites; •obtaining institutional review board, or IRB, approval at each trial site; •recruiting an adequate number of suitable patients to participate in a trial; •having subjects complete a trial or return for post-treatment follow-up;49 •encountering difficulties in gathering the range of biological data from patients needed to fully assess the impact of our drug candidates, such asthe challenges we encountered in collecting synovial fluid from OA patients in Part A of our Phase 1 clinical study; •clinical sites deviating from trial protocol or dropping out of a trial; •addressing subject safety concerns that arise during the course of a trial; •adding a sufficient number of clinical study sites; or •obtaining sufficient product supply of drug candidate for use in preclinical studies or clinical studies from third-party suppliers.We may experience numerous adverse or unforeseen events during, or as a result of, preclinical studies and clinical studies that could delay orprevent our ability to receive marketing approval or commercialize our drug candidates, including: •clinical studies of our drug candidates may produce negative or inconclusive results, and we may decide, or regulators may require us, to modifyclinical study design, conduct additional clinical studies or abandon drug development programs, including all of our senolytic programs; •the number of patients required for clinical studies of our drug candidates may be larger than we anticipate, enrollment in these clinical studiesmay be slower than we anticipate or participants may drop out of these clinical studies at a higher rate than we anticipate; •our third-party contractors may fail to comply with regulatory requirements, fail to maintain adequate quality controls, or be unable to provide uswith sufficient product supply to conduct and complete preclinical studies or clinical studies of our drug candidates in a timely manner, or at all; •we or our investigators might have to suspend or terminate clinical studies of our drug candidates for various reasons, including non-compliancewith regulatory requirements, a finding that our drug candidates have undesirable side effects or other unexpected characteristics, or a findingthat the participants are being exposed to unacceptable health risks; •the cost of clinical studies of our drug candidates may be greater than we anticipate; •the quality of our drug candidates or other materials necessary to conduct preclinical studies or clinical studies of our drug candidates may beinadequate; •regulators may revise the requirements for approving our drug candidates, or such requirements may not be as we anticipate; and •future collaborators may conduct clinical studies in ways they view as advantageous to them but that are suboptimal for us.If we are required to conduct additional clinical studies or other testing of our drug candidates beyond those that we currently contemplate, if weare unable to successfully complete clinical studies of our drug candidates or other testing, if the results of these trials or tests are not positive or are onlymoderately positive, or if there are safety concerns, we may: •incur unplanned costs; •be delayed in obtaining marketing approval for our drug candidates or not obtain marketing approval at all; •obtain marketing approval in some countries and not in others; •obtain marketing approval for indications or patient populations that are not as broad as intended or desired •obtain marketing approval with labeling that includes significant use or distribution restrictions or safety warnings, including boxed warnings; •be subject to additional post-marketing testing requirements; or •have the treatment removed from the market after obtaining marketing approval.50 We could also encounter delays if a clinical study is suspended or terminated by us, by the IRBs of the institutions in which such trials are beingconducted, by the Data Safety Monitoring Board, or DSMB, for such trial or by the FDA or other regulatory authorities. Such authorities may suspend orterminate a clinical study due to a number of factors, including failure to conduct the clinical study in accordance with regulatory requirements or ourclinical protocols, inspection of the clinical study operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinicalhold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations oradministrative actions or lack of adequate funding to continue the clinical study.Further, conducting clinical studies in foreign countries, as we may do for certain of our drug candidates, presents additional risks that may delaycompletion of our clinical studies. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result ofdifferences in healthcare services or cultural customs, managing additional administrative burdens associated with foreign regulatory schemes, as well aspolitical and economic risks relevant to such foreign countries.Principal investigators for our clinical studies may serve as scientific advisors or consultants to us from time to time and may receive cash or equitycompensation in connection with such services. If these relationships and any related compensation result in perceived or actual conflicts of interest, or aregulatory authority concludes that the financial relationship may have affected the interpretation of the trial, the integrity of the data generated at theapplicable clinical study site may be questioned and the utility of the clinical study itself may be jeopardized, which could result in the delay or rejection ofthe marketing application we submit. Any such delay or rejection could prevent or delay us from commercializing our current or future drug candidates.If we experience termination or delays in the completion of any preclinical study or clinical study of our drug candidates, the commercial prospectsof our drug candidates may be harmed, and our ability to generate revenues from any of these drug candidates will be delayed or unrealized. In addition, anydelays in completing our clinical studies may increase our costs, slow down our drug candidate development and approval process and jeopardize our abilityto commence product sales and generate revenues. Any of these occurrences may significantly harm our business, financial condition and prospects. Inaddition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical studies may also ultimately lead to the denial ofregulatory approval of our drug candidates. If one or more of our drug candidates or our senescence technology generally prove to be ineffective, unsafe orcommercially unviable, our entire platform and pipeline would have little, if any, value, which would have a material and adverse effect on our business,financial condition, results of operations and prospects.We may not be successful in our efforts to continue to create a pipeline of drug candidates or to develop commercially successful products. If wefail to successfully identify and develop additional drug candidates, our commercial opportunity may be limited.We are committed to developing senolytic medicines that slow, halt or reverse age-related diseases and are currently advancing multiple senolyticmolecules to address a variety of age-related diseases, including musculoskeletal, ophthalmologic and pulmonary disorders. As senolytic medicines are notlimited to intervention by a single mode of action or molecular target, we believe that we can modulate a number of biologic pathways in order to trigger thebeneficial elimination of senescent cells. However, our core therapeutic approach is based on our belief that the elimination of the accumulation of senescentcells and their accompanying SASP can treat a root cause of many diseases of aging, which may never be successfully validated in a human. The indicationswe are currently pursuing, including OA of the knee and several age-related eye diseases, are believed to be heterogeneous and multifactorial diseases that aredriven by multiple SASP factors. While evidence suggests that, in each case, individual SASP factors contribute to the disease, it is our belief that suppressionof multiple factors is likely needed for a meaningful clinical benefit to be observed and we do not yet know which of the SASP factors will be most importantor whether we can measure them.In addition, identifying, developing, obtaining regulatory approval and commercializing drug candidates for the treatment of age-related diseaseswill require substantial additional funding and is prone to the risks of failure inherent in drug development. Research programs to identify drug candidatesalso require substantial technical, financial and human resources, regardless of whether or not any drug candidates are ultimately identified, and even if51 our preclinical research programs initially show promise in identifying potential drug candidates, they may fail to yield drug candidates for clinicaldevelopment.In addition, we believe that many age-related diseases will require the development of senolytic medicines that can be administered systemicallyand that the full potential to extend human healthspan will require additional non-senescence based therapeutic approaches. As a result, we intend tocontinue to dedicate resources and effort to better understand fundamental aging mechanisms, such as loss of circulating youth factors and mitochondrialdysfunction and translate these insights into human medicines. However, the scientific evidence to support the feasibility of developing systemic senolyticmedicines is both preliminary and limited and our non-senolytic programs are based on emerging science. We therefore cannot provide any assurance that wewill be able to successfully identify or acquire additional drug candidates, advance any of these additional drug candidates through the development process,successfully commercialize any such additional drug candidates, if approved, or assemble sufficient resources to identify, acquire, develop or, if approved,commercialize additional drug candidates. If we are unable to successfully identify, acquire, develop and commercialize additional drug candidates, ourcommercial opportunity may be limited.It may be many years, if ever, before we develop senolytic medicines capable of systemic administration to treat systemic diseases of aging.We are focusing initially on the development of senolytic molecules for age-related diseases that can be treated by means of local treatment andintend to continue our research into the development of systemic senolytic medicines. However, we are still at a very early stage of developing locallyadministered senolytic medicines, and we must establish proof-of-concept in humans for local treatment before developing a systemically administeredsenolytic medicine. We still face significant risks in the development of localized treatments. As a result, it may be many years before we have sufficienthuman data and scientific understanding to effectively pursue a systemically administered senolytic medicine, if ever.If we encounter difficulties enrolling patients in our clinical studies, our clinical development activities could be delayed or otherwise adverselyaffected.The timely completion of clinical studies in accordance with their protocols depends, among other things, on our ability to enroll a sufficientnumber of patients who remain in the study until its conclusion. We may experience difficulties in patient enrollment in our clinical studies for a variety ofreasons. The enrollment of patients depends on many factors, including: •the patient eligibility criteria defined in the protocol; •the size of the patient population required for analysis of the trial’s primary endpoints; •the proximity of patients to trial sites; •the design of the trial; •our ability to recruit clinical study investigators with the appropriate competencies and experience; •clinicians’ and patients’ perceptions as to the potential advantages of the drug candidate being studied in relation to other available therapies,including any new drugs that may be approved for the indications we are investigating; and •our ability to obtain and maintain patient consents.In addition, our clinical studies may compete with other clinical studies for drug candidates that are in the same therapeutic areas as our drugcandidates, and this competition will reduce the number and types of patients available to us, because some patients who might have opted to enroll in ourtrials may instead opt to enroll in a trial being conducted by one of our competitors. Since the number of qualified clinical investigators is limited, we mayconduct some of our clinical studies at the same clinical study sites that some of our competitors use, which will reduce the number of patients who areavailable for our clinical studies in such clinical study site.Further, the administration of senolytic medicines designed to eliminate senescent cells and associated SASP may result in unforeseen events,including by harming healthy tissues. As a result, it is possible that safety concerns52 could negatively affect patient enrollment among the patient populations that we intend to treat, including among those in indications with a low risk ofmortality. Delays in patient enrollment may result in increased costs or may affect the timing or outcome of the planned clinical studies, which could preventcompletion of these trials and adversely affect our ability to advance the development of our drug candidates.Our drug candidates may cause undesirable side effects or have other properties that could delay or prevent their regulatory approval, limit thecommercial profile of an approved label, or result in significant negative consequences following marketing approval, if any.Undesirable side effects caused by our drug candidates could cause us or regulatory authorities to interrupt, delay or halt clinical studies and couldresult in a more restrictive label or the delay or denial of regulatory approval by the FDA or comparable foreign regulatory authorities. Other than in ourPhase 1 clinical study of UBX0101, which was initiated in the second quarter of 2018, senolytic medicines designed to eliminate senescent cells andassociated SASP have never been tested in humans. As a result, any clinical studies we initiate could reveal a high and unacceptable severity and prevalenceof side effects, and it is possible that patients enrolled in such clinical studies could respond in unexpected ways. For instance, in preclinical in vivo animaland ex vivo human tissue studies, our senolytic molecules have exhibited clearance of senescent cells, however the elimination of accumulated senescentcells may result in unforeseen events, including by harming healthy cells or tissues. In addition, the entry by cells into a senescent state is a natural biologicalprocess that we believe may have protective effects, such as halting the proliferation of damaged cells. The treatment of tissues with senolytic moleculescould interfere with such protective processes.If unacceptable side effects arise in the development of our drug candidates, we, the FDA, the IRBs at the institutions in which our studies areconducted, or the DSMB could suspend or terminate our clinical studies or the FDA or comparable foreign regulatory authorities could order us to ceaseclinical studies or deny approval of our drug candidates for any or all targeted indications. Treatment-related side effects could also affect patient recruitmentor the ability of enrolled patients to complete any of our clinical studies or result in potential product liability claims. In addition, these side effects may notbe appropriately recognized or managed by the treating medical staff. We expect to have to train medical personnel using our drug candidates to understandthe side effect profiles for our clinical studies and upon any commercialization of any of our drug candidates. Inadequate training in recognizing or managingthe potential side effects of our drug candidates could result in patient injury or death. Any of these occurrences may harm our business, financial conditionand prospects significantly.In addition, even if we successfully advance any of our drug candidates into and through clinical studies, such trials will likely only include alimited number of subjects and limited duration of exposure to our drug candidates. As a result, we cannot be assured that adverse effects of our drugcandidates will not be uncovered when a significantly larger number of patients are exposed to the drug candidate. Further, clinical studies may not besufficient to determine the effect and safety consequences of taking our drug candidates over a multi-year period.If any of our drug candidates receives marketing approval, and we or others later identify undesirable side effects caused by such products, anumber of potentially significant negative consequences could result, including: •regulatory authorities may withdraw their approval of the product; •we may be required to recall a product or change the way such product is administered to patients; •additional restrictions may be imposed on the marketing of the particular product or the manufacturing processes for the product or anycomponent thereof; •regulatory authorities may require the addition of labeling statements, such as a “black box” warning or a contraindication; •we may be required to implement a Risk Evaluation and Mitigation Strategy, or REMS, or create a Medication Guide outlining the risks of suchside effects for distribution to patients; •we could be sued and held liable for harm caused to patients;53 •the product may become less competitive; and •our reputation may suffer.Any of the foregoing events could prevent us from achieving or maintaining market acceptance of the particular drug candidate, if approved, andresult in the loss of significant revenues to us, which would materially and adversely affect our results of operations and business. In addition, if one or moreof our drug candidates or our senescence approach generally prove to be unsafe, our entire platform and pipeline could be affected, which would have amaterial and adverse effect on our business, financial condition, results of operations and prospects.Even if our lead drug candidates or any future drug candidates obtain regulatory approval, they may fail to achieve the broad degree ofphysician and patient adoption and use necessary for commercial success.Even if one or more of our drug candidates receive FDA or other regulatory approvals, the commercial success of any of our current or future drugcandidates will depend significantly on the broad adoption and use of the resulting product by physicians and patients for approved indications. Our drugcandidates may not be commercially successful for a variety of reasons, including: competitive factors, pricing or physician preference, reimbursement byinsurers, the degree and rate of physician and patient adoption of our current or future drug candidates. If approved, the commercial success of our drugcandidates will depend on a number of factors, including: •the clinical indications for which the product is approved and patient demand for approved products that treat those indications; •the safety and efficacy of our product as compared to other available therapies; •the availability of coverage and adequate reimbursement from managed care plans, insurers and other healthcare payors for any of our drugcandidates that may be approved; •acceptance by physicians, operators of clinics and patients of the product as a safe and effective treatment; •physician and patient willingness to adopt a new therapy over other available therapies to treat approved indications; •overcoming any biases physicians or patients may have toward particular therapies for the treatment of approved indications; •proper training and administration of our drug candidates by physicians and medical staff; •public misperception regarding the use of our therapies, or public bias against “anti-aging” companies; •patient satisfaction with the results and administration of our drug candidates and overall treatment experience, including, for example, theconvenience of any dosing regimen; •the cost of treatment with our drug candidates in relation to alternative treatments and reimbursement levels, if any, and willingness to pay forthe product, if approved, on the part of insurance companies and other third-party payers, physicians and patients; •the willingness of patients to pay for certain of our products, if approved; •the revenue and profitability that our products may offer a physician as compared to alternative therapies; •the prevalence and severity of side effects; •limitations or warnings contained in the FDA-approved labeling for our products; •the willingness of physicians, operators of clinics and patients to utilize or adopt our products as a solution; •any FDA requirement to undertake a REMS; •the effectiveness of our sales, marketing and distribution efforts; •adverse publicity about our products or favorable publicity about competitive products; and •potential product liability claims.54 We cannot assure you that our current or future drug candidates, if approved, will achieve broad market acceptance among physicians and patients.Any failure by our drug candidates that obtain regulatory approval to achieve market acceptance or commercial success would adversely affect our results ofoperations.We rely on third-party suppliers to manufacture preclinical supplies of our drug candidates and we intend to rely on third parties to produceclinical supplies as well as commercial supplies of any approved product. The loss of these suppliers, or their failure to comply with applicable regulatoryrequirements or to provide us with sufficient quantities at acceptable quality levels or prices, or at all, would materially and adversely affect our business.We do not have the infrastructure or capability internally to manufacture supplies of our drug candidates or the materials necessary to produce ourdrug candidates for use in the conduct of our preclinical studies or clinical studies, and we lack the internal resources and the capability to manufacture anyof our drug candidates on a preclinical, clinical or commercial scale. The facilities used by our contract manufacturers to manufacture our drug candidates aresubject to various regulatory requirements and may be subject to the inspection of the FDA or other regulatory authorities. We do not control themanufacturing process of, and are completely dependent on, our contract manufacturing partners for compliance with the regulatory requirements, known ascGMPs. If our contract manufacturers cannot successfully manufacture material that conforms to our specifications and the strict regulatory requirements ofthe FDA or comparable regulatory authorities in foreign jurisdictions, we may not be able to rely on their manufacturing facilities for the manufacture or ourdrug candidates. In addition, we have limited control over the ability of our contract manufacturers to maintain adequate quality control, quality assuranceand qualified personnel. If the FDA or a comparable foreign regulatory authority finds these facilities inadequate for the manufacture of our drug candidatesor if such facilities are subject to enforcement action in the future or are otherwise inadequate, we may need to find alternative manufacturing facilities, whichwould significantly impact our ability to develop, obtain regulatory approval for or market our drug candidates.We currently intend to supply all of our drug candidates in all territories for our clinical development programs. We currently rely on third partiesat key stages in our supply chain. For instance, the supply chains for our lead drug candidates involve several manufacturers that specialize in specificoperations of the manufacturing process, specifically, raw materials manufacturing, drug substance manufacturing, and drug product manufacturing. As aresult, the supply chain for the manufacturing of our drug candidates is complicated and we expect the logistical challenges associated with our supply chainto grow more complex as our drug candidates such as UBX0101 and UBX1967, progress through the clinical trial process.We do not have any control over the process or timing of the acquisition or manufacture of materials by our manufacturers. We generally do notbegin a preclinical study and we do not intend to initiate any clinical studies unless we believe we have access to a sufficient supply of a drug candidate tocomplete such study or trial. In addition, any significant delay in, or quality control problems with respect to, the supply of a drug candidate, or the rawmaterial components thereof, for an ongoing study or trial could considerably delay completion of our preclinical studies or future clinical studies, producttesting and potential regulatory approval of our drug candidates.We have not yet engaged any manufacturers for the commercial supply of our drug candidates. Although we intend to enter into such agreementsprior to commercial launch of any of our drug candidates, we may be unable to enter into any such agreement or do so on commercially reasonable terms,which could have a material adverse impact upon our business. Moreover, if there is a disruption to one or more of our third-party manufacturers’ or suppliers’relevant operations, or if we are unable to enter into arrangements for the commercial supply of our drug candidates, we will have no other means ofproducing our lead drug candidates until they restore the affected facilities or we or they procure alternative manufacturing facilities or sources of supply. Ourability to progress our preclinical and clinical programs could be materially and adversely impacted if any of the third-party suppliers upon which we relywere to experience a significant business challenge, disruption or failure due to issues such as financial difficulties or bankruptcy, issues relating to othercustomers such as regulatory or quality compliance issues, or other financial, legal, regulatory or reputational issues.Additionally, any damage to or destruction of our third-party manufacturers’ or suppliers’ facilities or equipment may significantly impair ourability to manufacture our drug candidates on a timely basis.55 In addition, to manufacture our lead drug candidates in the quantities that we believe would be required to meet anticipated market demand, ourthird-party manufacturers would likely need to increase manufacturing capacity and, in some cases, we would need to secure alternative sources ofcommercial supply, which could involve significant challenges and may require additional regulatory approvals. In addition, the development ofcommercial-scale manufacturing capabilities may require us and our third-party manufacturers to invest substantial additional funds and hire and retain thetechnical personnel who have the necessary manufacturing experience. Neither we nor our third-party manufacturers may successfully complete any requiredincrease to existing manufacturing capacity in a timely manner, or at all. If our manufacturers or we are unable to purchase the raw materials necessary for themanufacture of our drug candidates on acceptable terms, at sufficient quality levels, or in adequate quantities, if at all, the commercial launch of our lead drugcandidates or any future drug candidates would be delayed or there would be a shortage in supply, which would impair our ability to generate revenues fromthe sale of such drug candidates, if approved.We depend on third-party suppliers for key raw materials used in our manufacturing processes, and the loss of these third-party suppliers or theirinability to supply us with adequate raw materials could harm our business.We rely on third-party suppliers for the raw materials required for the production of our drug candidates. Our dependence on these third-partysuppliers and the challenges we may face in obtaining adequate supplies of raw materials involve several risks, including limited control over pricing,availability, and quality and delivery schedules. As a small company, our negotiation leverage is limited and we are likely to get lower priority than ourcompetitors who are larger than we are. We cannot be certain that our suppliers will continue to provide us with the quantities of these raw materials that werequire or satisfy our anticipated specifications and quality requirements. Any supply interruption in limited or sole sourced raw materials could materiallyharm our ability to manufacture our drug candidates until a new source of supply, if any, could be identified and qualified. We may be unable to find asufficient alternative supply channel in a reasonable time or on commercially reasonable terms. Any performance failure on the part of our suppliers coulddelay the development and potential commercialization of our drug candidates, including limiting supplies necessary for clinical studies and regulatoryapprovals, which would have a material adverse effect on our business.We rely on third parties in the conduct of critical portions of our preclinical studies and intend to rely on third parties in the conduct of criticalportions of our future clinical studies. If these third parties do not successfully carry out their contractual duties, fail to comply with applicable regulatoryrequirements or meet expected deadlines, we may be unable to obtain regulatory approval for our drug candidates.We currently do not have the ability to independently conduct preclinical studies that comply with the regulatory requirements known as goodlaboratory practice, or GLP, requirements. We also do not currently have the ability to independently conduct any clinical studies. The FDA and regulatoryauthorities in other jurisdictions require us to comply with regulations and standards, commonly referred to as good clinical practice, or GCP, requirementsfor conducting, monitoring, recording and reporting the results of clinical studies, in order to ensure that the data and results are scientifically credible andaccurate and that the trial subjects are adequately informed of the potential risks of participating in clinical studies. We rely on medical institutions, clinicalinvestigators, contract laboratories and other third parties, such as CROs, to conduct GLP-compliant preclinical studies and GCP-compliant clinical studieson our drug candidates properly and on time. While we have agreements governing their activities, we control only certain aspects of their activities and havelimited influence over their actual performance. The third parties with whom we contract for execution of our GLP-compliant preclinical studies and ourGCP-compliant clinical studies play a significant role in the conduct of these studies and trials and the subsequent collection and analysis of data. Thesethird parties are not our employees and, except for restrictions imposed by our contracts with such third parties, we have limited ability to control the amountor timing of resources that they devote to our programs. Although we rely on these third parties to conduct our GLP-compliant preclinical studies and GCP-compliant clinical studies, we remain responsible for ensuring that each of our GLP preclinical studies and clinical studies is conducted in accordance withits investigational plan and protocol and applicable laws and regulations, and our reliance on the CROs does not relieve us of our regulatory responsibilities.Many of the third parties with whom we contract may also have relationships with other commercial entities, potentially including our competitors,for whom they may also be conducting clinical studies or other drug56 development activities that could harm our competitive position. If the third parties conducting our preclinical studies or our clinical studies do notadequately perform their contractual duties or obligations, experience significant business challenges, disruptions or failures, do not meet expecteddeadlines, terminate their agreements with us or need to be replaced, or if the quality or accuracy of the data they obtain is compromised due to their failure toadhere to our protocols or to GCPs, or for any other reason, we may need to enter into new arrangements with alternative third parties. This could be difficult,costly or impossible, and our preclinical studies or clinical studies may need to be extended, delayed, terminated or repeated. As a result we may not be ableto obtain regulatory approval in a timely fashion, or at all, for the applicable drug candidate, our financial results and the commercial prospects for our drugcandidates would be harmed, our costs could increase, and our ability to generate revenues could be delayed.We face significant competition in an environment of rapid technological and scientific change, and our drug candidates, if approved, will facesignificant competition and our failure to effectively compete may prevent us from achieving significant market penetration. Most of our competitors havesignificantly greater resources than we do and we may not be able to successfully compete.The biotechnology and pharmaceutical industries in particular are characterized by rapidly advancing technologies, intense competition and astrong emphasis on developing proprietary therapeutics. Numerous companies are engaged in the development, patenting, manufacturing and marketing ofhealthcare products competitive with those that we are developing. We face competition from a number of sources, such as pharmaceutical companies,generic drug companies, biotechnology companies and academic and research institutions, many of which have greater financial resources, marketingcapabilities, sales forces, manufacturing capabilities, research and development capabilities, clinical study expertise, intellectual property portfolios,experience in obtaining patents and regulatory approvals for drug candidates and other resources than we do. Some of the companies that offer competingproducts also have a broad range of other product offerings, large direct sales forces and long-term customer relationships with our target physicians, whichcould inhibit our market penetration efforts. Mergers and acquisitions in the pharmaceutical industry may result in even more resources being concentratedamong a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly throughcollaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific andmanagement personnel and establishing clinical study sites and patient registration for clinical studies, as well as in acquiring technologies complementaryto, or necessary for, our programs. In addition, certain of our drug candidates, if approved, may compete with other products that treat age-related diseases,including over-the-counter, or OTC, treatments, for a share of some patients’ discretionary budgets and for physicians’ attention within their clinicalpractices.We are aware of other companies seeking to develop treatments to prevent or treat aging-related diseases through various biological pathways,including Calico and resTORbio. Within our three leading senolytic programs, our drug candidates would compete against current therapies from a widerange of companies and technologies, including: •Musculoskeletal diseases, including osteoarthritis: current standard of care treatments (though not disease-modifying and focused on symptommanagement) include anti-inflammatory drugs (Ibruprofen, Diclofenac, Celecoxib), analgesic pain relief (Acetaminophen), or narcotic pain relief(Tramadol). •Ophthalmology diseases, including diabetic retinopathy: potentially disease-modifying therapeutics are being sold and developed by severalpharmaceutical and biotechnology companies, including Roche/Genentech and Regeneron. •Pulmonary disease, including idiopathic pulmonary fibrosis: therapeutics are being sold and developed by several pharmaceutical andbiotechnology companies and academic institutions, including Genentech, Boehringer-Ingelheim, Cytokinetics and Mallinckrodt, and are invarious stages of clinical studies.Further, we believe that potential competitors may be able to develop senolytic medicines utilizing well-established molecules and pathways,which could enable the development of competitive drug candidates utilizing the same cellular senescence biological theories.Certain alternative treatments offered by competitors may be available at lower prices and may offer greater efficacy or better safety profiles.Furthermore, currently approved products could be discovered to have application57 for treatment of age-related diseases generally, which could give such products significant regulatory and market timing advantages over any of our drugcandidates. Our competitors also may obtain FDA, EMA or other regulatory approval for their products more rapidly than we may obtain approval for oursand may obtain orphan product exclusivity from the FDA for indications our drug candidates are targeting, which could result in our competitors establishinga strong market position before we are able to enter the market. Newly developed systemic or non-systemic treatments that replace existing therapies thatcurrently are only utilized in patients suffering from severe disease may also have lessened side effects or reduced prices compared to current therapies, whichmake them more attractive for patients suffering from mild to moderate disease. Even if a generic or OTC product is less effective than our drug candidates, itmay be more quickly adopted by physicians and patients than our competing drug candidates based upon cost or convenience.The successful commercialization of our drug candidates will depend in part on the extent to which governmental authorities and health insurersestablish adequate coverage, reimbursement levels and pricing policies. Failure to obtain or maintain coverage and adequate reimbursement for our drugcandidates, if approved, could limit our ability to market those products and decrease our ability to generate revenue.The availability and adequacy of coverage and reimbursement by governmental healthcare programs such as Medicare and Medicaid, privatehealth insurers and other third-party payors are essential for most patients to be able to afford prescription medications such as our drug candidates, assumingFDA approval. Our ability to achieve acceptable levels of coverage and reimbursement for products by governmental authorities, private health insurers andother organizations will have an effect on our ability to successfully commercialize our drug candidates. Assuming we obtain coverage for our drugcandidates by a third-party payor, the resulting reimbursement payment rates may not be adequate or may require co-payments that patients findunacceptably high. We cannot be sure that coverage and reimbursement in the U.S., the EU or elsewhere will be available for our drug candidates or anyproduct that we may develop, and any reimbursement that may become available may be decreased or eliminated in the future.Third-party payors increasingly are challenging prices charged for pharmaceutical products and services, and many third-party payors may refuseto provide coverage and reimbursement for particular drugs or biologics when an equivalent generic drug, biosimilar or a less expensive therapy is available.It is possible that a third-party payor may consider our drug candidates as substitutable and only offer to reimburse patients for the cost of the less expensiveproduct. Even if we show improved efficacy or improved convenience of administration with our drug candidates, pricing of existing third- party therapeuticsmay limit the amount we will be able to charge for our drug candidates. These payors may deny or revoke the reimbursement status of a given product orestablish prices for new or existing marketed products at levels that are too low to enable us to realize an appropriate return on our investment in our drugcandidates. If reimbursement is not available or is available only at limited levels, we may not be able to successfully commercialize our drug candidates, andmay not be able to obtain a satisfactory financial return on our investment in the development of drug candidates.There is significant uncertainty related to the insurance coverage and reimbursement of newly- approved products. In the U.S., third-party payors,including private and governmental payors, such as the Medicare and Medicaid programs, play an important role in determining the extent to which newdrugs and biologics will be covered. The Medicare and Medicaid programs increasingly are used as models in the U.S. for how private payors and othergovernmental payors develop their coverage and reimbursement policies for drugs and biologics. Some third-party payors may require pre-approval ofcoverage for new or innovative devices or drug therapies before they will reimburse healthcare providers who use such therapies. We cannot predict at thistime what third-party payors will decide with respect to the coverage and reimbursement for our drug candidates.No uniform policy for coverage and reimbursement for products exists among third-party payors in the U.S.. Therefore, coverage andreimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costlyprocess that will require us to provide scientific and clinical support for the use of our drug candidates to each payor separately, with no assurance thatcoverage and adequate reimbursement will be applied consistently or obtained in the first instance. Furthermore, rules and regulations regardingreimbursement change frequently, in some cases on short notice, and we believe that changes in these rules and regulations are likely.58 Outside the U.S., international operations are generally subject to extensive governmental price controls and other market regulations, and webelieve the increasing emphasis on cost-containment initiatives in Europe and other countries have and will continue to put pressure on the pricing andusage of our drug candidates. In many countries, the prices of medical products are subject to varying price control mechanisms as part of national healthsystems. Other countries allow companies to fix their own prices for medical products, but monitor and control company profits.Additional foreign price controls or other changes in pricing regulation could restrict the amount that we are able to charge for our drug candidates.Accordingly, in markets outside the U.S., the reimbursement for our drug candidates may be reduced compared with the U.S. and may be insufficient togenerate commercially-reasonable revenue and profits.Moreover, increasing efforts by governmental and third-party payors in the U.S. and abroad to cap or reduce healthcare costs may cause suchorganizations to limit both coverage and the level of reimbursement for newly approved products and, as a result, they may not cover or provide adequatepayment for our drug candidates. We expect to experience pricing pressures in connection with the sale of our drug candidates due to the trend towardmanaged health care, the increasing influence of health maintenance organizations and additional legislative changes. The downward pressure on healthcarecosts in general, particularly prescription drugs and biologics and surgical procedures and other treatments, has become intense. As a result, increasingly highbarriers are being erected to the entry of new products.We currently have no sales organization. If we are unable to establish sales capabilities on our own or through third parties, we may not be ableto market and sell our drug candidates effectively in the U.S. and foreign jurisdictions, if approved, or generate product revenue.We currently do not have a marketing or sales organization. In order to commercialize our drug candidates in the U.S. and foreign jurisdictions, wemust build our marketing, sales, distribution, managerial and other non-technical capabilities or make arrangements with third parties to perform theseservices, and we may not be successful in doing so. If any of our drug candidates receive regulatory approval, we expect to establish a sales organization withtechnical expertise and supporting distribution capabilities to commercialize each such drug candidate, which will be expensive and time consuming. Wehave no prior experience in the marketing, sale and distribution of pharmaceutical products and there are significant risks involved in building and managinga sales organization, including our ability to hire, retain, and incentivize qualified individuals, generate sufficient sales leads, provide adequate training tosales and marketing personnel, and effectively manage a geographically dispersed sales and marketing team. Any failure or delay in the development of ourinternal sales, marketing and distribution capabilities would adversely impact the commercialization of these products. We may choose to collaborate withthird parties that have direct sales forces and established distribution systems, either to augment our own sales force and distribution systems or in lieu of ourown sales force and distribution systems. If we are unable to enter into such arrangements on acceptable terms or at all, we may not be able to successfullycommercialize our drug candidates. If we are not successful in commercializing our drug candidates or any future drug candidates, either on our own orthrough arrangements with one or more third parties, we may not be able to generate any future product revenue and we would incur significant additionallosses.We will need to increase the size of our organization, and we may experience difficulties in managing growth.As of March 1, 2019, we had 106 full-time employees. We will need to continue to expand our managerial, operational, finance and other resourcesin order to manage our operations and clinical studies, continue our development activities and commercialize our lead drug candidates or any future drugcandidates. Our management and personnel, systems and facilities currently in place may not be adequate to support this future growth. Our need toeffectively execute our growth strategy requires that we: •manage our clinical studies effectively; •identify, recruit, retain, incentivize and integrate additional employees, including sales personnel; •manage our internal research, development and operational efforts effectively while carrying out our contractual obligations to third parties; and •continue to improve our operational, financial and management controls, reports systems and procedures.59 If we fail to attract and retain senior management and key scientific personnel, we may be unable to successfully develop our lead drugcandidates or any future drug candidates, conduct our clinical studies and commercialize our current or any future drug candidates.Our success depends in part on our continued ability to attract, retain and motivate highly qualified management, clinical and scientific personnel.We are highly dependent upon our senior management, particularly our President, Nathaniel E. David, and our Chief Executive Officer, Keith R. Leonard, aswell as our senior scientists and other members of our senior management team. The loss of services of any of these individuals could delay or prevent thesuccessful development of our product pipeline, initiation or completion of our planned clinical studies or the commercialization of our lead drug candidatesor any future drug candidates.Competition for qualified personnel in the biotechnology and pharmaceuticals field is intense due to the limited number of individuals whopossess the skills and experience required by our industry. We will need to hire additional personnel as we expand our clinical development and if we initiatecommercial activities. We may not be able to attract and retain quality personnel on acceptable terms, or at all. In addition, to the extent we hire personnelfrom competitors, we may be subject to allegations that they have been improperly solicited or that they have divulged proprietary or other confidentialinformation, or that their former employers own their research output.If product liability lawsuits are brought against us, we may incur substantial liabilities and may be required to limit commercialization of ourcurrent or future drug candidates.We face an inherent risk of product liability as a result of the clinical testing of our drug candidates and will face an even greater risk if wecommercialize any products. For example, we may be sued if any product we develop allegedly causes injury or is found to be otherwise unsuitable duringproduct testing, manufacturing, marketing or sale. Any such product liability claims may include allegations of defects in manufacturing, defects in design,and a failure to warn of dangers inherent in the product, negligence, strict liability, and a breach of warranty. Claims could also be asserted under stateconsumer protection acts. If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required tolimit commercialization of our drug candidates.Even a successful defense would require significant financial and management resources. Regardless of the merits or eventual outcome, liabilityclaims may result in: •decreased demand for our current or future drug candidates; •injury to our reputation; •withdrawal of clinical study participants; •costs to defend the related litigation; •a diversion of management’s time and our resources; •substantial monetary awards to trial participants or patients; •regulatory investigations, product recalls, withdrawals or labeling, marketing or promotional restrictions; •loss of revenue; and •the inability to commercialize our current or any future drug candidates.Our inability to obtain and maintain sufficient product liability insurance at an acceptable cost and scope of coverage to protect against potentialproduct liability claims could prevent or inhibit the commercialization of our current or any future drug candidates we develop. We currently carry productliability insurance covering our clinical studies. Although we maintain such insurance, any claim that may be brought against us could result in a courtjudgment or settlement in an amount that is not covered, in whole or in part, by our insurance or that is in excess of the limits of our insurance coverage. Ourinsurance policies also have various exclusions and deductibles, and we may be subject to a product liability claim for which we have no coverage. We willhave to pay any amounts awarded by a court or negotiated in a settlement that exceed our coverage limitations or that are not covered by our insurance, andwe may not have, or be able to obtain, sufficient funds to pay such amounts. Moreover, in the future, we may not be able to maintain insurance coverage at areasonable cost or in sufficient amounts to protect us against losses. If and60 when we obtain approval for marketing any of our drug candidates, we intend to expand our insurance coverage to include the sale of such drug candidate;however, we may be unable to obtain this liability insurance on commercially reasonable terms or at all.Our existing collaborations as well as additional collaboration arrangements that we may enter into in the future may not be successful, whichcould adversely affect our ability to develop and commercialize our drug candidates.We utilize external collaborations and currently maintain approximately ten active early-stage research and discovery focused collaborations. Inthe future, we may seek additional collaboration arrangements for the commercialization, or potentially for the development, of certain of our drugcandidates depending on the merits of retaining commercialization rights for ourselves as compared to entering into collaboration arrangements. To theextent that we decide to enter into additional collaboration agreements in the future, we may face significant competition in seeking appropriatecollaborators. Moreover, collaboration arrangements are complex and time-consuming to negotiate, document, implement and maintain and challenging tomanage. We may not be successful in our efforts to prudently manage our existing collaborations or to enter new ones should we chose to do so. The terms ofnew collaborations, or other arrangements that we may establish may not be favorable to us.The success of our collaboration arrangements will depend heavily on the efforts and activities of our collaborators and partners. Collaborations aresubject to numerous risks, which may include risks that: •collaborators and partners have significant discretion in determining the efforts and resources that they will apply to collaborations and they maynot devote the level of effort or resources we expect; •collaborators may not pursue development and commercialization of our drug candidates or may elect not to continue or renew development orcommercialization programs based on clinical study results, changes in their strategic focus due to their acquisition of competitive products ortheir internal development of competitive products, availability of funding or other external factors, such as a business combination that divertsresources or creates competing priorities; •collaborators may delay clinical studies, provide insufficient funding for a clinical study program, stop a clinical study, abandon a drugcandidate, repeat or conduct new clinical studies or require a new formulation of a drug candidate for clinical testing; •collaborators could independently develop, or develop with third parties, products that compete directly or indirectly with our products or drugcandidates; •a collaborator with marketing, manufacturing and distribution rights to one or more products may not commit sufficient resources to or otherwisenot perform satisfactorily in carrying out these activities; •we could grant exclusive rights to our collaborators that would prevent us from collaborating with others; •collaborators may not properly maintain or defend our intellectual property rights or may use our intellectual property or proprietary informationin a way that gives rise to actual or threatened litigation that could jeopardize or invalidate our intellectual property or proprietary informationor expose us to potential liability; •disputes may arise between us and a collaborator that cause the delay or termination of the research, development or commercialization of ourcurrent or future drug candidates or that result in costly litigation or arbitration that diverts management attention and resources; •collaborations may be terminated, resulting in a need for additional capital to pursue further development or commercialization of the applicablecurrent or future drug candidates; •collaborators may own or co-own intellectual property covering products that results from our collaborating with them, and in such cases, wewould not have the exclusive right to develop or commercialize such intellectual property; •disputes may arise with respect to the ownership of any intellectual property developed pursuant to our collaborations; and •a collaborator’s sales and marketing activities or other operations may not be in compliance with applicable laws resulting in civil or criminalproceedings.61 Unfavorable global economic or political conditions could adversely affect our business, financial condition or results of operations.Our results of operations could be adversely affected by general conditions in the global economy and in the global financial markets. Furthermore,the market for products with the potential to treat age-related diseases, particularly those affecting large populations in a wide range of geographic locations,may be particularly vulnerable to unfavorable economic conditions. A global financial crisis or a global or regional political disruption could cause extremevolatility in the capital and credit markets. A severe or prolonged economic downturn or political disruption could result in a variety of risks to our business,including weakened demand for our lead drug candidates or any future drug candidates, if approved, and our ability to raise additional capital when neededon acceptable terms, if at all. A weak or declining economy or political disruption could also strain our manufacturers or suppliers, possibly resulting insupply disruption, or cause our customers to delay making payments for our services. Any of the foregoing could harm our business and we cannot anticipateall of the ways in which the political or economic climate and financial market conditions could adversely impact our business.We or the third parties upon whom we depend may be adversely affected by earthquakes or other natural disasters and our business continuityand disaster recovery plans may not adequately protect us from a serious disaster.Our corporate headquarters and other facilities are located in the San Francisco Bay Area, which in the past has experienced both severeearthquakes and wildfires. Although we carry earthquake insurance, it is limited in scope. Earthquakes, wildfires or other natural disasters could severelydisrupt our operations, and have a material adverse effect on our business, results of operations, financial condition and prospects.If a natural disaster, power outage or other event occurred that prevented us from using all or a significant portion of our headquarters, thatdamaged critical infrastructure, such as our enterprise financial systems or manufacturing resource planning and enterprise quality systems, or that otherwisedisrupted operations, it may be difficult or, in certain cases, impossible, for us to continue our business for a substantial period of time. The disaster recoveryand business continuity plans we have in place currently are limited and are unlikely to prove adequate in the event of a serious disaster or similar event. Wemay incur substantial expenses as a result of the limited nature of our disaster recovery and business continuity plans, which, particularly when takentogether with our lack of earthquake insurance, could have a material adverse effect on our business.Furthermore, integral parties in our supply chain are similarly vulnerable to natural disasters or other sudden, unforeseen and severe adverse events.If such an event were to affect our supply chain, it could have a material adverse effect on our business.Significant disruptions of information technology systems or breaches of data security could materially adversely affect our business, results ofoperations and financial condition.We collect and maintain information in digital form that is necessary to conduct our business, and we are increasingly dependent on informationtechnology systems and infrastructure to operate our business. In the ordinary course of our business, we collect, store and transmit large amounts ofconfidential information, including intellectual property, proprietary business information and personal information. It is critical that we do so in a securemanner to maintain the confidentiality and integrity of such confidential information. We have established physical, electronic and organizational measuresto safeguard and secure our systems to prevent a data compromise, and rely on commercially available systems, software, tools, and monitoring to providesecurity for our information technology systems and the processing, transmission and storage of digital information. We have also outsourced elements of ourinformation technology infrastructure, and as a result a number of third-party vendors may or could have access to our confidential information. Our internalinformation technology systems and infrastructure, and those of our current and any future collaborators, contractors and consultants and other third partieson which we rely, are vulnerable to damage from computer viruses, malware, natural disasters, terrorism, war, telecommunication and electrical failures, cyber-attacks or cyber-intrusions over the Internet, attachments to emails, persons inside our organization, or persons with access to systems inside our organization.62 The risk of a security breach or disruption, particularly through cyber-attacks or cyber intrusion, including by computer hackers, foreigngovernments and cyber terrorists, has generally increased as the number, intensity and sophistication of attempted attacks and intrusions from around theworld have increased. In addition, the prevalent use of mobile devices that access confidential information increases the risk of data security breaches, whichcould lead to the loss of confidential information or other intellectual property. The costs to us to mitigate network security problems, bugs, viruses, worms,malicious software programs and security vulnerabilities could be significant, and while we have implemented security measures to protect our data securityand information technology systems, our efforts to address these problems may not be successful, and these problems could result in unexpectedinterruptions, delays, cessation of service and other harm to our business and our competitive position. If such an event were to occur and cause interruptionsin our operations, it could result in a material disruption of our product development programs. For example, the loss of clinical study data from completed orongoing or planned clinical studies could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce thedata.Moreover, if a computer security breach affects our systems or results in the unauthorized release of personally identifiable information, ourreputation could be materially damaged. In addition, such a breach may require notification to governmental agencies, the media or individuals pursuant tovarious federal and state privacy and security laws, if applicable, including the Health Insurance Portability and Accountability Act of 1996, as amended bythe Health Information Technology for Clinical Health Act of 2009, and its implementing rules and regulations, as well as regulations promulgated by theFederal Trade Commission and state breach notification laws. We would also be exposed to a risk of loss or litigation and potential liability, which couldmaterially adversely affect our business, results of operations and financial condition.Our employees and independent contractors, including principal investigators, consultants, commercial collaborators, service providers andother vendors may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements, which couldhave an adverse effect on our results of operations.We are exposed to the risk that our employees and independent contractors, including principal investigators, consultants, any future commercialcollaborators, service providers and other vendors may engage in misconduct or other illegal activity. Misconduct by these parties could include intentional,reckless and/or negligent conduct or other unauthorized activities that violate the laws and regulations of the FDA and other similar regulatory bodies,including those laws that require the reporting of true, complete and accurate information to such regulatory bodies; manufacturing standards; U.S. federaland state healthcare fraud and abuse, data privacy laws and other similar non-U.S. laws; or laws that require the true, complete and accurate reporting offinancial information or data. Activities subject to these laws also involve the improper use or misrepresentation of information obtained in the course ofclinical studies, the creation of fraudulent data in our preclinical studies or clinical studies, or illegal misappropriation of product, which could result inregulatory sanctions and cause serious harm to our reputation. It is not always possible to identify and deter misconduct by employees and other third-parties,and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting usfrom governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. In addition, we aresubject to the risk that a person or government could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted againstus, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business and financialresults, including, without limitation, the imposition of significant civil, criminal and administrative penalties, damages, monetary fines, disgorgements,possible exclusion from participation in Medicare, Medicaid and other U.S. healthcare programs, individual imprisonment, other sanctions, contractualdamages, reputational harm, diminished profits and future earnings and curtailment of our operations, any of which could adversely affect our ability tooperate our business and our results of operations.Our business involves the use of hazardous materials and we and our third-party manufacturers and suppliers must comply with environmentallaws and regulations, which can be expensive and restrict how we do business.Our research and development activities and our third-party manufacturers’ and suppliers’ activities involve the controlled storage, use anddisposal of hazardous materials owned by us, including the components of our product and drug candidates and other hazardous compounds. We and anythird-party manufacturers and suppliers we engage63 are subject to numerous federal, state and local environmental, health and safety laws, regulations and permitting requirements, including those governinglaboratory procedures; the generation, handling, use, storage, treatment, and disposal of hazardous and regulated materials and wastes; the emission anddischarge of hazardous materials into the ground, air and water; and employee health and safety. Our operations involve the use of hazardous and flammablematerials, including chemicals and biological and radioactive materials. Our operations also produce hazardous waste. In some cases, these hazardousmaterials and various wastes resulting from their use are stored at our and our manufacturers’ facilities pending their use and disposal. We generally contractwith third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination, which could cause an interruption of ourcommercialization efforts, research and development efforts and business operations, environmental damage resulting in costly clean-up and liabilities underapplicable laws and regulations governing the use, storage, handling and disposal of these materials and specified waste products.Although we believe that the safety procedures utilized by our third-party manufacturers for handling and disposing of these materials generallycomply with the standards prescribed by these laws and regulations, we cannot guarantee that this is the case or eliminate the risk of accidentalcontamination or injury from these materials. Under certain environmental laws, we could be held responsible for costs relating to any contamination at ourcurrent or past facilities and at third-party facilities. In such an event, we may be held liable for any resulting damages and such liability could exceed ourresources and state or federal or other applicable authorities may curtail our use of certain materials and/or interrupt our business operations. Furthermore,environmental laws and regulations are complex, change frequently and have tended to become more stringent. We cannot predict the impact of suchchanges and cannot be certain of our future compliance.Compliance with applicable environmental laws and regulations may be expensive, and current or future environmental laws and regulations mayimpair our research, product development and manufacturing efforts. In addition, we cannot entirely eliminate the risk of accidental injury or contaminationfrom these materials or wastes. Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to ouremployees resulting from the use of hazardous materials, this insurance may not provide adequate coverage against potential liabilities. We do not carryspecific biological or hazardous waste insurance coverage, and our property, casualty, and general liability insurance policies specifically exclude coveragefor damages and fines arising from biological or hazardous waste exposure or contamination. Accordingly, in the event of contamination or injury, we couldbe held liable for damages or be penalized with fines in an amount exceeding our resources, and our clinical studies or regulatory approvals could besuspended, which could have a material adverse effect on our business, results of operations and financial condition.Risks Related to Intellectual PropertyOur senolytic medicine platform and any future products that we commercialize could be alleged to infringe patent rights and other proprietaryrights of third parties, which may require costly litigation and, if we are not successful, could cause us to pay substantial damages and/ or limit our abilityto commercialize our products.Our commercial success depends on our ability to develop, manufacture and market our senolytic medicines and future drug candidates and use ourproprietary technology without infringing the patents and other proprietary rights of third parties. Intellectual property disputes can be costly to defend andmay cause our business, operating results and financial condition to suffer. We operate in an industry with extensive intellectual property litigation. As thebiopharmaceutical and pharmaceutical industries expand and more patents are issued, the risk increases that there may be patents issued to third parties thatrelate to our products and technology of which we are not aware or that we may need to challenge to continue our operations as currently contemplated.Whether merited or not, we may face allegations that we have infringed the trademarks, copyrights, patents and other intellectual property rights ofthird parties, including patents held by our competitors or by non-practicing entities. We may also face allegations that our employees have misappropriatedthe intellectual property rights of their former employers or other third parties.Litigation may make it necessary to defend ourselves by determining the scope, enforceability and validity of third-party proprietary rights, or toestablish our proprietary rights. Regardless of whether claims that we are infringing patents or other intellectual property rights have merit, the claims can betime consuming, divert management attention64 and financial resources and are costly to evaluate and defend. Results of any such litigation are difficult to predict and may require us to stop treating certainconditions, obtain licenses or modify our products and features while we develop non-infringing substitutes, or may result in significant settlement costs. Forexample, litigation can involve substantial damages for infringement (and if the court finds that the infringement was willful, we could be ordered to paytreble damages and the patent owner’s attorneys’ fees), and the court could prohibit us from selling or licensing our products unless the third party licensesrights to us, which it is not required to do at a commercially reasonable price or at all. If a license is available from a third party, we may have to paysubstantial royalties, upfront fees or grant cross-licenses to intellectual property rights for our products. We may also have to redesign our products so they donot infringe third-party intellectual property rights, which may not be possible at all or may require substantial monetary expenditures and time, duringwhich our products may not be available for manufacture, use, or sale.In addition, patent applications in the U.S. and many international jurisdictions are typically not published until 18 months after the filing ofcertain priority documents (or, in some cases, are not published until they issue as patents) and publications in the scientific literature often lag behind actualdiscoveries. Thus, we cannot be certain that others have not filed patent applications or made public disclosures relating to our technology or ourcontemplated technology. A third party may have filed, and may in the future file, patent applications covering our products or technology similar to ours.Any such patent application may have priority over our patent applications or patents, which could further require us to obtain rights to issued patentscovering such technologies. If another party has filed a U.S. patent application on inventions similar to ours, depending on whether the timing of the filingdate falls under certain patent laws, we may have to participate in a priority contest (such as an interference proceeding) declared by the U.S. Patent andTrademark Office, to determine priority of invention in the U.S. The costs of patent and other proceedings could be substantial, and it is possible that suchefforts would be unsuccessful if it is determined that the other party had independently arrived at the same or similar invention prior to our own invention,resulting in a loss of our U.S. patent position with respect to such inventions.From time to time, we may be subject to legal proceedings and claims in the ordinary course of business with respect to intellectual property.Although we are not currently subject to any claims from third parties asserting infringement of their intellectual property rights, in the future, we may receiveclaims from third parties asserting infringement of their intellectual property rights. Future litigation may be necessary to establish our intellectual propertyrights or to defend ourselves by determining the scope, enforceability and validity of third-party intellectual property rights. There can be no assurance withrespect to the outcome of any current or future litigation brought by or against us, and the outcome of any such litigation could have a material adverseimpact on our business, operating results and financial condition. Litigation is inherently unpredictable and outcomes are uncertain. Further, as the costs andoutcome of these types of claims and proceedings can vary significantly, it is difficult to estimate potential losses that may occur. Accordingly, we are unableat this time to estimate the effects of these potential future lawsuits on our financial condition, operations or cash flows.Some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantiallygreater resources. Even if resolved in our favor, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significantexpenses, and could distract our technical and management personnel from their normal responsibilities. In addition, there could be public announcements ofthe results of hearings, motions or other interim proceedings or developments, and if securities analysts or investors perceive these results to be negative, itcould have a material adverse effect on the price of our common stock. Finally, any uncertainties resulting from the initiation and continuation of anylitigation could have a material adverse effect on our ability to raise the funds necessary to continue our operations.If we are unable to obtain, maintain and enforce intellectual property protection directed to our senolytic medicine platform and any futuretechnologies that we develop, others may be able to make, use, or sell products substantially the same as ours, which could adversely affect our ability tocompete in the market.As of March 2019, we own, co-own, or have an exclusive license or option in certain fields of use to more than 100 patents and pendingapplications in the United States and foreign jurisdictions. This portfolio includes 27 issued U.S. patents, 33 pending U.S. applications (including 13provisional applications), and over 30 granted or pending applications in foreign jurisdictions.65 We have not pursued or maintained, and may not pursue or maintain in the future, patent protection for our products in every country or territory inwhich we may sell our products. In addition, we cannot be sure that any of our pending patent applications or pending trademark applications will issue orthat, if issued, they will issue in a form that will be advantageous to us. The U.S. Patent and Trademark Office, or the USPTO, international patent offices orjudicial bodies may deny or significantly narrow claims made under our patent applications and our issued patents may be successfully challenged, may bedesigned around, or may otherwise be of insufficient scope to provide us with protection for our commercial products. Further, the USPTO, internationaltrademark offices or judicial bodies may deny our trademark applications and, even if published or registered, these trademarks may not effectively protectour brand and goodwill. Like patents, trademarks also may be successfully opposed or challenged.We cannot be certain that the steps we have taken will prevent unauthorized use or unauthorized reverse engineering of our technology. Moreover,third parties may independently develop technologies that are competitive with ours and such competitive technologies may or may not infringe ourintellectual property. The enforcement of our intellectual property rights also depends on the success of our legal actions against these infringers in therespective country or forum, but these actions may not be successful. As with all granted intellectual property, such intellectual property may be challenged,invalidated or circumvented, may not provide specific protection and/or may not prove to be enforceable in actions against specific alleged infringers.The market for biopharmaceuticals, pharmaceuticals and treatments for age-related diseases is highly competitive and subject to rapidtechnological change. Our success depends, in part, upon our ability to maintain a competitive position in the development and protection of technologiesand products for use in these fields and upon our ability to obtain, maintain and enforce our intellectual property rights in connection therewith. We seek toobtain and maintain patents and other intellectual property rights to restrict the ability of others to market products that misappropriate our technologyand/or infringe our intellectual property to unfairly and illegally compete with our products. If we are unable to protect our intellectual property andproprietary rights, our competitive position and our business could be harmed, as third parties may be able to make, use, or sell products that are substantiallythe same as ours without incurring the sizeable development and licensing costs that we have incurred, which would adversely affect our ability to competein the market.We use a combination of patents, trademarks, know-how, confidentiality procedures and contractual provisions to protect our proprietarytechnology. However, these protections may not be adequate and may not provide us with any competitive advantage. For example, patents may not issuefrom any of our currently pending or any future patent applications, and our issued patents and any future patents that may issue may not survive legalchallenges to their scope, validity or enforceability, or provide significant protection for us.If we or one of our current or future collaborators were to initiate legal proceedings against a third party to enforce a patent covering one of our leaddrug candidates or future drug candidates, the defendant could counterclaim that our patent is invalid and/or unenforceable. In patent litigation in the U.S.,defendant counterclaims alleging invalidity and/or unenforceability are commonplace.Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, including lack of novelty, obviousnessor non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheldrelevant information from the USPTO, or made a misleading statement, during prosecution. Third parties may also raise similar claims before the USPTO,even outside the context of litigation. The outcome following legal assertions of invalidity and unenforceability is unpredictable.With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we and the patent examinerwere unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity and/or unenforceability, we would lose at least part, andperhaps all, of the patent protection on our drug candidates. Such a loss of patent protection would have a material adverse impact on our business.Even if our patents are determined by a court to be valid and enforceable, they may not be interpreted sufficiently broadly to prevent others frommarketing products similar to ours or designing around our patents. For example, third parties may be able to make products that are similar to ours but thatare not covered by the claims of our patents. Third parties may assert that we or our licensors were not the first to make the inventions covered by our66 issued patents or pending patent applications. The claims of our issued patents or patent applications when issued may not cover our proposed commercialtechnologies or the future products that we develop. We may not have freedom to commercialize unimpeded by the patent rights of others. Third parties mayhave dominating, blocking, or other patents relevant to our technology of which we are not aware. There may be prior public disclosures or art that could bedeemed to invalidate one or more of our patent claims. Further, we may not develop additional proprietary technologies in the future, and, if we do, they maynot be patentable.Patent law can be highly uncertain and involve complex legal and factual questions for which important principles remain unresolved. In the U.S.and in many international jurisdictions, policy regarding the breadth of claims allowed in patents can be inconsistent. The U.S. Supreme Court and the Courtof Appeals for the Federal Circuit have made, and will likely continue to make, changes in how the patent laws of the U.S. are interpreted. Similarly,international courts have made, and will likely continue to make, changes in how the patent laws in their respective jurisdictions are interpreted. We cannotpredict future changes in the interpretation of patent laws or changes to patent laws that might be enacted into law by U.S. and international legislativebodies. Those changes may materially affect our patents, our ability to obtain patents or the patents and patent applications of our licensors.Patent reform legislation in the U.S. could increase the uncertainties and costs surrounding the prosecution of our patent applications and theenforcement or defense of our issued patents. For example, on September 16, 2011, the Leahy-Smith America Invents Act, or Leahy-Smith Act, was signedinto law. The Leahy-Smith Act included a number of significant changes to U.S. patent law. These include provisions that affect the way patent applicationsare prosecuted, redefine prior art, may affect patent litigation, and switch the U.S. patent system from a “first-to-invent” system to a “first-to-file” system.Under a “first-to-file” system, assuming the other requirements for patentability are met, the first inventor to file a patent application generally will be entitledto the patent on an invention regardless of whether another inventor had made the invention earlier. The U.S. Patent and Trademark Office recentlydeveloped new regulations and procedures to govern administration of theLeahy-Smith Act, and many of the substantive changes to patent law associated with the Leahy-Smith Act, and in particular, the first-to-fileprovisions, only became effective on March 16, 2013. The Leahy-Smith Act and its implementation could increase the uncertainties and costs surroundingthe prosecution of our patent applications and the enforcement or defense of our issued patents, which could have a material adverse effect on our businessand financial condition.In addition, we have a number of international patents and patent applications, and expect to continue to pursue patent protection in many of thesignificant markets in which we intend to do business. The laws of some international jurisdictions may not protect intellectual property rights to the sameextent as laws in the U.S., and many companies have encountered significant difficulties in obtaining, protecting, and defending such rights in internationaljurisdictions. If we encounter such difficulties or we are otherwise precluded from effectively protecting our intellectual property rights in internationaljurisdictions, our business prospects could be substantially harmed.Varying filing dates in international countries may also permit intervening third parties to allege priority to certain technology.Patent terms may be shortened or lengthened by, for example, terminal disclaimers, patent term adjustments, supplemental protection certificates,and patent term extensions. Patent term extensions and supplemental protection certificates, and the like, may be impacted by the regulatory process and maynot significantly lengthen patent term. Non-payment or delay in payment of patent fees or annuities, delay in patent filings or delay in extension filing(including any patent term extension or adjustment filing), whether intentional or unintentional, may also result in the loss of patent rights important to ourbusiness. Certain countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to other parties. In addition,many countries limit the enforceability of patents against other parties, including government agencies or government contractors. In these countries, thepatent owner may have limited remedies, which could materially diminish the value of any patents.In addition to the protection afforded by patents, we rely on confidentiality agreements to protect confidential information and proprietary know-how that is not patentable or that we elect not to patent, processes for which patents are difficult to enforce and any other elements of our drug candidatediscovery and development processes that involve proprietary know-how, information or technology that is not covered by patents. We seek to protect ourproprietary67 technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and contractors. Wecannot guarantee that we have entered into such agreements with each party that may have or have had access to our confidential information or proprietarytechnology and processes. We also seek to preserve the integrity and confidentiality of our data and other confidential information by maintaining physicalsecurity of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals,organizations and systems, agreements or security measures may be breached and detecting the disclosure or misappropriation of confidential informationand enforcing a claim that a party illegally disclosed or misappropriated confidential information is difficult, expensive and time-consuming, and theoutcome is unpredictable. Further, we may not be able to obtain adequate remedies for any breach. In addition, our confidential information may otherwisebecome known or be independently discovered by competitors, in which case we would have no right to prevent them, or those to whom they communicateit, from using that technology or information to compete with us. We may in the future rely on trade secret protection, which would be subject to the risksidentified above with respect to confidential information.Monitoring unauthorized use of our intellectual property is difficult and costly. From time to time, we review our competitors’ products, and mayin the future seek to enforce our patents or other rights against potential infringement. However, the steps we have taken to protect our proprietary rights maynot be adequate to prevent misappropriation of our intellectual property. We may not be able to detect unauthorized use of, or take appropriate steps toenforce, our intellectual property rights. Our competitors may also independently develop similar technology. Any inability to meaningfully protect ourintellectual property could result in competitors offering products that incorporate our product or service features, which could reduce demand for ourproducts. In addition, we may need to defend our patents from third-party challenges, such as (but not limited to) interferences, derivation proceedings, re-examination proceedings, post-grant review, inter partes review, third-party submissions, oppositions, nullity actions or other patent proceedings. We mayneed to initiate infringement claims or litigation.Adverse proceedings such as litigation can be expensive, time consuming and may divert the efforts of our technical and managerial personnel,which could in turn harm our business, whether or not we receive a determination favorable to us. In addition, in an infringement proceeding, a court or otherjudicial body may decide that the patent we seek to enforce is invalid or unenforceable, or may refuse to stop the other party from using the technology atissue on the grounds that the patent in question does not cover the technology in question. An adverse result in any litigation could put one or more of ourpatents at risk of being invalidated or interpreted narrowly. Some of our competitors may be able to devote significantly more resources to intellectualproperty litigation, and may have significantly broader patent portfolios to assert against us if we assert our rights against them. Further, because of thesubstantial discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be disclosedor otherwise compromised during litigation.We may not be able to correctly estimate or control our future operating expenses in relation to obtaining intellectual property, enforcingintellectual property and/or defending intellectual property, which could affect operating expenses. Our operating expenses may fluctuate significantly in thefuture as a result of a variety of factors, including the costs of preparing, filing, prosecuting, defending, and enforcing patent and trademark claims and otherintellectual property-related costs, including adverse proceedings (such as litigation) costs.Our intellectual property agreements with third parties may be subject to disagreements over contract interpretation, which could narrow thescope of our rights to the relevant intellectual property or technology or increase our financial or other obligations to our licensors.Certain provisions in our intellectual property agreements may be susceptible to multiple interpretations. The resolution of any contractinterpretation disagreement that may arise could affect the scope of our rights to the relevant intellectual property or technology, or affect financial or otherobligations under the relevant agreement, either of which could have a material adverse effect on our business, financial condition, results of operations andprospects.In addition, while it is our policy to require our employees and contractors who may be involved in the conception or development of intellectualproperty to execute agreements assigning such intellectual property to us, we may be unsuccessful in executing such an agreement with each party who infact conceives or develops intellectual property that we regard as our own. Our assignment agreements may not be self-executing or may be breached, and68 we may be forced to bring claims against third parties, or defend claims they may bring against us, to determine the ownership of what we regard as ourintellectual property.We may be subject to claims challenging the inventorship or ownership of our patents and other intellectual property.We may also be subject to claims that former employees, collaborators or other third parties have an ownership interest in our patents or otherintellectual property. Litigation may be necessary to defend against these and other claims challenging inventorship or ownership. If we fail in defending anysuch claims, in addition to paying monetary damages, we may lose valuable intellectual property rights. Such an outcome could have a material adverseeffect on our business. Even if we are successful in defending against such claims, litigation could result in substantial costs and distraction to managementand other employees.We may not be able to protect our intellectual property rights throughout the world.Filing, prosecuting and defending patents on drug candidates in all countries throughout the world would be prohibitively expensive, and ourintellectual property rights in some countries outside the U.S. can be less extensive than those in the U.S. In addition, the laws of some foreign countries donot protect intellectual property rights to the same extent as federal and state laws in the U.S.. Consequently, we may not be able to prevent third parties frompracticing our inventions in all countries outside the U.S., or from selling or importing products made using our inventions in and into the U.S. or otherjurisdictions. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and further,may export otherwise infringing products to territories where we have patent protection, but enforcement is not as strong as that in the U.S. These productsmay compete with our products and our patents or other intellectual property rights may not be effective or sufficient to prevent them from competing.Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legalsystems of certain countries, particularly certain developing countries, do not favor the enforcement of patents and other intellectual property protection,particularly those relating to biopharmaceuticals, which could make it difficult for us to stop the infringement of our patents or marketing of competingproducts in violation of our proprietary rights generally. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial costs anddivert our efforts and attention from other aspects of our business, could put our patents at risk of being invalidated or interpreted narrowly and our patentapplications at risk of not issuing and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate and thedamages or other remedies awarded, if any, may not be commercially meaningful.Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercialadvantage from the intellectual property that we develop or license.If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interestand our business may be adversely affected.Our registered or unregistered trademarks or trade names may be challenged, infringed, circumvented, declared generic or conflict with third-partyrights. We may not be able to protect our rights to these trademarks and trade names, which we need to build name recognition by potential partners orcustomers in our markets of interest. In addition, third parties may file first for our trademarks in certain countries. If they succeeded in registering suchtrademarks, and if we were not successful in challenging such third-party rights, we may not be able to use these trademarks to market our products in thosecountries. In such cases, over the long term, if we are unable to establish name recognition based on our trademarks and trade names, then our marketingabilities may be impacted.If we are unable to protect the confidentiality of our proprietary information and know-how, the value of our technology and products could beadversely affected.We may not be able to protect our proprietary information and technology adequately. Although we use reasonable efforts to protect ourproprietary information, technology, and know-how, our employees, consultants,69 contractors and outside scientific advisors may unintentionally or willfully disclose our information to competitors. Enforcing a claim that a third partyillegally obtained and is using any of our proprietary information, technology or know-how is expensive and time consuming, and the outcome isunpredictable. In addition, courts outside the U.S. are sometimes less willing to protect proprietary information, technology, and know-how. We rely, in part,on non-disclosure and confidentiality agreements with our employees, consultants and other parties to protect our proprietary information, technology, andknow-how. These agreements may be breached and we may not have adequate remedies for any breach. Moreover, others may independently develop similaror equivalent proprietary information, and third parties may otherwise gain access to our proprietary knowledge.Risks Related to Government RegulationEven if we obtain regulatory approval for a drug candidate, our products will remain subject to regulatory scrutiny.If our drug candidates are approved, they will be subject to ongoing regulatory requirements for manufacturing, labeling, packaging, storage,advertising, promotion, sampling, record-keeping, conduct of post-marketing studies, and submission of safety, efficacy, and other post-market information,including both federal and state requirements in the U.S. and requirements of comparable foreign regulatory authorities.Manufacturers and manufacturers’ facilities are required to comply with extensive FDA and comparable foreign regulatory authority requirements,including ensuring that quality control and manufacturing procedures conform to cGMP regulations. As such, we and our contract manufacturers will besubject to continual review and inspections to assess compliance with cGMP and adherence to commitments made in any approved marketing application.Accordingly, we and others with whom we work must continue to expend time, money, and effort in all areas of regulatory compliance, includingmanufacturing, production, and quality control.We will have to comply with requirements concerning advertising and promotion for our products. Promotional communications with respect toprescription drugs and biologics are subject to a variety of legal and regulatory restrictions and must be consistent with the information in the product’sapproved label. As such, we may not promote our products for indications or uses for which they do not have approval. The holder of an approvedapplication must submit new or supplemental applications and obtain approval for certain changes to the approved product, product labeling, ormanufacturing process. We could also be asked to conduct post-marketing clinical studies to verify the safety and efficacy of our products in general or inspecific patient subsets. An unsuccessful post-marketing study or failure to complete such a study could result in the withdrawal of marketing approval.If a regulatory agency discovers previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, orproblems with the facility where the product is manufactured, or disagrees with the promotion, marketing or labeling of a product, such regulatory agencymay impose restrictions on that product or us, including requiring withdrawal of the product from the market. If we fail to comply with applicable regulatoryrequirements, a regulatory agency or enforcement authority may, among other things: •issue warning letters; •impose civil or criminal penalties; •suspend or withdraw regulatory approval; •suspend any of our clinical studies; •refuse to approve pending applications or supplements to approved applications submitted by us; •impose restrictions on our operations, including closing our contract manufacturers’ facilities; or •seize or detain products, or require a product recall.Any government investigation of alleged violations of law could require us to expend significant time and resources in response, and couldgenerate negative publicity. Any failure to comply with ongoing regulatory requirements may significantly and adversely affect our ability to commercializeand generate revenue from our70 products. If regulatory sanctions are applied or if regulatory approval is withdrawn, the value of our company and our operating results will be adverselyaffected.Moreover, the policies of the FDA and of other regulatory authorities may change and additional government regulations may be enacted thatcould prevent, limit or delay regulatory approval of our drug candidates. We cannot predict the likelihood, nature or extent of government regulation thatmay arise from future legislation or administrative or executive action, either in the U.S. or abroad. For example, certain policies of the Trump administrationmay impact our business and industry.Namely, the Trump administration has taken several executive actions, including the issuance of a number of Executive Orders, that could imposesignificant burdens on, or otherwise materially delay, the FDA’s ability to engage in routine oversight activities such as implementing statutes throughrulemaking, issuance of guidance, and review and approval of marketing applications. It is difficult to predict how these orders will be implemented, and theextent to which they will impact the FDA’s ability to exercise its regulatory authority. If these executive actions impose restrictions on the FDA’s ability toengage in oversight and implementation activities in the normal course, our business may be negatively impacted. In addition, if we are slow or unable toadapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we maylose any marketing approval that we may have obtained and we may not achieve or sustain profitability.If any of our small molecule drug candidates obtain regulatory approval, additional competitors could enter the market with generic versions ofsuch drugs, which may result in a material decline in sales of affected products.Under the Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Act, a pharmaceutical manufacturer may file anabbreviated new drug application, or ANDA, seeking approval of a generic version of an approved, small molecule innovator product. Under the Hatch-Waxman Act, a manufacturer may also submit a new drug application, or NDA, under section 505(b)(2) of the Federal Food, Drug, and Cosmetic Act thatreferences the FDA’s prior approval of the small molecule innovator product. A 505(b)(2) NDA product may be for a new or improved version of the originalinnovator product. The Hatch-Waxman Act also provides for certain periods of regulatory exclusivity, which preclude FDA approval (or in somecircumstances, FDA filing and review) of an ANDA or 505(b)(2) NDA. In addition to the benefits of regulatory exclusivity, an innovator NDA holder mayhave patents claiming the active ingredient, product formulation or an approved use of the drug, which would be listed with the product in the FDApublication, “Approved Drug Products with Therapeutic Equivalence Evaluations,” known as the Orange Book. If there are patents listed in the Orange Bookfor a product, a generic or 505(b)(2) applicant that seeks to market its product before expiration of the patents must include in their applications what isknown as a “Paragraph IV” certification, challenging the validity or enforceability of, or claiming non-infringement of, the listed patent or patents. Notice ofthe certification must be given to the patent owner and NDA holder and if, within 45 days of receiving notice, either the patent owner or NDA holder sues forpatent infringement, approval of the ANDA or 505(b)(2) NDA is stayed for up to 30 months.Accordingly, if any of our small molecule drug candidates, such as UBX0101 or UBX1967, are approved, competitors could file ANDAs for genericversions of our small molecule drug products or 505(b)(2) NDAs that reference our small molecule drug products. If there are patents listed for our smallmolecule drug products in the Orange Book, those ANDAs and 505(b)(2) NDAs would be required to include a certification as to each listed patent indicatingwhether the ANDA applicant does or does not intend to challenge the patent. We cannot predict which, if any, patents in our current portfolio or patents wemay obtain in the future will be eligible for listing in the Orange Book, how any generic competitor would address such patents, whether we would sue onany such patents, or the outcome of any such suit.We may not be successful in securing or maintaining proprietary patent protection for products and technologies we develop or license. Moreover,if any of our owned or in-licensed patents that are listed in the Orange Book are successfully challenged by way of a Paragraph IV certification andsubsequent litigation, the affected product could immediately face generic competition and its sales would likely decline rapidly and materially.Any biologic, or large molecule, drug candidates for which we intend to seek approval may face competition sooner than anticipated.71 If we are successful in achieving regulatory approval to commercialize any biologic drug candidate faster than our competitors, such drugcandidates may face competition from biosimilar products. In the U.S., large molecule drug candidates are regulated by the FDA as biologic products subjectto approval under the biologics license application, or BLA, pathway. The Biologics Price Competition and Innovation Act of 2009, or BPCIA, creates anabbreviated pathway for the approval of biosimilar and interchangeable biologic products following the approval of an original BLA. The abbreviatedregulatory pathway establishes legal authority for the FDA to review and approve biosimilar biologics, including the possible designation of a biosimilar as“interchangeable” based on its similarity to an existing brand product. Under the BPCIA, an application for a biosimilar product cannot be approved by theFDA until 12 years after the original branded product was approved under a BLA. The law is complex and is still being interpreted and implemented by theFDA. As a result, its ultimate impact, implementation, and meaning are subject to uncertainty.Moreover, the extent to which a biosimilar product, once approved, will be substituted for any one of our reference products in a way that is similarto traditional generic substitution for non-biologic products is not yet clear, and will depend on a number of marketplace and regulatory factors that are stilldeveloping. In addition, a competitor could decide to forego the biosimilar approval path and submit a full BLA after completing its own preclinical studiesand clinical studies. In such cases, any exclusivity to which we may be eligible under the BPCIA would not prevent the competitor from marketing itsproduct as soon as it is approved.If competitors are able to obtain marketing approval for biosimilars referencing our large molecule drug candidates, if approved, such products maybecome subject to competition from such biosimilars, with the attendant competitive pressure and potential adverse consequences. Such competitiveproducts may be able to immediately compete with us in each indication for which our drug candidates may have received approval.We may seek orphan drug designation for certain future drug candidates, but we may be unable to obtain such designations or to maintain thebenefits associated with orphan drug designation, including market exclusivity, which may cause our revenue, if any, to be reduced.We may pursue orphan drug designation for certain of our future drug candidates. Under the Orphan Drug Act, the FDA may designate a drug orbiologic product as an orphan drug if it is intended to treat a rare disease or condition, defined as a patient population of fewer than 200,000 in the U.S., or apatient population greater than 200,000 in the U.S. where there is no reasonable expectation that the cost of developing the drug will be recovered from salesin the U.S. In the European Union, the EMA’s Committee for Orphan Medicinal Products, or COMP, grants orphan drug designation to promote thedevelopment of products that are intended for the diagnosis, prevention, or treatment of a life-threatening or chronically debilitating condition affecting notmore than five in 10,000 persons in the European Union. Additionally, designation is granted for products intended for the diagnosis, prevention, ortreatment of a life-threatening, seriously debilitating or serious and chronic condition when, without incentives, it is unlikely that sales of the drug in theEuropean Union would be sufficient to justify the necessary investment in developing the drug or biological product or where there is no satisfactory methodof diagnosis, prevention, or treatment, or, if such a method exists, the medicine must be of significant benefit to those affected by the condition.In the U.S., orphan drug designation entitles a party to financial incentives such as opportunities for grant funding towards clinical study costs, taxadvantages, and application fee waivers. In addition, if a product receives the first FDA approval for the indication for which it has orphan designation, theproduct is entitled to orphan drug exclusivity, which means the FDA may not approve any other application to market the same drug for the same indicationfor a period of seven years, except in limited circumstances, such as a showing of clinical superiority over the product with orphan exclusivity or where themanufacturer is unable to assure sufficient product quantity for the orphan patient population. In the European Union, orphan drug designation entitles aparty to financial incentives such as reduction of fees or fee waivers and ten years of market exclusivity following drug or biological product approval. Thisperiod may be reduced to six years if the orphan drug designation criteria are no longer met, including where it is shown that the product is sufficientlyprofitable not to justify maintenance of market exclusivity.Even if we obtain orphan drug designation, we may not be the first to obtain marketing approval for any particular orphan indication due to theuncertainties associated with developing pharmaceutical products. Further, even if we obtain orphan drug exclusivity for a drug candidate, that exclusivitymay not effectively protect the product from competition because different drugs with different active moieties can be approved for the same condition. Even72 after an orphan drug is approved, the FDA or EMA can subsequently approve the same drug with the same active moiety for the same condition if the FDA orEMA concludes that the later drug is clinically superior in that it is safer, more effective, or makes a major contribution to patient care. Orphan drugdesignation neither shortens the development time or regulatory review time of a drug or biologic nor gives the drug or biologic any advantage in theregulatory review or approval process.Enacted and future healthcare legislation may increase the difficulty and cost for us to obtain marketing approval of and commercialize ourdrug candidates and may affect the prices we may set.In the U.S., the EU and other jurisdictions, there have been, and we expect there will continue to be, a number of legislative and regulatory changesand proposed changes to the healthcare system that could affect our future results of operations. In particular, there have been and continue to be a number ofinitiatives at the U.S. federal and state levels that seek to reduce healthcare costs and improve the quality of healthcare. For example, in March 2010, thePatient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, or collectively the Affordable Care Act, wasenacted, which substantially changed the way healthcare is financed by both governmental and private insurers. Among the provisions of the Affordable CareAct, those of greatest importance to the pharmaceutical and biotechnology industries include the following: •an annual, non-deductible fee payable by any entity that manufactures or imports certain branded prescription drugs and biologic agents (otherthan those designated as orphan drugs), which is apportioned among these entities according to their market share in certain governmenthealthcare programs; •a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 50% point-of-sale discounts off negotiatedprices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugsto be covered under Medicare Part D; •new requirements to report certain financial arrangements with physicians and teaching hospitals, including reporting “transfers of value” madeor distributed to prescribers and other healthcare providers and reporting investment interests held by physicians and their immediate familymembers; •an increase in the statutory minimum rebates a manufacturer must pay under the Medicaid Drug Rebate Program to 23.1% and 13.0% of theaverage manufacturer price for branded and generic drugs, respectively; •a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled,infused, instilled, implanted or injected; •extension of a manufacturer’s Medicaid rebate liability to covered drugs dispensed to individuals who are enrolled in Medicaid managed careorganizations; •expansion of eligibility criteria for Medicaid programs by, among other things, allowing states to offer Medicaid coverage to certain individualswith income at or below 133% of the federal poverty level, thereby potentially increasing a manufacturer’s Medicaid rebate liability; •a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research,along with funding for such research; •creation of the Independent Payment Advisory Board, which, once empaneled, will have the authority to recommend certain changes to theMedicare program that could result in reduced payments for prescription drugs and those recommendations could have the effect of law unlessoverruled by a supermajority vote of Congress; and •establishment of a Center for Medicare Innovation at the Centers for Medicare & Medicaid Services, or CMS, to test innovative payment andservice delivery models to lower Medicare and Medicaid spending, potentially including prescription drug spending.Since its enactment, there have been judicial and Congressional challenges to certain aspects of the Affordable Care Act, and we expect there willbe additional challenges and amendments to the Affordable Care Act in the future. The current presidential administration and Congress will likely continueto seek to modify, repeal, or otherwise invalidate all, or certain provisions of, the Affordable Care Act. It is uncertain the extent to which any such changesmay impact our business or financial condition.73 In addition, other legislative changes have been proposed and adopted in the U.S. since the Affordable Care Act was enacted. In August 2011, theBudget Control Act of 2011, among other things, led to aggregate reductions of Medicare payments to providers of 2% per fiscal year. These reductions wentinto effect in April 2013 and, due to subsequent legislative amendments to the statute, will remain in effect through 2025 unless additional action is taken byCongress. In January 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, further reduced Medicare payments toseveral types of providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for thegovernment to recover overpayments to providers from three to five years.Individual states in the U.S. have also become increasingly aggressive in passing legislation and implementing regulations designed to controlpharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access andmarketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.Legally-mandated price controls on payment amounts by third-party payors or other restrictions could harm our business, results of operations, financialcondition and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine whatpharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimatedemand for our drug candidates or put pressure on our product pricing. Moreover, payment methodologies may be subject to changes in healthcarelegislation and regulatory initiatives. For example, CMS may develop new payment and delivery models, such as bundled payment models. In addition,recently there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products.In the EU, similar political, economic and regulatory developments may affect our ability to profitably commercialize our drug candidates, ifapproved. In addition to continuing pressure on prices and cost containment measures, legislative developments at the EU or member state level may result insignificant additional requirements or obstacles that may increase our operating costs. The delivery of healthcare in the EU, including the establishment andoperation of health services and the pricing and reimbursement of medicines, is almost exclusively a matter for national, rather than EU, law and policy.National governments and health service providers have different priorities and approaches to the delivery of health care and the pricing and reimbursementof products in that context. In general, however, the healthcare budgetary constraints in most EU member states have resulted in restrictions on the pricingand reimbursement of medicines by relevant health service providers. Coupled with ever-increasing EU and national regulatory burdens on those wishing todevelop and market products, this could prevent or delay marketing approval of our drug candidates, restrict or regulate post-approval activities and affectour ability to commercialize our drug candidates, if approved. In markets outside of the U.S. and EU, reimbursement and healthcare payment systems varysignificantly by country, and many countries have instituted price ceilings on specific products and therapies.We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action in theU.S., the EU or any other jurisdiction. If we or any third parties we may engage are slow or unable to adapt to changes in existing requirements or theadoption of new requirements or policies, or if we or such third parties are not able to maintain regulatory compliance, our drug candidates may lose anyregulatory approval that may have been obtained and we may not achieve or sustain profitability.Our business operations and current and future relationships with investigators, healthcare professionals, consultants, third-party payors,patient organizations and customers will be subject to applicable healthcare regulatory laws, which could expose us to penalties.Our business operations and current and future arrangements with investigators, healthcare professionals, consultants, third-party payors, patientorganizations and customers, may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations. These laws may constrain thebusiness or financial arrangements and relationships through which we conduct our operations, including how we research, market, sell and distribute ourdrug candidates, if approved.74 Such laws include: •the U.S. federal Anti-Kickback Statute, which prohibits, among other things, persons or entities from knowingly and willfully soliciting, offering,receiving or providing any remuneration (including any kickback, bribe, or certain rebate), directly or indirectly, overtly or covertly, in cash orin kind, to induce or reward, or in return for, either the referral of an individual for, or the purchase, lease, order or recommendation of, any good,facility, item or service, for which payment may be made, in whole or in part, under U.S. federal and state healthcare programs such as Medicareand Medicaid. A person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committeda violation; •the U.S. federal false claims and civil monetary penalties laws, including the civil False Claims Act, which, among other things, impose criminaland civil penalties, including through civil whistleblower or qui tam actions, against individuals or entities for knowingly presenting, or causingto be presented, to the U.S. federal government, claims for payment or approval that are false or fraudulent, knowingly making, using or causingto be made or used, a false record or statement material to a false or fraudulent claim, or from knowingly making a false statement to avoid,decrease or conceal an obligation to pay money to the U.S. federal government. In addition, the government may assert that a claim includingitems and services resulting from a violation of the U.S. federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of theFalse Claims Act; •the U.S. federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, which imposes criminal and civil liability for, amongother things, knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program, or knowinglyand willfully falsifying, concealing or covering up a material fact or making any materially false statement, in connection with the delivery of, orpayment for, healthcare benefits, items or services; similar to the U.S. federal Anti-Kickback Statute, a person or entity does not need to haveactual knowledge of the statute or specific intent to violate it in order to have committed a violation; •HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act of 2009 and its implementing regulations,which also imposes certain obligations, including mandatory contractual terms, with respect to safeguarding the privacy, security andtransmission of individually identifiable health information without appropriate authorization by covered entities subject to the rule, such ashealth plans, healthcare clearinghouses and healthcare providers as well as their business associates that perform certain services involving theuse or disclosure of individually identifiable health information; •the FDCA, which prohibits, among other things, the adulteration or misbranding of drugs, biologics and medical devices; •the U.S. Public Health Service Act, which prohibits, among other things, the introduction into interstate commerce of a biological product unlessa biologics license is in effect for that product; •the U.S. Physician Payments Sunshine Act and its implementing regulations, which require certain manufacturers of drugs, devices, biologics andmedical supplies that are reimbursable under Medicare, Medicaid, or the Children’s Health Insurance Program to report annually to thegovernment information related to certain payments and other transfers of value to physicians and teaching hospitals, as well as ownership andinvestment interests held by the physicians described above and their immediate family members;75 •analogous U.S. state laws and regulations, including: state anti-kickback and false claims laws, which may apply to our business practices,including but not limited to, research, distribution, sales and marketing arrangements and claims involving healthcare items or servicesreimbursed by any third-party payor, including private insurers; state laws that require pharmaceutical companies to comply with thepharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the U.S. federal government,or otherwise restrict payments that may be made to healthcare providers and other potential referral sources; state laws and regulations thatrequire drug manufacturers to file reports relating to pricing and marketing information, which requires tracking gifts and other remuneration anditems of value provided to healthcare professionals and entities; and state laws governing the privacy and security of health information incertain circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicatingcompliance efforts; and •similar healthcare laws and regulations in the EU and other jurisdictions, including reporting requirements detailing interactions with andpayments to healthcare providers.Ensuring that our internal operations and future business arrangements with third parties comply with applicable healthcare laws and regulationswill involve substantial costs. It is possible that governmental authorities will conclude that our business practices do not comply with current or futurestatutes, regulations, agency guidance or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are foundto be in violation of any of the laws described above or any other governmental laws and regulations that may apply to us, we may be subject to significantpenalties, including civil, criminal and administrative penalties, damages, fines, exclusion from government-funded healthcare programs, such as Medicareand Medicaid or similar programs in other countries or jurisdictions, disgorgement, individual imprisonment, contractual damages, reputational harm,diminished profits and the curtailment or restructuring of our operations. Further, defending against any such actions can be costly, time-consuming and mayrequire significant personnel resources. Therefore, even if we are successful in defending against any such actions that may be brought against us, ourbusiness may be impaired.Recent U.S. tax legislation and future changes to applicable U.S. tax laws and regulations may have a material adverse effect on our business,financial condition and results of operations.Changes in laws and policy relating to taxes may have an adverse effect on our business, financial condition and results of operations. For example,the U.S. government recently enacted significant tax reform, and certain provisions of the new law for tax years beginning after December 31, 2017 mayadversely affect us. Changes include, but are not limited to, a federal corporate tax rate decrease to 21%, a reduction to the maximum deduction allowed fornet operating losses generated in tax years after December 31, 2017, eliminating carrybacks of net operating losses, and providing for indefinite carryforwardsfor losses generated in tax years after December 31, 2017. The legislation is unclear in many respects and could be subject to potential amendments andtechnical corrections, and will be subject to interpretations and implementing regulations by the Treasury and Internal Revenue Service, any of which couldmitigate or increase certain adverse effects of the legislation. In addition, it is unclear how these U.S. federal income tax changes will affect state and localtaxation. Generally, future changes in applicable U.S. tax laws and regulations, or their interpretation and application could have an adverse effect on ourbusiness, financial conditions and results of operations.Risks Related to Ownership of Our Common StockOur stock price may be volatile and you may not be able to resell shares of our common stock at or above the price you paid.The trading price of our common stock may be highly volatile and may be subject to wide fluctuations in response to various factors, some ofwhich are beyond our control.These factors include those discussed in this “Risk Factors” section of this report and others such as: •results from, and any delays in, commencing, conducting or completing our clinical studies for our lead drug candidates, or any other futureclinical development programs;76 •announcements by academic or other third parties challenging the fundamental premises underlying our approach to treating age-relateddiseases and/or drug development; •announcements of regulatory approval or disapproval of our current or any future drug candidates; •failure or discontinuation of any of our research and development programs; •announcements relating to future licensing, collaboration, or development agreements; •delays in the commercialization of our current or any future drug candidates; •public misperception regarding the use of our therapies, or public bias of against “anti-aging” companies; •acquisitions and sales of new products, technologies, or businesses; •manufacturing and supply issues related to our drug candidates for clinical studies or future drug candidates for commercialization; •quarterly variations in our results of operations or those of our future competitors; •changes in earnings estimates or recommendations by securities analysts; •announcements by us or our competitors of new products, significant contracts, commercial relationships, acquisitions, or capital commitments; •developments with respect to intellectual property rights; •our commencement of, or involvement in, litigation; •changes in financial estimates or guidance, including our ability to meet our future revenue and operating profit or loss estimates or guidance; •any major changes in our board of directors or management; •new legislation in the U.S. relating to the sale or pricing of pharmaceuticals; •FDA or other U.S. or foreign regulatory actions affecting us or our industry; •product liability claims or other litigation or public concern about the safety of our drug candidates; •market conditions in the pharmaceutical, biopharmaceutical and biotechnology sectors; and •general economic conditions in the U.S. and abroad.In addition, the stock markets in general, and the markets for pharmaceutical, biopharmaceutical, and biotechnology stocks in particular, haveexperienced extreme volatility that may have been unrelated to the operating performance of the issuer. These broad market fluctuations may adversely affectthe trading price or liquidity of our common stock. In the past, when the market price of a stock has been volatile, holders of that stock have sometimesinstituted securities class action litigation against the issuer. If any of our stockholders were to bring such a lawsuit against us, we could incur substantialcosts defending the lawsuit and the attention of our management would be diverted from the operation of our business.An active, liquid and orderly market for our common stock may not develop and may not be maintained.Prior to our initial public offering in May 2018, there was no public market for shares of our common stock. Although our common stock is listedon the Nasdaq Global Select Market, an active trading market for our common stock may never be sustained on the Nasdaq Global Select or any otherexchange in the future. The lack of an active market may impair your ability to sell your shares at the time you wish to sell them or at a price that youconsider reasonable. An inactive market may also impair our ability to raise capital by selling shares and may impair our ability to acquire other businesses,applications, or technologies using our shares as consideration.77 If securities or industry analysts do not publish research or reports about our business, or if they issue an adverse or misleading opinionregarding our stock, our stock price and trading volume could decline.The trading market for our common stock is influenced by the research and reports that industry or securities analysts publish about us or ourbusiness. We only recently obtained research coverage by securities and industry analysts. If no additional new or few securities or industry analystscommence coverage of us, the trading price for our stock would be negatively impacted. In the event any of the analysts who cover us issue an adverse ormisleading opinion regarding us, our business model, our intellectual property or our stock performance, or if our clinical studies and operating results fail tomeet the expectations of analysts, our stock price would likely decline. If one or more of these analysts cease coverage of us or fail to publish reports on usregularly, we could lose visibility in the financial markets, which in turn could cause our stock price or trading volume to decline.We are an “emerging growth company” and as a result of the reduced disclosure and governance requirements applicable to emerging growthcompanies, our common stock may be less attractive to investors.We are an “emerging growth company,” as defined in the JOBS Act, and we intend to take advantage of certain exemptions from various reportingrequirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required tocomply with the auditor attestation requirements of Section 404, reduced disclosure obligations regarding executive compensation in our periodic reportsand proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval ofany golden parachute payments not previously approved. In addition, as an “emerging growth company” the JOBS Act allows us to delay adoption of new orrevised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. We have electedto use this extended transition period under the JOBS Act. As a result, our financial statements may not be comparable to the financial statements of issuerswho are required to comply with the effective dates for new or revised accounting standards that are applicable to public companies, which may makecomparison of our financials to those of other public companies more difficult.We cannot predict if investors will find our common stock less attractive because we will rely on these exemptions. If some investors find ourcommon stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile. We maytake advantage of these reporting exemptions until we are no longer an emerging growth company. We will remain an emerging growth company until theearlier of (1) the last day of the year following the fifth anniversary of the consummation of our IPO, (2) the last day of the year in which we have total annualgross revenue of at least $1.07 billion, (3) the last day of the year in which we are deemed to be a “large accelerated filer” as defined in Rule 12b-2 under theExchange Act, which would occur if the market value of our common stock held by non-affiliates exceeded $700.0 million as of the last business day of thesecond fiscal quarter of such year or (4) the date on which we have issued more than $1.0 billion in non-convertible debt securities during the prior three-yearperiod.If we sell shares of our common stock in future financings, stockholders may experience immediate dilution and, as a result, our stock price maydecline.We may from time to time issue additional shares of common stock at a discount from the current trading price of our common stock. As a result,our stockholders would experience immediate dilution upon the purchase of any shares of our common stock sold at such discount. In addition, asopportunities present themselves, we may enter into financing or similar arrangements in the future, including the issuance of debt securities, preferred stockor common stock. If we issue common stock or securities convertible into common stock, our common stockholders would experience additional dilutionand, as a result, our stock price may declineOur principal stockholders and management own a significant percentage of our stock and will be able to exert significant control over matterssubject to stockholder approval.As of December 31, 2018, our executive officers, directors, holders of 5% or more of our capital stock and their respective affiliates beneficiallyowned approximately 66.1% of our voting stock. Therefore, these stockholders have the ability to influence us through this ownership position. Thesestockholders may be able to determine all matters requiring stockholder approval. For example, these stockholders may be able to control elections ofdirectors,78 amendments of our organizational documents, or approval of any merger, sale of assets, or other major corporate transaction. This may prevent or discourageunsolicited acquisition proposals or offers for our common stock that you may feel are in your best interest as one of our stockholders.Sales of a substantial number of shares of our common stock in the public market could cause our stock price to fall.Sales of a substantial number of shares of our common stock in the public market could occur at any time. These sales, or the perception in themarket that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock. Moreover, holders ofapproximately 15.7 million shares of our common stock have rights, subject to certain conditions, to require us to file registration statements covering theirshares or to include their shares in registration statements that we may file for ourselves or other stockholders. We have registered and intend to continue toregister all shares of common stock that we may issue under our equity compensation plans. Once we register these shares, they can be freely sold in thepublic market upon issuance, subject to volume limitations applicable to affiliates.We incur increased costs as a result of operating as a public company, and our management devote substantial time to new complianceinitiatives. We may fail to comply with the rules that apply to public companies, including Section 404 of the Sarbanes-Oxley Act of 2002, which couldresult in sanctions or other penalties that would harm our business.We have incurred and will continue to incur significant legal, accounting and other expenses as a public company, including costs resulting frompublic company reporting obligations under the Exchange Act and regulations regarding corporate governance practices. The listing requirements of theNasdaq Global Select Market and the rules of the Securities and Exchange Commission, or SEC, require that we satisfy certain corporate governancerequirements relating to director independence, filing annual and interim reports, stockholder meetings, approvals and voting, soliciting proxies, conflicts ofinterest and a code of conduct. Our management and other personnel have devoted and will need to devote a substantial amount of time to ensure that wecomply with all of these requirements. Moreover, the reporting requirements, rules and regulations will increase our legal and financial compliance costs andwill make some activities more time-consuming and costlier. Any changes we make to comply with these obligations may not be sufficient to allow us tosatisfy our obligations as a public company on a timely basis, or at all. These reporting requirements, rules and regulations, coupled with the increase inpotential litigation exposure associated with being a public company, could also make it more difficult for us to attract and retain qualified persons to serveon our board of directors or board committees or to serve as executive officers, or to obtain certain types of insurance, including directors’ and officers’insurance, on acceptable terms.We are subject to Section 404 of The Sarbanes-Oxley Act of 2002, or Section 404, and the related rules of the SEC, which generally require ourmanagement and independent registered public accounting firm to report on the effectiveness of our internal control over financial reporting. Beginning withthe second annual report that we will be required to file with the SEC, Section 404 requires an annual management assessment of the effectiveness of ourinternal control over financial reporting. However, for so long as we remain an emerging growth company as defined in the JOBS Act, we intend to takeadvantage of certain exemptions from various reporting requirements that are applicable to public companies that are not emerging growth companies,including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404. Once we are no longer an emerginggrowth company or, if prior to such date, we opt to no longer take advantage of the applicable exemption, we will be required to include an opinion from ourindependent registered public accounting firm on the effectiveness of our internal controls over financial reporting.To date, we have never conducted a review of our internal control for the purpose of providing the reports required by these rules. During thecourse of our review and testing, we may identify deficiencies and be unable to remediate them before we must provide the required reports.79 Furthermore, if we have a material weakness in our internal controls over financial reporting, we may not detect errors on a timely basis and ourfinancial statements may be materially misstated. We or our independent registered public accounting firm may not be able to conclude on an ongoing basisthat we have effective internal control over financial reporting, which could harm our operating results, cause investors to lose confidence in our reportedfinancial information and cause the trading price of our stock to fall. In addition, as a public company we will be required to file accurate and timely quarterlyand annual reports with the SEC under the Exchange Act. In order to report our results of operations and financial statements on an accurate and timely basis,we will depend in part on CROs to provide timely and accurate notice of their costs to us. Any failure to report our financial results on an accurate and timelybasis could result in sanctions, lawsuits, delisting of our shares from The Nasdaq Global Select Market or other adverse consequences that would materiallyharm to our business.Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.We have incurred substantial losses during our history and do not expect to become profitable in the near future, and we may never achieveprofitability. To the extent that we continue to generate taxable losses, unused losses will carry forward to offset a portion of future taxable income, if any,until such unused losses expire, if ever. Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, if a corporation undergoes an“ownership change,” generally defined as a greater than 50 percentage point change (by value) in its equity ownership by certain stockholders over a three-year period, the corporation’s ability to use its pre-change net operating loss carryforwards, or NOLs, and other pre-change tax attributes (such as research anddevelopment tax credits) to offset its post- change income or taxes may be limited. We may have experienced ownership changes prior to December 31, 2018,and may experience ownership changes in the future as a result of subsequent shifts in our stock ownership (some of which shifts are outside our control). As aresult, if we earn net taxable income, our ability to use our pre-change NOLs to offset such taxable income could be subject to limitations. Similar provisionsof state tax law may also apply. As a result, even if we attain profitability, we may be unable to use a material portion of our NOLs and other taxattributes.Additionally, the Tax Act, which was enacted on December 22, 2017, significantly reforms the Code, including changes to the rules governing netoperating loss carryforwards arising in tax years ending after December 31, 2017. For net operating loss carryforwards, the Tax Act limits a taxpayer’s abilityto utilize such carryforwards to 80% of taxable income. In addition, net operating loss carryforwards arising in tax years ending after December 31, 2017 canbe carried forward indefinitely, but carryback is generally prohibited. Net operating loss carryforwards generated by us before January 1, 2018 will not besubject to the taxable income limitation and will continue to have a twenty- year carryforward period. However, the changes in the carryforward andcarryback periods as well as the new limitation on use of net operating losses may significantly impact our ability to use net operating loss carryforwardsgenerated after December 31, 2017, as well as the timing of any such use, and could adversely affect our results of operations.Provisions in our charter documents and under Delaware law could discourage a takeover that stockholders may consider favorable and maylead to entrenchment of management.Our amended and restated certificate of incorporation and amended and restated bylaws contain provisions that could delay or prevent changes incontrol or changes in our management without the consent of our board of directors. These provisions include the following: •a classified board of directors with three-year staggered terms, which may delay the ability of stockholders to change the membership of amajority of our board of directors; •no cumulative voting in the election of directors, which limits the ability of minority stockholders to elect director candidates; •the exclusive right of our board of directors to elect a director to fill a vacancy created by the expansion of the board of directors or theresignation, death or removal of a director, which prevents stockholders from being able to fill vacancies on our board of directors; •the ability of our board of directors to authorize the issuance of shares of preferred stock and to determine the price and other terms of thoseshares, including preferences and voting rights, without stockholder approval, which could be used to significantly dilute the ownership of ahostile acquiror; •the ability of our board of directors to alter our amended and restated bylaws without obtaining stockholder approval;80 •the required approval of at least 66 2/3% of the shares entitled to vote at an election of directors to adopt, amend or repeal our amended andrestated bylaws or repeal the provisions of our amended and restated certificate of incorporation regarding the election and removal of directors; •a prohibition on stockholder action by written consent, which forces stockholder action to be taken at an annual or special meeting of ourstockholders; •the requirement that a special meeting of stockholders may be called only by the chief executive officer or the president or the board of directors,which may delay the ability of our stockholders to force consideration of a proposal or to take action, including the removal of directors; and •advance notice procedures that stockholders must comply with in order to nominate candidates to our board of directors or to propose matters tobe acted upon at a stockholders’ meeting, which may discourage or deter a potential acquiror from conducting a solicitation of proxies to electthe acquiror’s own slate of directors or otherwise attempting to obtain control of us.We are also subject to the anti-takeover provisions contained in Section 203 of the Delaware General Corporation Law. Under Section 203, acorporation may not, in general, engage in a business combination with any holder of 15% or more of its capital stock unless the holder has held the stock forthree years or, among other exceptions, the board of directors has approved the transaction.Claims for indemnification by our directors and officers may reduce our available funds to satisfy successful third-party claims against us andmay reduce the amount of money available to us.Our amended and restated certificate of incorporation and amended and restated bylaws provide that we will indemnify our directors and officers,in each case to the fullest extent permitted by Delaware law.In addition, as permitted by Section 145 of the Delaware General Corporation Law, our amended and restated bylaws and our indemnificationagreements that we have entered into with our directors and officers provide that: •We will indemnify our directors and officers for serving us in those capacities or for serving other business enterprises at our request, to the fullestextent permitted by Delaware law. Delaware law provides that a corporation may indemnify such person if such person acted in good faith and ina manner such person reasonably believed to be in or not opposed to the best interests of the registrant and, with respect to any criminalproceeding, had no reasonable cause to believe such person’s conduct was unlawful. •We may, in our discretion, indemnify employees and agents in those circumstances where indemnification is permitted by applicable law. •We are required to advance expenses, as incurred, to our directors and officers in connection with defending a proceeding, except that suchdirectors or officers shall undertake to repay such advances if it is ultimately determined that such person is not entitled to indemnification. Wewill not be obligated pursuant to our amended and restated bylaws to indemnify a person with respect to proceedings initiated by that personagainst us or our other indemnitees, except with respect to proceedings authorized by our board of directors or brought to enforce a right toindemnification. •The rights conferred in our amended and restated bylaws are not exclusive, and we are authorized to enter into indemnification agreements withour directors, officers, employees and agents and to obtain insurance to indemnify such persons. •We may not retroactively amend our amended and restated bylaw provisions to reduce our indemnification obligations to directors, officers,employees and agents.We do not currently intend to pay dividends on our common stock, and, consequently, your ability to achieve a return on your investment willdepend on appreciation in the price of our common stock.We do not currently intend to pay any cash dividends on our common stock for the foreseeable future. We currently intend to invest our futureearnings, if any, to fund our growth. Therefore, you are not likely to receive any dividends on your common stock for the foreseeable future. Since we do notintend to pay dividends, your ability to receive a return on your investment will depend on any future appreciation in the market value of our common stock.There is no guarantee that our common stock will appreciate or even maintain the price at which our holders have purchased it.81 Item 1B. Unresolved Staff Comments.None.Item 2. Properties..Our corporate headquarters are located in Brisbane, California, where we currently lease approximately 39,000 square feet of office and laboratory spacepursuant to a lease dated May 13, 2016. Although this facility is sufficient for our current needs, we will require additional space by the end of 2019 toaccommodate our anticipated growth. Therefore, on February 28, 2019, we entered into a lease for a new facility which we anticipate will be ready foroccupancy during the fourth quarter of 2019. The new facility is located in South San Francisco, California, and is comprised of approximately 62,00 squarefeet of office and laboratory space. The new lease has a term of 10 years from the lease commence date. Substantially all our employees work at our currentfacility and will also work at the new facility..Item 3. Legal Proceedings.We are not currently a party to any material litigation or other material legal proceedings.Item 4. Mine Safety Disclosures.Not applicable.82 PART IIItem 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.Market Information for Common StockOur common stock has been listed on The Nasdaq Global Select Market under the symbol “UBX” since May 3, 2018. As of March 1, 2019, therewere 98 holders of record of our common stock. Because many of our shares of common stock are held by brokers and other institutions on behalf ofstockholders, we are unable to estimate the total number of beneficial owners of our common stock represented by these record holders.Dividend PolicyWe have never declared or paid any cash dividends on our common stock or any other securities. We anticipate that we will retain all availablefunds and any future earnings, if any, for use in the operation of our business and do not anticipate paying cash dividends in the foreseeable future. Inaddition, future debt instruments may materially restrict our ability to pay dividends on our common stock. Payment of future cash dividends, if any, will beat the discretion of the board of directors after taking into account various factors, including our financial condition, operating results, current andanticipated cash needs, the requirements of current or then-existing debt instruments and other factors the board of directors deems relevant.Performance GraphThis graph is not “soliciting material” or deemed “filed” with the SEC for purposes of Section 18 of the Exchange Act, or otherwise subject toliabilities under that Section, and shall not be deemed incorporated by reference into any filing of Unity Biotechnology, Inc. under the Securities Act of1933, as amended (the “Securities Act”), whether made before or after the date hereof and irrespective of any general incorporation language in any suchfiling.The following graph compares the cumulative total return on our common stock relative to the cumulative total returns of the Nasdaq CompositeIndex and the Nasdaq Biotechnology Index. Pursuant to applicable Securities and Exchange Commission rules, all values assume reinvestment of the fullamount of all dividends, however no dividends have been declared on our common stock to date. The stockholder returns shown on the graph below are83 based on historical results and are not necessarily indicative of future performance, and we do not make or endorse any predictions as to future stockholderreturns. Sales of Unregistered SecuritiesFrom January 1, 2018 through December 31, 2018, we sold and issued the following unregistered securities, which share numbers have beenadjusted, as appropriate, for the 1-for-2.95 reverse stock split that occurred on April 20, 2018: 1.Prior to filing our registration statement on Form S-8 in May 2018, we granted stock options and stock awards to employees, directors andconsultants under our 2013 Stock Incentive Plan, as amended, covering an aggregate of 6,640,219 shares of common stock, at a weighted-averageaverage exercise price of $2.60 per share. Of these, options covering an aggregate of 155,519 shares were cancelled without being exercised and143,181 unvested shares were repurchased concurrent with employee terminations. 2.Prior to filing our registration statement on Form S-8 in May 2018, we sold an aggregate of 2,161,731 shares of common stock to employees,directors and consultants for cash consideration in the aggregate amount of $0.1 million upon the exercise of stock options. 3.In March and April 2018, we authorized 11,554,669 and issued 3,913,425 shares of Series C convertible preferred stock, $0.0001 par value,original issue price of $15.3317 per share, for cash proceeds of approximately $59.9 million. 4.In May 2018, upon the closing of our IPO, all 32,073,149 shares of our then-outstanding convertible preferred stock automatically converted into32,073,149 shares of common stock.Use of Proceeds from our Initial Public Offering of Common StockOn May 2, 2018, the U.S. Securities and Exchange Commission declared effective our registration statement on Form S-1 (File No. 333-224163), asamended, filed in connection with our initial public offering (IPO). There has been no material change in the planned use of proceeds from our IPO from thatdescribed in the related prospectus dated May 2, 2018, filed with the SEC pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended.84 Repurchase of Shares or of Company Equity SecuritiesNone.Item 6. Selected Financial Data.You should read the following selected historical financial data below together with “Management’s Discussion and Analysis of FinancialCondition and Results of Operations” and our audited financial statements, related notes and other financial information included elsewhere in this report.The selected financial data in this section are not intended to replace the financial statements and are qualified in their entirety by the audited financialstatements and related notes included elsewhere in this report.We derived our selected statements of operations data for the years ended December 31, 2018, 2017 and 2016 and the balance sheet data as ofDecember 31, 2018, 2017 and 2016 from our audited financial statements included elsewhere in this report. Our historical results are not necessarilyindicative of the results that may be expected in any future period. The selected financial data below should be read in conjunction with the section entitled“Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our financial statements and related notes includedelsewhere in this report. Year Ended December 31, 2018 2017 2016 (in thousands, except share and per share data) Statement of Operations Data: Contribution revenue $— $1,382 $— Operating expenses: Research and development 58,907 37,373 13,707 General and administrative 16,016 9,617 5,137 Fair value of contingent consideration 4,542 — — Total operating expenses 79,465 46,990 18,844 Loss from operations (79,465) (45,608) (18,844)Loss on extinguishment of promissory notes — — (9,377)Interest income (expense), net 3,312 1,055 (2,183)Other expense, net (245) (103) — Net loss $(76,398) $(44,656) $(30,404)Net loss per share, basic and diluted(1) $(2.70) $(13.97) $(11.42)Weighted average number of shares used in computing net loss per share, basic and diluted(1) 28,269,907 3,197,516 2,662,841 (1)See Note12 to our audited financial statements for an explanation of the calculations of our basic and diluted net loss per common share and theweighted-average number of common shares used in the computation of the per share amounts. As of December 31, 2018 2017 2016 (in thousands) Balance Sheet Data: Cash and cash equivalents $15,399 $7,298 $89,286 Marketable securities 155,736 84,330 — Working capital 156,383 80,983 89,718 Total assets 181,375 102,024 96,648 Convertible preferred stock — 173,956 131,089 Accumulated deficit (163,278) (86,880) (42,224)Total stockholders’ equity (deficit) 160,693 (83,113) (41,536) 85 Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.You should read the following discussion and analysis of our financial condition and results of operations together with the section entitled“Selected Financial Data” and our audited financial statements and related notes included elsewhere in this report. This discussion and other parts of thisreport contain forward-looking statements that involve risks and uncertainties, such as our plans, objectives, expectations, intentions and beliefs. Ouractual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differencesinclude, but are not limited to, those identified below and those discussed in the section entitled “Risk Factors” included elsewhere in this report.OverviewWe are a biotechnology company engaged in researching and developing therapeutics to extend healthspan by slowing, halting or reversing age-related diseases. Our initial focus is on creating senolytic medicines to selectively eliminate senescent cells and thereby treat age-related diseases, such asmusculoskeletal, opthalmologic and pulmonary diseases. Since the commencement of our operations, we have invested a significant portion of our efforts and financial resources in research anddevelopment activities, and we have incurred net losses each year since inception. Our net losses were $76.4 million and $44.7 million for the years endedDecember 31, 2018 and 2017, respectively. We do not have any products approved for sale, and we have never generated any revenue from contracts withcustomers. As of December 31, 2018, we had an accumulated deficit of $163.3 million, and we do not expect positive cash flows from operations in theforeseeable future. We expect to continue to incur net operating losses for at least the next several years as we continue our research and development efforts,advance our drug candidates through preclinical and clinical development, seek regulatory approval, prepare for and, if approved, proceed tocommercialization. Prior to our initial public offering, or IPO, we had funded our operations primarily from the issuance and sale of convertible preferred stock andconvertible promissory notes. In May 2018, we completed our IPO pursuant to which we issued 5,000,000 shares of our common stock at a price of $17.00per share. We received proceeds of approximately $75.9 million, after deducting underwriting discounts, commissions, and offering-related transaction costsfrom the IPO.We do not expect to generate revenue from any drug candidates that we develop until we obtain regulatory approval for one or more of such drugcandidates and commercialize our products or enter into collaborative agreements with third parties. Substantially all of our net losses have resulted fromcosts incurred in connection with our research and development programs and from general and administrative costs associated with our operations. As aresult, we will need to raise additional capital. If sufficient funds on acceptable terms are not available when needed, we could be required to significantlyreduce our operating expenses and delay, reduce the scope of, or eliminate one or more of our development programs.We rely on third parties in the conduct of our preclinical studies and clinical trials and for manufacturing and supply of our drug candidates. Wehave no internal manufacturing capabilities, and we will continue to rely on third parties, many of whom are single-source suppliers, for our preclinical andclinical trial materials, as well as the commercial supply of our products. In addition, we do not yet have a marketing or sales organization or commercialinfrastructure. Accordingly, we will incur significant expenses to develop a marketing and sales organization and commercial infrastructure in advance ofgenerating any product sales.86 Components of Our Results of OperationsResearch and Development ExpensesResearch and development expenses consist primarily of costs incurred for the development of our drug candidates, which include: •personnel-related expenses, including salaries, benefits and stock-based compensation for personnel contributing to research anddevelopment activities; •laboratory expenses including supplies and services; •expenses incurred under agreements with third-party contract manufacturing organizations, contract research organizations, research anddevelopment service providers, academic research institutions, and consultants; •expenses related to license and sponsored research agreements; •clinical trial expenses; and •facilities and other allocated expenses, including expenses for rent and facilities maintenance, and depreciation and amortization.We expect our research and development expenses to increase as we advance our drug candidates into and through preclinical and clinical trialsand pursue regulatory approval of our drug candidates. The process of conducting the clinical trials required to obtain regulatory approval is costly and time-consuming. Clinical trials generally become larger and costlier to conduct as they advance into later stages and we are required to make estimates for expenseaccruals related to clinical trial expenses. The actual probability of success for our drug candidates may be affected by a variety of factors including: thesafety and efficacy of our drug candidates, early clinical data, investment in our clinical program, the ability of collaborators, if any, to successfully developany drug candidates we license to them, competition, manufacturing capability and commercial viability. We may never succeed in achieving regulatoryapproval for any of our drug candidates. Program costs that are direct external expenses are tracked on a program-by-program basis once they enter clinicalstudies. Due to the early-stage nature of our lead programs, the costs of our programs are not material. As a result of the uncertainties discussed above, we areunable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue fromthe commercialization and sale of our drug candidates.General and Administrative ExpensesOur general and administrative expenses consist primarily of personnel costs, allocated facilities costs and other expenses for outside professionalservices, including legal, audit and accounting services, and depreciation and amortization expense related to property and equipment. Personnel costsconsist of salaries, benefits, insurance and stock-based compensation. We expect to continue to incur additional expenses associated with operating as apublic company, including expenses related to compliance with the rules and regulations of the Securities and Exchange Commission and standardsapplicable to companies listed on a national securities exchange, additional insurance expenses, investor relations activities and other administrative andprofessional services. We also expect to increase the size of our administrative headcount to support the growth of our business and operate as a publiccompany. Fair Value of Contingent ConsiderationOur license agreements include contingent consideration in the form of the obligation to issue additional shares of our common stock based if weachieve certain milestones. To determine whether such contingent consideration constitutes an asset acquisition, we assess whether it meets the definition ofa derivative and/or whether it can be classified within stockholders’ equity, until such time that equity classification criteria are met or the milestones expire.As of December 31, 2018, we have recorded a liability related to contingent consideration because the net settlement criteria required for the contingentconsideration to be defined as a derivative had been met whereas the equity classification criteria had not been met. The derivative related to this contingentconsideration is measured at fair value as of each balance sheet date with the related change in fair value being reflected in operating expenses. Thecontingent consideration expense is driven by the change in the estimated fair value of the liability, which is87 determined using a probability-weighted valuation approach model that reflects the probability and timing of future issuances common shares. Interest IncomeInterest income is primarily related to interest earned on our marketable securities for the years ended December 31, 2018, 2017 and 2016. Results of OperationsComparison of the Years Ended December 31, 2018 and 2017The following table sets forth the significant components of our results of operations (in thousands): Year Ended December 31, 2018 2017 Increase/(Decrease) Summary of Operations Data: Contribution revenue $— $1,382 $(1,382)Operating expenses: Research and development 58,907 37,373 21,534 General and administrative 16,016 9,617 6,399 Change in fair value of contingent consideration 4,542 — 4,542 Total operating expenses 79,465 46,990 32,475 Loss from operations (79,465) (45,608) (33,857)Interest income 3,312 1,055 2,257 Other expense, net (245) (103) (142)Net loss $(76,398) $(44,656) $(31,742) Contribution RevenueContribution revenue for the year ended December 31, 2017 was related to funding we recognized from a third-party organization in 2017 for theperformance of certain research and development activities in pursuit of that organization’s philanthropic mission. We did not engage in similar activities in2018, therefore we did not recognize any contribution revenue for the year ended December 31, 2018.Research and DevelopmentResearch and development expenses increased by $21.5 million, to $58.9 million for the year ended December 31, 2018 from $37.4 million forthe year ended December 31, 2017. The increase was primarily due to increases of $11.3 million for personnel-related expenses, of which $4.3 million wasrelated to non-cash stock-based compensation, $7.8 million for direct research and development activities and $2.4 million for facilities-related costs.General and AdministrativeGeneral and administrative expenses increased by $6.4 million, to $16.0 million for the year ended December 31, 2018 from $9.6 million for theyear ended December 31, 2017. The increase was primarily due to increases of $4.8 million for personnel related expenses, of which $2.1 million was relatedto non-cash stock-based compensation, $1.9 million in professional services expenses primarily related to activities in preparation of becoming a publiccompany, $0.5 million in insurance expense and $0.5 million for facilities-related costs. The increases were partially offset by a $1.3 million in unconditionalfunding provided to academic institutions.88 Change in fair value of contingent considerationExpenses related to the change in fair value of contingent consideration was $4.5 million for the year ended December 31, 2018. The contingentconsideration expense was due to a change in the estimated fair value of the liability under our license agreements as the probability of milestone eventsrequiring settlement through the issuance of shares of our common stock increase. The fair value is determined using a probability-weighted valuationapproach model which considers our stock price and the probability and timing of the achievement of certain milestones at the balance sheet date. Interest IncomeOur interest income was $3.3 million for the year ended December 31, 2018, as compared to $1.1 million for the year ended December 31, 2017,as we invested our cash and proceeds from our Series C financing and IPO in marketable securities.Comparison of the years ended December 31, 2017 and 2016The following table sets forth the significant components of our results of operations: Year Ended December 31, 2017 2016 Increase/(Decrease) (in thousands) Summary of Operations Data: Contribution revenue $1,382 $— $1,382 Operating expenses: Research and development 37,373 13,707 23,666 General and administrative 9,617 5,137 4,480 Total operating expenses 46,990 18,844 28,146 Loss from operations (45,608) (18,844) (26,764)Loss on extinguishment of promissory notes — (9,377) 9,377 Interest income (expense), net 1,055 (2,183) 3,238 Other expense, net (103) — (103)Net loss $(44,656) $(30,404) $(14,252) Contribution RevenueContribution revenue for the year ended December 31, 2017 was related to funding we recognized from a third-party organization in 2017 for theperformance of certain research and development activities in pursuit of that organization’s philanthropic mission.Research and DevelopmentResearch and development expenses increased by $23.7 million from $13.7 million for the year ended December 31, 2016 to $37.4 million forthe year ended December 31, 2017. The increase was primarily due to an increase of $10.4 million for direct research and development costs related toconsultants, third-party contract research organizations, and preclinical studies as we expanded and continued to progress our development programs.Additionally, we had a $8.6 million increase in personnel-related expenses, of which $1.5 million related to stock-based compensation due to an increase inour headcount, an increase of $1.9 million in lab supplies as we expanded our lab space, $1.0 million in facility-related costs, and a $1.0 million increase indepreciation and amortization primarily related to leasehold improvements associated with our new space.89 General and AdministrativeGeneral and administrative expenses increased by $4.5 million from $5.1 million for the year ended December 31, 2016 to $9.6 million for theyear ended December 31, 2017. The increase was primarily due to an increase in personnel-related expenses of $2.9 million, of which $1.3 million related tostock-based compensation, as a result of an increase in our headcount and an increase of $1.3 million related to unconditional funding provided to academicinstitutions in 2017.Loss on Extinguishment of Promissory NotesWe recognized a loss on extinguishment of promissory notes issued in July, September, and October 2016 of $9.4 million upon the settlement ofsuch notes in 2016 for shares of Series B convertible preferred stock.Interest Income (Expense), netOur interest income was $1.1 million for the year ended December 31, 2017 as we invested our cash in marketable securities.We recognized interest expense of $2.2 million for the year ended December 31, 2016 primarily related to the discount created from a contingentbeneficial conversion on the February, April, and May 2016 promissory notes which was recognized upon the conversion of such notes in 2016 into shares ofSeries B preferred stock.Liquidity, Capital Resources and Capital RequirementsSources of LiquidityWe have incurred net losses each year since inception. We do not have any products approved for sale and have never generated any revenuefrom product sales. Historically, we have incurred operating losses as a result of ongoing efforts to develop our drug candidates, including conductingongoing research and development, preclinical studies and providing general and administrative support for these operations. As of December 31, 2018, wehad an accumulated deficit of $163.3 million, and we do not expect positive cash flows from operations in the foreseeable future. We expect our operatinglosses and net cash used in operating activities will increase over at least the next several years as we continue our research and development activities,advance our drug candidates through preclinical and clinical testing and move into later and more costly stages of drug development, hire personnel andprepare for regulatory submissions and the commercialization of our drug candidates.We have historically financed our operations primarily through issuance and sale of common stock, convertible preferred stock and convertiblepromissory notes and will continue to be dependent upon equity and/or debt financing until we are able to generate positive cash flows from our operations.In March 2018, we sold 3,590,573 shares of Series C convertible preferred stock at $15.3317 per share for proceeds of $54.9 million. In April 2018, we sold322,852 shares of Series C convertible preferred stock at $15.3317 per share for additional proceeds of $5.0 million. In May 2018, we completed our IPO andreceived net proceeds of $75.9 million, after deducting underwriting discounts, commissions and offering expenses payable by us. As of December 31, 2018,we had $171.1 million in cash, cash equivalents and marketable securities.Future Funding RequirementsTo date we have not generated any revenue for contracts with customers and have only received a contribution from a third-party organization forcertain research and development activities to support their philanthropic mission. We expect to continue to incur significant losses for the foreseeablefuture, and we expect the losses to increase as we continue the development of, and seek regulatory approvals for, our drug candidates, and begin tocommercialize any approved products. We are subject to all of the risks typically related to the development of new drug candidates, and we may encounterunforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. Moreover, following thecompletion of our IPO, we have incurred additional ongoing costs associated with operating as a public company. We anticipate that we will need substantialadditional funding in connection with our continuing operations.90 Until we can generate a sufficient amount of revenue from the commercialization of our drug candidates or from collaborative agreements withthird parties, if ever, we expect to finance our future cash needs through public or private equity or debt financings. Additional capital may be raised throughthe sale of our equity securities, incurring debt, entering into licensing, collaboration agreements with partners, receiving research contributions, grants orother sources of financing to fund our operations. There can be no assurance that sufficient funds will be available to us on attractive terms or at all. If we areunable to obtain additional funding from these or other sources, it may be necessary to significantly reduce our rate of spending through reductions in staffand delaying, scaling back, or stopping certain research and development programs. Insufficient liquidity may also require us to relinquish rights to drugcandidates at an earlier stage of development or on less favorable terms than we would otherwise choose.Since our inception, we have incurred significant losses and negative cash flows from operations. We have an accumulated deficit of $163.3million through December 31, 2018. We expect to incur substantial additional losses in the future as we conduct and expand our research and developmentactivities. We believe that our existing cash, cash equivalents and marketable securities will be sufficient to enable us to fund our projected operationsthrough at least the next 12 months. Based on our current operating plans, we expect our existing capital resources will fund our planned operating expensesinto 2021, including through clinical data readout from our Phase 1 clinical study of UBX0101 and data readouts from additional Phase 1 clinical studies ofour lead program for ophthalmologic diseases.We have based our projections of operating capital requirements on assumptions that may prove to be incorrect and we may use all our availablecapital resources sooner than we expect. Because of the numerous risks and uncertainties associated with research, development and commercialization ofbiotechnology products, we are unable to estimate the exact amount of our operating capital requirements. Our future funding requirements will depend onmany factors, including, but not limited to: •the scope, progress, results and costs of researching and developing UBX0101, UBX1967 or any other drug candidates, and conductingpreclinical studies and clinical trials, including our ongoing Phase 1 clinical study of UBX0101, which was initiated in the second quarterof 2018; •the timing of, and the costs involved in, obtaining regulatory approvals for our lead drug candidates or any future drug candidates; •the number and characteristics of any additional drug candidates we develop or acquire; •the timing and amount of any milestone payments we are required to make pursuant to our license agreements; •the cost of manufacturing our lead drug candidates or any future drug candidates and any products we successfully commercialize; •the cost of building a sales force in anticipation of product commercialization; •the cost of commercialization activities if our lead drug candidates or any future drug candidates are approved for sale, including marketing,sales and distribution costs; •our ability to establish and maintain strategic collaborations, licensing or other arrangements and the financial terms of any suchagreements, including the timing and amount of any future milestone, royalty or other payments due under any such agreement; •any product liability or other lawsuits related to our products; •the expenses needed to attract, hire and retain skilled personnel; •the costs associated with being a public company; •the costs involved in preparing, filing, prosecuting, maintaining, defending and enforcing our intellectual property portfolio; and •the timing, receipt and amount of sales of any future approved or cleared products, if any.91 Cash FlowsThe following table sets forth a summary of the primary sources and uses of cash and restricted cash for each of the periods presented below (inthousands): Year Ended December 31, 2018 2017 2016 Cash used in operating activities $(56,623) $(38,358) $(16,398)Cash used in investing activities (72,206) (86,305) (2,744)Cash provided by financing activities 136,930 42,775 107,938 Net increase (decrease) in cash and restricted cash $8,101 $(81,888) $88,796 Operating ActivitiesCash used in operating activities of $56.6 million for the year ended December 31, 2018 consisted primarily of a net loss of $76.4 millionadjusted for net non-cash charges of $14.6 million and net changes to our operating assets and liabilities of $5.1 million. Our non-cash charges consistedprimarily of $9.4 million in stock-based compensation, $4.5 million change in fair value of contingent consideration and $2.2 million in depreciation andamortization, partially offset by a $1.0 million in amortization of premium and discounts on marketable securities and $0.6 million in accretion of our tenantimprovement allowance. The net change in our operating assets and liabilities consisted of a decrease of $1.4 million in contribution receivable, andincreases of $2.2 million in accounts payable, $1.6 million in accrued compensation and $1.4 million in accrued liabilities and other current liabilities,partially offset by a decrease of $0.6 million in other long-term assets and $0.8 million in prepaid expenses and other current assets.Cash used in operating activities of $38.4 million for the year ended December 31, 2017 consisted primarily of a net loss of $44.7 million, whichwas partially offset by non-cash charges of $4.0 million and a decrease in our net operating assets of $2.3 million. Our non-cash charges primary consisted of$1.3 million for depreciation and amortization expense and $3.0 million for stock-based compensation expense. The decrease in our net operating assets of$2.3 million was primarily due to an increase in accrued compensation of $1.6 million related to our bonus accrual and increases in accounts payable of$1.2 million and accrued and other current liabilities of $1.3 million as we expand our operations, partially offset by an increase in our contributionreceivable of $1.4 million.Cash used in operating activities of $16.4 million for the year ended December 31, 2016 consisted primarily of a net loss of $30.4 million, whichwas partially offset by non-cash charges of $12.0 million and a decrease in our net operating assets of $2.0 million. Our non-cash charges primarily consistedof $9.4 million for loss on extinguishment of our July, September, and October 2016 promissory notes and $2.2 million for interest expense related to ourFebruary, April and May 2016 promissory notes. The decrease in our net operating assets was due primarily to an increase in accrued and other currentliabilities of $1.0 million primarily related to deferred rent for our facility lease entered into in 2016 and an increase in our accrued compensation of$0.5 million.Investing ActivitiesCash used in investing activities of $72.2 million for the year ended December 31, 2018 was related to purchases of marketable securities of$204.1 million, purchases of property and equipment of $1.2 million and the purchase of an investment in stock of $0.5 million, which were offset bymaturities of marketable securities of $133.6 million.Cash used in investing activities of $86.3 million for the year ended December 31, 2017 was related to purchases of marketable securities of$134.5 million and purchases of property and equipment of $1.7 million, which were partially offset by maturities of marketable securities of $49.8 million.Cash used in investing activities of $2.7 million for the year ended December 31, 2016 was related to the purchases of property and equipment of$2.2 million and the purchase of an investment in stock of $0.5 million.92 Financing ActivitiesCash provided by financing activities of $136.9 million for the year ended December 31, 2018 was primarily related to net proceeds from our saleof common stock in our IPO of $75.9 million, net proceeds from issuance of Series C convertible preferred stock of $59.9 million, proceeds from repayment ofrecourse notes of $0.9 million, and proceeds from issuance of common stock upon exercise of stock options of $0.4 million.Cash provided by financing activities of $42.8 million for the year ended December 31, 2017 was primarily related to net proceeds from theissuance of shares of our convertible preferred stock.Cash provided by financing activities of $107.9 million for the year ended December 31, 2016 was primarily related to net proceeds of $91.0million from the issuance of shares of our convertible preferred stock and proceeds of $16.9 million from the issuance of convertible promissory notes whichhave since been converted into or settled with shares of convertible preferred stock.Contractual Obligations and Other CommitmentsThe following table summarizes our contractual obligations as of December 31, 2018: Payments due by period Less than1 year 1 to 3years 3 to 5 years More than5 years Total (in thousands) Contractual obligations: Operating lease(1) $2,012 $4,207 $1,621 $— $7,840 Capital lease 78 46 — — 124 Total contractual obligations $2,090 $4,253 $1,621 $— $7,964 (1)Our contractual obligations and commitments primarily relate to our facilities lease agreement. We have a lease for laboratory and office space inBrisbane, California. The current lease is for approximately 39,000 square feet and the lease period expires in October 2022.We are party to various license agreements pursuant to which we have in-licensed rights to various technologies, including patents, research“know-how” and proprietary research tools, for the discovery, research, development and commercialization of drug products to treat age-related diseases.The license agreements obligate us to make certain milestone payments related to specified clinical development and sales milestone events, as well as tieredroyalties in the low-single digits based on sales of licensed products. This table does not include any milestone payments or royalty payments to third partiesas the amounts, timing and likelihood of such payments are not known. See Note 5 to our financial statements “License Agreements” for additionalinformation.In February 2019, we entered into a lease agreement for approximately 62,655 rentable square feet of office and laboratory space in South SanFrancisco, California. The term of the lease agreement will commence on the later of: (i) the earlier to occur of (a) October 1, 2019, and (b) the date uponwhich we begin conducting business on the premises, and (ii) the date the landlord’s construction and tenant improvements have been completed. The leasehas an initial term of ten years from the commencement date, and we have an option to extend the initial term for an additional eight years at the then fairrental value as determined pursuant to the lease agreement. The total base rent for the first twelve months will be $5.25 per rental square foot and willescalate by approximately 3.5% annually beginning from the 13th month of the lease agreement. We will also be responsible for the operating expenses andtax expenses allocated to the building, and the operating expenses and tax expenses attributable to the common areas. The landlord will provide us with atenant improvement allowance of up to a maximum amount of approximately $7.8 million, and we have the right to use up to approximately $2.8 million asan additional tenant improvement allowance that must be paid back as described in the lease agreement. In connection with the execution of the leaseagreement, we delivered a letter of credit of approximately $0.9 million to the landlord.Off-Balance Sheet ArrangementsWe have not entered into any off-balance sheet arrangements. While we have an investment in a variable interest entity, its purpose is not toprovide off-balance sheet financing.93 Critical Accounting Polices and EstimatesThis discussion and analysis of our financial condition and results of operations is based on our financial statements, which have been preparedin accordance with GAAP. The preparation of these financial statements requires us to make estimates and assumptions that affect the reported amounts ofassets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported expenses incurredduring the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under thecircumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent fromother sources. Actual results may differ from these estimates under different assumptions or conditions. While our significant accounting policies aredescribed in more detail in the notes to our financial statements included elsewhere in this prospectus, we believe that the following accounting policies arecritical to understanding our historical and future performance, as these policies relate to the more significant areas involving management’s judgments andestimates.Research and Development ExpensesCosts related to research and development of drug candidates are charged to research and development expense as incurred. Research anddevelopment costs include, but are not limited to, payroll and personnel expenses for personnel contributing to research and development activities,laboratory supplies, outside services, licenses acquired to be used in research and development and allocated overhead, including rent, equipment,depreciation and utilities. Payments made prior to the receipt of goods or services to be used in research and development are deferred and recognized asexpense in the period in which the related goods are received or services are rendered. Such payments are evaluated for current or long-term classificationbased on when they will be realized.We have and may continue to enter into license agreements to access and utilize certain technology. We evaluate if the license agreement is anacquisition of an asset or a business. To date none of our license agreements have been considered to be an acquisition of a business. For asset acquisitions,the upfront payments to acquire such licenses, as well as any future milestone payments made before product approval, are immediately recognized asresearch and development expense when due, provided there is no alternative future use of the rights in other research and development projects. Theselicense agreements may also include contingent consideration in the form of cash and additional issuances of our common stock.Contingent Consideration LiabilityWe have entered into license agreements to access and utilize certain intellectual property and technology and may enter into additional licenseagreements in the future. In each case, we evaluate if the license agreement results in the acquisition of an asset or a business. To date, none of our licenseagreements have been considered an acquisition of a business. If a license agreement is deemed to constitute an asset acquisition, the upfront payments toacquire such licenses, as well as any future milestone payments made before product approval, are immediately recognized as research and developmentexpense when due, provided there is no alternative future use of the rights in other research and development projects. Several of our license agreements alsoinclude contingent consideration in the form of an obligation to issue additional shares of our common stock if we achieve certain milestones. To determinewhether such contingent consideration constitutes anasset acquisition, we assess on a continuous basis whether the contingent consideration meets thedefinition of a derivative and/or whether it can be classified within stockholders’ equity, until such time that equity classification criteria are met or themilestones expireThe derivative related to the contingent consideration arising from our license agreements is measured at fair value as of each balance sheetdate with the related change in fair value being reflected in operating expenses. Upon a reassessment event that results in the contingent consideration nolonger meeting the definition of a derivative and/or meeting equity classification critera, the final change in fair value of the insutrment is recorded withinoperating expenses and the liability is reclassified into stockholders’ equity.We value the contingent consideration liability using a probability-weighted valuation approach model that reflects the probability and timingof achieving the milestones which trigger the obligation to issue additional shares of common stock. The probability of achieving the defined milestones foreach licensed product is estimated on a quarterly basis by our management team. The total contingent consideration may change significantly over time aspreclinical and/or clinical development progresses and additional data is obtained, impacting our assumptions regarding the probability of successfullyachieving the relevant milestones and the time frame in which they are94 expected to be achieved. For example, significant increases in the estimated probability of achieving a milestone would result in a significantly higher fairvalue measurement, while significant decreases in the estimated probability of achieving a milestone would result in a significantly lower fair valuemeasurement. Judgment is employed in determining these assumptions at each subsequent period. Updates to assumptions could have a significant impacton our results of operations in any given period. Actual results may differ from estimates.We believe the fair values used to record contingent consideration liability are based upon reasonable estimates and assumptions given the factsand circumstances as of the related valuation dates.Variable Interest EntitiesAt the inception of each arrangement that we enter into with a third party entity, and at each reporting date thereafter, we assess whether we arethe primary beneficiary of that arrangement such that it constitutes a variable interest entity, or VIE. This assessment is based on our power to direct theactivities of the third party that most significantly impact the third party’s economic performance and our obligation to absorb losses or the right to receivebenefits from the third party that could potentially be significant to it.Stock-Based CompensationWe recognize compensation costs related to stock options granted to employees and nonemployees based on the estimated fair value of theawards on the date of grant, and we recognize forfeitures as they occur. For awards that vest solely based on service conditions or a combination of serviceand performance conditions, we estimate the grant date fair value, and the resulting stock-based compensation expense, using the Black-Scholes option-pricing model. The grant date fair value of the awards is generally recognized on a straight-line basis over the requisite service period, which is typically theirvesting period. Forfeitures are recognized as they occur.Prior to our IPO, the fair value of our shares of common stock underlying the stock options was the responsibility of and determined by ourBoard. Because there was no public market for our common stock, the Board determined the fair value of common stock at the time of grant of the option byconsidering a number of objective and subjective factors, including, among others: the prices at which we sold shares of our convertible preferred stock tooutside investors in arms-length transactions; the rights, preferences and privileges of our convertible preferred stock relative to those of our common stock;our results of operations, financial position and capital resources; current business conditions and projections; the lack of marketability of our commonstock; the hiring of key personnel and the experience of management; progress of our research and development activities; our stage of development andmaterial risks related to its business; the fact that the option grants involve illiquid securities in a private company; and the likelihood of achieving aliquidity event, such as an initial public offering or sale, in light of prevailing market conditions.Following the IPO, the market traded price of the shares of common stock underlying the stock options is the fair value of our stock as reportedon The Nasdaq Global Select Market on the grant date.The Black-Scholes option-pricing model requires the use of highly subjective assumptions to determine the fair value of stock-based awards.These assumptions include: •Expected term—The expected term represents the period that the stock-based awards are expected to be outstanding. We use, due toinsufficient historical data, the simplified method to determine the expected term, which is based on the average of the time-to-vesting andthe contractual life of the options. •Expected volatility—Due to our limited trading history for our common stock, the expected volatility is estimated based on the averagehistorical volatilities of common stock of comparable publicly traded entities over a period equal to the expected term of the stock optiongrants. The comparable companies are chosen based on their size, stage in the product development cycle or area of specialty. We willcontinue to apply this process until a sufficient amount of historical information regarding the volatility of our own stock price becomesavailable.95 •Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S.Treasury notes with maturities approximately equal to the expected term of the awards. •Expected dividend—We have never paid dividends on our common stock and have no plans to pay dividends on our common stock.Therefore, we used an expected dividend yield of zero.For options granted to non-employee consultants, the fair value of these options is also remeasured using the Black-Scholes option-pricingmodel reflecting consistent assumptions as applied to employee options in each of the reported periods, other than the expected term, which is assumed to bethe remaining contractual life of the option.We have also granted stock options to certain key employees that vest in conjunction with certain performance and market conditions. Weestimate the fair value of these awards using a lattice model, taking into consideration the market conditions. No expense will be recorded related to theseawards until the achievement of the performance condition becomes probable. Once the achievement of the performance condition becomes probable,expense related to these awards is recognized using the accelerated attribution method with a cumulative catch-up adjustment over the derived service periodrelating to the market conditions, if the market conditions have not been met. As these awards vest in their entirety upon achievement of the marketconditions, any unrecognized expense would be accelerated if the market conditions are achieved prior to the completion of the derived service period.We will continue to use judgment in evaluating the expected volatility, expected terms and forfeiture rates utilized for our stock-basedcompensation expense calculations on a prospective basis. In addition to the Black-Scholes assumptions, we estimate our forfeiture rate based on an analysisof our actual forfeitures and we will continue to evaluate the adequacy of the forfeiture rate based on actual forfeiture experience, analysis of employeeturnover behavior and other factors. The impact from any forfeiture rate adjustment would be recognized in full in the period of adjustment, and if the actualnumber of future forfeitures differs from our estimates, we might be required to record adjustments to stock-based compensation in future periods.As of December 31, 2018, we had $20.6 million of unrecognized compensation expense related to unvested stock options, which is expected tobe recognized over an estimated weighted-average period of 4.1 years. For stock option awards subject to ratable vesting, we recognize compensation cost ona straight-line basis over the service period for the entire award. In future periods, our stock-based compensation expense is expected to increase as a result ofrecognizing our existing unrecognized stock-based compensation for awards that will vest and as we issue additional stock-based awards to attract and retainour employees.Income TaxesWe use the asset and liability method of accounting for income taxes, in which deferred tax assets and liabilities are recognized for future taxconsequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities, their respective tax bases, netoperating loss carryforwards, and credit carryforwards. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxableincome in the years in which those temporary differences are expected to be reversed. Current income tax expense or benefit represents the amount of incometaxes expected to be payable or refundable for the current year. The effect on deferred tax assets and liabilities of a change in tax rates is recognized asincome in the period that includes the enactment date. We record a valuation allowance to reduce our deferred tax assets to reflect the net amount that webelieve is more likely than not to be realized. Realization of our deferred tax assets is dependent on the generation of future taxable income, the amount andtiming of which are uncertain. The valuation allowance requires an assessment of both positive and negative evidence when determining whether it is morelikely than not that deferred tax assets are recoverable. Based upon the weight of available evidence at December 31, 2018, we continue to maintain a fullvaluation allowance against all of our deferred tax assets after management considered all available evidence both positive and negative, including but notlimited to our historical operating results, income or loss in recent periods, cumulative income in recent years, forecasted earnings, future taxable income, andsignificant risk and uncertainty related to forecasts..We recognize the tax effects of an uncertain tax position only if it is more likely than not to be sustained based solely on its technical merits as ofthe reporting date and only in an amount more likely than not to be sustained upon review by the tax authorities. We recognize interest accrued and penaltiesrelated to unrecognized tax benefits in our tax96 provision. We evaluate uncertain tax positions on a quarterly basis. The evaluations are based on a number of factors, including changes in facts andcircumstances, changes in tax law, correspondence with tax authorities during the course of the audit, and effective settlement of audit issues. To the extentthat the final tax outcome of these matters is different than the amounts recorded, such differences will impact the income tax provision in the period in whichsuch determination is made. The resolution of our uncertain income tax positions is dependent on uncontrollable factors such as law changes, new case law,and the willingness of the income tax authorities to settle, including the timing thereof and other factors. Although we do not anticipate significant changesto our uncertain income tax positions in the next twelve months, items outside of our control could cause our uncertain income tax positions to change in thefuture, which would be recorded in our statements of operations. Our provision for income taxes includes the effects of any accruals that we believe areappropriate, as well as the related net interest and penalties.On December 22, 2017, the Tax Cuts and Jobs Act (“Tax Act”) was signed into law. The Tax Act lowered the Federal corporate tax rate from 35%to 21% and made numerous other tax law changes. The Company has measured deferred tax assets at the enacted tax rate expected to apply when thesetemporary differences are expected to be realized or settled. U.S. GAAP requires companies to recognize the effect of tax law changes in the period ofenactment.As a result of the impact of the Tax Act, in December 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (SAB 118), Income TaxAccounting Implications of the Tax Act or TCJA, which allows SEC registrants to record provisional amounts during a measurement period not to extendbeyond one year of the enactment date. Since the Act was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation areexpected over the next 12 months, Management considers its accounting of the various tax laws impacted by the Tax Act to be reasonable despite anyforthcoming guidance. Any subsequent adjustment to these amounts will be adjusted accordingly as further guidance comes out. In the fourth quarter of2018, we completed our analysis to determine the effect of the Tax Act and no material adjustments were recognized as of December 31, 2018.As of December 31, 2018, our total deferred tax assets were $38 million. Due to our lack of earnings history and uncertainties surrounding ourability to generate future taxable income, the net deferred tax assets have been fully offset by a valuation allowance. The deferred tax assets were primarilycomprised of federal and state tax net operating losses, and Research and Development Credits. Utilization of NOLs may be limited by the “ownershipchange” rules, as defined in Section 382 of the Code. The Company has engaged a third party to perform a Section 382 analysis covering from inception in2010 to December 31, 2018 balance sheet reporting date. The Company has had various rounds of funding since inception (Series A-1, A-2, B) that haveresulted in a change in ownership which limits the amount of net operating losses that may be used in the future. The Company has written off any deferredtax assets that will not be accessible due to the limitation from Section 382/383 with a corresponding adjustment to the valuation allowance..JOBS Act Accounting ElectionWe are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. Under the JOBS Act,emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time asthose standards apply to private companies.We have elected to use this extended transition period to enable us to comply with new or revised accounting standards that have differenteffective dates for public and private companies until the earlier of the date we (i) are no longer an emerging growth company or (ii) affirmatively andirrevocably opt out of the extended transition period provided in the JOBS Act. As a result, our financial statements may not be comparable to companies thatcomply with new or revised accounting pronouncements as of public company effective dates.Recent Accounting PronouncementsSee Note 2 to our Financial Statements “Summary of Significant Accounting Policies” for information.97 Item 7A. Quantitative and Qualitative Disclosures About Market Risk.We are exposed to market risks in the ordinary course of our business. These risks primarily relate to interest rate sensitivities. We had cash, cash equivalentsand marketable securities of $171.1 million as of December 31, 2018, which consist of bank deposits, money market funds, and marketable securities. Theprimary objective of our investment activities is to preserve capital to fund our operations. We also seek to maximize income from our investments withoutassuming significant risk. Because our investments are primarily short-term in duration, we believe that our exposure to interest rate risk is not significant,and a 1% movement in market interest rates would not have a significant impact on the total value of our portfolio. We had no debt outstanding as ofDecember 31, 2018.98 Item 8. Financial Statements and Supplementary Data. UNITY BIOTECHNOLOGY, INC.Index to Financial Statements Page Report of Independent Registered Public Accounting Firm 100 Balance Sheets 101 Statements of Operations and Comprehensive Loss 102 Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit) 103 Statements of Cash Flows 104 Notes to the Financial Statements 105 99 Report of Independent Registered Public Accounting FirmTo the Stockholders and the Board of Directors ofUnity Biotechnology, Inc.Opinion on the Financial StatementsWe have audited the accompanying balance sheets of Unity Biotechnology, Inc. (the Company) as of December 31, 2018 and 2017, and related statements ofoperations and comprehensive loss, statements of convertible preferred stock and stockholders’ equity (deficit) and cash flows for each of the three years inthe period ended December 31, 2018, and the related notes (collectively referred to as the “financial statements”). In our opinion, the financial statementspresent fairly, in all material respects, the financial position of the Company at December 31, 2018 and 2017, and the results of its operations and its cashflows for each of the three years ended December 31, 2018 in conformity with U.S. generally accepted accounting principles.Basis for OpinionThese financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financialstatements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB)and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations ofthe Securities and Exchange Commission and the PCAOB.We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonableassurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, norwere we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding ofinternal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control overfinancial reporting. Accordingly, we express no such opinion.Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, andperforming procedures that respond to those risks. Such procedures include examining, on a test basis, evidence regarding the amounts and disclosures in thefinancial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well asevaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion./s/ Ernst & Young LLPWe have served as the Company’s auditor since 2017.Redwood City, CaliforniaMarch 6, 2019,100 UNITY BIOTECHNOLOGY, INC.Balance Sheets(in thousands, except share and per share amounts) December 31, 2018 2017 Assets Current assets: Cash and cash equivalents $15,399 $7,298 Contribution receivable — 1,382 Short-term marketable securities 155,736 79,212 Prepaid expenses and other current assets 1,830 988 Total current assets 172,965 88,880 Property and equipment, net 6,238 6,958 Long-term marketable securities — 5,118 Restricted cash 550 550 Other long-term assets 1,622 518 Total assets $181,375 $102,024 Liabilities, Convertible Preferred Stock, and Stockholders’ Equity (Deficit) Current liabilities: Accounts payable $4,847 $2,378 Accrued compensation 3,791 2,181 Accrued and other current liabilities 4,990 3,338 Settlement liability 2,059 — Contingent consideration liability 895 — Total current liabilities 16,582 7,897 Deferred rent, net of current portion 2,467 3,166 Contingent consideration liability, net of current portion 1,588 — Other non-current liabilities 45 118 Total liabilities 20,682 11,181 Commitments and contingencies (Note 7) Convertible preferred stock, $0.0001 par value; 10,000,000 and 91,739,149 shares authorized as of December 31, 2018 and 2017, respectively; 0 and 28,159,724 shares issued and outstanding as of December 31, 2018 and 2017, respectively; aggregate liquidation preference of $0 and $190,825 as of December 31, 2018 and 2017, respectively — 173,956 Stockholders’ equity (deficit): Common stock, $0.0001 par value; 300,000,000 and 122,000,000 shares authorized as of December 31, 2018 and 2017, respectively; 42,414,294 and 4,830,389 shares issued and outstanding as of December 31, 2018 and 2017, respectively 4 1 Additional paid-in capital 324,663 4,072 Related party promissory notes for purchase of common stock (201) (202)Employee promissory notes for purchase of common stock (400) — Accumulated other comprehensive loss (95) (104)Accumulated deficit (163,278) (86,880)Total stockholders’ equity (deficit) 160,693 (83,113)Total liabilities, convertible preferred stock, and stockholders’ equity (deficit) $181,375 $102,024 See accompanying notes to the financial statements.101 UNITY BIOTECHNOLOGY, INC.Statements of Operations and Comprehensive Loss(in thousands, except share and per share amounts) Year ended December 31, 2018 2017 2016 Contribution revenue $— $1,382 $— Operating expenses: Research and development 58,907 37,373 13,707 General and administrative 16,016 9,617 5,137 Change in fair value of contingent consideration 4,542 — — Total operating expenses 79,465 46,990 18,844 Loss from operations $(79,465) $(45,608) $(18,844)Loss on extinguishment of promissory notes — — (9,377)Interest income (expense), net 3,312 1,055 (2,183)Other expense, net (245) (103) — Net loss $(76,398) $(44,656) $(30,404)Other comprehensive loss Unrealized gain (loss) on marketable securities, net of tax 9 (104) — Comprehensive loss $(76,389) $(44,760) $(30,404)Net loss per share, basic and diluted $(2.70) $(13.97) $(11.42)Weighted average number of shares used in computing net loss per share, basic and diluted 28,269,907 3,197,516 2,662,841 See accompanying notes to the financial statements. 102 UNITY BIOTECHNOLOGY, INC.Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit)(in thousands, except share amounts) ConvertiblePreferred Stock Common Stock AdditionalPaid-In Related PartyPromissory Notesfor Purchase of EmployeePromissoryNotes forPurchase of AccumulatedOtherComprehensive Accumulated TotalStockholders’ Shares Amount Shares Amount Capital Common Stock Common Stock Loss Deficit Equity (Deficit) Balances at December 31, 2015 8,713,925 $7,579 2,054,204 $1 $123 $(49) $— $— $(11,820) $(11,745)Issuance of Series A-2 convertiblepreferred stock at $0.876 per share for cash, net of issuance costs of$1 4,671,430 4,092 — — — — — — — — Issuance of Series B convertiblepreferred stock at $12.125 per share for cash, net of issuance costs of$214 11,235,260 119,418 — — — — — — — — Issuance of common stock upon exerciseof stock options, net of amount related to early exercisedoptions of $408 — — 1,436,902 — 38 — — — — 38 Vesting of early exercised options — — — — 58 — — — — 58 Issuance of restricted stock — — 76,271 — — — — — — — Common stock granted to third parties — — 736,161 — 446 — — — — 446 Stock-based compensation — — — — 224 — — — — 224 Receipt of promissory note from relatedparty for purchase of common stock — — — — — (153) — — — (153)Net loss — — — — — — — — (30,404) (30,404)Balances at December 31, 2016 24,620,615 $131,089 4,303,538 $1 $889 $(202) $— $— $(42,224) $(41,536)Issuance of Series B convertiblepreferred stock at $12.125 per share for cash, net of issuance costs of$43 3,539,109 42,867 — — — — — — — — Issuance of common stock upon exerciseof stock options, net of amount related to early exercisedoptions of $5 — — 43,727 — 8 — — — — 8 Vesting of early exercised options — — — — 97 — — — — 97 Issuance of restricted stock — — 625,931 — — — — — — — Common stock granted to third party — — 12,711 — 44 — — — — 44 Stock-based compensation — — — — 3,034 — — — — 3,034 Unrealized loss on marketable securities,net of tax — — — — — — — (104) — (104)Repurchase of early exercised shares ofcommon stock — — (155,518) — — — — — — — Net loss — — — — — — — — (44,656) (44,656)Balances at December 31, 2017 28,159,724 $173,956 4,830,389 $1 $4,072 $(202) $— $(104) $(86,880) $(83,113)Issuance of Series C convertiblepreferred stock at $15.3317 per share for cash, net of issuance costs of$119 3,913,425 59,881 — — — — — — — — Issuance of common stock upon initialpublic offering, net of issuance costs of $9,149 — — 5,000,000 1 75,851 — — — — 75,852 Conversion of Series A-1, A-2, B and Cconvertible preferred stock to common stock (32,073,149) (233,837) 32,073,149 2 233,837 — — — — 233,839 Issuance of common stock upon exerciseof warrants and stock options, net of amount related to early exercisedoptions of $1,212 — — 510,756 — 374 — — — — 374 Vesting of early exercised stock options — — — — 584 — — — — 584 Stock-based compensation — — — — 9,441 — — — — 9,441 Unrealized gain on available-for-salemarketable securities, net of tax — — — — — — — 9 — 9 Receipt of promissory note from relatedparty for purchase of common stock — — — — — (390) — — — (390)Receipt of promissory note fromemployee for purchase of common stock — — — — — — (400) — — (400)Repayment of promissory note fromrelated party — — — — 504 391 — — — 895 Net loss — — — — — — — — (76,398) (76,398)Balances at December 31, 2018 — $— 42,414,294 $4 $324,663 $(201) $(400) $(95) $(163,278) $160,693 See accompanying notes to the financial statements. 103 UNITY BIOTECHNOLOGY, INC.Statements of Cash Flows(in thousands) Year Ended December 31, 2018 2017 2016 Operating activities Net loss $(76,398) $(44,656) $(30,404)Adjustments to reconcile net loss to net cash used in operating activities: Depreciation and amortization 2,180 1,304 153 Net accretion and amortization of premium and discounts on marketable securities (955) 182 — Stock-based compensation 9,441 3,034 224 Loss on extinguishment of promissory notes — — 9,377 Non-cash interest expense — — 2,223 Loss on disposal of property and equipment 45 15 — Common stock granted to third party — 44 447 Accretion of tenant improvement allowance (605) (605) (403)Change in fair value of contingent consideration for license agreements 4,542 — — Changes in operating assets and liabilities: Contribution receivable 1,382 (1,382) — Prepaid expenses and other current assets (842) (746) (229)Other long-term assets (604) 23 (41)Accounts payable 2,228 1,198 198 Accrued compensation 1,610 1,607 504 Accrued liabilities and other current liabilities 1,446 1,258 1,046 Deferred rent, net of current portion (93) 366 27 Other non-current liabilities — — 480 Net cash used in operating activities (56,623) (38,358) (16,398)Investing activities Purchase of marketable securities (204,086) (134,465) — Maturities of marketable securities 133,644 49,849 — Purchase of investment in stock (500) — (500)Purchase of property and equipment (1,264) (1,689) (2,244)Net cash used in investing activities (72,206) (86,305) (2,744)Financing activities Proceeds from issuance of convertible promissory notes payable — — 16,887 Proceeds from issuance of convertible preferred stock, net of issuance costs 59,881 42,867 90,956 Proceeds from issuance of common stock upon exercise of stock options, net of repurchases 374 (37) 95 Proceeds from initial public offering, net of issuance costs 79,055 — — Payment of initial public offering costs (3,201) — — Proceeds from repayment of recourse notes 895 — — Payments made on capital lease obligations (74) (55) — Net cash provided by financing activities 136,930 42,775 107,938 Net increase (decrease) in cash, cash equivalents and restricted cash 8,101 (81,888) 88,796 Cash, cash equivalents and restricted cash at beginning of year 7,848 89,736 940 Cash, cash equivalents and restricted cash at end of year $15,949 $7,848 $89,736 Supplemental Disclosures of Non-Cash Investing and Financing Activities Conversion and settlement of convertible notes and accrued interest into convertible preferred stock $— $— $15,667 Property and equipment included in accounts payable $241 $314 $98 Property and equipment acquired under capital leases $— $243 $— Lessor funded lease incentives included in property and equipment $— $3,881 $— Receipt of promissory note for purchase of common stock $400 $— $— Receipt of promissory note from related party for purchase of common stock $390 $— $153 See accompanying notes to the financial statements.104 UNITY BIOTECHNOLOGY, INC.NOTES TO THE FINANCIAL STATEMENTS1. OrganizationDescription of BusinessUnity Biotechnology, Inc. (the “Company”) is a biotechnology company engaged in the research and development of therapeutics to extend humanhealthspan. The Company devotes substantially all of its time and efforts to performing research and development, raising capital and recruiting personnel.The Company is located in Brisbane, California and was incorporated in the State of Delaware in 2009. Need for Additional CapitalThe accompanying financial statements have been prepared assuming that the Company will continue as a going concern. Since inception, the Company hasincurred net losses and negative cash flows from operations. During the year ended December 31, 2018, the Company incurred a net loss of $76.4 million andused $56.6 million of cash in operations. At December 31, 2018, the Company had an accumulated deficit of $163.3 million and does not expect positivecash flows from operations in the foreseeable future. The Company has historically financed its operations primarily through the issuance and sale ofconvertible preferred stock and convertible promissory notes. To date, none of the Company’s drug candidates have been approved for sale and therefore theCompany has not generated any revenue from contracts with customers. The Company has evaluated and concluded there are no conditions or events,considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern for a period of one year following thedate that these financial statements are issued. Management expects operating losses to continue for the foreseeable future. As a result, the Company willneed to raise additional capital. If sufficient funds on acceptable terms are not available when needed, the Company could be required to significantly reduceits operating expenses and delay, reduce the scope of, or eliminate one or more of its development programs. Failure to manage discretionary spending orraise additional financing, as needed, may adversely impact the Company’s ability to achieve its intended business objectives.2. Summary of Significant Accounting PoliciesBasis of PresentationThese financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).Reverse Stock SplitOn April 19, 2018, the Company’s board of directors approved an amendment to the Company’s amended and restated certificate of incorporation to effect a1-for-2.95 reverse split (“Reverse Split”) of shares of the Company’s common and convertible preferred stock, which was effected on April 20, 2018. The parvalue and authorized shares of common stock and convertible preferred stock were not adjusted as a result of the Reverse Split. All of the share and per shareinformation included in the accompanying financial statements has been adjusted to reflect the Reverse Split.Initial Public OfferingOn May 7, 2018, the Company closed its initial public offering (“IPO”), of 5,000,000 shares of common stock, at an offering price to the public of $17.00 pershare. The Company received net proceeds of approximately $75.9 million, after deducting underwriting discounts, commissions and offering relatedtransaction costs of approximately $9.1 million. In connection with the IPO, all of the Company’s outstanding shares of convertible preferred stock wereautomatically converted into 32,073,149 shares of common stock. In addition, all of the Company’s convertible preferred stock warrants were converted intowarrants to purchase shares of common stock.In connection with the completion of its IPO, on May 7, 2018, the Company’s certificate of incorporation was amended and restated to provide for300,000,000 authorized shares of common stock with a par value of $0.0001 per share and 10,000,000 authorized shares of preferred stock with a par value of$0.0001 per share.105 Use of EstimatesThe preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported inthe financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevantassumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s balance sheets and theamount of expenses and income reported for each of the periods presented are affected by estimates and assumptions, which are used for, but are not limitedto, determining the fair value of assets and liabilities, contingent consideration liability, common stock valuation, and stock-based compensation. Actualresults could differ from such estimates or assumptions.SegmentsThe Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operationson a consolidated basis for the purposes of allocating resources.Cash, Cash Equivalents and Restricted CashThe Company considers all highly liquid investments with original maturities of 90 days or less from the date of purchase to be cash equivalents. Cashequivalents primarily include money market funds that invest in U.S. Treasury obligations which are stated at fair value.The Company has issued a letter of credit under a lease agreement which has been collateralized. This cash is classified as noncurrent restricted cash on thebalance sheet based on the term of the underlying lease.The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets that sum to the total of the sameamounts shown in the statements of cash flows. December 31, 2018 2017 2016 (in thousands) Cash and cash equivalents $15,399 $7,298 $89,286 Restricted cash 550 550 450 Total cash, cash equivalents, and restricted cash $15,949 $7,848 $89,736 Marketable SecuritiesThe Company generally invests its excess cash in investment grade, short to intermediate-term, fixed income securities. Such investments are consideredavailable-for-sale, and reported at fair value with unrealized gains and losses included as a component of stockholders’ deficit. Marketable securities withoriginal maturities of greater than 90 days from the date of purchase but less than one year from the balance sheet date are classified as short-term, whilemarketable securities with maturities in one year or beyond one year from the balance sheet date are classified as long-term. The amortized cost of debtsecurities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest income on the statements ofoperations and comprehensive loss. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on marketable securities areincluded in interest income (expense), net. The cost of securities sold is determined using the specific identification method.The Company periodically evaluates whether declines in fair values of its marketable securities below their book value are other-than-temporary. Thisevaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s abilityand intent to hold the marketable security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or itis more likely than not it will be required to sell any marketable securities before recovery of its amortized cost basis. Factors considered include quotedmarket prices, recent financial results and operating trends, implied values from any recent transactions or offers of investee securities, credit quality of debtinstrument issuers, other publicly available information that may affect the value of the marketable security, duration and severity of the decline in value, and106 management’s strategy and intentions for holding the marketable security. To date, the Company has not recorded any impairment charges on its marketablesecurities related to other-than-temporary declines in market value.Fair Value of Financial InstrumentsThe Company’s financial instruments during the periods presented consist of cash and cash equivalents, restricted cash, contribution receivable, marketablesecurities, prepaid expenses and other current assets, accounts payable, accrued compensation, accrued and other current liabilities. Fair value estimates ofthese instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involveuncertainties and matters of significant judgment.Concentrations of RiskFinancial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, restrictedcash, marketable securities and contribution receivable. Substantially all of the Company’s cash and cash equivalents and restricted cash is deposited inaccounts with financial institutions that management believes are of high credit quality. Such deposits have and will continue to exceed federally insuredlimits. The Company maintains its cash with accredited financial institutions and accordingly, such funds are subject to minimal credit risk. The Companyhas not experienced any losses on its cash deposits. The contribution receivable is unsecured and is concentrated with one third-party organization, andaccordingly the Company may be exposed to credit risk. To date, the Company has not experienced any loss related to its contributions receivable.The Company’s investment policy limits investments to certain types of securities issued by the U.S. government, its agencies and institutions withinvestment-grade credit ratings and places restrictions on maturities and concentration by type and issuer. The Company is exposed to credit risk in the eventof a default by the financial institutions holding its cash, cash equivalents, restricted cash and marketable securities and issuers of marketable securities to theextent recorded on the balance sheets. As of December 31, 2018, the Company had no off-balance sheet concentrations of credit risk.The Company depends on third-party suppliers for key raw materials used in its manufacturing processes and is subject to certain risks related to the loss ofthese third-party suppliers or their inability to supply the Company with adequate raw materials.Contribution Revenue and ReceivablesThe Company recognizes contribution revenue related to the receipt of cash from third-party resource providers not considered to be customers and where thetransfer of assets is not an exchange transaction or financing of research and development. Contribution revenue and related receivables are recognized forconditional contributions as the conditions related to the contribution are relieved.In July 2017, the Company entered an arrangement with a third-party organization under which the Company would be provided with up to $1.5 million offunding for the performance of certain research and development activities during the 90-day period following the arrangement in pursuit of the third-partyorganization’s philanthropic mission. All conditions related to this contribution were met during 2017 and the Company recognized $1.4 million under thisarrangement, which was recorded as contribution revenue in the statement of operations and a contribution receivable on the balance sheet.Research and Development ExpensesCosts related to research, design and development of drug candidates are charged to research and development expense as incurred. Research anddevelopment costs include, but are not limited to, payroll and personnel expenses for personnel contributing to research and development activities,laboratory supplies, outside services, licenses acquired to be used in research and development and allocated overhead, including rent, equipment,depreciation and utilities. Payments made prior to the receipt of goods or services to be used in research and development are deferred and107 recognized as expense in the period in which the related goods are received or services are rendered. Such payments are evaluated for current or long-termclassification based on when they will be realized.Contingent Consideration LiabilityThe Company has entered into and may continue to enter into, license agreements to access and utilize certain technology. In each case, the Companyevaluates if the license agreement results in the acquisition of an asset or a business. To date none of the Company’s license agreements have been consideredan acquisition of a business. For asset acquisitions, the upfront payments to acquire such licenses, as well as any future milestone payments made beforeproduct approval, are immediately recognized as research and development expense when due, provided there is no alternative future use of the rights inother research and development projects. These license agreements also include contingent consideration in the form of additional issuances of theCompany’s common stock based on the achievement of certain milestones. For asset acquisitions, the Company assesses on a continuous basis whether suchcontingent consideration meets the definition of a derivative and can or cannot be classified within stockholders’ equity, until such time that equityclassification criteria are met or the milestones expire. The derivative related to this contingent consideration is measured at fair value as of each balancesheet date with the related change in fair value being reflected in operating expenses. Upon a reassessment event that results in the contingent considerationno longer meeting the definition of a derivative and/or meeting equity classification critera, the final change in fair value of the instrument is recorded withinoperating expenses and the liability is reclassified into stockholders’ equity.Variable Interest EntitiesThe Company reviews agreements it enters into with third-party entities, pursuant to which the Company may have a variable interest in the entity, in orderto determine if the entity is a variable interest entity (“VIE”). If the entity is a VIE, the Company assesses whether or not it is the primary beneficiary of thatentity. In determining whether the Company is the primary beneficiary of an entity, the Company applies a qualitative approach that determines whether ithas both (i) the power to direct the economically significant activities of the entity and (ii) the obligation to absorb losses of, or the right to receive benefitsfrom, the entity that could potentially be significant to that entity. If the Company determines it is the primary beneficiary of a VIE, it consolidates that VIEinto the Company’s financial statements. The Company’s determination about whether it should consolidate such VIEs is made continuously as changes toexisting relationships or future transactions may result in a consolidation or deconsolidation event.Property and Equipment, NetProperty and equipment are stated at cost, less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated usefullives of the respective assets, generally three years. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated usefullives or the term of the lease. Depreciation and amortization begins at the time the asset is placed in service. Maintenance and repairs are charged to expenseas incurred and costs of improvement are capitalized.Impairment of Long-Lived AssetsThe Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not befully recoverable. If indicators of impairment exist and the undiscounted future cash flows that the assets are expected to generate are less than the carryingvalue of the assets, the Company reduces the carrying amount of the assets through an impairment charge, to their estimated fair values based on a discountedcash flow approach or, when available and appropriate, to comparable market values. No impairment losses have been recorded for the periods presented.LeasesThe Company leases office space and laboratory facilities under non-cancelable operating lease agreements and recognizes related rent expense on a straight-line basis over the term of the lease. Incentives granted under the Company’s facilities lease, including allowances to fund leasehold improvements and rentholidays, and are recognized as reductions to rental expense on a straight-line basis over the term of the lease. Lessor funded leasehold108 improvement incentives not yet received are recorded in prepaid expense and other current assets on the balance sheet. The Company does not assumerenewals in its determination of the lease term unless they are deemed to be reasonably assured at the inception of the lease and begins recognizing rentexpense on the date that it obtains the legal right to use and control the leased space. Deferred rent consists of the difference between cash payments and therent expense recognized.The Company entered into capital lease agreements for certain equipment with a lease term of three years. The current portion of capital lease obligations isincluded in accrued and other liabilities and the noncurrent capital lease obligations is included in other noncurrent liabilities in the balance sheet.Convertible Preferred StockThe Company records all shares of convertible preferred stock at their respective issuance price less issuance costs on the dates of issuance. Upon theoccurrence of certain change in control events that are outside the Company’s control, including liquidation, sale or transfer of the Company, holders of theconvertible preferred stock can cause redemption for cash. Therefore, convertible preferred stock is classified outside of stockholders’ deficit on the balancesheet as events triggering the liquidation preferences are not solely within the Company’s control. The carrying values of the convertible preferred stock areadjusted to their liquidation preferences when and if it becomes probable that such an event will occur.Stock-Based CompensationThe Company measures employee and director stock-based compensation expense for all stock-based awards based on their grant date fair value. For stock-based awards with service conditions only, stock-based compensation expense is recognized over the requisite service period using the straight-line method.For awards with performance conditions, the Company evaluates the probability of achieving performance condition at each reporting date. The Companybegins to recognize stock-based compensation expense using an accelerated attribution method when it is deemed probable that the performance conditionwill be met. Forfeitures are recognized as they occur.The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock option awards that do not contain market conditions. TheBlack-Scholes option-pricing model requires assumptions to be made related to the expected term of an award, expected dividends, expected volatility andrisk-free rate. The Company uses the Monte Carlo simulation models to estimate the fair value of stock option awards that contain market conditions. TheMonte Carlo simulation models require the use of subjective and complex assumptions which determine the fair value of such awards including pricevolatility of the underlying stock and derived service periods.The Company recognizes stock-based compensation expense for stock options granted to non-employees based on the estimated fair value of the award as itis more readily measurable than the fair value of the services received. The fair value of stock options granted to non-employees is estimated at grant date andre-measured at each reporting period using the Black-Scholes option-pricing model until the awards vest and the resulting change in value, if any, isrecognized in the statements of operations.Income TaxesThe Company uses the asset and liability method of accounting for income taxes, in which deferred tax assets and liabilities are recognized for future taxconsequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases.Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporarydifferences are expected to be reversed. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income in the period thatincludes the enactment date. A valuation allowance is established if it is more likely than not that all or a portion of the deferred tax asset will not be realized.The Company’s tax positions are subject to income tax audits. The Company recognizes the tax benefit of an uncertain tax position only if it is more likelythan not that the position is sustainable upon examination by the taxing authority, based on the technical merits. The tax benefit recognized is measured asthe largest amount of benefit which is more109 likely than not to be realized upon settlement with the taxing authority. The Company recognizes interest accrued and penalties related to unrecognized taxbenefits in its tax provision. The Company evaluates uncertain tax positions on a regular basis. The evaluations are based on a number of factors, includingchanges in facts and circumstances, changes in tax law, correspondence with tax authorities during the course of the audit, and effective settlement of auditissues. The provision for income taxes includes the effects of any accruals that the Company believes are appropriate, as well as the related net interest andpenalties.Net Loss per Common ShareBasic net loss per share is calculated by dividing net loss by the weighted average number of shares outstanding for the period. Diluted net loss per share iscalculated by dividing net loss by the weighted average number of shares of common stock and potential dilutive common stock equivalents outstandingduring the period if the effect is dilutive. The calculation of diluted earnings (loss) per share also requires that, to the extent the presumed issuance ofadditional shares as contingent consideration is dilutive to earnings (loss) per share for the period, adjustments to net income or net loss used in thecalculation are required to remove the change in fair value of the contingent consideration liability for the period. Likewise, adjustments to the denominatorare required to reflect the related dilutive shares. In all periods presented, the Company’s outstanding stock options, convertible preferred stock, earlyexercised common stock subject to future vesting, restricted stock accounted for as options common and preferred stock warrants and presumed issuance ofadditional shares as contingent consideration were excluded from the calculation of diluted net loss per share because their effects were antidilutive.Comprehensive LossComprehensive loss includes net loss and certain changes in stockholders’ deficit that are excluded from net loss, primarily unrealized losses on theCompany’s marketable securities.Recently Issued Accounting PronouncementsIn August 2018, the FASB issued ASU No. 2018-15, Intangibles (Topic 350): Customer’s Accounting for Implementation Costs Incurred in a CloudComputing Arrangement That Is a Service Contract, which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangementthat is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This new standardalso requires customers to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hostingarrangement. This standard is effective for the Company for annual reporting periods beginning after December 15, 2020, and interim periods within annualperiods beginning after December 15, 2021. This new standard can be applied either retrospectively or prospectively to all implementation costs incurredafter the date of adoption. The Company is currently evaluating the impact of adoption on its financial statements.In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-13, Fair Value Measurement(Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. This ASU eliminates, modifies and addsdisclosure requirements for fair value measurements. The amendments in this ASU are effective for fiscal years, and for interim periods within those fiscalyears, beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the effects of this ASU on its financialstatements and related disclosures.In August 2018, the SEC adopted amendments to certain disclosure requirements in Securities Act Release No. 33-10532, Disclosure Update andSimplification. The Company adopted these SEC amendments on November 5, 2018 and will present the analysis of changes in stockholders’ equity in itsinterim financial statements in its March 31, 2019 Form 10-Q. The Company does not anticipate that the adoption of these SEC amendments will have amaterial effect on the Company’s financial position, results of operations, cash flows or shareholders’ equity.In June 2018, the FASB issued ASU No. 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based PaymentAccounting. The amendments in this ASU expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services fromnonemployees. This new guidance is110 effective for the Company in fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020.Early adoption is permitted. The Company is currently evaluating the effects of this ASU on its financial statements and related disclosures.In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. This ASU clarifies thedefinition of a business when evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The guidance iseffective for the Company for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019.Early adoption is permitted. The Company does not expect the adoption of this ASU to have a significant impact on its financial statements and relateddisclosures.In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230: Classification of Certain Cash Receipts and Cash Payments). Thisguidance addresses specific cash flow issues with the objective of reducing the diversity in practice for the treatment of these issues. The areas identifiedinclude: debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments; contingent consideration payments made after abusiness combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies;distributions received from equity method investees; beneficial interests in securitization transactions; and application of the predominance principle withrespect to separately identifiable cash flows. The guidance will generally be applied retrospectively and is effective for fiscal years beginning after December15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. The Company does not expect theadoption of this ASU to have a significant impact on its financial statements.In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which supersedes the guidance in former ASC 840, Leases. The new standard, asamended by subsequent ASUs on the Topic, requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on theprinciple of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognizedbased on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a leaseliability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted forsimilar to existing guidance for operating leases today. For the Company, this standard is effective for annual reporting periods beginning after December 15,2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted. The ASU is expected to impact theCompany’s financial statements as the Company has certain operating lease arrangements for which the Company is the lessee. While the Company iscurrently evaluating the impact of the adoption of this standard on its financial statements, the Company anticipates the recognition of additional assets andcorresponding liabilities on its balance sheet related to these leases. The adoption of this accounting standard update is also expected to impact theCompany’s financial statement disclosuresIn January 2016, the FASB issued ASU No. 2016-01, Financial Instruments Overall (Subtopic 825-10): Recognition and Measurement of Financial Assetsand Financial Liabilities. This guidance makes amendments to the classification and measurement of financial instruments and revises the accountingrelated to: (1) the classification and measurement of investments in equity securities (except for investments accounted for under the equity method ofaccounting); and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. In addition, the update also amends certaindisclosure requirements associated with the fair value of financial instruments. The guidance is effective for the Company for annual periods beginning in2019 and interim periods beginning in 2020. Early adoptions of certain amendments within the update are permitted. The Company is currently evaluatingthe effects of this ASU on its financial statements and related disclosures.In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718)- Scope of Modification Accounting (ASU 2017- 09). Theamendments included in this update provide guidance about which changes to the terms or conditions of a share-based payment award require an entity toapply modification accounting. The amendments in this update will be applied prospectively to an award modified on or after the adoption date. Theamendments in ASU 2017-09 became effective for the Company on January 1, 2018 and the adoption of this standard did not have a material impact on theCompany’s financial statements.111 3. Fair Value MeasurementsThe Company determines the fair value of financial and non-financial assets and liabilities based on the assumptions that market participants would use inpricing the asset or liability in an orderly transaction between market participants at the measurement date. The identification of market participantassumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A fair value hierarchy has been established whichgives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputsinto three broad levels as follows: •Level 1: Quoted prices in active markets for identical instruments •Level 2: Other significant observable inputs (including quoted prices in active markets for similar instruments) •Level 3: Significant unobservable inputs (including assumptions in determining the fair value of certain investments)The carrying amounts of financial instruments such as cash and cash equivalents, restricted cash, contribution receivable, prepaid expenses and other currentassets, accounts payable, accrued compensation, accrued and other current liabilities approximate the related fair values due to the short maturities of theseinstruments.The Company’s financial assets subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows (inthousands): December 31, 2018 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $14,131 $14,131 $— $— Total cash equivalents 14,131 14,131 — — Short-term marketable securities: U.S. treasuries 34,121 — 34,121 — U.S. and foreign commercial paper 10,635 — 10,635 — U.S. and foreign corporate debt securities 26,533 — 26,533 — Asset-backed securities 2,748 — 2,748 — U.S. government debt securities 81,699 — 81,699 — Total short-term marketable securities 155,736 — 155,736 — Total assets subject to fair value measurements on a recurring basis $169,867 $14,131 $155,736 $— Liabilities: Contingent consideration liability $2,483 $— $— $2,483 Total liabilities subject to fair value measurements on a recurring basis $2,483 $— $— $2,483112 December 31, 2017 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $5,709 $5,709 $— $— Total cash equivalents 5,709 5,709 — — Short-term marketable securities: U.S. and foreign commercial paper 6,359 — 6,359 — U.S. and foreign corporate debt securities 16,149 — 16,149 — Asset-backed securities 14,588 — 14,588 — U.S. government debt securities 40,362 — 40,362 — U.S. treasuries 1,754 — 1,754 — Total short-term marketable securities 79,212 — 79,212 — Long-term marketable securities: Asset-backed securities 2,742 — 2,742 — U.S. government debt securities 2,376 — 2,376 — Total long-term marketable securities 5,118 — 5,118 — Total marketable securities 84,330 — 84,330 — Total assets subject to fair value measurements on a recurring basis $90,039 $5,709 $84,330 $— The Company estimates the fair value of its money market funds, U.S. and foreign commercial paper, U.S. and foreign corporate debt securities, asset-backedsecurities, U.S. treasuries and U.S. government debt securities by taking into consideration valuations obtained from third-party pricing services. The pricingservices utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable,either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuercredit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs.The fair value of the contingent consideration liability includes inputs not observable in the market and thus represents a Level 3 measurement. TheCompany has recorded a contingent consideration liability related to two agreements executed in February 2016 with a privately held clinical-stagebiopharmaceutical company: (a) a license agreement granting the Company the right to research, develop, and seek and obtain marketing approval for aninitial licensed compound, and (b) a compound library and option agreement granting the Company the right to identify and take licenses to additionalcompounds, in each case for the treatment of indications outside of oncology (collectively, the “Commercial Agreements”). The Commercial Agreementsinclude contingent consideration of up to an aggregate of 666,670 additional shares of common stock to be issued based on achievement of certain specifiedclinical development and sales milestone events. The Company valued the contingent consideration liability using a probability-weighted valuationapproach model which reflects the probability and timing of future issuances of shares. The probability of achieving the defined milestones for each licensedproduct was estimated by the Company’s management. Total contingent consideration may change significantly as preclinical and clinical developmentunder the Commercial Agreements progresses and additional data is obtained, impacting the Company’s assumptions regarding probabilities of successfulachievement of related development and commercial milestones used to estimate the fair value of the liability and the timing in which they are expected tobe achieved. For example, significant increases in the estimated probability of achieving a milestone would result in a significantly higher fair valuemeasurement while significant decreases in the estimated probability of achieving a milestone would result in a significantly lower fair value measurement.The potential outstanding contingent consideratin value results in shares to be issued ranging from zero, if none of the milestones are achieved, to amaximum of $8.7 million at December 31, 2018 (using the Company’s stock price as of December 31, 2018). As of December 31, 2018 and 2017, none of thecommercial milestones had been achieved and no royalties were due from the sales of licensed products.As of December 31, 2018, the Company determined that the net settlement criteria of the definition of a derivative had been met for 133,333 shares ofcommon stock to the third parties. The Company issued 106,666 of these shares113 in January 2019 and will issue the remaining 26,667 shares in early 2019 and recorded a settlement liability of $2.0 million at December 31, 2018. TheCompany recorded a contingent consideration liability of $2.5 million at December 31, 2018 related to additional potential shares subject to theachievement of certain specified clinical development and sales milestone events under the agreements. No liability was recorded at December 31, 2017 asthe net settlement criteria were not met. The following table provides a reconciliation of assets and liabilities measured at fair value on a recurring basis usingsignificant unobservable inputs (Level 3) (in thousands): Amount Balance at December 31, 2017 $— Additions — Settlements — Change in fair value 4,542 Balance at December 31, 2018 $4,542 There were no transfers within the hierarchy during the years ended December 31, 2018 and 2017. See Note 4 for further information regarding the carrying value of the Company's financial instruments.4. Marketable SecuritiesMarketable securities, which are classified as available-for-sale, consisted of the following (in thousands): December 31, 2018 AmortizedCost Basis UnrealizedGains UnrealizedLosses FairValue Cash equivalents: Money market funds $14,131 $— $— $14,131 Total cash equivalents 14,131 — — 14,131 Short-term marketable securities: U.S. and foreign commercial paper 10,638 — (3) 10,635 U.S. and foreign corporate debt securities 26,552 2 (21) 26,533 Asset-backed securities 2,750 — (2) 2,748 U.S. government debt securities 81,755 1 (57) 81,699 U.S. treasuries 34,136 1 (16) 34,121 Total short-term marketable securities 155,831 4 (99) 155,736 Total marketable securities $169,962 $4 $(99) $169,867114 December 31, 2017 AmortizedCost Basis UnrealizedGains UnrealizedLosses FairValue Cash equivalents: Money market funds $5,709 $— $— $5,709 Total cash equivalents 5,709 — — 5,709 Short-term marketable securities: U.S. and foreign commercial paper 6,369 — (10) 6,359 U.S. and foreign corporate debt securities 16,162 — (13) 16,149 Asset-backed securities 14,604 — (16) 14,588 U.S. government debt securities 40,418 — (56) 40,362 U.S. treasuries 1,754 — — 1,754 Total short-term marketable securities 79,307 — (95) 79,212 Long-term marketable securities: Asset-backed securities 2,752 — (10) 2,742 U.S. government debt securities 2,375 1 — 2,376 Total long-term marketable securities 5,127 1 (10) 5,118 Total marketable securities $90,143 $1 $(105) $90,039 There have been no significant realized gains or losses on available-for-sale securities for the periods presented. Available-for-sale debt securities that were ina continuous loss position but were not deemed to be other than temporarily impaired were immaterial at both December 31, 2018 and 2017. The Companydoes not intend to and believes it is not more likely than not that it will be required to sell these securities before their maturities.See Note 3 for further information regarding the fair value of the Company's financial instruments.5. License AgreementsLicense and Compound Library and Option AgreementIn February 2016, the Company entered into a license agreement with a privately held clinical-stage biopharmaceutical company (the “Licensor”) toresearch, develop, and seek and obtain marketing approval for a licensed compound. In February 2016, in conjunction with this license agreement, theCompany also entered into a compound library and option agreement with the Licensor to identify compounds with potential utility in the treatment of age-related conditions other than indications in oncology (collectively, the “Commerical Agreements”). As part of these agreements, the Company issued533,335 shares of common stock to the Licensor and 133,333 shares of common stock to an academic institution from whom the Licensor had previouslylicensed the technology.The Commercial Agreements referenced above include cash payments of up to $70.3 million as well as the equity payments of up to an aggregate 666,670additional shares of common stock, in each case to be issued based on the Company’s achievement of certain specified clinical development and salesmilestone events. The milestones include the filing of an investigational drug application, the commencement of clinical studies, Food and DrugAdministration and/or European Medicines Agency approval, and a net sales threshold. The license agreement also includes tiered royalties in the low-singledigits based on sales of licensed products.115 In December 2018, the Company elected to advance a second compound into formal preclinical development which gave rise to an obligation under thecompound library and option agreement to issue an additional 133,333 shares of common stock to the Licensor and the academic institution. In connectionwith the issuance of these shares, the Company issued 106,666 shares of common stock to the Licensor in January 2019 and the remaining 26,667 will beissued to the academic institution in 2019. The Company recorded a settlement liability of $2.0 million at December 31, 2018. In connection with theadditional shares of common stock that the Company may be obligated to issue under the Commercial Agreements upon achievement of the specifiedmilestones and preclinical development events, the Company recorded a contingent consideration liability of $2.5 million at December 31, 2018. As ofDecember 31, 2017, none of those milestones or events had been achieved. As of December 31, 2018 and 2017, no royalties were due from the sales oflicensed products.In April 2016, in connection with the Commercial Agreements the Company purchased an equity interest in an affiliate of the Licensor for an aggregatepurchase price of $0.5 million. The equity interest represents an insignificant level of ownership in the entity and has been recorded within other assets in theCompany’s balance sheet. In May 2018 these shares were exchanged for new shares of a newly formed affiliate of the Licensor as part of a reorganization ofthose entities. The Company also invested an additional $0.5 million in the newly formed affiliate of the Licensor in May 2018. The Company agreed to provide funding to the Licensor for research and development work performed at a cost of up to $2.0 million through February 2020.The research and development expense under the research services agreement was $0.5 million and $0.5 million for the years ended December 31, 2018 and2017.Under the consolidation guidance, the Company determined that the Licensor is a VIE. The Company does not have the power to direct the activities thatmost significantly affect the economic performance of this entity and as such the Company is not the primary beneficiary and consolidation is not required.As of December 31, 2018 and 2017, the Company has not provided financial, or other, support to the Licensor that was not contractually required.Other License Agreements with Research InstitutionsThe Company has entered into license agreements with various research institutions which have provided the Company with rights to patents, and in certaincases, research “know-how” and proprietary research tools to research, develop and commercialize drug candidates. In addition to upfront consideration paidto these various research institutions in either cash or shares of the Company’s common stock, the Company may be obligated to pay milestone payments incash or the issuance of the Company’s common stock upon achievement of certain specified clinical development and/or sales events. The contingentconsideration liability considered to be a derivative associated with the potential issuance of common stock related to these license agreements was notsignificant at December 31, 2018 or 2017. To date, none of these events has occurred and no contingent consideration, milestone or royalty payments havebeen recognized.6. Balance Sheet ComponentsProperty and Equipment, NetProperty and equipment, net, consists of the following: December 31, 2018 2017 (in thousands) Laboratory equipment $4,162 $2,614 Computer equipment 247 137 Furniture and fixtures 113 105 Leasehold improvements 5,366 5,346 Construction in progress — 226 Total property and equipment 9,888 8,428 Less: accumulated depreciation and amortization (3,650) (1,470)Total property and equipment, net $6,238 $6,958116 Depreciation expense related to property and equipment was $2.2 million, 1.3 million and $0.2 million for the years ended December 31, 2018, 2017 and2016 respectively.Accrued and Other Current LiabilitiesAccrued and other current liabilities consist of the following: December 31, 2018 2017 (in thousands) Accrued research and development $1,837 $2,105 Deferred rent, current portion 783 702 Professional fees 26 70 Liability related to early exercise shares 885 257 Accrued other 1,459 204 $4,990 $3,338 7. Commitments and ContingenciesIndemnificationsThe Company indemnifies each of its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or wasserving at the Company’s request in such capacity, as permitted under Delaware law and in accordance with the Company’s amended and restated certificateof incorporation and bylaws. The term of the indemnification period lasts as long as an officer or director may be subject to any proceeding arising out of actsor omissions of such officer or director in such capacity.The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. Thisinsurance allows the transfer of risk associated with the Company’s exposure and may enable the Company to recover a portion of any future amounts paid.The Company believes that the fair value of these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilitiesrelating to these obligations for any period presented.Operating LeaseIn May 2016, the Company executed a non-cancellable lease agreement for office and laboratory space in Brisbane, California which commenced in May2016 and continues through October 2022. The lease agreement includes an escalation clause for increased rent and a renewal provision allowing theCompany to extend this lease for an additional four years by giving the landlord written notice of the election to exercise the option at least fifteen monthsprior to the original expiration of the lease term. The lease provides for monthly base rent amounts escalating over the term of the lease and the lessorprovided the Company a $3.9 million tenant improvement allowance to complete the laboratory and office renovation which was recorded as deferred rentliability and leasehold improvement within property and equipment, net. In May 2017, the Company entered into an amendment to expand the leased spaceand received a three-month rent holiday for the expanded space.As of December 31, 2018, the Company’s future minimum payments under the noncancelable operating lease is as follows (in thousands): Amount 2019 $2,012 2020 2,072 2021 2,135 2022 1,621 Total future minimum lease payments $7,840117 Rent expense was $1.8 million, $2.0 million and $0.8 million and for the years ended December 31, 2018, 2017 and 2016, respectively.8. Related-Party TransactionsRecourse NotesIn December 2015, April 2016, and July 2016, the Company issued three full-recourse promissory notes to two executive officers for an aggregate principalamount of $0.2 million with an interest rate of 2.5% per annum. All of the principal was used to early exercise options for 667,253 shares of the Company’scommon stock, in aggregate. All of these related party full-recourse notes were repaid on April 4, 2018 in accordance with the terms of such notes.In October 2017, the Company issued two promissory notes to an executive officer for $1.6 million and $0.5 million, each with an interest rate of 1.85% perannum. The aggregate principal amount of $2.1 million was used to purchase 625,084 shares of restricted stock. The promissory notes were considered to benon-recourse in substance and accordingly, the shares sold subject to such promissory notes are considered to be an option for accounting purposes. In April2018, the Company’s board of directors approved the forgiveness of all outstanding principal and accrued interest of the $1.6 million non-recoursepromissory note. The non-recourse promissory note outstanding of $0.5 million was repaid on April 4, 2018 in accordance with the terms of the note. Theforgiveness of the promissory note was accounted for as a modification of a share-based payment. The Company recorded an incremental charge of $1.5million related to the modification for the year ended December 31, 2018.In January 2018, the Company issued full-recourse promissory notes to an executive and an executive officer of the Company for an aggregate principalamount of $0.4 million with an interest rate of 2.5% per annum. All of the principal was used to early exercise options for 114,406 shares of the Company’scommon stock. The full recourse note of $0.2 million for the executive officer was repaid on April 4, 2018 in accordance with the terms of the note. Financing ActivitiesDuring the year ended December 31, 2018, the Company issued convertible preferred stock for total proceeds of $3.0 million to shareholders who areconsidered to be related parties. During the year ended December 31, 2017, the Company issued additional shares of Series B convertible preferred stock fortotal proceeds of $8.0 million to one of these related party shareholders. During the year ended December 31, 2016, the Company issued convertible preferredstock and convertible notes for total proceeds of $32.8 million to shareholders and certain executive officers who are considered to be related parties. All ofthe convertible notes converted into shares of series B preferred stock during 2016.OtherIn 2017, the Company entered into a master services agreement with a significant shareholder who was considered a related party. The Company incurred atotal of $0.4 million and $0.6 million of research and development expenses during the years ended December 31, 2018 and 2017, respectively, related tothis agreement.9. Convertible Preferred Stock and Common StockConvertible Preferred StockThe Company is authorized to issue two classes of stock: convertible preferred stock and common stock. Convertible preferred stock is carried at the issuanceprice, net of issuance costs.In July 2013, the Company sold an aggregate of 2,887,086 shares of Series A-1 convertible preferred stock at $0.864 per share for gross proceeds of $2.0million. From January 2014 through March 2015, the Company closed three tranches of Series A-2 convertible preferred stock financing and sold anaggregate of 5,826,839 shares of Series A-2 convertible preferred stock at $0.876 per share for gross proceeds of $4.9 million.118 In February 2016, the Company closed the final tranche of Series A-2 convertible preferred stock financing by selling an aggregate of 4,671,430 shares ofSeries A-2 convertible preferred stock at $0.876 per share for gross proceeds of $4.0 million.In October 2016, the Company closed the first tranche of its Series B round of financing by selling an aggregate of 7,519,592 shares of Series B convertiblepreferred stock at $12.125 per share for gross proceeds of $91.2 million, with an additional $9.0 million of Series B convertible preferred stock to be sold totwo investors within 180 days of the first tranche closing at the issuance price per share of the Series B convertible preferred stock. The Company accountedfor this issuance as forward options to issue shares at a fixed price. As the forward options expired in 180 days, and there was limited expected volatility inthe Series B convertible preferred stock issuance price, the value of the forward options was considered immaterial at December 31, 2016. In March 2017, theCompany issued an aggregate of 659,821 shares of Series B convertible preferred stock at $12.125 per share for gross proceeds of $8.0 million in fullsettlement of one of the forward options while the other expired unexercised.In June 2017, the Company closed the second and final tranche of its Series B convertible preferred stock round of financing by selling an aggregate of2,879,288 shares of Series B convertible preferred stock at $12.125 per share for gross proceeds of $34.9 million.Included in the terms of the Series B Preferred Stock Agreement were rights to purchase additional tranches of Series B convertible preferred stock under thesame terms as those provided at the initial closing. The Company did not separately account for these tranche purchase rights as a forward option as neitherthe purchasers nor the Company had a commitment or obligation to purchase or sell additional shares until the tranche closing occurred.In March 2018, the Company amended and restated its certificate of incorporation to, among other things, (i) increase its authorized shares of common stockfrom 122,000,000 to 140,000,000 shares, (ii) increase its authorized shares of preferred stock from 91,739,149 to 103,283,818 shares, of which 11,544,669shares were designated as Series C convertible preferred stock, and (iii) set forth the rights, preferences and privileges of the Series C convertible preferredstock. In March 2018, the Company sold 3,590,573 shares of Series C convertible preferred stock at $15.3317 per share for net proceeds of $54.9 million andin April 2018, the Company sold an additional 322,852 shares of Series C convertible preferred stock $15.3317 per share for net proceeds of $5.0 million.Each share of Series C convertible preferred stock was convertible into one share of the Company’s common stock. Each share of preferred stock wasautomatically converted into one share of common stock upon the consummation of a qualified public offering. A qualified public offering was defined as aninitial public offering that resulted in listing on a U.S. national securities exchange and at least $30.0 million of gross proceeds at a per share price of not lessthan the Series C original issue price of $15.3317.The Company evaluated the other rights, preferences and privileges of each series of convertible preferred stock and concluded that there were nofreestanding derivative instruments or any embedded derivatives requiring bifurcation.Upon the closing of the IPO, all of the Company’s outstanding shares of convertible preferred stock were converted into 32,073,149 shares of common stock.In addition, all 763,501 of the Company’s convertible preferred stock warrants were converted into warrants to purchase shares of common stock. As ofDecember 31, 2018, the Company had no shares of convertible or preferred stock issued or outstanding.As of December 31, 2017, convertible preferred stock consisted of the following (in thousands, except share amounts): SharesAuthorized Shares Issuedand Outstanding LiquidationPreference CarryingValue Series A-1 9,085,738 2,887,086 $2,495 $2,457 Series A-2 32,653,411 10,498,269 9,198 9,214 Series B 50,000,000 14,774,369 179,132 162,285 Total convertible preferred stock 91,739,149 28,159,724 $190,825 $173,956 119 Prior to the conversion of the convertible preferred stock upon closing of the IPO, the rights, preferences and privileges of the convertible preferred stock wereas follows:Conversion RightsEach share of convertible preferred stock was convertible at the right and option of the stockholder, at any time after the date of issuance, into such number offully paid and non-assessable shares of common stock on a one for one ratio (1:1 conversion ratio). The Series A-1 conversion price was $0.864 per share, theSeries A-2 conversion price was $0.876 per share, the Series B conversion price was $12.125 per share and the Series C conversion price was $15.3317 pershare, in each case, subject to certain antidilution adjustments as provided in the Company’s amended and restated certificate of incorporation.Each share of convertible preferred stock was automatically convertible into a fully paid, non-assessable share of common stock at the then-effectiveconversion rate for such share (i) upon the closing of a firm commitment, underwritten initial public offering of the Company’s common stock with aggregategross proceeds of not less than $30.0 million and a price per share to the public of not less than $15.3317 per share; or (ii) upon the receipt by the Companyof a written request for such conversion from at least 60% of the holders of the convertible preferred stock then outstanding (voting together as a single classand on an as-converted basis), or if later, the effective date for conversion specified in such requests.Liquidation RightsIn the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or a deemed liquidation event, as further defined in theCompany’s amended and restated certificate of incorporation, prior to and in preference to any distribution of any of the assets of the Company to the holdersof Series B convertible preferred stock and the Series A-1 and Series A-2 convertible preferred stock and common stock, the holders of Series C convertiblepreferred stock would have been paid, on a pari passu basis, an amount per share equal to the Series C liquidation preference of $15.3317 per share, plus anamount equal to any dividends declared but unpaid thereon (the “Series C Liquidation Preference”). If upon any such liquidation, dissolution or winding upof the Company or a deemed liquidation event, the assets of the Company available for distribution to its stockholders had been insufficient to pay theholders of Series C convertible preferred stock the full amount to which they were entitled, the holders of the Series C convertible preferred stock would haveshared ratably in any distribution of the assets available for distribution in proportion to the respective amounts which would otherwise have been payable inrespect of the shares held by them upon such distribution if all amounts payable on or with respect to such shares were paid in full.After the payment or setting aside for payment to the holders of the Series C convertible preferred stock of the full amount of the Series C LiquidationPreference, prior to any distribution of any of the assets of the Company to the holders of the Series A-1 and Series A-2 convertible preferred stock andcommon stock, the holders of Series B convertible preferred stock would have been paid, on a pari passu basis, an amount per share equal to the Series Bliquidation preference of $12.125 per share for Series B, plus, in each case, an amount equal to any dividends declared but unpaid thereon (the “Series BLiquidation Preference”). If upon any such liquidation, dissolution or winding up of the Company or deemed liquidation event, the assets of the Companyavailable for distribution to its stockholders had been insufficient to pay the holders of shares of Series B convertible preferred stock the full amount to whichthey shall be entitled, the holders of the Series B convertible preferred stock would have shared ratably in any distribution of the assets available fordistribution in proportion to the respective amounts which would otherwise have been payable in respect of the shares held by them upon such distribution ifall amounts payable on or with respect to such shares were paid in full.After the payment or setting aside for payment to the holders of the Series B convertible preferred stock of the full amount of the Series B LiquidationPreference, prior to any distribution of any of the assets of the Company to the holders of the common stock, the holders of Series A-1 and Series A-2convertible preferred stock would have been paid, on a pari passu basis, an amount per share equal to $0.864 per share for Series A-1 and $0.876 per share forSeries A-2, plus, in each case, an amount equal to any dividends declared but unpaid thereon (the “Series A Liquidation Preference”). If upon any suchliquidation, dissolution or winding up of the Company or deemed liquidation event, the assets of the Company available for distribution to its stockholdershad been insufficient to pay the holders of shares of Series A-1 and Series A-2 convertible preferred stock the full amount to which they shall be entitled, theholders of the Series A-1 and Series A-2 convertible preferred stock would have shared ratably in any distribution of the assets available for distribution inproportion to the respective amounts which would otherwise have been payable120 in respect of the shares held by them upon such distribution if all amounts payable on or with respect to such shares were paid in full.After the payments or setting aside for payment to the holders of convertible preferred stock of the full amounts specified above, the entire remaining assets ofthe Company legally available for distribution shall be distributed pro rata to holders of the common stock of the Company in proportion to the number ofshares of common stock held by them.Voting RightsThe holders of outstanding shares of Series A-1 and Series A-2 convertible preferred stock, voting together as a single class, were entitled to elect twomembers of the Company’s Board of Directors. The holders of outstanding shares of Series B convertible preferred stock, voting together as a single class,were entitled to elect one member of the Company’s Board of Directors.Additionally, each holder of the Company’s convertible preferred stock was entitled to a vote equal to the number of shares of common stock into which theshares of convertible preferred stock could have been converted as of the record date. The holders of convertible preferred were entitled to vote on all matterson which the common stock shall be entitled to vote.Dividend RightsHolders of the Series A-1, Series A-2, Series B and Series C convertible preferred stock were entitled to receive non-cumulative dividends at a rate of 6% ofthe original respective series of convertible preferred stock issuance price. Only after payment of the dividends to the holders of Series C convertible preferredstock were the holders of shares of Series B, Series A-1 and Series A-2 convertible preferred stock be entitled to receive dividends, out of any assets legallyavailable therefore, prior and in preference to any declaration or payment of any dividend (other than dividends on the common stock payable solely incommon stock) on the common stock.After the payment or setting aside for payment of the dividends described above, any additional dividends (other than dividends on common stock payablesolely in common stock) set aside or paid in any fiscal year could have been set aside or paid among the holders of the convertible preferred stock andcommon stock then outstanding on a pari passu basis in proportion to the greatest whole number of shares of common stock which would have been held byeach such holder if all shares of convertible preferred stock were converted at the then-effective conversion rate.Dividends were only payable as and if declared by the Board of Directors. To date, the Company has not declared or paid any dividends.Redemption RightsThe convertible preerred stock was not mandatorily redeemable as it did not have a set redemption date or a date after which the shares may be redeemed bythe holders. A redemption event would have occurred only upon the occurrence of certain change in control events that are outside the Company’s control,including a sale, lease, transfer, or other disposition of all or substantially all of the Company’s assets. The Company has elected not to adjust the carryingvalues of the convertible preferred stock to the liquidation preferences of such shares because it is uncertain whether or when an event would have occurredthat would obligate the Company to pay the liquidation preferences to holders of shares of convertible preferred stock. Subsequent adjustments to thecarrying values of the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur. 10. Stock-Based CompensationEquity Incentive PlansIn March 2018, the Company’s board of directors adopted the Company’s 2018 Incentive Award Plan (the “2018 Plan”). The 2018 Plan was approved by theCompany’s stockholders in April 2018 and became effective on May 2, 2018. The 2018 Plan initially reserved 4,289,936 shares for the issuance of stockoptions as well as any automatic121 annual increases in the number of shares of common stock reserved for future issuance under the 2018 Plan. Awards granted under the 2018 Plan expire nolater than ten years from the date of grant. For stock options, the option price shall not be less than 100% of the estimated fair value on the day of grant.Options granted typically vest over a four-year period but may be granted with different vesting terms. Unvested options not exercised at the time of anemployee’s termination of employment are added back to the 2018 Plan.Following the Company’s IPO and in connection with the effectiveness of the 2018 Plan, the 2013 Equity Incentive Plan (the “2013 Plan”) terminated andno further awards will be granted under that plan. All outstanding awards under the 2013 Plan will continue to be governed by their existing terms and theshares that remained outstanding for issuance under the 2013 Plan were transferred into the 2018 Plan. As of December 31, 2018, there was an aggregate5,058,434 shares of common stock authorized for issuance under the 2018 Plan.Prior to its termination, the 2013 Plan provided for the granting of incentive stock options (“ISOs”), non-statutory stock options (“NSOs”) and restrictedshares to employees, directors, and consultants at the discretion of management and the Board of Directors. The exercise price of an ISO and NSO shall not beless than 100% of the estimated fair value of the shares on the date of grant, and the exercise price of an ISO and NSO granted to a 10% stockholder shall notbe less than 110% of the estimated fair value of the shares on the date of grant. For awards granted between September 2017 and February 2018 with anexercise price of $3.42, a deemed fair value ranging from $3.95 to $8.47 per share was used in calculating stock-based compensation expense, which wasdetermined using management hindsight. Options granted under the 2013 Plan expire no later than 10 years from the date of grant and generally vest over afour-year period but may be granted with different vesting terms. Unvested options not exercised at the time of an employee’s termination of employment areadded back to the 2018 Plan.Under the 2013 Plan, the Company permited early exercise of certain stock options prior to vesting. These unvested shares are subject to repurchase by theCompany at the original issuance price in the event the optionee’s employment is terminated either voluntarily or involuntarily. The amounts paid for sharespurchased under an early exercise of stock options and subject to repurchase by the Company are reported as a liability and reclassified into additional paid-in capital as the shares vest.Stock Option ActivityA summary of the Company’s stock option activity under the 2013 and 2018 Plan is as follows: SharesAvailablefor Grant OutstandingOptions Weighted-AverageExercisePrice Weighted-AverageRemainingContractTerm AggregateIntrinsicValue (in Years) (in thousands) Balances at December 31, 2017 918,595 4,196,213 $3.06 Retired from 2013 Plan (378,875) — — Authorized 4,289,936 — — Granted (2,082,265) 2,082,265 13.20 Exercised — (501,329) 3.17 Canceled 280,411 (276,618) 5.82 Balances at December 31, 2018 3,027,802 5,500,531 $6.75 8.49 $53,051 Vested and exercisable at December 31, 2018 1,619,419 $2.72 7.65 $21,929 Vested and expected to vest at December 31, 2018 5,500,531 $6.75 8.49 $53,051 The total intrinsic value of options exercised was $1.5 million, $0.1 million and $20,000 for the years ended December 31, 2018, 2017 and 2016,respectively. The weighted-average estimated fair value of stock options granted was $13.20, $3.40 and $0.32 for the years ended December 31, 2018, 2017and 2016, respectively.The aggregate intrinsic value of options exercisable was $21.9 million and $3.3 million as of December 31, 2018 and 2017, respectively.122 As of December 31, 2018, the total stock-based compensation cost related to options granted but not yet amortized was $20.6 million and will be recognizedover a weighted-average period of approximately 4.1 years. The total grant-date fair value of stock options granted to employees that vested during the yearsended December 31, 2018 and 2017 was approximately $3.5 million and $1.5 million. respectively.Stock Options Granted to Employees with Service-Based VestingThe fair value of stock options granted to employees was estimated on the date of grant using the Black-Scholes option pricing model using the followingassumptions: Year Ended December 31, 2018 2017 2016 Expected dividend yield — — — Expected term of options (in years) 6.1 5.6–6.7 5.3–6.1 Risk-free interest rate 2.6%-3.0% 1.8%–2.2% 1.2%–2.1% Expected stock price volatility 87.4%-92.6% 77.0%–82.0% 76.1%–79.7% The valuation assumptions were determined as follows:Expected Term—The expected term represents the period that the options granted are expected to be outstanding and is determined using the simplifiedmethod (based on the mid-point between the vesting date and the end of the contractual term) as the Company has concluded that its stock option exercisehistory does not provide a reasonable basis upon which to estimate expected term.Expected Volatility—The Company used an average historical stock price volatility of comparable public companies within the biotechnology andpharmaceutical industry that were deemed to be representative of future stock price trends as the Company does not have a sufficient historical tradinghistory for its own common stock. The Company will continue to apply this process until a sufficient amount of historical information regarding thevolatility of its own stock price becomes available.Risk-Free Interest Rate—The Company based the risk-free interest rate over the expected term of the options based on the constant maturity rate of U.S.Treasury securities with similar maturities as of the date of the grant.Expected Dividends—The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future. Therefore, the expecteddividend yield is zero.Performance Contingent Stock Options Granted to EmployeesDuring the year endend December 31, 2018, the Board of Directors granted performance contingent stock option awards exercisable for 53,575 shares, tocertain members of the Company’s executive team. These awards had a weighted average exercise price of $3.42 which was based on the fair market value onthe grant date, as determined by the Board of Directors, and vest upon the successful achievement of one or more specified performance goals.The total estimated fair value of employee performance contingent stock option awards was $0.4 million and was estimated at the date of grant using a Black-Scholes option-pricing model using the same assumptions as the stock options granted to employees with service-based vesting conditions. As of December 31, 2018, and 2017, there were 329,498 and 275,922 performance contingent stock option awards outstanding with a total grant date fairvalue of $0.7 million and $0.3 million respectively. As of December 31, 2018, and 2017, the Company determined that the achievement of the requisiteperformance conditions was not probable and, as a result, no compensation cost was recognized for these awards.123 Performance and Market Contingent Stock Options Granted to EmployeesDuring the year ended December 31, 2018, the Board of Directors granted performance and market contingent stock option awards exercisable for 160,727shares of common stock to certain members of the Company’s executive team. These awards had a weighted average exercise price of $3.42, which was basedon the fair market value on the grant date, as determined by the Board of Directors. The total estimated grant-date fair value of these options was $0.7 million.Key assumptions in the valuation model included expected volatility, a risk-free interest rate, expected dividend yield, and an expected term unique to theterms of these awards.Under the performance and market contingent awards, 53,575 of the shares have three separate market triggers for vesting based upon (i) the closing of afinancing where the Company sells shares of its equity securities to institutional investors at a minimum price per share, (ii) a change in control withaggregate proceeds payable for the Company’s common stock at a minimum price per share, or (iii) an initial public offering that becomes effective at aminimum specified price per share. The remaining 107,152 shares have three separate market triggers for vesting based upon (i) the closing of a financingwhere the Company sells shares of its equity securities to institutional investors at a minimum pre-money valuation, (ii) a change in control with minimumaggregate proceeds payable for the Company’s common stock at a minimum price per share, or (iii) either an initial public offering or an achievement of aminimum market capitalization, as measured by a trailing 30 day volume-weighted average price. By definition, the market condition in these awards can only be achieved after the performance condition of a liquidity event has been achieved. As such, therequisite service period is based on the estimated period over which the market condition can be achieved. When a performance goal is deemed to beprobable of achievement, which for liquidity events is generally upon achievement, time-based vesting and recognition of stock-based compensationexpense commence. As of December 31, 2018 and 2017, there were 454,584 and 360,594 performance and market contingent stock option awards outstanding with a grant datetotal fair value of $1.0 million and $0.4 million respectively. As of December 31, 2018 and 2017, the Company determined that the achievement of therequisite performance conditions was not probable and, as a result, no compensation cost was recognized for these awards.Stock-Based Compensation for NonemployeesThe Company has granted options to purchase shares of common stock to consultants in exchange for services performed. During the years endedDecember 31, 2018 and 2017, the Company granted options to purchase an aggregate of 20,337 and 235,250 shares (of which an aggregate of 169,491 wereissued outside of the 2018 and 2013 Plans) of the Company’s common stock with a weighted average exercise price of $6.19 and $3.39 per share,respectively.The fair value of stock options granted to nonemployees was estimated on the date of grant using the Black-Scholes option pricing model. The valuationassumptions used were substantially consistent with the assumption used to value the employee options with the exception of the expected term which wasbased on the contractual term of the award. During the years ended December 31, 2018 and 2017, stock-based compensation expense recognized related tononemployee options was $1.2 million and $0.4 million, respectively.Restricted StockA summary of the Company’s restricted stock activity for the year ended December 31, 2018 was as follows: Shares Weighted-AverageGrant DateFair Value Unvested at December 31, 2017 478,971 $4.57 Granted — $4.57 Vested (119,742) $4.57 Unvested at December 31, 2018 359,229 $4.57124 In October 2017, the Company and an executive officer entered into two restricted stock agreements whereby the executive officer purchased an aggregate of625,084 shares of restricted stock of which 146,113 shares vested immediately, 119,742 shares vest on January 1, 2018 and 359,229 shares vest on January 1,2019. As discussed in Note 8, the purchase of the restricted stock was through the issuance of promissory notes which were considered to be non-recourse insubstance and accordingly, considered an option for accounting purposes. The Company measured compensation cost for this option based on its fair valueon the grant date using the Black-Scholes option pricing model considering an expected term commensurate with the expected timing to a liquidity eventwhich would trigger repayment of these promissory notes and an exercise price consistent with the repayment term of the promissory notes. The Companyrecognized compensation cost over the requisite service period with an offsetting credit to additional paid-in capital. The shares of restricted stock have onlybeen included in the shares issued and outstanding as such shares are legally issued.2018 Employee Stock Purchase PlanIn March 2018, the Company’s board of directors adopted the Company’s 2018 Employee Stock Purchase Plan (the “2018 ESPP”). The 2018 ESPP wasapproved by the Company’s stockholders in April 2018 and became effective on May 2, 2018. The 2018 ESPP reserved 536,242 shares of common stock forissuance pursuant to future awards, as well as any automatic increases in the number of shares of our common stock reserved for future issuance under thisplan. Under the 2018 ESPP, employees are offered the option to purchase the Company’s common stock at a discount during the offering periods, at semi-annualintervals, with their accumulated payroll deductions. The option purchase price will be 85% of the lower of the closing trading price per share at thebeginning of the offering period or at the purchase date. The 2018 ESPP provides for consecutive offering periods and eligible employees may elect towithhold up to 15% of their compensation through payroll deductions during the offering period for the purchase of stock. The maximum number of sharesthat may be purchased by any one participant is limited to 15,000 shares in each offering period and $25,000 in fair market value during any calendar yearper the Internal Revenue Code limits. The first offering period commenced on September 16, 2018.The fair values of the rights granted under the 2018 ESPP were calculated using the following assumptions: Year Ended December 31, 2018 Expected dividend yield — Expected term of options (in years) 0.7 Risk-free interest rate 2.41% Expected stock price volatility 73.18% Stock-Based Compensation ExpenseThe following table sets forth the total stock-based compensation expense for all options granted to employees and nonemployees, including shares soldthrough the issuance of non-recourse promissory notes which are considered to be options for accounting purposes, and costs associated with the Company’s2018 ESPP included in the Company’s statement of operations (in thousands): Year Ended December 31, 2018 2017 2016 Research and development $6,043 $1,695 $164 General and administrative 3,398 1,339 60 Total $9,441 $3,034 $224 125 11. WarrantsIn June 2013, the Company granted warrants to its then Chief Executive Officer (“CEO”), considered to be a related party, to purchase 192,823 shares ofSeries A-1 convertible preferred stock with an exercise price of $0.65 per share and 190,226 shares of Series A-2 convertible preferred stock at a price of $0.66per share as compensation. In January 2015, the Company granted warrants to the aforementioned CEO to purchase an aggregate of 380,452 shares of SeriesA-2 convertible preferred stock with an exercise price of $0.66 per share as compensation. Upon the completion of the IPO, these warrants converted tocommon stock warrants. These warrants were exercisable beginning on January 1, 2018 and expired on the earlier of (i) December 31, 2018, (ii) December 31of the year in which a change of control occurs or (iii) December 31 of the year in which the holder terminates service. All of the vested warrants expiredunexercised on December 31, 2018.In October 2013, the Company granted warrants to a nonemployee to purchase an aggregate of 96,610 shares of common stock with an exercise price of$0.18 per share of which 9,425 warrants vested immediately. During April 2018 the nonemployee exercised the vested shares and the remaining unvestedwarrants expired on May 3, 2018 upon the closing of the IPO.12. Net Loss per Common ShareBasic net loss per share is calculated by dividing net loss by the weighted average number of shares outstanding for the period. Diluted net loss per share iscalculated by dividing net loss by the weighted average number of shares of common stock and potential dilutive common stock equivalents outstandingduring the period if the effect is dilutive.The calculation of diluted earnings (loss) per share also requires that, to the extent the presumed issuance of additional shares as contingent consideration isdilutive to earnings (loss) per share for the period, adjustments to net income or net loss used in the calculation are required to remove the change in fairvalue of the contingent consideration liability for the period. Likewise, adjustments to the denominator are required to reflect the related dilutive shares. Inall periods presented, the Company’s outstanding stock options, convertible preferred stock, early exercised common stock subject to future vesting,restricted stock accounted for as options common and preferred stock warrants, shares subject to the 2018 ESPP and presumed issuance of additional shares ascontingent consideration were excluded from the calculation of diluted net loss per share because their effects were antidilutive.A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except pershare amounts): December 31, 2018 2017 2016 (in thousands, except share and per share amounts) Numerator: Net loss $(76,398) $(44,656) $(30,404)Denominator: Weighted average number of shares outstanding—basic and diluted 28,269,907 3,197,516 2,662,841 Net loss per share—basic and diluted $(2.70) $(13.97) $(11.42) 126 Since the Company was in a loss position for all periods presented, basic net loss per common share is the same as diluted net loss per common share as theinclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted pershare calculations because they would be anti-dilutive were as follows: Year Ended December 31, 2018 2017 2016 Convertible preferred stock — 28,159,724 24,620,615 Options to purchase common stock 5,500,531 4,365,694 508,418 Early exercised common stock subject to future vesting 704,028 831,439 1,287,435 Restricted stock accounted for as options 359,228 625,084 — Warrants to purchase convertible preferred stock — 763,501 763,501 Warrants to purchase common stock — 96,610 96,610 Shares subject to the 2018 ESPP 27,622 — — Total 6,591,409 34,842,052 27,276,579 Up to 606,218 shares may be contingently issued, if certain performance conditions are met under the Company’s in-licensing agreements.13. Defined Contribution PlanThe Company sponsors a 401(k) Plan that stipulates that eligible employees can elect to contribute to the 401(k) Plan, subject to certain limitations, on apretax basis. The Company does not match any employee contributions. In January 2019, the Company began to match 4% of employees’ salary.14. Income TaxesThe Company has incurred net operating losses for all the periods presented. The Company has not reflected the benefit of any such net operating losscarryforwards in the accompanying financial statements. The Company has established a full valuation allowance against its deferred tax assets due to theuncertainty surrounding the realization of such assets. All losses to date have been incurred domestically as the Company has no international operations orsubsidiaries.No provision for U.S. income taxes exists due to tax losses incurred in all periods presented. All losses incurred were U.S. based.The effective tax rate for the years ended December 31, 2018, 2017 and 2016 is different from the federal statutory rate primarily due to the valuationallowance against deferred tax assets as a result of insufficient sources of income. The effective tax rate of the provision for income taxes differs from thefederal statutory rate as follows: Year Ended December 31, 2018 2017 2016 Taxes at the U.S. statutory income tax rate 21.0 % 34.0 % 34.0 %State tax, net of federal benefit 0.9 — — Other (0.1) (2.2) — Stock-based compensation 0.3 — — General business credits 1.0 — — Change in valuation allowance (23.1) (13.3) (21.0) Non-deductible interest expense — — (13.0) Change in income tax rate due to Tax Act — (18.5) — Total provision for income taxes — % — % — % On December 22, 2017, the U.S. federal government enacted the Tax Cuts and Jobs Act (Tax Act). The Tax Act contains, among other things, significantchanges to corporate taxation, including reduction of the corporate tax rate127 from a top marginal rate of 35% to a flat rate of 21% for tax years beginning after December 31, 2017, limitation of the deduction for net operating losses to80% of current year taxable income and elimination of net operating loss carrybacks, implementing a territorial tax system, and requiring a mandatory one-time tax on U.S. owned undistributed foreign earnings and profits known as the transition tax.Pursuant to SAB 118, an entity may select between one of three scenarios to determine a reasonable estimate arising from the Tax Act. The scenarios are (i) afinal estimate which effectively closes the measurement window; (ii) a reasonable estimate leaving the measurement window open for future revisions; and(iii) no estimate as the law is still being analyzed. The Company was able to provide a reasonable estimate for the revaluation of deferred taxes. As such, theCompany recorded a $8.3 million reduction in deferred tax assets for the revaluation of deferred taxes in 2017 which was offset by a corresponding decreaseto the Company’s full valuation allowance. The ultimate impact of the Act did not differ materially from provision amounts recorded. Adjustments, if any,would not have impacted the statement of operations and comprehensive loss due to the full valuation allowance on the Company’s deferred tax assets.The tax effects of significant items comprising the Company’s deferred tax assets are as follows: December 31, 2018 2017 (in thousands) Deferred tax assets: Net operating loss $29,926 $16,530 Research and development credits 3,865 1,879 Stock-based compensation 1,839 671 Contingent consideration 954 — Accruals and other 1,040 895 Charitable contributions 253 330 Total deferred tax assets 37,877 20,305 Valuation allowance (37,877) (20,236)Net deferred tax assets — 69 Deferred tax liability — (69)Net deferred tax assets $— $— ASC 740 requires that the tax benefit of net operating losses, temporary differences and credit carryforwards be recorded as an asset to the extent thatmanagement assesses that realization is "more likely than not." Realization of the future tax benefits is dependent on the Company's ability to generatesufficient taxable income within the carryforward period. Because of the Company's recent history of operating losses, management believes that recognitionof the deferred tax assets arising from the above-mentioned future tax benefits is currently not likely to be realized and, accordingly, has provided a valuationallowance.Realization of the net deferred tax assets is dependent upon future taxable income, if any, the amount and timing of which is uncertain. Based on the weightof available positive and negative objective evidence, management believes it more likely than not that the Company’s deferred tax assets are not realizable.Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. For the years ended December 31, 2018 and 2017, the net increase inthe valuation allowance was $17.6 million and $9.4 million, respectively.Net operating losses and tax credit carryforwards as of December 31, 2018 are as follows: Amount Expiration YearsNet operating losses, federal (post December 31, 2017) $64,593 indefiniteNet operating losses, federal (pre January 1, 2018) 64,136 2030 - 2038Net operating losses, state 64,663 2030 - 2039Tax credits, federal 2,988 2031 - 2039Tax credits, state 2,692 Indefinite128 The net operating loss and research and development credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service(“IRS”) and state tax authorities and may become subject to an annual limitation in the event of certain future cumulative changes in the ownership interestof significant stockholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code of 1986. TheCompany has performed this analysis and concluded that an additional $1.6 million of net operating losses and research development credits, collectively,were limited under Section 382, which has been reflected in the amounts disclosed in the financials.The Company determines its uncertain tax positions based on a determination of whether and how much of a tax benefit taken by the Company in its taxfilings is more likely than not to be sustained upon examination by the relevant income tax authorities.A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: December 31, 2018 2017 (in thousands) Gross unrecognized tax benefits at January 1 $3,065 $2,800 Additions for tax positions taken in the current year 753 478 Reductions for tax positions taken in the prior year (104) (213)Gross unrecognized tax benefits at December 31 $3,714 $3,065 If recognized, none of the unrecognized tax benefits as of December 31, 2018 and 2017 would reduce the annual effective tax rate, primarily due tocorresponding adjustments to the valuation allowance. The Company will recognize both accrued interest and penalties related to unrecognized benefits inincome tax expense. As of December 31, 2018 and 2017, no liability has been recorded for potential interest or penalties. The Company does not expect theunrecognized tax benefits to change significantly over the next 12 months.Since the Company is in a loss carryforward position, the Company is generally subject to examination by the U.S. federal, state and local income taxauthorities for all tax years in which a loss carryforward is available.15. Subsequent EventsIn February 2019, the Company entered into a lease agreement for approximately 62,655 square feet of office, research and development and laboratory spacein South San Francisco, California. The lease is expected to commence on October 1, 2019. The lease has an approximately ten year term with an option toextend for a period of eight years subject to certain conditions. Pursuant to the lease agreement, the Company provided a $0.9 million letter of credit to the landlord for the term of the lease.16. Selected Quarterly Financial Data (Unaudited)The following tables show a summary of the Company’s quarterly financial information for each of the four quarters of 2018 and 2017 and has been preparedin accordance with GAAP for interim financial reporting (in thousands, except for per share data): Quarter Year Ended December 31, 2018 First Second Third Fourth Loss from operations $(16,482) $(20,798) $(19,377) $(22,808)Net loss $(16,133) $(20,002) $(18,346) $(21,917)Net loss per common share, basic and diluted $(4.69) $(0.76) $(0.45) $(0.53)129 Quarter Year Ended December 31, 2017 First Second Third Fourth Loss from operations $(9,040) $(11,698) $(12,083) $(12,787)Net loss $(8,934) $(11,428) $(11,750) $(12,544)Net loss per common share, basic and diluted $(2.90) $(3.62) $(3.63) $(3.67) 130 Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure.None.Item 9A. Controls and Procedures.Evaluation of Disclosure Controls and ProceduresOur management, with the participation of our chief executive and financial officers, evaluated the effectiveness of our disclosures controls and procedures,as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, as of December 31, 2018. The term “disclosure controls and procedures,” as defined inRules 13a-15(e) and 15d-15(e) under the Exchange Act, means controls and other procedures of a company that are designed to ensure that informationrequired to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported withinthe time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed toensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated andcommunicated to the company’s management, including its principal executive and principal financial officers, as appropriate, to allow timely decisionsregarding required disclosure. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide onlyreasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possiblecontrols and procedures. Based on the evaluation of our disclosure controls and procedures as of December 31, 2018, our chief executive officer and chieffinancial officer concluded that, as of such date, our disclosure controls and procedures were effective at a reasonable assurance level.Management’s Annual Report on Internal Control over Financial ReportingThis Annual Report on Form 10-K does not include a report of management’s assessment regarding internal control over financial reporting due to atransition period established by rules of the SEC for newly public companies.Attestation Report of the Registered Public Accounting FirmThis Annual Report on Form 10-K does not include an attestation report of our registered public accounting firm due to an exemption established by theJOBS Act for “emerging growth companies.”This Annual Report on Form 10-K does not include a report of management’s assessment regarding internal control over financial reporting due to atransition period established by rules of the SEC for newly public companies.Changes in Internal Control over Financial ReportingManagement determined that, as of December 31, 2018, there were no changes in our internal control over financial reporting that occurred during the fiscalquarter then ended that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.Item 9B. Other Information.None.131 PART IIIItem 10. Directors, Executive Officers and Corporate Governance.Information required by this Item is incorporated herein by reference to the sections titled “Executive Officers,” “Election of Directors,” “CorporateGovernance” and “Section 16(a) Beneficial Ownership and Reporting Compliance” in our Definitive Proxy Statement with respect to our 2019 AnnualMeeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.Item 11. Executive Compensation.Information required by this Item is incorporated herein by reference to the section titled “Executive Compensation,” “Director Compensation” and“Corporate Governance” in our Definitive Proxy Statement with respect to our 2019 Annual Meeting of Stockholders to be filed with the SEC within 120days after the end of the fiscal year covered by this Annual Report on Form 10-K.Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.Information required by this Item is incorporated herein by reference to the section titled “Security Ownership of Certain Beneficial Owners andManagement” and “Equity Compensation Plan Information” in our Definitive Proxy Statement with respect to our 2019 Annual Meeting of Stockholders tobe filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.Item 13. Certain Relationships and Related Transactions, and Director Independence.Information required by this Item is incorporated herein by reference to the section titled “Certain Relationships and Related Party Transactions” and“Corporate Governance” in our Definitive Proxy Statement with respect to our 2019 Annual Meeting of Stockholders to be filed with the SEC within 120days after the end of the fiscal year covered by this Annual Report on Form 10-K.Item 14. Principal Accounting Fees and Services.Information required by this Item is incorporated herein by reference to the section titled “Ratification of Selection of Independent Registered PublicAccounting Firm” in our Definitive Proxy Statement with respect to our 2019 Annual Meeting of Stockholders to be filed with the SEC within 120 days afterthe end of the fiscal year covered by this Annual Report on Form 10-K.132 PART IVItem 15. Exhibits, Financial Statement Schedules. (a)The following documents are filed as part of this report:1. Financial StatementsSee Index to Financial Statements in Part II Item 8 of this Annual Report on Form 10-K.2. Financial Statement SchedulesAll schedules are omitted because they are not applicable or the required information is shown in the financial statements or notesthereto.3. Exhibits133 Exhibit Index Incorporated by ReferenceExhibitNumber Description Form Number Filing Date FiledHerewith3.1 Amended and Restated Certificate of Incorporation of Unity Biotechnology, Inc. 8-K 3.1 5-7-18 3.2 Amended and Restated Bylaws of Unity Biotechnology, Inc. 8-K 3.2 5-7-18 4.1 Reference is made to exhibits 3.1 through 3.2. 4.2 Form of Common Stock Certificate. S-1 4.2 4-23-18 4.3 Amended and Restated Investors’ Rights Agreement, dated as of March 15, 2018, byand among Unity Biotechnology, Inc. and the investors party thereto. S-1 4.3 4-5-18 10.1(a) Lease Agreement, dated as of May 13, 2016, by and between Unity Biotechnology,Inc. and BMR-Bayshore Boulevard L.P. S-1 10.1(a) 4-5-18 10.1(b) First Amendment to Lease Agreement, dated as of May 23, 2017, by and betweenUnity Biotechnology, Inc. and BMR-Bayshore Boulevard L.P. S-1 10.1(b) 4-5-18 10.2(a) Space License Agreement, dated as of October 20, 2016, by and between UnityBiotechnology, Inc. and BMR-Bayshore Boulevard L.P. S-1 10.2(a) 4-5-18 10.2(b) First Amendment to Space License Agreement, dated as of December 5, 2016, by andbetween Unity Biotechnology, Inc. and BMR-Bayshore Boulevard L.P. S-1 10.2(b) 4-5-18 10.2(c) Second Amendment to Space License Agreement, dated as of January 30, 2017, byand between Unity Biotechnology, Inc. and BMR-Bayshore Boulevard L.P. S-1 10.2(c) 4-5-18 10.3(a)# 2013 Equity Incentive Plan. S-1 10.3(a) 4-5-18 10.3(b)# Form of Stock Option Agreement under 2013 Equity Incentive Plan. S-1 10.3(b) 4-5-18 10.4(a)# 2018 Incentive Award Plan. S-1 10.4(a) 4-23-18 10.4(b)# Form of Stock Option Grant Notice and Stock Option Agreement under the 2018Incentive Award Plan. S-1 10.4(b) 4-5-18 10.4(c)# Form of Restricted Stock Award Grant Notice and Restricted Stock Award Agreementunder the 2018 Incentive Award Plan. S-1 10.4(c) 4-5-18 10.4(d)# Form of Restricted Stock Unit Award Grant Notice and Restricted Stock Unit AwardAgreement under the 2018 Incentive Award Plan. S-1 10.4(d) 4-5-18 10.5# 2018 Employee Stock Purchase Plan. S-1 10.5 4-23-18 10.6# Amended and Restated Non-Employee Director Compensation Program (EffectiveJanuary 1, 2019) X10.7# Form of Indemnification Agreement for directors and officers. S-1 10.7 4-5-18 10.8# Employment Agreement, dated January 29, 2018, by and between UnityBiotechnology, Inc. and Keith R. Leonard Jr. S-1 10.8 4-5-18 10.9# Employment Agreement, dated January 29, 2018, by and between UnityBiotechnology, Inc. and Nathaniel E. David. S-1 10.9 4-5-18 10.10# Employment Agreement, dated January 29, 2018, by and between UnityBiotechnology, Inc. and Robert C. Goeltz II. S-1 10.10 4-5-18 10.11# Employment Agreement, dated January 29, 2018, by and between UnityBiotechnology, Inc. and Jamie Dananberg. S-1 10.11 4-5-18 10.12# Employment Agreement, dated January 29, 2018, by and between UnityBiotechnology, Inc. and Daniel G. Marquess. S-1 10.12 4-5-18 10.13# Employment Agreement, dated January 29, 2018, by and between UnityBiotechnology, Inc. and Tamara L. Tompkins. S-1 10.13 4-5-18 134 10.14† Compound Library and Option Agreement, dated as of February 2, 2016, by andbetween Ascentage Pharma Group Corp. Ltd. and Unity Biotechnology, Inc. S-1 10.14 4-23-18 10.15† APG1252 License Agreement, dated as of February 2, 2016, by and betweenAscentage Pharma Group Corp. Ltd. and Unity Biotechnology, Inc. S-1 10.15 4-23-18 10.16† Research Services Agreement, dated as of February 2, 2016, by and betweenAscentage Pharma Group Corp. Ltd. and Unity Biotechnology, Inc. S-1 10.16 4-5-18 10.17† Amendment to APG1252 License Agreement, dated as of February 2, 2016, by andbetween Ascentage Pharma Group Corp. Ltd. S-1 10.17 4-5-18 10.18† Amendment to Compound Library and Option Agreement, dated as of February 2,2016, by and between Ascentage Pharma Group Corp. Ltd. and Unity Biotechnology,Inc. S-1 10.18 4-5-18 10.19(a)† Exclusive License Agreement, dated as of June 28, 2013, by and between the MayoFoundation for Medical Education and Research and Unity Biotechnology, Inc. S-1 10.19(a) 4-23-18 10.19(b)† Amendment No. 1 to Exclusive License Agreement, dated as of September 10, 2014,by and between the Mayo Foundation for Medical Education and Research and UnityBiotechnology, Inc. S-1 10.19(b) 4-23-18 10.19(c)† Amendment No. 2 to Exclusive License Agreement, dated as of November 17, 2014,by and between the Mayo Foundation for Medical Education and Research and UnityBiotechnology, Inc. S-1 10.19(c) 4-23-18 10.19(d)† Amendment No. 3 to Exclusive License Agreement, dated as of May 5, 2015, by andbetween the Mayo Foundation for Medical Education and Research and UnityBiotechnology, Inc. S-1 10.19(d) 4-23-18 10.19(e)† Amendment No. 4 to Exclusive License Agreement, dated as of September 15, 2016,by and between the Mayo Foundation for Medical Education and Research and UnityBiotechnology, Inc. S-1 10.19(e) 4-23-18 10.19(f)† Addendum to Amendment No. 4 to Exclusive License Agreement, dated as ofSeptember 15, 2016, by and between the Mayo Foundation for Medical Educationand Research and Unity Biotechnology, Inc. S-1 10.19(f) 4-23-18 10.19(g)† Amendment No. 5 to Exclusive License Agreement, dated as of October 17, 2016, byand between the Mayo Foundation for Medical Education and Research and UnityBiotechnology, Inc. S-1 10.19(g) 4-23-18 10.20† Amended and Restated License Agreement, dated as of January 27, 2017, by andbetween the Buck Institute for Research on Aging and Unity Biotechnology, Inc. S-1 10.20 4-23-18 10.21† License Agreement, dated as of November 3, 2016, by and between The JohnsHopkins University and Unity Biotechnology, Inc. S-1 10.21 4-23-18 10.22†† License Agreement for APG1197, dated as of January 2, 2019, by and betweenAscentage Pharma Group Corp. Ltd. And Unity Biotechnology, Inc. X10.23 Lease Agreement, dated as of February 28, 2019, by and between UnityBiotechnology, Inc. and Bayside Area Development, LLC X23.1 Consent of Independent Registered Public Accounting Firm X24.1 Power of Attorney. Reference is made to the signature page. X135 31.1 Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a)under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of theSarbanes-Oxley Act of 2002. X 31.2 Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a)under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of theSarbanes-Oxley Act of 2002. X 32.1** Certification of Principal Executive Officer and Principal Financial Officer Pursuant to18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-OxleyAct of 2002. X101.INS XBRL Instance Document X101.SCH XBRL Taxonomy Extension Schema Document X101.CAL XBRL Taxonomy Extension Calculation Linkbase Document X101.DEF XBRL Taxonomy Extension Definition Linkbase Document X101.LAB XBRL Taxonomy Extension Label Linkbase Document X101.PRE XBRL Taxonomy Extension Presentation Linkbase Document X †Confidential treatment has been granted for certain information contained in this exhibit. Such information has been omitted and filed separately withthe Securities and Exchange Commission.††Portions of this exhibit (indicated by asterisks) have been omitted pursuant to a request for confidential treatment filed separately with the Securitiesand Exchange Commission.#Indicates management contract or compensatory plan. **The certification attached as Exhibit 32.1 that accompanies this Annual Report on Form 10-K is not deemed filed with the Securities and ExchangeCommission and is not to be incorporated by reference into any filing of Unity Biotechnology, Inc. under the Securities Act of 1933, as amended, or theSecurities Exchange Act of 1934, as amended, whether made before or after the date of this Annual Report on Form 10-K, irrespective of any generalincorporation language contained in such filing.Item 16. Form 10-K Summary.None.136 SIGNATURESPursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused thisAnnual Report on Form 10-K to be signed on its behalf by the undersigned, thereunto duly authorized. Unity Biotechnology, Inc. Date: March 6, 2019By:/s/ Keith R. Leonard Jr. Keith R. Leonard Jr. Chief Executive Officer POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints each of Keith R.Leonard, Robert C. Goeltz II and Tamara L. Tompkins his or her true and lawful attorney-in-fact andagent, with full power of substitution, for him or her andin his or her name, place and stead, in any and allcapacities, to sign any and all amendments to this Annual Report on Form 10-K, and to file the same, withall exhibits thereto, and other documents in connection therewith, with the U.S. Securities and Exchange Commission, granting unto said attorneys-in-factand agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connectiontherewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming that all said attorneys-in-fact andagents, or their, his or her substitutes or substitutes, may lawfully do or cause to be done by virtue hereof.137 Pursuant to the requirements of the Securities Exchange Act of 1934, this Annual Report on Form 10-K has been signed by the following personson behalf of the Registrant in the capacities and on the dates indicated. Name Title Date /s/ Keith R. Leonard Jr. Chairman, Chief Executive Officer and Director(Principal Executive Officer) March 6, 2019Keith R. Leonard Jr. /s/ Robert C. Goeltz II Chief Financial Officer(Principal Financial and Accounting Officer) March 6, 2019Robert C. Goeltz II /s/ Paul L. Berns Director March 6, 2019Paul L. Berns /s/ Kristina M. Burow Director March 6, 2019Kristina M. Burow /s/ Graham K. Cooper Director March 6, 2019Graham K. Cooper /s/ Nathaniel E. David President and Director March 6, 2019Nathaniel E. David /s/ David L. Lacey Director March 6, 2019David L. Lacey /s/ Robert T. Nelsen Director March 6, 2019Robert T. Nelsen /s/ Margo Roberts Director March 6, 2019Margo Roberts /s/ Camille D. Samuels Director March 6, 2019Camille D. Samuels 138Exhibit 10.6UNITY BIOTECHNOLOGY, INC.AMENDED AND RESTATED NON-EMPLOYEE DIRECTOR COMPENSATION PROGRAM(EFFECTIVE JANUARY 1, 2019)Whereas the Unity Biotechnology, Inc. (the “Company”) Non-Employee Director Compensation Program was adopted under theCompany’s 2018 Incentive Award Plan (the “Plan”) and became effective upon the closing of the Company’s initial public offering ofits common stock (the “IPO”). This Amended and Restated Non-Employee Director Compensation Program (the “Amended Program”)shall be effective as of January 1, 2019. Capitalized terms not otherwise defined herein shall have the meaning ascribed in the Plan. Cash CompensationEffective on January 1, 2019, annual retainers will be paid in the following amounts to Non-Employee Directors: Non-Employee Director:$35,000Lead Independent Director$25,000Chair of Audit Committee:$15,000Chair of Compensation Committee:$10,000Chair of Nominating and Corporate Governance Committee:$8,000Audit Committee Member (other than Chair):$7,500Compensation Committee Member (other than Chair):$5,000Nominating and Corporate Governance Committee Member (other than Chair):$4,000 All annual retainers will be paid in cash quarterly in arrears promptly following the end of the applicable calendar quarter, but in noevent more than thirty (30) days after the end of such quarter. In the event a Non-Employee Director does not serve as a Non-EmployeeDirector, or in the applicable positions described above, for an entire calendar quarter, the retainer paid to such Non-Employee Directorshall be prorated for the portion of such calendar quarter actually served as a Non-Employee Director, or in such position, as applicable.Equity Compensation  Initial Stock Option Grant:Each Non-Employee Director who is initially elected or appointed to serve on the Board after theIPO shall be granted an Option under the Plan or any other applicable Company equity incentiveplan then-maintained by the Company to purchase that number of shares of Common Stock suchthat the Option has a Grant Date Value (as defined below) equal to $450,000 (the “InitialOption”). For the purposes of this Amended Program, “Grant Date Value” shall mean the fairvalue of an option determined using the Black-Scholes pricing model with the volume weightedaverage trading price of a share of Common Stock on the stock exchange on which the CommonStock is then listed or traded for the thirty (30) consecutive trading daysending on the trading day prior to the date of grant and the volatility, risk-free rate and lifeexpectancy assumptions in the Company’s most recent public filings disclosing thoseassumptions. The Initial Option will be automatically granted on the date on which such Non-EmployeeDirector commences service on the Board, and will vest as to 1/36th of the shares subject theretoon each monthly anniversary of the applicable date of grant such that the shares subject to theInitial Option are fully vested on the third anniversary of the grant, subject to the Non-EmployeeDirector continuing in service on the Board through each vesting date. Annual Stock Option Grant:Each Non-Employee Director who is serving on the Board as of the date of each annualshareholder meeting of the Company (each, an “Annual Meeting”) shall be granted an Optionunder the Plan or any other applicable Company equity incentive plan then-maintained by theCompany to purchase that number of shares of Common Stock such that the Option has a GrantDate Value equal to $225,000 (the “Annual Option”), provided that the number of shares subjectto the Annual Option will be prorated for any partial year of service as a Non-Employee Director. The Annual Option will be automatically granted on the date of the applicable Annual Meeting,and will vest in full on the earlier of (i) the first anniversary of the date of grant and (ii)immediately prior to the Annual Meeting following the date of grant, subject to the Non-Employee Director continuing in service on the Board through such vesting date. The per share exercise price of each Option granted to a Non-Employee Director shall equal the Fair Market Value of a share ofcommon stock on the date the Option is granted.The term of each Option granted to a Non-Employee Director shall be ten (10) years from the date the Option is granted.No portion of an Initial Option or Annual Option which is unvested or unexercisable at the time of a Non-Employee Director’stermination of service on the Board shall become vested and exercisable thereafter.Members of the Board who are employees of the Company or any parent or subsidiary of the Company who subsequently terminatetheir service with the Company and any parent or subsidiary of the Company and remain on the Board will not receive an InitialOption, but to the extent that they are otherwise eligible, will be eligible to receive, after termination from service with the Companyand any parent or subsidiary of the Company, Annual Options as described above.Change in ControlUpon a Change in Control of the Company, all outstanding equity awards granted under the Plan and any other equity incentive planmaintained by the Company that are held by a Non-Employee Director shall become fully vested and/or exercisable, irrespective of anyother provisions of the Non-Employee Director’s Award Agreement.  ReimbursementsThe Company shall reimburse each Non-Employee Director for all reasonable, documented, out-of-pocket travel and other businessexpenses incurred by such Non-Employee Director in the performance of his or her duties to the Company in accordance with theCompany’s applicable expense reimbursement policies and procedures as in effect from time to time.MiscellaneousThe other provisions of the Plan shall apply to the Options granted automatically pursuant to this Amended Program, except to theextent such other provisions are inconsistent with this Amended Program. All applicable terms of the Plan apply to this AmendedProgram as if fully set forth herein, and all grants of Options hereby are subject in all respect to the terms of such Plan. The grant ofany Option under this Amended Program shall be made solely by and subject to the terms set forth in a written agreement in a form tobe approved by the Board and duly executed by an executive officer of the Company.EffectivenessThis Amended Program is effective as of January 1, 2019. * * * * *I hereby certify that the foregoing Amended Program was duly adopted by the Board of Directors of Unity Biotechnology, Inc. onJanuary 29, 2019.Executed on this 29th day of January, 2019. /s/ Tamara L. TompkinsCorporate Secretary  Exhibit 10.22Compound License Agreement for APG1197This Compound License Agreement (the “Agreement”) effective as of the 2nd day of January, 2019, (the “Effective Date”)is made by and between Ascentage Pharma Group Corp. Ltd., a Hong Kong corporation and its affiliates (collectively,“Ascentage”), with a business address at 11/F, AXA CENTRE, Gloucester Road, Wanchai, Hong Kong, and Unity Biotechnology,Inc., a Delaware corporation (“Unity”), with a business address at 3280 Bayshore Blvd, Suite 100, Brisbane, California 94005. Eachof Ascentage and Unity shall be a “Party,” and both the “Parties.”BACKGROUNDA.Unity and Ascentage entered into (i) that certain Compound Library and Option Agreement dated February 2,2016, which was amended by that First Amendment dated March 28, 2018 (as amended the “Library Agreement”), pursuant to whichUnity has certain rights to acquire a license under the Licensed Intellectual Property to commercialize specified compounds, and (ii)that certain license agreement dated February 2, 2016, which was amended by that First Amendment dated March 28, 2018 (asamended “APG-1252 License Agreement”), pursuant to which Unity obtained a license to commercialize that certain BCL-2/BCL-xLinhibitor known as “APG-1252” (“APG-1252”, as further defined in the APG-1252 License Agreement) for treatment of age-relatedconditions; andB.Unity has exercised its rights under the Library Agreement to acquire from Ascentage such a license under theLicensed Intellectual Property for the Licensed Compound, all as set forth below on the terms and conditions herein.NOW, THEREFORE, for and in consideration of the covenants, conditions, and undertakings hereinafter set forth, it isagreed by and between the Parties as follows:ARTICLE 1DEFINITIONS1.1The following terms have the meanings set forth in the Library Agreement:Active CompoundAffiliateBack-up CompoundsCompoundsDevelopment CandidatesGreater ChinaINDOncology IndicationsPatentsStock AgreementThird Party  1.2“Ascentage Intellectual Property” means all Patents and Technology owned or Controlled by Ascentage or itsAffiliates during the Term.1.3“Ascentage Manufacturing Improvements” means any existing and future improvements to AscentageManufacturing IP developed by or for Ascentage during the Term (including Patents covering such improvements).1.4“Ascentage Manufacturing IP” means (a) Technology that is under the Control of Ascentage or its Affiliates as ofthe Effective Date Covering the manufacture of APG-1197 and/or the Back-up Compound or intermediates thereof, that is necessaryand/or reasonably useful for the manufacture of the Licensed Compound or the Back-up Compound, and (b) Technology Coveringany inventions described in clause (a).1.5“Fair Market Value” means with respect to a share of Unity common stock (i) the average price that Unitycommon stock is publicly trading at for [***] ([***]) days prior to the date in question, determined by the reported closing price of ashare of Common Stock on the NASDAQ National Market System, or (ii) if the common stock is not publicly traded, the value ofsuch stock as determined in good faith by Unity’s board of directors in reliance upon Unity’s most recent IRC Section 409Aindependent valuation of Unity’s common stock that it used for the purposes of granting stock options to its employees.1.6“Control” and its correlative terms, “Controlled” or “Controls” means, with respect to any Patent or item ofTechnology, that a Party or one of its Affiliates owns or possesses rights to such Patent or item of Technology sufficient to grant theaccess, license or sublicense contemplated in this Agreement without violating the terms of any agreement or other arrangement withany Third Party.1.7“Cover” and its correlative terms, “Covers”, “Covered” or “Covering” means (a) with respect to an issued patent,that, in the absence of a license, the use, offer for sale, sale, importation or manufacture of the product in question would infringe oneor more claims of such patent or (b) with respect to a pending patent application, that, in the absence of a license, the use, offer for sale,sale, importation or manufacture of the product in question would infringe one or more claims of such patent application, should suchclaims issue as published.1.8“Designation Letter” means the Development Candidate designation letter from Unity to Ascentage [***], a copyof which is attached hereto as Schedule 1.8.1.9“Enabling IP” means Patents and/or Technology of a Third Party that Covers or relates to a Licensed Product andis necessary or useful for the research, development, manufacture, use, sale or import of Licensed Products, including Patents directedto the composition and manufacture of Licensed Compound, but excluding Patents related to formulation and therapeutic methods.1.10“EMA” means the European Medicines Agency and any successor agency.1.11“Existing Agreements” means (a) that certain Exclusive License Agreement between Unity and the MayoFoundation for Medical Education and Research originally entered into by the parties effective June 28th, 2013; (b) that certainExclusive License Agreement2  between Unity and the Buck Institute for Research on Aging originally entered into by the parties effective February 3rd, 2014, asamended; and (c) that certain Exclusive License Agreement between Unity and the Board of Trustees of the University of Arkansasoriginally entered into by the parties effective April 28th, 2015.1.12“FDA” means the United States Food and Drug Administration and any successor agency.1.13“Field” means the prophylaxis and treatment of, and palliation of symptoms associated with, indications otherthan Oncology Indications.1.14“Generic Product” means a product which (a) contains as its active pharmaceutical ingredient a compound that is(or is substantially the same as) the Licensed Compound, and (b) has been placed on the market pursuant to a validly grantedmarketing authorization.1.15“Licensed Compound” means (a) the Development Candidate that was designated in the Designation Letter,[***], or (b) if the Back-up Compound that was designated in the Designation Letter is substituted under Section 3.3 below, aSubstitute Licensed Compound [***]. 1.16“Licensed Intellectual Property” means the Licensed Patents and Licensed Technology.1.17“Licensed Patents” means (i) the Patents set forth on Schedule 1.15 hereto, and (ii) any additional Patents ownedor Controlled by Ascentage or its Affiliates during the Term, in each case to the extent Covering the development, manufacture, use,sale, offering for sale, import, export or distribution of the Licensed Compound or a Licensed Product.1.18“Licensed Product” means a pharmaceutical product containing the Licensed Compound (either alone or withother active pharmaceutical ingredients), in all forms, presentations, formulation and dosage forms. Unity acknowledges and agreesthat in the event Unity [***].1.19“Licensed Product-Specific Patents” means those Licensed Patents that [***] the Licensed Compound and/orLicensed Product and [***].1.20“Licensed Technology” means Technology owned or Controlled by Ascentage or its Affiliates during the Term,in each case to the extent such Technology is necessary or reasonably useful for the development, manufacture or commercialization ofthe Licensed Compound or a Licensed Product.1.21“Manufacturing Process Improvement” means (a) the Unity Manufacturing Improvements and (b) AscentageManufacturing Improvements.3  1.22“Marketing Approval Application” or “MAA” means a New Drug Application (or its equivalent), as defined inthe U.S. Food, Drug and Cosmetic Act and the regulations promulgated thereunder, or any corresponding or similar application,registration or certification in any country.1.23“Net Sales” means the gross amount invoiced to non-Affiliate Third Parties on sales of Licensed Products byUnity or its Affiliates or Third Party Sublicensees, less the actual amounts incurred, allowed, or paid for the following items (if notpreviously deducted from the amount invoiced and provided that such deductions are calculated in accordance with generally acceptedaccounting principles of the United States of America (“GAAP”) on a consistent basis): (a) trade, cash, and quantity discounts; (b)amounts for claims, allowances or credits for returns, rejections or recalls; (c) freight, shipping and insurance charges allocable to suchLicensed Products; (d) sales taxes, duties and other governmental charges (including value added tax) on particular sales, but excludingwhat is commonly known as income taxes; (e) government mandated rebates; (f) contracted rebates; and (g) a provision foruncollectible accounts; in each case as determined from books and records of the selling party maintained in accordance with GAAP,as consistently applied by such selling party. In the event that Unity grants a sublicense to a Third Party Sublicensee hereunder, andreceives payments based upon such Third Party Sublicensee’s sales of Licensed Product, Unity may, with Ascentage’s consent, whichconsent shall not be unreasonably withheld or delayed, substitute the definition of “Net Sales,” used by such Third Party Sublicenseeto calculate its payments to Unity in place of the foregoing definition of “Net Sales” for purposes of calculating royalties payable toAscentage on such Third Party Sublicensee’s sales.1.24“Phase I Clinical Trial” means a human clinical trial, the principal purpose of which is preliminary determinationof safety of a drug in healthy individuals or patients, that would satisfy the requirements of 21 C.F.R. §312.21(a).1.25“Phase II Clinical Trial” means a clinical trial of a drug conducted on a limited number of patients for thepurpose of preliminary evaluation of clinical efficacy and safety of such drug, and/or to obtain an indication of the dosage regimenrequired, in each case that would satisfy the requirements of 21 C.F.R. 312.21(b).1.26“Phase III Clinical Trial” means a pivotal human clinical trial intended to gather additional information regardingthe safety and efficacy of the drug in patients with the disease being studied, which clinical study is designed to be of a size andstatistical power sufficient to support the filing of an MAA and that would satisfy the requirements of 21 C.F.R. 312.21(c).1.27“Prodrug” means a derivative of an Active Compound, which is transformed to release the Active Compound,which transformation can include, but is not limited to, [***].1.28“Technology” means all inventions, discoveries, improvements, trade secrets and proprietary methods andmaterials, whether or not patentable, directly relating to one or more structurally related Compounds, in each case that is Controlled byAscentage or its Affiliates during the Term of this Agreement and is necessary and/or reasonably useful to Unity in exercising its rightsor performing its obligations under this Agreement, including (a)4  methods of production or use of, Compounds and (b) data, formulations and techniques arising from the synthesis or characterizationof Compounds.1.29“Territory” means the entire world excluding Greater China.1.30“Third Party Sublicensee” means any Third Party to which Unity sublicenses the right to manufacture and/orcommercialize any Licensed Product. For the avoidance of doubt, “Third Party Sublicensee” shall not include Third Party distributors,service providers, vendors and suppliers that do not have the right to manufacture, market or promote Licensed Product.1.31“UM License Agreement” means that certain license agreement entered into by Ascentage and the Regents ofthe University of Michigan (“UM”) effective as of December 1, 2010, as amended by all amendments to such license agreementexisting as of the Effective Date.1.32“Unity Manufacturing Improvements” means existing and future (a) improvements to the AscentageManufacturing IP that are developed by of for Unity during the Term, and (b) Patents Covering any inventions described in clause(a). 1.33“Valid Claim” means a claim contained in an issued Patent within the Licensed Patents in any country that (a)has not expired; (b) has not been disclaimed; (c) has not been cancelled or superseded, or if cancelled or superseded, has beenreinstated; and (d) has not been revoked, held invalid, or otherwise declared unenforceable or not allowable by a tribunal or patentauthority of competent jurisdiction over such claim in such country from which no further appeal has or may be taken.5  1.34The following terms have the meanings set forth in the referenced provisions of this Agreement: Agreement RecitalsAPG-1252 RecitalsAPG-1252 License Agreement RecitalsAscentage RecitalsAscentage Indemnitees Section 11.1Bankruptcy Code Section 15.14China JVCO Section 9.1Competitive Product Section 8.2.1(a)Confidential Information Section 10.1Effective Date RecitalsEnforcement Action Section 8.2.1(a)Enforcing Party Section 8.4Indemnitee Section 11.3Inventing Party Section 4.2JCS Section 5.1Joint Steering Committee Section 5.1Liabilities Section 11.1Library Agreement RecitalsNon-Inventing Party Section 4.2Party/Parties RecitalsSubstitute Licensed Compound Section 3.3.1Substitution Notice Section 3.3.2Term Section 13.1Third Party Intellectual Property Section 2.3Unity RecitalsUnity Indemnitees Section 11.2 ARTICLE 2LICENSES2.1Licenses.2.1.1Development Licenses.(a)Subject to the terms and conditions of this Agreement, Ascentage hereby grants to Unity aroyalty-free, exclusive license in the Field and the Territory, with the right to grant sublicenses as provided in Section 2.2, under theLicensed Intellectual Property to research, develop and seek and obtain marketing approval for the Licensed Compound and LicensedProducts in the Field and Territory, and to have any of the foregoing performed on its behalf by a Third Party.(b)For the avoidance of doubt, until such time as Unity elects to discontinue development ofthe Licensed Compound and designate the Back-up Compound as a Substitute Licensed Compound as provided in Section 3.3 herein,the Parties agree that Unity6  will be permitted to continue to conduct activities with respect to the Back-up Compound as an Active Compound under the terms andconditions set forth in the Library Agreement.(c)Additionally, and notwithstanding Section 3.1 of the Library Agreement, Ascentage furtheragrees that Unity will be permitted to pursue formal preclinical development of the Back-Up Compound, including by initiating GLPtoxicity studies until the earlier of such time as (i) Unity designates the Back-Up Compound as a Substitute Licensed Compound inaccordance with Section 3.3. herein, (ii) Unity declares the Back-Up Compound to be a separate Development Candidate, in whichcase the Parties shall complete and execute a separate form of Compound License Agreement in accordance with Section 3.3 of theLibrary Agreement, or (iii) the Back-Up Compound is released pursuant to Section 3.5.3 of the Library Agreement. 2.1.2Manufacturing Licenses. Subject to the terms and conditions of this Agreement:(a)Ascentage hereby grants to Unity a royalty-free, non-exclusive license in the Field and theTerritory, with the right to grant sublicenses as provided in Section 2.2, under the Ascentage Intellectual Property, including allAscentage Manufacturing Improvements, to manufacture or have manufactured the Licensed Compound or the Back-up Compoundand Licensed Product for research, development, and commercialization purposes.(b)Unity hereby grants to Ascentage a worldwide, royalty-free, non-exclusive license, with theright to grant sublicenses as provided in Section 2.2, under the Unity Manufacturing Improvements to manufacture or havemanufactured BCL-2/BCL-xL inhibitor compounds outside the Field for research, development, and commercializationpurposes. Such license shall be subject to the terms and conditions of the Library Agreement, including without limitation, theexclusivity provisions and restrictions on compound development set forth in Article 4 therein.2.1.3Commercialization Licenses. Subject to the terms and conditions of this Agreement, Ascentagehereby grants to Unity a royalty-bearing, exclusive license in the Field and the Territory, with the right to grant sublicenses as providedin Section 2.2, under the Licensed Intellectual Property: (a) to use the Licensed Compound to make or have made the LicensedProducts; (b) to make or have made Licensed Products and all components thereof (including without limitation, Licensed Compound);and (c) to use, offer for sale, sell, import, export, market, promote and distribute Licensed Compound and Licensed Products; in eachcase, solely for use in the Field and Territory, and to have any of the foregoing performed on its behalf by a Third Party. For clarity, itis understood and agreed that Unity’s right under subsection (b) above to make or have made Licensed Products and all componentsthereof may only be exercised as (i) contemplated by Article 9, and (ii) permitted under Section 2.1.2(a).2.2Sublicenses. Either Party may grant and authorize sublicenses (through multiple tiers of sublicensees) within thescope of the licenses granted to it pursuant to this Agreement subject to the following: (a) the sublicensing Party shall not be relieved ofits obligations pursuant to this Agreement as a result of such sublicense and shall remain fully responsible and liable for any action oromission of such sublicensee which would constitute a breach of this7  Agreement if committed by the sublicensing Party as if the sublicensing Party had committed such action or inaction itself, (b) thesublicensee shall expressly agree in writing to be bound by and be subject to the terms and conditions of this Agreement in the samemanner and to the same extent as the sublicensing Party, (c) the sublicensing Party shall, at its own expense, investigate each report andindication of breach of any of its sublicense agreements, and the sublicensing Party shall promptly report to non-sublicensing Party anybreach learned of or discovered by sublicensing Party, (d) the sublicensing Party shall diligently enforce the terms and conditions ofeach sublicense agreement, including without limitation, by (i) pursuing all appropriate judicial and administrative action and relief inthe event of any breach of its sublicense agreement and (ii) upon the non-sublicensing Party’s request, terminating the sublicenseagreement upon a breach thereof, (e) with the prior written consent of the non-sublicensing Party, not to be unreasonablywithheld. For clarity, Unity shall remain responsible for all activities, including milestone and other payments due to Ascentage underthis Agreement, by or relating to Unity’s sublicensees.2.3Third Party Intellectual Property. If after the Effective Date, Ascentage acquires or licenses from a Third Partysubject matter that would fall within the Licensed Intellectual Property (“Third Party Intellectual Property”) that is subject to anypayment obligation to the Third Party, then Ascentage shall so notify Unity and Unity shall inform Ascentage if it wishes such subjectmatter to be included within the Licensed Intellectual Property. If Unity notifies Ascentage that it does wish such subject matter to beso included, the rights granted to Unity hereunder with respect to such Third Party Intellectual Property shall be subject to Unitypromptly reimbursing Ascentage for [***] and Unity shall reimburse Ascentage for [***]. Upon request by Unity, Ascentage shalldisclose to Unity a written description of such payment obligations. Notwithstanding the foregoing, Unity shall have the right to treatamounts paid to Ascentage as reimbursements for payments for Enabling IP for purposes of Section 6.5.2.4No Implied Licenses. Nothing herein shall be construed as granting Unity, by implication, estoppel or otherwise,any license or other right (a) to any intellectual property of Ascentage other than the Licensed Intellectual Property, (b) tocommercialize Licensed Products outside of the Field and Territory, (c) not relating to the Licensed Compound and Licensed Productsor (d) any right or license other than those expressly granted herein.2.5Exclusivity with Respect to Licensed Compound. Ascentage hereby covenants that except as expressly permittedunder any future agreement that the Parties may enter into pursuant to Article 9 below pertaining to the China JVCO, Ascentage shallnot: (a) research, develop, use or commercialize, and shall not authorize any Affiliate or other Third Party to research, develop, use orcommercialize, the Licensed Compound or any Licensed Product in the Field in the Territory, or (b) manufacture, or authorize anyThird Party to manufacture, the Licensed Compound or any Licensed Product in the Field in the Territory.2.6[***]. The Parties agree that within [***] of the Effective Date of this Agreement the Joint Steering Committeeshall determine whether it is necessary put in place a procedure pursuant to which [***] shall [***] that [***] to [***].8  ARTICLE 3DUE DILIGENCE3.1General. Unity shall use commercially reasonable efforts to develop and obtain marketing approval for at leastone Licensed Product hereunder, and thereafter shall use commercially reasonable efforts to launch and commercialize each suchLicensed Product and to fulfill the market demand therefor.3.2Diligence Milestones. Without limiting its general diligence obligations under Section 3.1 above, Unity agreesthat it shall achieve the following diligence milestones with respect to the Licensed Compound by the deadlines specified below:MilestoneTime Period1.[***]Within [***] ([***]) [***] of the Effective Date2.[***]Within [***] ([***]) [***] of the Effective Date3.[***]Within [***] ([***]) [***] of (i) the Effective Date, in the case ofthe Licensed Compound, or (ii) the date of the Substitution Notice,in the event Unity designates the Back-Up Compound as aSubstitute Licensed Compound4.[***]Within [***] ([***]) [***] of (i) the Effective Date, in the case ofthe Licensed Compound, or (ii) the date of the Substitution Notice,in the event Unity designates the Back-Up Compound If Unity is unable to meet [***], as applicable, by the specified deadline, Unity shall nonetheless be deemed to be in compliance withits diligence obligations hereunder so long as it [***]. 3.3Substitution of Licensed Compound.3.3.1General. If Unity elects to discontinue development of a Licensed Compound for [***] reasons, thenUnity shall have a right to replace such abandoned Licensed Compound with the Back-up Compound designated in the DesignationLetter, together with all salts, hydrates and polymorphic forms of such Back-Up Compound. Following such replacement pursuant tothis Section 3.3, the Back-up Compound shall be considered a “Substitute Licensed Compound”.3.3.2Designation. In the event that Unity wishes to exercise its right under this Article 3 to select aSubstitute Licensed Compound, Unity will provide Ascentage with written notice specifying the Licensed Compound for whichdevelopment is being discontinued and the Back-up Compound that it wishes to replace it with (“Substitution Notice”).9  3.3.3Following designation of a Substitute Licensed Compound, the Parties shall promptly updateSchedule 1.13 to reflect the substitution of the Substitute Licensed Compound for the current Licensed Compound. Upon any suchsubstitution, all references to the “Licensed Compound” in this Agreement shall thereafter be deemed to refer to such SubstituteLicensed Compound, and the compound for which such Substitute Licensed Compound was substituted shall cease to be considered aLicensed Compound.ARTICLE 4TECH TRANSFER; MANUFACTURING PROCESS IMPROVEMENTS4.1Technology Transfer of Ascentage Manufacturing IP. Subject to the terms and conditions of this Agreement,following the Effective Date (or if applicable, the date Unity elects to substitute the Back-up Compound as a Substitute LicensedCompound) and upon Unity’s written request, Ascentage shall conduct or cause to be conducted a customary technology transfer ofthe then-most current version of the Ascentage Manufacturing IP in a format, scope and manner reasonably deemed by Unity to besufficient to enable Unity to manufacture the Licensed Compound and Licensed Products (including if applicable, a SubstituteLicensed Compound). All written portions of the technology transfer package shall be provided in the English language.4.2Disclosure of Manufacturing Process Improvements. Each Party (the “Inventing Party”) shall disclose to the otherParty (the “Non-Inventing Party”) all Manufacturing Process Improvements conceived, discovered, or generated by such InventingParty which the Inventing Party intends to implement in its own manufacturing processes, including any invention disclosures, or othersimilar documents submitted to it by its employees, agents or independent contractors describing such inventions as well as anyCompound-Related Patents covering such inventions, and shall promptly respond to reasonable requests from the Non-Inventing Partyfor additional information relating to such inventions. Such disclosures shall be made through the Joint Steering Committee asprovided in Section 5.1 herein.4.3Technology Transfer of Manufacturing Process Improvements. Upon the written request of the Non-InventingParty, the Inventing Party shall conduct or cause to be conducted a customary technology transfer of the Manufacturing ProcessImprovement in a format, scope and manner reasonably deemed by the Non-Inventing Party to be sufficient to enable the Non-Inventing Party to exercise its rights under Section 2.1.2. All written portions of any technology transfer package shall be provided inthe English language.4.4Technology Transfer Fees. All costs other than document transfer for the technology transfers described inSections 4.1 and 4.3 above shall be borne by the Non-Inventing Party.4.5Process Improvement Records. During the term of this Agreement and for the period of time, if any, thereafterrequired by applicable law or regulations, the Parties shall maintain records of any use by Third Parties of any Manufacturing ProcessImprovements owned or Controlled by the other Party. Each sublicensing Party agrees to either: (a) require each of its Third PartySublicensees to maintain similar records and to open such records for inspection by an independent Third Party, reasonably satisfactoryto such non-sublicensing Party for the10  purpose of auditing use of Manufacturing Process Improvements hereunder, or (b) obtain such audits rights from the Third PartySublicensee for the non-sublicensing Party and exercise such audit rights on behalf of the non-sublicensing Party, at such non-sublicensing Party’s request and cost and disclose the results thereof to the sublicensing Party.ARTICLE 5JOINT STEERING COMMITTEE5.1Joint Steering Committee. Ascentage and Unity will establish a committee (the “Joint SteeringCommittee” or “JSC”) to coordinate the Parties activities under this Agreement. The responsibilities of the Joint Research Committeeshall consist of:5.1.1Facilitating the exchange of information and materials hereunder, including, without limitation, bymanaging (i) the initial technology transfer of the Ascentage Manufacturing IP under Section 4.1 above, (ii) the disclosure ofManufacturing Process Improvements under Section 4.2 above, and (iii) any subsequent technology transfers under Section 4.3 above;5.1.2Determining whether it is necessary to implement a procedure for [***] as set forth in Section 2.6above and, if it deemed necessary, then managing the implementation of such procedure;5.1.3Monitoring and reporting on Unity’s due diligence obligations under Article 3 above;5.1.4Reviewing and discussing issues that may arise regarding the designation or release of the Back-UpCompound;5.1.5Managing the initial, informal mediation of any dispute that arises under this Agreement; and5.1.6Assuming such other responsibilities as both parties may mutually agree to delegate to the JSC.5.2Membership. The JSC shall include two (2) employees to serve as members of each of Ascentage andUnity, with each Party’s members selected by that Party. Ascentage and Unity may each replace its JSC member at any time, uponwritten notice to the other Party. The chairperson shall serve for a term of one (1) year, beginning on the Effective Date or ananniversary thereof, as the case may be. The right to name the chairperson of the JSC shall alternate between the Parties. The initialchairperson shall be selected by [***]. Neither Party shall have the right to remove a sitting member of the other Party. 5.3Meetings. The JSC shall meet at least [***], or more frequently as agreed by the parties, at suchlocations as the parties agree, and will otherwise communicate regularly. With the consent of the parties, other representatives ofAscentage or Unity may attend JSC meetings as nonvoting observers. Each party shall be responsible for all of its own expensesassociated with attendance of such meetings.11  5.4Decision Making. With respect to decisions taken on matters placed by either party before the JSC,each Party shall have one vote. Decisions of the JSC shall be made by unanimous approval of the Parties. If the members of the JSCcannot reach an agreement after commercially reasonable efforts to do so, then either Party’s representative to the JSC may refer suchdispute to the [***] of each Party, who shall meet in person or by telephone within [***] ([***]) days after such referral to attempt ingood faith to resolve such dispute.ARTICLE 6PAYMENTS6.1Equity Grants.6.1.1[***]. Upon the [***], Unity shall issue (i) One Hundred Six Thousand Six Hundred Sixty-Seven(106,667) shares of Unity common stock to Ascentage, and (ii) Twenty-Six Thousand Six Hundred Sixty-Six (26,666) shares of Unitycommon stock to UM, in each case pursuant to a restricted stock issuance agreement substantially in the form set forth on Schedule5.1.1 hereto and within [***] ([***]) days of date that [***] occurs. For clarity, [***].6.1.2[***]. Upon the [***], Unity shall issue to Ascentage and UM the following number of shares ofUnity common stock based on how long after the Effective Date of the Library Agreement such [***], in each case pursuant to arestricted stock issuance agreement substantially in the form set forth on Schedule 5.1.1 hereto and within [***] ([***]) days of datethat such [***] occurs:(a)If such [***] occurs within [***] ([***]) [***] of the Effective Date of the LibraryAgreement, then (i) [***] ([***]) shares of Unity common stock to Ascentage, and (ii) [***] ([***]) shares of Unity common stock toUM.(b)If such [***] occurs more than [***] ([***]) [***] after the Effective Date of the LibraryAgreement but less than [***] ([***]) [***] after the Effective Date of the Library Agreement then (i) [***] ([***]) shares of Unitycommon stock to Ascentage, and (ii) [***] ([***]) shares of Unity common stock to UM.(c)If such [***] occurs more than [***] ([***]) [***] after the Effective Date of the LibraryAgreement then (i) [***] ([***]) shares of Unity common stock to Ascentage, and (ii) [***] ([***]) shares of Unity common stock toUM.6.1.3Equity Cap. Notwithstanding anything in the contrary in this Agreement, the Library Agreement, theAPG-1252 License Agreement or any other Compound License Agreement, the maximum cumulative aggregate number of shares ofUnity common stock that Ascentage and UM are collectively eligible to receive under Sections 6.1 and 6.2 of the Library Agreement,Section 5.1 of the APG-1252 License Agreement, this Section 6.1 and Section 5.1 of any other Compound License Agreement is:(a)[***] ([***]) shares of Unity common stock (as adjusted for stock splits, reverse stock splits,stock dividends, recapitalizations and the like) if only one Licensed Product (as defined in the applicable Compound LicenseAgreement) has been developed (i.e., [***]); and12  (b)One Million Three Hundred Thirty Three Thousand Three Hundred and Thirty-Nine(1,333,339) shares of Unity common stock (as adjusted for stock splits, reverse stock splits, stock dividends, recapitalizations and thelike) if two or more Licensed Products (as defined in the applicable Compound License Agreement) are developed (i.e., [***). 6.1.4Fractional Shares. No fractional shares of Unity common stock shall be issued in connection with thisAgreement. In lieu of any fractional shares to which Ascentage or UM would be entitled as the result of any stock split, reverse stocksplit, dividend, recapitalization or the like, Unity shall pay cash equal to such fraction multiplied by the Fair Market Value of a share ofcommon stock.6.2Development/Sales Milestones. In partial consideration of the rights and licenses granted herein to Unity, Unityshall pay Ascentage the following milestone payments. For the avoidance of doubt, each development milestone pursuant to thisSection 6.2 is across all indications for a Licensed Product, such that Unity shall only have the obligation to pay once for eachdevelopment milestone for each Licensed Product, regardless of indication.(a)Within [***] ([***]) days after the first achievement by Unity (or any of its Affiliates orThird Party Sublicensees) of each of the following milestones with respect to the first Licensed Product to achieve such milestone,Unity shall pay Ascentage the corresponding milestone payment set forth below, in accordance with the payment provisions of Article7 below: Milestone EventMilestone Payment1.[***]:$[***]2.[***]:$[***]3.[***]:$[***]4.[***]$[***]5.[***]$[***]Total per Licensed Product$[***] (b)Within [***] ([***]) days after the first achievement by Unity (or any of its Affiliates orThird Party Sublicensees) of each of the following milestones with respect to the second and each Licensed Product to achieve suchmilestone, Unity shall pay Ascentage the corresponding milestone payment set forth below, in accordance with the payment provisionsof Article 7 below:13  Milestone EventMilestone Payment1.[***]:$[***]2.[***]:$[***]3.[***]:$[***]Total per Licensed Product$[***] 6.2.2Certain Additional Terms.(a)For clarity, all forms, presentations, formulation and dosage forms of a Licensed Productshall be considered one and the same Licensed Product for purposes of Section 5.1 and this Section 6.2.(b)If Unity begins development of one Licensed Product and a milestone payment is madeunder this Section 6.2, and then Unity terminates development of such Licensed Product and begins development of a second LicensedProduct, the milestone which was already paid under this Section 6.2 for the abandoned Licensed Product will not be repeated, but theremaining milestone payments hereunder will be due as the second Licensed Product advances. For clarity, it is acknowledged andagreed that should the first Licensed Product be abandoned prior to achieving all of the milestones set forth Section 6.2(a), suchremaining unpaid milestones shall become due and payable when first achieved by the next Licensed Product.(c)In its sole discretion, Unity may elect in lieu of the payment of the milestone paymentsowing to Ascentage under this Section 6.2, to grant to Ascentage that number of shares of Unity common stock of equivalent value(based on the Fair Market Value of such Unity common stock at the time of such grant).6.3Royalties. In partial consideration of the licenses granted herein to Unity, Unity shall pay to Ascentage a runningroyalty equal to the percentage set forth below on the Net Sales of Licensed Product, subject to any adjustments set forth in Sections6.5 and 6.6, and in accordance with the payment provisions of Article 7 below.14  (a)With respect to Net Sales of the [***] to receive marketing approval, Unity shall pay toAscentage the royalties set forth below:Annual Net Sales of Licensed ProductApplicable Royalty RatePortion of worldwide annual Net Sales of the Licensed Product less than or equal to [***]Dollars (US$[***])[***]%Portion of worldwide annual Net Sales of the Licensed Product over [***] Dollars(US$[***])[***]% (b)With respect to Net Sales of the [***] to receive marketing approval, Unity shall pay toAscentage the royalties set forth below:Annual Net Sales of Licensed ProductApplicable Royalty RatePortion of worldwide annual Net Sales of the Licensed Product less than or equal to [***]Dollars (US$[***])[***]%Portion of worldwide annual Net Sales of the Licensed Product over [***] Dollars(US$[***])[***0]% 6.4Royalty Term. Unity’s obligation to pay royalties on Net Sales of Licensed Product under this Agreement shallcontinue on a country-by-country and Licensed Product-by-Licensed Product basis until the later of (a) abandonment or expiration ofthe last Valid Claim that claims the [***] of the Compound contained in such Licensed Product in such country, (b) the date of expiryof any applicable regulatory, pediatric, orphan drug or data exclusivity obtained for such Licensed Product in such country, or (c) ten(10) years after the first commercial sale of the Licensed Product by or under the authority of Unity in any country in the Territory.6.5Royalty Stacking. Unity shall be entitled to deduct from the amounts owing to Ascentage under Sections 6.2 and6.3 above [***] percent ([***]%) of any royalties or other payments made to Third Parties for Enabling IP, provided that (a) the totalaggregate amount payable to Ascentage under Sections 6.2 and 6.3 in any [***] may not be reduced to less than [***] percent([***]%) of the amounts that would otherwise be due Ascentage in such [***], and (b) Unity shall not be entitled to deduct anyroyalties or other payments made under the Existing Agreements. If, in any [***], Unity is not able to fully recover its [***] percent([***]%) portion of the payments due to a Third Party, it shall be entitled to carry forward such right of off-set to future [***] withrespect to the excess amount.6.6Generic Products. If at any time during the term of this Agreement a Generic Product enters the market in anycountry and has for a period of at least [***] ([***])15  consecutive [***] a market share in such country of at least [***] percent ([***]%) of the then combined unit volume of thecorresponding Licensed Product (i.e., the Licensed Product containing the same active pharmaceutical ingredient(s) as are present inthe Generic Product) and such Generic Product, then Unity’s obligation to pay royalties to Ascentage on Net Sales of such LicensedProduct in such country shall be reduced to [***] percent ([***]%) of the amounts that would otherwise be due Ascentage underSection 6.3 in such [***].6.7Maximum Reduction to Royalties. Notwithstanding anything to the contrary in this Article 6, in no event shall theroyalties owing to Ascentage with respect to Net Sales of a Licensed Product in any country be reduced by cumulative operation ofSections 6.5 and 6.6 to less than [***] percent ([***]%) of the amounts that would otherwise be due Ascentage under Section 6.3 insuch [***].6.8Combination Products. In the event that a Licensed Product is sold for a single price in combination with anothertherapeutically active pharmaceutical ingredient, or other product or service, for which no royalty would be due hereunder if soldseparately, Net Sales from such combination sales, for purposes of calculating the applicable royalty rate and the applicable royalty dueunder Section 6.3 shall be calculated by multiplying the Net Sales of the combination product by the fraction A/(A + B), where A isthe average gross selling price during the previous [***] of the Licensed Product sold separately and B is the gross selling price duringthe previous [***] of the therapeutically active ingredient, product or service. In the event that separate sales of the Licensed Product orthe additional therapeutically active ingredient, product or service were not made during the previous [***], then the Net Sales shall bereasonably allocated between such Licensed Product and such other active ingredient, product or service as agreed upon by the Parties,or failing agreement, determined in accordance with Section 14.1 (Dispute Resolution) below.6.9Unity’s Covenant. Unity hereby agrees that any shares of common stock issued to Ascentage will not be dilutedunless diluted in good faith by Unity on a proportionate basis to the other shares of common stock of Unity outstanding at the time ofany such dilution, and subject to the anti-dilution protections as set forth in Unity’s certificate of incorporation, as may be amendedfrom time to time in good faith; provided further, that Unity shall not take actions that specifically treat Ascentage differently from otherholders of common stock, or issue any capital stock in a manner which is intended to circumvent this covenant. The shares of commonstock issued to Ascentage shall be duly adjusted for any bonus issue, share split, consolidation, subdivision, reclassification,recapitalization or similar arrangement of Unity, in each case in accordance with, and as expressly contemplated by, Unity’s certificateof incorporation, as may be amended from time to time in good faith.ARTICLE 7ACCOUNTING; RECORDS; METHOD OF PAYMENT7.1Royalty Reports; Payments, Invoices. After the first sale of a Licensed Product on which royalties are payable byUnity hereunder, Unity shall make quarterly written reports to Ascentage within [***] ([***]) days after the end of each calendarquarter, stating in each such report the number, description, and aggregate Net Sales of Licensed Product sold during the calendarquarter upon which a royalty is payable under Article 6 above. Concurrently with the16  making of such reports, Unity shall pay to Ascentage all amounts payable pursuant to Article 6 above, in accordance with the paymentprovisions of Section 7.3.7.2Records; Inspection. During the term of this Agreement and for a period of [***] ([***]) years thereafter, Unityand its Affiliates shall keep complete, true and accurate books of account and records for the purpose of determining the amountspayable to Ascentage under this Agreement. Ascentage shall have the right to cause an independent, certified public accountantreasonably acceptable to Unity to audit such records to confirm gross sales, Net Sales and royalty payments for a period covering notmore than the preceding [***] ([***]) years. Unity agrees to either: (a) require each of its Third Party Sublicensees to maintain similarbooks and records and to open such records for inspection by an independent, certified public accountant reasonably satisfactory tosuch Third Party Sublicensee, on behalf of, and as required by, Ascentage for the purpose of verifying payments hereunder, or (b)obtain such audits rights from the Third Party Sublicensee for itself and exercise such audit rights on behalf of Ascentage uponAscentage’s request and disclose the results thereof to Ascentage. All such inspections may be made no more than once each calendaryear at reasonable times and on reasonable notice. No accounting period of Unity or its Affiliate or Third Party Sublicensee shall besubject to audit more than one time hereunder. Such independent, certified public accountant will be obliged to execute a reasonableconfidentiality agreement prior to commencing any such inspection. The results of any inspection hereunder shall be provided to bothParties, and Unity shall pay any underpayment to Ascentage within [***] ([***]) days. Inspections conducted under this Section 7.2shall be at the expense of Ascentage (and Ascentage will reimburse Unity’s reasonable out-of-pocket costs of those inspectionsconducted by Unity at Ascentage’s request under (b) above), unless a variation or error producing an increase exceeding [***] percent([***]%) of the amount stated for any period is established in the course of any such inspection, whereupon all costs of such audit ofsuch period will be paid by Unity.7.3Payment Method. All payments due hereunder shall be made in U.S. dollars, and shall be made by bank wiretransfer in immediately available funds to an account designated by Ascentage in a written notice to Unity. If any currency conversionshall be required in connection with the payment of royalties hereunder, such conversion shall be made by using the exchange ratesused by Unity in calculating Unity’s own revenues for financial reporting purposes.7.4Late Payments. Any payments due from Unity that are not paid on the date such payments are due under thisAgreement shall bear interest at [***] ([***]%) above the then prevailing US Federal Funds Target Rate (Bloomberg page: FDTR) per annum calculated on a daily basis and payable for the period from the date payment is due until the date payment isactually made. This Section 7.4 shall in no way limit any other remedies available to any Party.17  ARTICLE 8PATENT PROSECUTION AND ENFORCEMENT8.1Prosecution of Patents within the Licensed Intellectual Property.8.1.1General.(a)Except as set forth in Section 8.1.1(b) or Section 8.1.1(c) hereof, Ascentage shall have thesole right to control the preparation, filing, prosecution and maintenance of all Licensed Patents using patent counsel of its choice.(b)Unity shall have the first right, but not the obligation, to prepare, file, prosecute and maintainLicensed Product-Specific Patents. Unity shall keep Ascentage reasonably informed as to its filing and prosecution strategy forLicensed Product-Specific Patents and the filing, prosecution and maintenance of Licensed Product-Specific Patents with a reasonableopportunity to review drafts of proposed patent office submissions with respect to Licensed Product-Specific Patents; and (ii) considerin good faith the requests and suggestions of Ascentage with respect to strategies for filing and prosecuting such Licensed Product-Specific Patents. In the event that Unity desires to abandon or decline further responsibility for any such Licensed Product-SpecificPatent, Unity shall provide reasonable prior written notice to Ascentage of such intention to abandon or decline responsibility, but in nocase later than [***] ([***]) days prior to any required action relating to the filing, prosecution or maintenance of such LicensedProduct-Specific Patent, and Ascentage shall have the right, at its discretion, to assume such responsibility.(c)With respect to any Licensed Patent (other than a Licensed Product-Specific Patent) thatclaims the Licensed Compound and/or Licensed Product, Ascentage shall have the first right, but not the obligation, to prepare, file,prosecute and maintain such Licensed Patent and shall (i) keep Unity reasonably informed as to its filing and prosecution strategy forsuch Licensed Patent and the filing, prosecution and maintenance of such Licensed Patent, (ii) provide Unity with a reasonableopportunity to review drafts of proposed patent office submissions with respect to such Licensed Patent; and (iii) follow the directionsgiven by Unity with respect to filing and prosecuting such Licensed Patents, unless [***], in which case [***] and [***]. In the eventthat Ascentage desires to abandon or decline further responsibility for any Licensed Patent, Ascentage shall provide Unity [***] noticeand he opportunity to assume responsibility for such Licensed Patent.8.1.2For purposes of this Article 8, “prosecution and maintenance” of patents and patent applications shallbe deemed to include, without limitation, the conduct of interferences or oppositions, and/or requests for re-examinations, reissues orextensions of patent terms.8.2Enforcement of Licensed Patents. If either Party determines that a Third Party is making, using or selling aproduct that may infringe any Licensed Patent, that Party shall notify the other Party in writing.18  8.2.1Infringement by a Competitive Product.(a)With respect to any such infringing activity that involves the manufacture, use or sale by aThird Party of any product that [***] (“Competitive Product”), Unity shall have the first right, at its sole option, to bring suit to enforceany Licensed Patent, and/or to defend any declaratory judgment action with respect thereto (“Enforcement Action”); provided,however, that Unity shall keep Ascentage reasonably informed as to the defense and/or settlement of any such Enforcement Action.Ascentage shall have the right to participate in any such Enforcement Action with counsel of its own choice at its own expense. Allrecoveries received by Unity from an Enforcement Action shall be first applied to reimburse Unity’s and then Ascentage’sunreimbursed expenses, including without limitation, reasonable attorney’s fees and court costs. Any remainder shall, to the extent thesame pertains to an infringing activity that involves the manufacture, use or sale by a Third Party of any Competitive Product, betreated as Net Sales.(b)In the event Unity elects not to initiate an Enforcement Action with respect to anycommercially significant infringing activity that involves the manufacture, use or sale by a Third Party of any Competitive Productwithin [***] ([***]) days of a request by Ascentage to do so ([***]), Ascentage may initiate such action at its expense. Unity shallhave the right to participate in any such action with counsel of its own choice at its own expense. All recoveries received by Ascentagefrom an Enforcement Action shall be first applied to reimburse Ascentage’s and then Unity’s unreimbursed expenses, includingwithout limitation, reasonable attorney’s fees and court costs. Any remainder shall, to the extent the same pertains to an infringement ofthe Licensed Patents, be split [***].8.2.2Other Instances of Infringement. With respect to any such infringing activity that does not involve themanufacture, use or sale by a Third Party of a Competitive Product, Ascentage shall have the sole right, at its sole option, to bring suitto enforce any Licensed Patent, and/or to defend any declaratory judgment action with respect thereto and to retain all recoveriesreceived by Ascentage in connection therewith.8.3Infringement Claims Against Unity. If the production, sale or use of a Licensed Product pursuant to thisAgreement results in any claim, suit or proceeding alleging patent infringement against Unity (or its Affiliates or sublicensees), Unityshall promptly notify Ascentage thereof in writing setting forth the facts of such claim in reasonable detail. As between the Parties,Unity will be entitled to control the defense in any such action(s). Unity agrees to keep Ascentage reasonably informed of all materialdevelopments in connection with any such claim, suit or proceeding as it relates to the Licensed Intellectual Property. Notwithstandingthe above, Unity shall not admit the invalidity of any Licensed Patent without written consent from Ascentage.8.4Cooperation. In any legal action undertaken by a Party pursuant to Sections 8.2 or 8.3 of this Agreement (theParty bringing or defending such legal action, the “Enforcing Party”), the non-Enforcing Party shall cooperate fully with the EnforcingParty, including without limitation by joining as a party plaintiff if necessary for legal standing and executing such documents as theEnforcing Party may reasonably request. Upon the request of, and at the expense of, the Enforcing Party, the non-Enforcing Party shallmake available at reasonable19  times and under appropriate conditions all relevant personnel, records, papers, information, samples, specimens and other similarmaterials in its possession.8.5No Implied Obligations. Except as expressly provided in this Article 8, neither Party has any obligation to bringor prosecute actions or suits against any Third Party for patent infringement.8.6UM License Agreement. Notwithstanding the foregoing provisions of this Article 8, with respect to the LicensedPatents subject of the UM License Agreement, Unity’s rights under this Article 8 shall be limited to the extent of Ascentage’s rights toprosecute and enforce such Licensed Patents under the UM License Agreement, provided that (a) with respect to Licensed Product-Specific Patents that have been in-licensed from UM, to the extent the UM License Agreement will not permit Unity to control theprosecution of such patents, Ascentage agrees to (i) share with Unity the information Ascentage receives from UM under Section 7.2of the UM License Agreement with respect to such patents, (ii) provide Unity with a reasonable opportunity to review and commentupon such information; and (iii) pass along to UM Unity’s comments and requested actions, and (b) Ascentage shall at Unity’s requestand expense cooperate with Unity in order exercise the enforcement rights granted to Ascentage under Section 8.1 of the UM LicenseAgreement, in each case permitted by the UM License Agreement.ARTICLE 9OPTION FOR CHINA JOINT VENTURE9.1Option for China JVCO. Unity shall grant to Ascentage an option to commercialize Licensed Products in GreaterChina jointly with Unity through the joint venture entity (“China JVCO”) to be established as described in Section 8.2.3 of the LibraryAgreement.9.2Limitation of Obligations; Certain Covenants.9.2.1Notwithstanding anything to the contrary, nothing in this Agreement shall be deemed to have grantedUnity or any of its sublicensees the right to develop, manufacture, distribute, sell or otherwise commercialize the Licensed Products inGreater China.9.2.2Ascentage hereby covenants that it shall not develop, manufacture, distribute, sell or otherwisecommercialize the Licensed Compound (including any Licensed Products containing the Licensed Compound) in Greater Chinaexcept through the China JVCO. In the event of a breach by Ascentage of its obligations under this Section 9.2.2, the [***] and [***],shall [***].9.2.3Unity and Ascentage hereby covenant that they shall cooperate with respect to the establishment ofthe China JVCO, including without limitation by (a) continuing discussions between [***] of Ascentage and Unity regarding the formagreements relating to the JVCO, (b) using commercially reasonable efforts to reach agreement on such form agreements within areasonable amount of time after the Effective Date, and (c) signing the agreements for establishment of the China JVCO agreed upon[***] of Ascentage and Unity.20  ARTICLE 10CONFIDENTIALITY10.1Confidential Information. Except as otherwise expressly provided herein, the parties agree that the receivingparty shall not, except as expressly provided in this Article 10, disclose to any Third Party or use for any purpose any informationwhich is disclosed to it by the other party, whether orally or in writing, and identified as confidential (“Confidential Information”),except to the extent that it can be established by the receiving party by competent proof that such information:(a)Was already known to the receiving party, other than under an obligation of confidentiality,at the time of disclosure;(b)Was generally available to the public or otherwise part of the public domain at the time of itsdisclosure to the receiving party;(c)Became generally available to the public or otherwise part of the public domain after itsdisclosure and other than through any act or omission of the receiving party in breach of this Agreement;(d)Was independently developed by the receiving party without reference to informationprovided by the disclosing party as demonstrated by documented evidence prepared contemporaneously with such independentdevelopment; or(e)Was disclosed to the receiving party, other than under an obligation of confidentiality, by aThird Party who had no obligation to the disclosing party not to disclose such information to others.10.2Permitted Use and Disclosures. Each party hereto may use or disclose Confidential Information of the otherparty to the extent such use or disclosure is reasonably necessary in the following instances: (a) exercising the rights granted to ithereunder (including, in the case of Unity, developing, manufacturing, commercializing and/or sublicensing of Licensed Products) orin carrying out its obligations hereunder; (b) filing or prosecuting Patents as permitted by this Agreement; (c) prosecuting or defendinglitigation; and (d) complying with applicable court orders or governmental regulations. Notwithstanding the foregoing, in the event aparty is required to make a disclosure of the other party’s Confidential Information pursuant to clause (c) or (d) of this Section 10.2, itwill, except where impracticable, give reasonable advance notice to the disclosing party of such disclosure and use efforts to secureconfidential treatment of such information at least as diligent as such party would use to protect its own confidential information, but inno event less than reasonable efforts. In addition, Unity shall have the right to disclose Confidential Information regarding the LicensedCompound or Licensed Products to Third Parties in connection with due diligence or similar investigations, to potential Third Partyinvestors, and others on a need to know basis, in each case under terms of confidentiality that are appropriate for the circumstances, orto the extent required by law.10.3Nondisclosure of Terms. Each of the parties hereto agrees not to disclose the terms of this Agreement to anyThird Party without the prior written consent of the other party hereto, which consent shall not be unreasonably withheld; provided thata party may disclose the21  terms of this Agreement without such consent to such party’s attorneys and advisors, to Third Parties in connection with due diligenceor similar investigations, to potential Third Party investors, and others on a need to know basis, in each case under terms ofconfidentiality that are appropriate for the circumstances, or to the extent required by law.10.4Public Announcement. Unity may, in its discretion, issue a press release announcing the formation of thisAgreement, which shall be substantially in a form approved by Ascentage prior to execution of the Agreement. Except with respect tosuch initial release or as otherwise required by law, neither party shall issue an additional press release or public announcement relatingto this Agreement without the prior written approval of the other party, which shall not be withheld unreasonably. Either party mayrefer to the license granted under this Agreement in promotional and other communications with prospective customers and investors,subject to the prior written approval of the other party of the form, substance and intended use of such reference, and provided thatsuch disclosure shall not include any technical details or any financial terms of the license. For purposes of clarification, after a partyhas obtained the other party’s written approval of the form, substance and intended use of a particular reference, no further approval ofthe other party will be required for inclusion of the same reference in future communications that are intended for the same use.ARTICLE 11INDEMNIFICATION11.1Unity. Unity agrees to indemnify and defend Ascentage and its directors, officers, employees, agents and theirrespective successors, heirs and assigns (the “Ascentage Indemnitees”) against any losses, costs, claims, damages, liabilities or expense(including reasonable attorneys’ and professional fees and other expenses of litigation) (collectively, “Liabilities”) arising, directly orindirectly out of or in connection with Third Party claims, suits, actions, demands or judgments, to the extent (a) relating to LicensedProducts developed, manufactured, used, sold or otherwise distributed by or on behalf of Unity, its Affiliates, sublicensees or otherdesignees (excluding Ascentage, its Affiliates and licensees) including, without limitation, product liability and patent infringementclaims, (b) resulting from a breach by Unity of its representations and warranties under this Agreement, or (c) the exercise of itsmanufacturing license set forth in Section 2.1.2(b), except, in each case, to the extent such Liabilities result from the negligence orintentional misconduct of Ascentage or Ascentage’s breach of its representations and warranties under this Agreement.11.2Ascentage. Ascentage agrees to indemnify and defend Unity and its directors, officers, employees, agents andtheir respective heirs and assigns (the “Unity Indemnitees”) against any Liabilities arising, directly or indirectly out of or in connectionwith Third Party claims, suits, actions, demands or judgments, to the extent resulting from (a) a breach by Ascentage of itsrepresentations and warranties under this Agreement or (b) the exercise of its manufacturing license set forth in Section 2.1.2(a),except, in each case, to the extent such Liabilities result from the negligence or intentional misconduct of Unity or Unity’s breach of itsrepresentations and warranties under this Agreement.11.3Procedure. In the event that any party intends to claim indemnification under this Article 11 (each such party, an“Indemnitee”) it shall promptly notify the other Party in writing22  of such alleged Liability. The indemnifying Party shall have the right to control the defense thereof with counsel of its choice as long assuch counsel is reasonably acceptable to Indemnitee; provided, however, that any Indemnitee shall have the right to retain its owncounsel at its own expense, for any reason, including if representation of any Indemnitee by the counsel retained by the indemnifyingParty would be inappropriate due to actual or potential differing interests between such Indemnitee and any other Party reasonablyrepresented by such counsel in such proceeding. The indemnifying Party shall keep the Indemnitee regularly informed of the status ofthe defense of any action, claim or liability covered by this Article 11 and shall take into consideration the Indemnitee’s reasonablecomments thereon. The affected Indemnitee shall cooperate with the indemnifying Party and its legal representatives in theinvestigation of any action, claim or liability covered by this Article 11. The Indemnitee shall not compromise or settle any claim orsuit, or voluntarily incur any expense with respect to any such claim or suit, in each case, without the prior written consent of theindemnifying Party, which such Party shall not be required to give. The failure to deliver written notice to the indemnifying Partywithin a reasonable time after the commencement of any action with respect to any action, claim or liability covered by this Article 11,if prejudicial to its ability to defend such action, shall relieve the indemnifying Party of any liability to the Indemnitee under this Article11.ARTICLE 12REPRESENTATIONS AND WARRANTIES12.1General Warranties. Each Party represents and warrants to the other Party that it is a corporation duly organizedand validly existing under the laws of the state or country of its incorporation, the execution, delivery and performance of thisAgreement by such Party has been duly authorized by all requisite corporate action, and it has the power and authority to execute anddeliver this Agreement and to perform its obligations hereunder (including, in the case of Ascentage, granting the rights and licensesdescribed in Article 2).12.2Ascentage Warranties. Ascentage represents and warrants on its own behalf and on behalf of its Affiliates that asof the Effective Date:(a)except as otherwise disclosed to Unity in writing prior to the Effective Date, (i) Ascentagehas not received written notice from a Third Party claiming that the Licensed Compound infringes the intellectual property rights ofany Third Party, and (ii) Ascentage is not a party to any legal action, suit or proceeding relating to the Licensed Compound.(b)except as otherwise disclosed to Unity in writing prior to the Effective Date, there are noactual or pending actions, suits or claims, by any Third Party (i) challenging the ownership of the Licensed Compound; or (ii)challenging the validity, effectiveness, enforceability, or ownership of the Licensed Intellectual Property.(c)except as otherwise disclosed to Unity in writing prior to the Effective Date, the LicensedPatents are subsisting, in force or pending, as the case may be, and are not the subject of any interference, reissue, reexamination,opposition, cancellation or similar administrative proceedings.23  (d)except as otherwise disclosed to Unity in writing prior to the Effective Date, Ascentage hasnot brought a claim alleging an infringement by a Third Party of any of the Licensed Patents and to Ascentage’s actual knowledge,there is no actual or alleged infringement by a Third Party of any of the Patents within the Licensed Patents.(e)there are no Patents: (i) filed by Ascentage and subsequently assigned to Third Party, or (ii)with respect to which Ascentage or its Affiliates have acquired rights from a Third Party (i.e., through in-licenses, cross-licenses orotherwise), in each case that (A) would be required for Unity to research, develop, manufacture, use or commercialize the LicensedCompound and (B) are not included within the Licensed Intellectual Property.(f)except as otherwise disclosed to Unity in writing prior to the Effective Date, there are noactual or pending suits or claims by any Third Party asserting that the manufacture, use, sale, offer for sale or importing of the LicensedCompound infringes the intellectual property of a Third Party and to Ascentage’s knowledge, the development and commercializationof the Licensed Compound would not infringe (i) any issued Patents of any Third Party (other than Patents in-licensed from UM), or(ii) any published Patent claim of any Third Party (other than claims of Patents in-licensed from UM) if such claim were to issue aspublished.(g)Ascentage has disclosed to Unity all material agreements with Third Parties in effect as ofthe Effective Date pursuant to which Licensed Intellectual Property was licensed, acquired or sold, including without limitation allamendments to the UM License Agreement entered into by UM and Ascentage subsequent to the effective date of the UM LicenseAgreement.(h)Ascentage has not previously granted and will not grant any rights in the LicensedIntellectual Property that are inconsistent with the rights and licenses granted to Unity herein.12.3Certain Rights and Obligations under the UM License Agreement.(a)Ascentage shall not modify, amend or otherwise alter the UM License Agreement to theextent the same would materially and adversely affect Unity’s rights under this Agreement.(b)Ascentage shall not (i) exercise or fail to exercise any right under the UM License Agreementor (ii) provide or fail to provide any consent or approval with respect to any right or obligation under the UM License Agreement, ineach case to the extent the same would materially and adversely affect Unity’s rights under this Agreement.(c)Ascentage shall not unilaterally terminate the UM License Agreement.12.4Disclaimer. EXCEPT AS OTHERWISE EXPRESSLY SET FORTH IN THIS AGREEMENT, NEITHERPARTY MAKES ANY REPRESENTATIONS OR EXTENDS ANY WARRANTIES TO THE OTHER PARTY OF ANYKIND, EITHER EXPRESS OR IMPLIED, REGARDING THE LICENSED COMPOUND, LICENSED PRODUCTS OR THE24  LICENSED INTELLECTUAL PROPERTY, INCLUDING, BUT NOT LIMITED TO, WARRANTIES OFMERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, AND VALIDITY OFLICENSED INTELLECTUAL PROPERTY CLAIMS, ISSUED OR PENDING.12.5Limitation of Liability. EXCEPT FOR LIABILITY FOR BREACH OF ARTICLE 10, NEITHER PARTYSHALL BE ENTITLED TO RECOVER FROM THE OTHER PARTY ANY SPECIAL, INCIDENTAL, CONSEQUENTIALOR PUNITIVE DAMAGES IN CONNECTION WITH THIS AGREEMENT; provided, however, that this Section 12.5 shall notbe construed to limit either party’s indemnification obligations under Article 11.ARTICLE 13TERM AND TERMINATION13.1Term. The term of this Agreement shall commence on the Effective Date and, unless earlier terminated asprovided in this Article 13, shall continue in full force and effect on a country-by-country basis until the expiration of all royaltyobligations pursuant to this Agreement for such country, as provided in Section 6.4 above (the “Term”). Unity’s license with respect tothe Licensed Technology shall survive the expiration (but not an earlier termination) of this Agreement, provided that such license shallthereafter become nonexclusive and fully paid-up.13.2Termination for Breach. Either Party may terminate this Agreement in the event that the other Party shall havematerially breached or defaulted in the performance of any of its material obligations hereunder, and such breach or default shall havecontinued for sixty (60) days after written notice of such breach and intent to terminate this Agreement therefor was provided to thebreaching Party by the nonbreaching Party. Any such termination shall become effective at the end of such sixty (60) day period unlessthe breaching Party has cured any such breach or default prior to the expiration of the sixty (60) day period. Notwithstanding theforegoing, if the Party alleged to be in breach of this Agreement in good faith disputes such breach within such sixty (60) day period,the nonbreaching Party shall not have the right to terminate this Agreement unless it has been determined by arbitration pursuant toSection 14.2 that this Agreement was materially breached, and the breaching Party fails to comply with its obligations hereunder withinsixty (60) days after such determination. 13.3Termination by Unity for Convenience. Any provision herein notwithstanding, Unity may terminate thisAgreement, in its entirety or as to any particular Patent within the Licensed Patents, or as to any particular Licensed Product, at anytime by giving Ascentage at least ninety (90) days prior written notice. From and after the effective date of a termination under thisSection 13.3 with respect to a particular Patent in a particular country, such Patent shall cease to be within the Licensed Patents for allpurposes of this Agreement, and all rights and obligations of Unity with respect to such Patent(s) shall terminate. From and after theeffective date of a termination under this Section 13.3 with respect to a particular Licensed Product, the license granted under Section2.1 above shall terminate with respect to such Licensed Product, and the same shall cease to be a Licensed Product for all purposes ofthis Agreement. Upon a termination of this Agreement in its entirety under this Section 13.3, all25  rights and obligations of the Parties shall terminate, except as provided in Section 13.4 below. For clarity, Unity shall remain obligatedto pay any and all milestone and other payments accrued, due and payable to Ascentage prior to such termination.13.4Effect of Termination.13.4.1Termination due to Breach by Unity. Upon a termination by Ascentage under Section 13.2 due toan uncured breach by Unity, the licenses granted under Sections 2.1 and 2.2 above shall terminate immediately, subject to Section13.4.5.13.4.2Termination due to Breach by Ascentage. Upon a termination by Unity under Section 13.2 due toan uncured breach by Ascentage, the licenses granted under Sections 2.1.2(b) and 2.2 above shall terminate immediately.13.4.3Accrued Obligations. Expiration or any termination of this Agreement for any reason shall notrelease either Party hereto from any liability which at the time of such expiration or termination has already accrued to such Party orwhich is attributable to a period prior to such expiration or termination, subject to the terms of this Agreement, nor preclude either Partyfrom pursuing any rights and remedies it may have hereunder or at law or in equity which accrued to it prior to such expiration ortermination, subject to the terms of this Agreement.13.4.4Sales of Existing Inventory of Licensed Product. In the event this Agreement is terminated for anyreason with respect to a Licensed Product after the first approval of an MAA for such Licensed Product, Unity shall provide Ascentagewith a written inventory of all quantities of such Licensed Product that Unity and its Affiliates have in stock and, for a period of [***]([***]) [***] after such termination, Unity and its Affiliates shall have the right to sell or otherwise dispose of such Licensed Product,all subject to the payment to Ascentage of royalties pursuant to Article 6 hereof.13.4.5Survival of Sublicenses. Upon termination of this Agreement for any reason, any sublicense grantedby Unity hereunder to a Third Party Sublicensee shall survive or terminate in accordance with Section 2.2; provided that for anysurviving Third Party Sublicense, such Third Party Sublicensee not only continues to pay to Ascentage the milestones and royaltiesthat would have been due to Ascentage under this Agreement based on such Third Party Sublicensee’s activities had this Agreementnot terminated but also remain fully responsible and liable for all terms and conditions of such Third Party Sublicense. For clarity, inthe event that a Third Party Sublicensee fails to pay to Ascentage the applicable milestones and royalties due to Ascentage based onsuch Third Party Sublicensee’s activities, Ascentage shall be entitled to terminate such surviving sublicense in accordance with theterms of the Third Party Sublicense.13.4.6Library Agreement. This Agreement is independent of, and shall not be affected by, the expirationor termination of the Library Agreement, and vice versa.13.4.7Survival. Articles 1 (Definitions), 7 (Accounting; Records; Method of Payment), 10(Confidentiality), 11 (Indemnification), 14 (Dispute Resolution) and 15 (Miscellaneous) and Sections 8.2.1 (with respect to anyongoing Enforcement Action), 12.3, 12.4 and 13.4 shall survive the expiration or termination of this Agreement for any reason. Exceptas26  otherwise provided in this Article 13, all rights and obligations of the parties under this Agreement shall terminate upon the expirationor termination of this Agreement.ARTICLE 14DISPUTE RESOLUTION14.1Dispute Resolution. If an unresolved dispute arises out of or relates to this Agreement, or the breach thereof,either Party may refer such dispute to the [***] of Unity and Ascentage, who shall meet in person or by telephone within [***] ([***])days after such referral to attempt in good faith to resolve such dispute. If such matter cannot be resolved by discussion of such officerswithin such [***] ([***]) days period (as may be extended by mutual agreement), either Party shall be entitled to seek resolution ofsuch dispute pursuant to Section 14.2 below.14.2Arbitration. If the parties are unable to resolve a dispute on an issue of interpretation, breach or enforcement ofthis Agreement, the parties shall refer such dispute to be finally resolved by binding arbitration under the terms of this Section 14.2,except that all disputes with respect to the validity or infringement of Patents shall be subject to applicable federal court jurisdiction andnot subject to the terms of this Section 14.2. Whenever a party shall decide to institute arbitration proceedings, it shall give writtennotice to that effect to the other party. Any such arbitration shall be conducted under the [***] by a panel of three (3) arbitrators in[***]. Each party shall select one (1) arbitrator who is not employed by, or otherwise affiliated with, such party within [***] ([***])days after the institution of arbitration proceedings, and the two (2) arbitrators so selected shall designate the third arbitrator. The partiesshall use their commercially reasonable efforts to conclude the arbitration hearings within [ ***] ([***]) [***] following theconfirmation of the third and presiding arbitrator.14.3Injunctive Relief. Each Party shall be free to seek preliminary or permanent injunctive relief, restraining order ordegree of specific performance in any court of competent jurisdiction. For avoidance of doubt, any such equitable remedies providedunder this Section 14.3 shall be cumulative and not exclusive and are in addition to any other remedies, which either Party may haveunder this Agreement or applicable law.ARTICLE 15MISCELLANEOUS15.1Governing Laws. This Agreement and any dispute arising from the construction, performance or breach hereofshall be governed by and construed, and enforced in accordance with, the laws of the state of New York, USA, without reference toconflicts of laws principles.15.2Waiver. It is agreed that no waiver by either Party hereto of any breach or default of any of the covenants oragreements herein set forth shall be deemed a waiver as to any subsequent and/or similar breach or default.15.3Assignment. This Agreement shall not be assignable by either party without the written consent of the otherparty hereto, except that either party may assign this Agreement, without such consent, to an entity that acquires all or substantially allof the business or assets of such party to which this Agreement relates, whether by merger, reorganization, acquisition, sale, orotherwise; provided, however, that within [***] ([***]) days of such an assignment, the27  assignee shall agree in writing to be bound by the terms and conditions of this Agreement. Subject to the foregoing, this Agreementshall bind and inure to the benefit of each party’s successors and permitted assigns.15.4Independent Contractors. The relationship of the Parties hereto is that of independent contractors. The Partieshereto are not deemed to be agents, partners or joint venturers of the others for any purpose as a result of this Agreement or thetransactions contemplated hereby.15.5Compliance with Laws. In exercising their rights under this Agreement, the Parties shall fully comply in allmaterial respects with the requirements of any and all applicable laws, regulations, rules and orders of any governmental body havingjurisdiction over the exercise of rights under this license including, without limitation, those applicable to the discovery, development,manufacture, distribution, import and export and sale of Licensed Products pursuant to this Agreement.15.6Notices. All notices, requests and other communications hereunder shall be in writing and shall be sent to theaddress specified below, or at such other address a party may specify in writing, and is deemed received when: (a) if personallydelivered, on the day of delivery; or (b) if sent by a commercial delivery service such as Federal Express, DHL or United ParcelService, in each case with shipment tracking, on the day delivery is confirmed by the tracking service; or (c) sent by e-mail, on the daythe email is confirmed received by the receiving party: If to Unity: Unity Biotechnology, Inc.3280 Bayshore Blvd, Suite 100Brisbane, CA 94005, USAAttention: General CounselEmail: [***]If to Ascentage priorJanuary 15, 2019: Ascentage Pharma Group Inc.9400 Key West Avenue, Suite 220Rockville, MD 20850Attention: SVP, Legal AffairsEmail: [***]If to Ascentage after January 15, 2019: Ascentage Pharma Group Inc.800 King Farm BoulevardRockville, MD 20850Attention: SVP, Legal AffairsEmail:[***] 15.7Severability. In the event that any provision of this Agreement becomes or is declared by a court of competentjurisdiction to be illegal, unenforceable or void, this Agreement shall continue in full force and effect to the fullest extent permitted bylaw without said provision, and the Parties shall amend the Agreement to the extent feasible to lawfully include28  the substance of the excluded term to as fully as possible realize the intent of the Parties and their commercial bargain.15.8Advice of Counsel. Unity and Ascentage have each consulted counsel of their choice regarding this Agreement,and each acknowledges and agrees that this Agreement shall not be deemed to have been drafted by one Party or another and will beconstrued accordingly.15.9Performance Warranty. Each Party hereby warrants and guarantees the performance of any and all rights andobligations of this Agreement by its Affiliates, licensees and sublicensees.15.10Force Majeure. Neither Party shall lose any rights hereunder or be liable to the other Party for damages orlosses (except for payment obligations) on account of failure of performance by the defaulting Party if the failure is occasioned by war,strike, fire, Act of God, earthquake, flood, lockout, embargo, unusual and unexpected governmental intervention, failure of suppliers,or any other reason where failure to perform is beyond the reasonable control and not caused by the negligence, intentional conduct ormisconduct of the non-performing Party and such Party has exerted all reasonable efforts to avoid or remedy such force majeure;provided, however, that in no event shall a Party be required to settle any labor dispute or disturbance.15.11Complete Agreement. This Agreement with its schedules, together with the Library Agreement and its exhibits,constitutes the entire agreement, both written and oral, between the Parties with respect to the subject matter hereof, and all prioragreements respecting the subject matter hereof, either written or oral, express or implied, shall be abrogated, canceled, and are null andvoid and of no effect. No amendment or change hereof or addition hereto shall be effective or binding on either of the Parties heretounless reduced to writing and executed by the respective duly authorized representatives of Unity and Ascentage.15.12Headings. The captions to the several Sections and Articles hereof are not a Part of this Agreement, but areincluded merely for convenience of reference and shall not affect its meaning or interpretation.15.13Counterparts. This Agreement may be executed in counterparts, each of which shall be deemed to be anoriginal and all of which together shall be deemed to be one and the same agreement.15.14Bankruptcy. All rights and licenses granted under or pursuant to this Agreement by each Party as a licensor are,and shall otherwise be deemed to be, for purposes of (a) Section 365(n) of Title II, U.S. Code (the “Bankruptcy Code”), licenses ofrights to “intellectual property” as defined under section 101(35A) of the Bankruptcy Code and (b) any similar provisions underbankruptcy laws outside the United States. The Parties agree that each licensee of such rights under this Agreement, shall retain andmay fully exercise all rights and elections it would have in the case of a licensor bankruptcy under the Bankruptcy Code or othersimilar bankruptcy laws outside the United States. Each Party agrees during the term of this Agreement to create or maintain currentcopies, or if not amenable to copying, detailed descriptions or other appropriate embodiments, of all such intellectual property licensedto the other Party.[Signature Page Follows]29  IN WITNESS WHEREOF, the Parties hereto have caused their duly authorized representatives to execute this Agreement. ASCENTAGE PHARMA GROUP CORP. LTD. UNITY BIOTECHNOLOGY, INC. By:/s/ Dajun Yang, MD, PhD By:/s/ Keith R. Leonard Jr. Name: Dajun Yang, MD, PhD Name: Keith R. Leonard Jr. Title: Chief Executive Officer Title: Chief Executive Officer SCHEDULESSchedule 1.8–Designation LetterSchedule 1.15–Licensed PatentsSchedule 5.1.1–Restricted Stock Issuance Agreement 30  SCHEDULE 1.8DESIGNATION LETTER [copy attached] Schedule 1.8 [***]Via DHL and EmailAscentage Pharma Group Corp. Ltd.218 Xinghu Street, Building 87, 7th FloorSuzhou Industrial Park, Suzhou, Jiangsu, 215000P.R. ChinaAttention: [***]Email: [***]Via Federal ExpressAscentage Pharma Group Inc.9400 Key West Avenue, Suite 220Rockville, MD 20850Attention: [***]Dear [***]:I am writing in connection with the Compound Library and Option Agreement by and between Ascentage Pharma Group Corp. Ltd.(“Ascentage”) and Unity Biotechnology, Inc. (“UNITY”) dated February 2, 2016 (the “Library Agreement”). This letter shall serve asformal notice under Article 3 of the Library Agreement, including without limitation Section 3.3.1, of the following designations:l.Development CandidateUNITY designates the Ascentage compound known as APG-1197 (also known as BM-1197 and UBX-1967) having the chemicalstructure set forth below to be a Development Candidate (as defined in the Library Agreement).APG-1197 [***]2.Back-up CompoundUNITY designates the Ascentage compound known as ***] (also known as [***]) having the chemical structure set forth below to bea Back-up Compound (as defined in the Library Agreement).[***]As provided in Section 3.3.2(a) of the Library Agreement, we look forward to entering into a Compound License Agreement coveringthese compounds within [***] ([***]) days.More importantly, we view this as further validation of the fruitful relationship between our companies and look forward to progressingour development of these compounds in the coming months.Regards,Schedule 1.8UNITY BIOTECHNOLOGY • 3280 BAYSHORE BLVD., SUITE 100 • BRISBANE, CA 94005 /s/ Keith LeonardKeith LeonardChief Executive OfficerCC: [***] [***] Schedule 1.8UNITY BIOTECHNOLOGY • 3280 BAYSHORE BLVD., SUITE 100 • BRISBANE, CA 94005  SCHEDULE 1.15LICENSED PATENTS[***] [***] Schedule 1.15  SCHEDULE 5.1.1RESTRICTED STOCK ISSUANCE AGREEMENT [copy attached]US-DOCS\106256636.1 UNITY BIOTECHNOLOGY, INC.STOCK ISSUANCE AGREEMENTThis Stock Issuance Agreement (the “Agreement”) is made as of [●] by and between Unity Biotechnology, Inc., aDelaware corporation (the “Company”), and Ascentage Pharma Group Corp Limited (the “Licensor”).In consideration of the mutual covenants and representations set forth below, the Company and Licensor agree as follows:1.Issuance of the Shares. Subject to the terms and conditions of this Agreement, the Company agrees to issue toLicensor, and Licensor agrees to acquire from the Company, on the Closing (as defined below) 106,667 shares of the Company’sCommon Stock, $0.0001 par value per share (the “Shares”), as partial consideration for the rights granted by Licensor to Companyunder that certain Compound License Agreement for APG-1197 dated as of [●] by and between the Company and the Licensor and asrequired by Section 6.2 of that certain Compound Library and Option Agreement dated February 2, 2016, as amended by the FirstAmendment dated March 28, 2018, by and between the Company and the Licensor.2.Closing. The transfer of the Shares shall occur at a closing (the “Closing”) to be held on the date first set forthabove, or at any other time mutually agreed upon by the Company and Licensor. The Closing will take place at the principal office ofthe Company or at such other place as shall be designated by the Company. As promptly after the Closing as practicable, theCompany shall issue or deliver to the Licensor evidence of a book entry position evidencing the Shares issued to the Licensorhereunder, registered in the name of the Licensor, or in such nominee name(s) as designated by the Licensor, representing the Shares tobe issued by the Licensor at the Closing upon execution and delivery of the License Agreement by the Licensor.3.Restrictions on Transfer.A.Investment Representations and Legend Requirements. The Licensor hereby makes theinvestment representations listed on Exhibit A to the Company as of the date of this Agreement and as of the date of the Closing, andagrees that such representations are incorporated into this Agreement by this reference, such that the Company may rely on them inissuing the Shares. Licensor understands and agrees that the Company shall cause the legends set forth below, or substantiallyequivalent legends, to be placed upon any certificate(s) evidencing ownership of the Shares, together with any other legends that maybe required by the Company or by applicable state or federal securities laws:THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTEREDUNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANYSTATE, AND MAY NOT BE SOLD, TRANSFERRED, ASSIGNED, PLEDGED OR HYPOTHECATEDUNLESS AND UNTIL REGISTERED UNDER SUCH ACT AND/OR APPLICABLE STATESECURITIES LAWS, OR UNLESS THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL OROTHER EVIDENCE,2US-DOCS\106256636.1 REASONABLY SATISFACTORY TO THE COMPANY AND ITS COUNSEL, THAT SUCHREGISTRATION IS NOT REQUIRED.B.Reporting Status. The Company has timely filed or furnished, as applicable, all reports,schedules, forms, statements and other documents required to be filed or furnished by it with the SEC pursuant to the Securities Act orthe Securities Exchange Act of 1934, as amended (the “Exchange Act”) and the rules and regulations promulgated thereunder (all ofthe foregoing documents filed with or furnished to the SEC and all exhibits included therein and financial statements, notes andschedules thereto and documents incorporated by reference therein being hereinafter referred to as the “SEC Documents”)C.Rule 144 Requirements. For purposes of Rule 144(d) promulgated under the Securities Act, asin effect on the Closing, the Company shall, at all times prior to the date of sale or other disposition by the Licensor, use commerciallyreasonable efforts to timely file all SEC Documents and otherwise timely take all actions necessary to permit the Licensor to sell orotherwise dispose of the Shares pursuant to Rule 144 promulgated under the Securities Act. If the Licensor proposes to sell the Sharesin compliance with Rule 144, then, upon the Licensor’s written request to the Company, the Company shall furnish to the Licensor,within five (5) Business Days after receipt of such request, a written statement confirming the Company’s compliance with the filingand other requirements of Rule 144.4.General Provisions.A.Choice of Law. This Agreement shall be governed by the internal law of the State of Delaware,without regard to conflict of law principles that would result in the application of any law other than the law of the State ofDelaware. Each party agrees that all legal proceedings concerning the interpretations, enforcement and defense of the transactionscontemplated by this Agreement (whether brought against a party hereto or its respective affiliates, directors, officers, shareholders,employees or agents) shall be commenced exclusively in the state and federal courts sitting in the State of Delaware. Each partyhereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the State of Delaware for theadjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein(including with respect to the enforcement of any of this Agreement), and hereby irrevocably waives, and agrees not to assert in anysuit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action orproceeding is improper or is an inconvenient venue for such proceeding. Each party hereby irrevocably waives personal service ofprocess and consents to process being served in any such suit, action or proceeding by mailing a copy thereof via registered or certifiedmail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Agreement andagrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall bedeemed to limit in any way any right to serve process in any other manner permitted by law.B.Integration. This Agreement, including all exhibits hereto, represents the entire agreementbetween the parties with respect to the acquisition of the Shares by the Licensor and supersedes and replaces any and all prior writtenor oral agreements regarding the subject matter of this Agreement including, but not limited to, any representations made during anyinterviews, relocation discussions or negotiations whether written or oral.3US-DOCS\106256636.1 C.Notices. Any notice, demand, offer, request or other communication required or permitted to begiven by either the Company or the Licensor pursuant to the terms of this Agreement shall be in writing and shall be deemedeffectively given the earlier of (i) when received, (ii) when delivered personally, (iii) one business day after being delivered byfacsimile (with receipt of appropriate confirmation), (iv) one business day after being deposited with an overnight courier service or (v)four days after being deposited in the U.S. mail, First Class with postage prepaid and return receipt requested, and addressed to theparties at the addresses provided to the Company (which the Company agrees to disclose to the other parties upon request) or suchother address as a party may request by notifying the other in writing.D.Successors. Any successor to the Company (whether direct or indirect and whether bypurchase, merger, consolidation, liquidation or otherwise) to all or substantially all of the Company’s business and/or assets shallassume the obligations under this Agreement and agree expressly to perform the obligations under this Agreement in the same mannerand to the same extent as the Company would be required to perform such obligations in the absence of a succession. For all purposesunder this Agreement, the term “Company” shall include any successor to the Company’s business and/or assets which executes anddelivers the assumption agreement described in this section or which becomes bound by the terms of this Agreement by operation oflaw. Subject to the restrictions on transfer set forth in this Agreement, this Agreement shall be binding upon Licensor and its heirs,executors, administrators, successors and assigns.E.Assignment; Transfers. Except as set forth in this Agreement, this Agreement, and any and allrights, duties and obligations hereunder, shall not be assigned, transferred, delegated or sublicensed by the Licensor without the priorwritten consent of the Company. Any attempt by the Licensor without such consent to assign, transfer, delegate or sublicense anyrights, duties or obligations that arise under this Agreement shall be void. Except as set forth in this Agreement, any transfers inviolation of any restriction upon transfer contained in any section of this Agreement shall be void, unless such restriction is waived inaccordance with the terms of this Agreement.F.Waiver. Either party’s failure to enforce any provision of this Agreement shall not in any waybe construed as a waiver of any such provision, nor prevent that party from thereafter enforcing any other provision of thisAgreement. The rights granted both parties hereunder are cumulative and shall not constitute a waiver of either party’s right to assertany other legal remedy available to it.G.Licensor Investment Representations and Further Documents. The Licensor agrees uponrequest to execute any further documents or instruments necessary or reasonably desirable in the view of the Company to carry out thepurposes or intent of this Agreement, including (but not limited to) the applicable exhibits and attachments to this Agreement.H.Severability. Should any provision of this Agreement be found to be illegal or unenforceable,the other provisions shall nevertheless remain effective and shall remain enforceable to the greatest extent permitted by law.4US-DOCS\106256636.1 I.Rights as Stockholder. Subject to the terms and conditions of this Agreement, Licensor shallhave all of the rights of a stockholder of the Company with respect to the Shares from and after the date that Licensor delivers a fullyexecuted copy of this Agreement (including the applicable exhibits and attachments to this Agreement) and full payment for the Sharesto the Company, and until such time as Licensor disposes of the Shares in accordance with this Agreement. Upon such transfer,Licensor shall have no further rights as a holder of the Shares so purchased except (in the case of a transfer to the Company) the rightto receive payment for the Shares so purchased in accordance with the provisions of this Agreement, and Licensor shall forthwithcause the certificate(s) evidencing the Shares so purchased to be surrendered to the Company for transfer or cancellation.J.Reliance on Counsel and Advisors. Licensor acknowledges that Latham & Watkins LLP, isrepresenting only the Company in this transaction. Licensor acknowledges that he or she has had the opportunity to review thisAgreement, including all attachments hereto, and the transactions contemplated by this Agreement with his or her own legal counsel,tax advisors and other advisors. Licensor is relying solely on his or her own counsel and advisors and not on any statements orrepresentations of the Company or its agents for legal or other advice with respect to this investment or the transactions contemplatedby this Agreement.K.Counterparts. This Agreement may be executed in one or more counterparts, each of whichwill be deemed an original, but all of which together will constitute one and the same agreement. Facsimile copies or electronicportable document format copies of signed signature pages shall be binding originals.(Signature page follows) 5US-DOCS\106256636.1 The parties represent that they have read this Agreement in its entirety, have had an opportunity to obtain the advice ofcounsel prior to executing this Agreement and fully understand this Agreement.COMPANY:UNITY BIOTECHNOLOGY, INC. By: Name:Keith R. Leonard Jr.Title:Chief Executive Officer US-DOCS\106256636.1 The parties represent that they have read this Agreement in its entirety, have had an opportunity to obtain the advice ofcounsel prior to executing this Agreement and fully understand this Agreement. The Licensor agrees to notify the Company of anychange in its address below.GRANTEE:ASCENTAGE PHARMA GROUP CORP LIMITED Name:Dajun Yang, M.D., Ph.D.Title:Chief Executive Officer Address:11/F, AXA Centre 151 Gloucester RoadWanchai, Hong Kong, China US-DOCS\106256636.1 EXHIBIT AINVESTMENT REPRESENTATION STATEMENT GRANTEE : ASCENTAGE PHARMA GROUP CORP LIMITED COMPANY : UNITY BIOTECHNOLOGY, INC. SECURITY : COMMON STOCK AMOUNT : 106,667 SHARES DATE : [●] In connection with the acquisition of the 106,667 shares of the Company’s Common Stock, $0.0001 par value per share (the“Shares”), Ascentage Pharma Group Corp Limited (“Ascentage”) as the undersigned, represent to the Company as follows:1.The Company may rely on these representations. Ascentage understands that the Company’s sale of theShares has not been registered under the Securities Act of 1933, as amended (the “Securities Act”), because the Company believes,relying in part on these representations in this document, that an exemption from such registration requirement is available for suchsale. Ascentage understands that the availability of this exemption depends upon the representations Ascentage am making to theCompany in this document being true and correct.A.Ascentage has conducted its own due diligence examination of the Company’s business,financial condition, results of operations, and prospects and has reviewed the Company’s filings with the United States Securities andExchange Commission (the “SEC”), in each case, to the extent it deems necessary and in a manner sufficient to enable it to evaluate itspurchase of the Shares. Ascentage understands that its investment in the Shares involves a high degree of risk. Ascentage has soughtsuch accounting, legal and tax advice as it has considered necessary to make an informed investment decision with respect to itsacquisition of the Securities. Ascentage further represents that it has relied solely upon the aforementioned examination, review andevaluation and has not relied on any representation or action made or taken by Seller or any of its affiliates or any of its or their officers,directors or representatives in connection with such Buyer’s decision to acquire the Securities, other than those expressly set forthherein. Ascentage understands and agrees that the Company, its affiliates and its and their respective officers, directors andrepresentatives have not made any representation or warranty whatsoever with respect to the business, condition (financial orotherwise), properties, prospects, creditworthiness, status or affairs of the Company, or with respect to the value of the Shares.2.I am purchasing for investment. Ascentage is purchasing the Shares solely for investment purposes, andnot for further distribution. The entire legal and beneficial ownership interest in the Shares is being acquired and shall be held solelyfor Ascentage’s account. Ascentage is not a party to, and do not presently intend to enter into, any contract or other arrangement withany other person or entity involving the resale, transfer, grant of participation with respect to or other distribution of any of theShares. Its investment intent is not limited to any present intention US-DOCS\106256636.1 to hold the Shares for the minimum capital gains period specified under any applicable tax law, for a deferred sale, for a specifiedincrease or decrease in the market price of the Shares, or for any other fixed period in the future.3.Ascentage can protect its own interests. Ascentage can properly evaluate the merits and risks of aninvestment in the Shares and can protect its own interests in this regard, whether by reason of its own business and financial expertise,the business and financial expertise of certain professional advisors unaffiliated with the Company with whom Ascentage haveconsulted, or my preexisting business or personal relationship with the Company or any of its officers, directors or controlling persons.4.Ascentage is informed about the Company. Ascentage am sufficiently aware of the Company’s businessaffairs and financial condition to reach an informed and knowledgeable decision to acquire the Shares. Ascentage has had opportunityto discuss the plans, operations and financial condition of the Company with its officers, directors or controlling persons, and havereceived all information Ascentage deems appropriate for assessing the risk of an investment in the Shares.5.Ascentage is an “accredited investor.” Ascentage is an Accredited Investor as defined in Rule 501(a)under the Securities Act. Ascentage understands and acknowledges that the Company is offering and selling the Shares in relianceupon an exemption from the registration requirements of the Securities Act and that the Shares are “restricted securities” within themeaning of Rule 144(a)(3) under the Securities Act. Ascentage is not purchasing its portion of the Shares with a view to, or for offeror sale in connection with, any distribution thereof (within the meaning of the Securities Act) that would be in violation of the securitieslaws of the United States or any state thereof. Ascentage became aware of the offering of Shares by the Company solely by directcontact between itself and the Company or between itself and one or more agents acting on behalf of the Company, with whom it hada pre-existing business relationship. Ascentage did not become aware of the offering or the Shares by any other means, including byany form of general advertising or general solicitation.6.Ascentage recognizes the economic risk. Ascentage realizes that the acquisition of the Shares involves ahigh degree of risk, and that the Company’s future prospects are uncertain. Ascentage is able to hold the Shares indefinitely ifrequired, and is able to bear the loss of the entire investment in the Shares.7.Ascentage recognizes this is not a general solicitation. Ascentage understands that the acquisition of theShares was not the result of any “general solicitation or general advertising” within the meaning contemplated by Rule 502(c) ofRegulation D of the Securities Act. US-DOCS\106256636.1 8.Ascentage knows that the Shares are restricted securities. Ascentage understand that the Shares are“restricted securities” in that the Company’s sale of the Shares has not been registered under the Securities Act in reliance upon anexemption for non-public offerings. In this regard, Ascentage also understands and agrees that:A.Ascentage must hold the Shares indefinitely, unless any subsequent proposed resale isregistered under the Securities Act, or unless an exemption from registration is otherwise available (such as Rule 144);B.the Company is under no obligation to register any subsequent proposed resale ofC.the Shares; and the certificate evidencing the Shares will be imprinted with a legendwhich prohibits the transfer of the Shares unless such transfer is registered or such registration is not required in the opinion of counselfor the Company.9.Ascentage is familiar with Rule 144. Ascentage is familiar with Rule 144 adopted under the SecuritiesAct, which in some circumstances permits limited public resales of “restricted securities” like the shares acquired from an issuer in anon-public offering. Ascentage understands that its ability to sell the Shares under Rule 144 in the future is uncertain, and may dependupon, among other things: (i) the availability of certain current public information about the Company; (ii) the resale occurring morethan a specified period after its acquisition and full payment (within the meaning of Rule 144) for the Shares; and (iii) if Ascentage isan affiliate of the Company (A) the sale being made in an unsolicited “broker’s transaction”, transactions directly with a market makeror riskless principal transactions, as those terms are defined under the Securities Exchange Act of 1934, as amended, (B) the amount ofshares being sold during any three-month period not exceeding the specified limitations stated in Rule 144, and (C) timely filing of anotice of proposed sale on Form 144, if applicable.10.Ascentage knows that Rule 144 may never be available. Ascentage understands that the requirements ofRule 144 may not be met, and that the Shares may not be saleable under Rule 144, other than through the Company’s failure tocomply with the requirements of Rule 144. Ascentage further understands that at the time Ascentage wish to sell the Shares, there maybe no public market for the Company’s stock upon which to make such a sale, or the current public information requirements of Rule144 may not be satisfied other than through the Company’s failure to satisfy such requirements, either of which may preclude it fromselling the Shares under Rule 144 even if the relevant holding period had been satisfied.11.Ascentage knows that Ascentage is subject to further restrictions on resale. Ascentage understands thatin the event Rule 144 is not available to it, absent an effective registration under the Securities Act, the Shares may only be offered,sold or otherwise transferred (x) to the Company, (y) outside the United States in accordance with Rule 904 of Regulation S or (z)pursuant to an exemption from registration under the Securities Act,(which may or may not be available), or each of the following: (i)its written notice to the Company containing detailed information regarding the proposed sale, (ii) its providing an opinion of itscounsel to the effect that such sale will not require registration, and (iii) the Company notifying Ascentage in writing that its counselconcurs in such opinion. Ascentage understands that although Rule 144 is not US-DOCS\106256636.1 exclusive, the Staff of the SEC has stated that persons proposing to sell private placement securities other than in a registered offeringor pursuant to Rule 144 will have a substantial burden of proof in establishing that an exemption from registration is available for suchoffers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk.12.Non-U.S. Investor. If Ascentage is not a United States person, Ascentage hereby represents thatAscentage is satisfied as to the full observance of the laws of its jurisdiction in connection with any invitation to receive the Sharesissuable pursuant to this Agreement, or any use of this Agreement, including the legal requirements within its jurisdiction for theacquisition of the shares pursuant to this Agreement, any foreign exchange restrictions applicable to such receipt or transfer, (iii) anygovernmental or other consents that may need to be obtained and (iv) the income tax and other tax consequences, if any, that may berelevant to the acquisition, holding, redemption, sale or transfer of such securities. Ascentage’s subscription for, and its continuedbeneficial ownership of the Shares will not violate any applicable securities or other laws of its jurisdiction.13.Principal Place of Business. The address of its principal place of business is set forth on the signaturepage below.By signing below, the undersigned acknowledge their agreement with each of the statements contained in this InvestmentRepresentation Statement as of the date first set forth above, and their intent for the Company to rely on such statements in issuing theShares. US-DOCS\106256636.1 ASCENTAGE PHARMA GROUP CORP LIMITED Address of Licensor’s Principal Place of Business: Address: 11/F, AXA Centre 151 Gloucester RoadWanchai, Hong Kong, China  Exhibit 10.23285 EAST GRAND AVENUELEASEThis Lease (the "Lease"), dated as of the date set forth in Section 1 of the Summary of Basic Lease Information (the "Summary"), below, is madeby and between BAYSIDE AREA DEVELOPMENT, LLC, a Delaware limited liability company ("Landlord"), and UNITY BIOTECHNOLOGY, INC., aDelaware corporation ("Tenant").SUMMARY OF BASIC LEASE INFORMATION TERMS OF LEASEDESCRIPTION1. Date:February 28, 20192. Premises(Article 1). 2.1 Building:285 East Grand AvenueSouth San Francisco, CA 940802.2 Premises:Deemed to be approximately 62,655 rentable square feet of space consisting ofthe entire Building, as further set forth in Exhibit A to the Lease.3. Lease Term(Article 2). 3.1 Length of Term:Approximately ten (10) years.3.2 Lease CommencementDate:The later of (i) the earlier to occur of (a) October 1, 2019, and (b) the date uponwhich Tenant commences to conduct business from the Premises for thePermitted Use (as opposed to accessing the Premises for move-in purposes),and (ii) the date the Premises are "Ready for Occupancy", as defined in theTenant Work Letter attached hereto as Exhibit B.3.3 Lease Expiration Date:If the Lease Commencement Date shall be the first day of a calendar month,then the day immediately preceding the tenth (10th) anniversary of the LeaseCommencement Date; or, if the Lease Commencement Date shall be other thanthe first day of a calendar month, then the last day of the month in which thetenth (10th) anniversary of the Lease Commencement Date occurs.792986.06/WLA186772-00003/2-28-19/gjn/gjn Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  4. Base Rent (Article 3): Lease YearAnnualBase RentMonthlyInstallmentof Base RentApproximateMonthly BaseRent per RentableSquare Foot1*$3,947,265.00*$328,938.75*$5.252$4,082,599.80$340,216.65$5.433$4,225,490.79$352,124.23$5.624$4,373,382.97$364,448.58$5.825$4,526,451.37$377,204.28$6.026$4,684,877.17$390,406.43$6.237$4,848,847.87$404,070.66$6.458$5,018,557.55$418,213.13$6.679$5,194,207.06$432,850.59$6.9110$5,376,004.31$448,000.36$7.15*Note: Tenant shall have no obligation to pay any Base Rent for the Premises attributable to the first two (2) full calendar months of the Lease Term (the"Base Rent Abatement Period"); provided, however, Tenant shall be required to pay Tenant's Share of Direct Expenses attributable to such period, as well asfor all utilities and other services furnished to the Premises.5. Tenant Improvement Allowance (Exhibit B):$7,831,875.00 (i.e., $125.00 multiplied by 62,655 rentable square feet in thePremises).6. Tenant's Share(Article 4):One hundred percent (100%). 7. Permitted Use(Article 5):General office, research and development, engineering, laboratory, vivarium,storage and/or warehouse uses, including, but not limited to, administrativeoffices and other lawful uses reasonably related to or incidental to suchspecified uses, all consistent with first class life sciences projects located inthe South San Francisco, California area that are comparable in age (based onthe original construction or the latest major renovation), location, quality ofconstruction, services and amenities to the Building ("ComparableBuildings"). 8. Letter of Credit(Article 21):$896,000.72.792986.06/WLA186772-00003/2-28-19/gjn/gjn-2-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  9. Parking(Article 28):2.6 unreserved parking spaces for every 1,000 rentable square feet of thePremises (which based on the rentable square feet of the Premises is 163parking spaces). Such parking spaces are located in the on-site parkingfacilities which serve the Project and shall be without additional charge.10. Address of Tenant(Section 29.18):Prior to the Lease Commencement Date:Unity Biotechnology, Inc.3280 Bayshore Boulevard, Suite 100Brisbane, CA 94005Attention: General Counsel With a copy to: legal@unitybiotechnology.com After the Lease Commencement Date:Unity Biotechnology, Inc.285 East Grand AvenueSouth San Francisco, CA 94080Attention: General Counsel With a copy to: legal@unitybiotechnology.com11. Address of Landlord(Section 29.18):See Section 29.18 of the Lease.12. Broker(s)(Section 29.24):CBRE, Inc. (representing Landlord)andCornish & Carey Commercial dba Newmark Knight Frank (representingTenant) 792986.06/WLA186772-00003/2-28-19/gjn/gjn-3-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  1.PREMISES, BUILDING, PROJECT, AND COMMON AREAS1.1Premises, Building, Project and Common Areas.1.1.1The Premises. Landlord hereby leases to Tenant and Tenant hereby leases from Landlord the premises set forth inSection 2.2 of the Summary (the "Premises"). The outline of the Premises is set forth in Exhibit A attached hereto. The outline of the "Building" and the"Project," as those terms are defined in Section 1.1.2 below, are further depicted on the Site Plan attached hereto as Exhibit A-1. The parties hereto agree thatthe lease of the Premises is upon and subject to the terms, covenants and conditions herein set forth, and each of Tenant and Landlord hereby covenants as amaterial part of the consideration for this Lease to keep and perform each and all of such terms, covenants and conditions by it to be kept and performed andthat this Lease is made upon the condition of such performance. The parties hereto hereby acknowledge that the purpose of Exhibit A is to show theapproximate location of the Premises only, and such Exhibit is not meant to constitute an agreement, representation or warranty as to the construction of thePremises, the precise area thereof or the specific location of the "Common Areas," as that term is defined in Section 1.1.3, below, or the elements thereof or ofthe accessways to the Premises or the "Project," as that term is defined in Section 1.1.2, below. Except as specifically set forth in this Lease and in the TenantWork Letter attached hereto as Exhibit B (the "Tenant Work Letter"), Landlord shall not be obligated to provide or pay for any improvement work orservices related to the improvement of the Premises. Tenant also acknowledges that neither Landlord nor any agent of Landlord has made any representationor warranty regarding the condition of the Premises, the Building or the Project or with respect to the suitability of any of the foregoing for the conduct ofTenant's business, except as specifically set forth in this Lease and the Tenant Work Letter. The taking of possession of the Premises by Tenant shallconclusively establish that the Premises and the Building were at such time in good and sanitary order, condition and repair, subject to latent defects, theterms and conditions of this Lease and the Tenant Work Letter (including without limitation, Landlord’s obligations with respect to any “Punch List Work,”as that term is defined in the Tenant Work Letter, and Landlord’s express maintenance and repair obligations under this Lease). Landlord shall deliverexclusive possession of the Building and Premises to Tenant, including the Building Structure (as that term is defined in Section 7.4 below), in good workingcondition and repair, with the roof and roof membrane watertight, with the existing "Building Systems", as defined in Section 7.1, below, including withoutlimitation HVAC, electrical, lighting, plumbing, ceiling tiles, structural integrity, roof and roof membrane, fire protection system, parking facilities andlandscape irrigation (but excluding all laboratory services, process utilities and emergency generator), the Tenant Improvements and the Common Areas, ingood working condition, and in compliance with all "Applicable Laws" (as that term is defined in Article 24 below) existing as of the Lease CommencementDate, including, without limitation, the Americans with Disabilities Act of 1990, to the extent required to allow the legal occupancy of the Premises (the"Delivery Condition"). Notwithstanding the foregoing, Tenant shall accept all laboratory services, process utilities and emergency generator in theirpresently existing, as-is condition and Tenant shall be solely responsible for all costs related to their conditional use.1.1.2The Building and The Project. The Premises constitutes the entire building set forth in Section 2.1 of the Summary(the "Building"). The Building comprises the office/laboratory project currently known as Britannia Modular Labs II." The term "Project," as used in thisLease, shall mean (i) the Building and the Common Areas, (ii) the land (which is improved with landscaping, parking facilities and other improvements) uponwhich the Building and the Common Areas are located, and (iii) at Landlord's discretion, any additional real property, areas, land, buildings or otherimprovements added thereto outside of the Project. 1.1.3Common Areas. Tenant shall have the non-exclusive right to use in common with other tenants in the Project, andsubject to the rules and regulations referred to in Article 5 of this Lease, those portions of the Project which are provided, from time to time, for use incommon by Landlord, Tenant and any other tenants of the Project (such areas, together with such other portions of the Project designated by Landlord, in itsdiscretion, are collectively referred to herein as the "Common Areas"). Landlord shall maintain and operate the Common Areas in good condition and repairand consistent with the manner in which common areas are maintained in "Comparable Buildings" (as that term is defined in Section 7 of the Summary)) andthe use thereof shall be subject to such reasonable and non-discriminatory rules, regulations and restrictions as Landlord may make from time to time andprovide to Tenant in writing. Landlord reserves the right to close temporarily, make alterations or additions to, in accordance with the terms of Section 29.29below, or change the location of elements of the Project (other than the Premises) and792986.06/WLA186772-00003/2-28-19/gjn/gjn-4-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  the Common Areas, provided that the same do not materially and adversely interfere with Tenant’s use of or access to the Premises or the parking facilitiesserving the Project.1.2Rentable Square Feet of Premises. The rentable square footage of the Premises is hereby deemed to be as set forth in Section 2.2 ofthe Summary, and shall not be subject to measurement or adjustment during the Lease Term. 2.LEASE TERM; OPTION TERM2.1Lease Term. The terms and provisions of this Lease shall be effective as of the date of this Lease. The term of this Lease (the "LeaseTerm") shall be as set forth in Section 3.1 of the Summary, shall commence on the date set forth in Section 3.2 of the Summary (the "Lease CommencementDate"), and shall terminate on the date set forth in Section 3.3 of the Summary (the "Lease Expiration Date") unless this Lease is sooner terminated orextended as hereinafter provided. As used in this Lease, the term “Lease Term” shall include any extension term pursuant to Section 2.2 below orotherwise. For purposes of this Lease, the term "Lease Year" shall mean each consecutive twelve (12) month period during the Lease Term; provided if theLease Commencement Date shall be other than the first day of a calendar month, the first Lease Year shall include the partial month during which the LeaseCommencement Date occurs plus the immediately following consecutive twelve (12) month period. Within the first one hundred twenty (120) days of theLease Term, Landlord shall deliver to Tenant a notice in the form as set forth in Exhibit C, attached hereto, as a confirmation only of the information set forththerein, which Tenant shall execute and return to Landlord within fifteen (15) days of receipt thereof assuming the same is factually correct. Notwithstandingthe foregoing, if Landlord has not delivered possession of the Premises to Tenant Ready for Occupancy, (1) on or before January 31, 2020, then, as Tenant’ssole remedy for such delay (except as set forth in subsections (2) and (3) below), Tenant shall be entitled to one (1) day of abatement of Rent for every two (2)days that the delivery date is delayed beyond such date (which abatement shall be in addition to the abatement set forth in Section 4 of the Summary), (2) onor before February 29, 2020, then, as Tenant’s sole remedy for such delay (except as set forth in subsection (3) below), Tenant shall be entitled to one (1) dayof abatement of Rent for each day that the delivery date is delayed beyond such date (which abatement shall be in addition to the abatement set forth inSection 4 of the Summary), or (3) March 31, 2020, then, as Tenant’s sole remedy for such delay (except as set forth in subsections (1) and (2) above), Tenantshall also have the right to terminate this Lease by written notice thereof to Landlord, whereupon any monies previously paid by Tenant to Landlord shall bereimbursed to Tenant and the parties shall be relieved of all obligations under this Lease. The foregoing dates in subsections (1), (2) and (3) shall beextended to the extent of any delays in delivery of possession caused by (i) Tenant Delay, as that term is defined in Section 1(j) of the Tenant Work Letter,and the foregoing date in subsection (3) shall be extended to the extent of any delays in delivery of possession caused by “Unavoidable Delays”, as that termis defined in Section 1(l) of the Tenant Work Letter (provided that any such delay due to Unavoidable Delays shall not extend such date by more than fortyfive (45) days in the aggregate). If Landlord contends that a delay in delivery of possession due to Unavoidable Delays has occurred, Landlord shall notifyTenant in writing of the event that constitutes Unavoidable Delay and the date upon which the Unavoidable Delay is anticipated to end, and the delay due toUnavoidable Delay shall not be deemed to have occurred until the date of Tenant’s receipt of such notice. Landlord shall use commercially reasonableefforts to mitigate any Unavoidable Delay.2.2Option Term. 2.2.1Option Right. Landlord hereby grants the Tenant originally named in this Lease (the “Original Tenant”), and anyassignee of Original Tenant's entire interest in the Lease that has been approved or deemed approved in accordance with the terms of Article 14, below or anyassignee of Original Tenant's entire interest in the Lease who does not require Landlord’s consent under Article 14 below (a “Permitted Assignee”), one (1)option to extend the Lease Term for a period of eight (8) years (the “Option Term”). Such option to extend shall be exercisable only by written notice (the"Option Exercise Notice") delivered by Tenant to Landlord not more than twelve (12) months nor less than nine (9) months prior to the expiration of theinitial Lease Term, stating that Tenant is thereby irrevocably exercising its option to lease the Premises during the Option Term. Upon the proper exercise ofthe option to extend, and provided that, at Landlord’s option, as of the date of delivery of such notice, Tenant is not in monetary or material non-monetarydefault under this Lease (beyond the applicable notice and cure periods) and has not previously been in monetary or material non-monetary default underthis Lease (beyond the applicable notice792986.06/WLA186772-00003/2-28-19/gjn/gjn-5- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  and cure periods) more than once during the prior eighteen (18)-month period, and as of the end of the initial Lease Term, Tenant is not in monetary ormaterial non-monetary default under this Lease (beyond the applicable notice and cure periods), the Lease Term shall be extended for a period of eight (8)years on all of the terms and conditions set forth in this Lease, except that the Base Rent payable during the Option Term shall be determined as set forth inthis Section 2.2. The rights contained in this Section 2.2 shall be personal to Original Tenant and any Permitted Assignee (and not any other assignee,sublessee or “Transferee,” as that term is defined in Section 14.1, below, of Tenant’s interest in this Lease). In the event that Tenant fails to timely andappropriately exercise its option to extend the Lease Term in accordance with the terms of this Section 2.2, then such option shall automatically terminateand shall be of no further force or effect. 2.2.2Option Rent. The Base Rent payable by Tenant during the Option Term (the "Option Rent") shall be equal to the "FairRental Value," as that term is defined below, for the Premises as of the commencement date of the Option Term. The "Fair Rental Value," as used in thisLease, shall be equal to the annual base rent per rentable square foot (considering any "base year" or "expense stop" applicable thereto), including allescalations, at which tenants (pursuant to leases consummated within the twelve (12) month period preceding the first day of the Option Term), are leasingnon-sublease, non-encumbered, non-equity space which is not significantly greater or smaller in size than the subject space, for a comparable lease term, in anarm's length transaction, which comparable space is located in the Building or in "Comparable Buildings," as that term is defined in Section 7 of theSummary (transactions satisfying the foregoing criteria shall be known as the "Comparable Transactions"), taking into consideration the followingconcessions (the "Concessions"): (a) rental abatement concessions, if any, being granted such tenants in connection with such comparable space; (b) tenantimprovements or allowances provided or to be provided for such comparable space, and taking into account the value, if any, of the existing improvements inthe subject space, such value to be based upon the age, condition, design, quality of finishes and layout of the improvements; and (c) other reasonablemonetary concessions being granted such tenants in connection with such comparable space. The Concessions (A) shall be reflected in the effective rentalrate (which effective rental rate shall take into consideration the total dollar value of such Concessions as amortized on a straight-line basis over theapplicable term of the Comparable Transaction (in which case such Concessions evidenced in the effective rental rate shall not be granted to Tenant))payable by Tenant, or (B) at Landlord’s election and with Tenant’s reasonable approval, all such Concessions shall be granted to Tenant in kind. 2.2.3Determination of Option Rent. In the event Tenant timely and appropriately exercises its option to extend the LeaseTerm for the Option Term, Landlord shall notify Tenant of Landlord's good faith determination of the Option Rent (“Landlord’s Option RentDetermination”) on or before the date that is thirty (30) days following Landlord's receipt of the Option Exercise Notice. If Tenant, on or before the datewhich is thirty (30) days following the date upon which Tenant receives Landlord's Option Rent Determination, in good faith objects to Landlord's OptionRent Determination, then Landlord and Tenant shall attempt to agree upon the Option Rent using their good-faith efforts. If Landlord and Tenant fail toreach agreement within thirty (30) days following Tenant's objection to Landlord's Option Rent Determination (the "Outside Agreement Date"), then eachparty shall thereafter make a separate determination of the Option Rent, within five (5) business days of the Outside Agreement Date, and such determinationsshall be submitted to arbitration in accordance with Sections 2.2.3.1 through 2.2.3.7, below. If Tenant fails to object to Landlord's Option RentDetermination within the time period set forth herein, then Tenant shall be deemed to have rejected Landlord's Option Rent Determination, and the mattershall be submitted to arbitration in accordance with the terms hereof. 2.2.3.1Landlord and Tenant shall each appoint one arbitrator who shall be, at the option of the appointing party,a MAI appraiser or a real estate broker, who shall have been active over the five (5) year period ending on the date of such appointment in the leasing orappraisal, as the case may be, of life science properties in South San Francisco, California. Each such arbitrator shall be appointed within twenty (20) daysafter the Outside Agreement Date. Landlord and Tenant may consult with their selected arbitrators prior to appointment and may select an arbitrator who isfavorable to their respective positions. The arbitrators so selected by Landlord and Tenant shall be deemed "Advocate Arbitrators."2.2.3.2The two (2) Advocate Arbitrators so appointed shall be required by Landlord and Tenant within ten (10)days of the date of the appointment of the last appointed Advocate Arbitrator to agree upon and appoint a third arbitrator ("Neutral Arbitrator") who shall bequalified under the same criteria set forth792986.06/WLA186772-00003/2-28-19/gjn/gjn-6- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  hereinabove for qualification of the two Advocate Arbitrators, except that neither the Landlord or Tenant or either parties' Advocate Arbitrator may, directlyor indirectly, consult with the Neutral Arbitrator prior or subsequent to his or her appointment. The Neutral Arbitrator shall be retained via an engagementletter jointly prepared by Landlord's counsel and Tenant’s counsel.2.2.3.3The Neutral Arbitrator shall, within thirty (30) days of his/her appointment, reach a decision as to whetherLandlord's or Tenant's submitted Option Rent is closest to the Fair Rental Value, and simultaneously publish a ruling indicating whether Landlord’s orTenant’s determination of Option Rent is closest to the Fair Rental Value as determined by such Neutral Arbitrator. The determination of the NeutralArbitrator shall be limited solely to the issue of whether Landlord's or Tenant's submitted Option Rent is the closest to the actual Fair Rental Value, takinginto account the requirements of Section 2.2.2 of this Lease, as determined by the arbitrators.2.2.3.4The decision of the Neutral Arbitrator shall be binding upon Landlord and Tenant. 2.2.3.5If either Landlord or Tenant fails to appoint an Advocate Arbitrator within twenty (20) days after theOutside Agreement Date, then either party may petition the presiding judge of the Superior Court of San Francisco County to appoint such AdvocateArbitrator subject to the criteria in Section 2.2.3.1 of this Lease, or if he or she refuses to act, either party may petition any judge having jurisdiction over theparties to appoint such Advocate Arbitrator.2.2.3.6If the two (2) Advocate Arbitrators fail to agree upon and appoint the Neutral Arbitrator within ten (10)days after the appointment of the last appointed Advocate Arbitrator, then either party may petition the presiding judge of the Superior Court of SanFrancisco County to appoint the Neutral Arbitrator, subject to criteria in Section 2.2.3.2 of this Lease, or if he or she refuses to act, either party may petitionany judge having jurisdiction over the parties to appoint such arbitrator.2.2.3.7Each party shall pay the fees and expenses of the Advocate Arbitrator it appoints, and each party shallpay fifty percent (50%) of the fees and expenses of the Neutral Arbitrator.2.2.4In the event that the Option Rent shall not have been determined pursuant to the terms hereof prior to thecommencement of the Option Term, Tenant shall be required to pay as Option Rent, the Base Rent payable by Tenant as of the expiration of the initial LeaseTerm, and upon the final determination of the Option Rent, the payments made by Tenant shall be reconciled with the actual amounts of Option Rent due,and the appropriate party shall make any corresponding payment to the other party.3.BASE RENT Tenant shall pay, without prior notice or demand, to Landlord or Landlord's agent at the management office of the Project, or, atLandlord's option, at such other place within the continental United States as Landlord may from time to time designate in writing, by a check for currencywhich, at the time of payment, is legal tender for private or public debts in the United States of America, base rent ("Base Rent") as set forth in Section 4 of theSummary, payable in equal monthly installments as set forth in Section 4 of the Summary in advance on or before the first day of each and every calendarmonth during the Lease Term, without any setoff or deduction whatsoever, except to the extent otherwise expressly provided in this Lease. The Base Rent forthe third (3rd) full month of the Lease Term shall be paid at the time of Tenant's execution of this Lease. If any Rent payment date (including the LeaseCommencement Date) falls on a day of the month other than the first day of such month or if any payment of Rent is for a period which is shorter than onemonth, the Rent for any fractional month shall accrue on a daily basis for the period from the date such payment is due to the end of such calendar month orto the end of the Lease Term at a rate per day which is equal to 1/365 of the applicable annual Rent. All other payments or adjustments required to be madeunder the terms of this Lease that require proration on a time basis shall be prorated on the same basis.4.ADDITIONAL RENT4.1General Terms. 4.1.1Direct Expenses; Additional Rent. In addition to paying the Base Rent specified in Article 3 of this Lease,commencing on the Lease Commencement Date Tenant shall pay "Tenant's Share" of the792986.06/WLA186772-00003/2-28-19/gjn/gjn-7- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  annual "Direct Expenses," as those terms are defined in Sections 4.2.6 and 4.2.2 of this Lease, respectively. Such payments by Tenant, together with any andall other amounts payable by Tenant to Landlord pursuant to the terms of this Lease, are hereinafter collectively referred to as the "Additional Rent", and theBase Rent and the Additional Rent are herein collectively referred to as "Rent." All amounts due under this Article 4 as Additional Rent shall be payable forthe same periods and in the same manner as the Base Rent. Without limitation on other obligations of Tenant which survive the expiration of the LeaseTerm, the obligations of Tenant to pay the Additional Rent provided for in this Article 4 shall survive the expiration of the Lease Term.4.1.2Triple Net Lease. Landlord and Tenant acknowledge that, except as otherwise provided to the contrary in this Lease,it is their intent and agreement that this Lease be a "TRIPLE NET" lease and that as such, the provisions contained in this Lease are intended to pass on toTenant or reimburse Landlord for the costs and expenses reasonably associated with this Lease, the Building and the Project, and Tenant's operationtherefrom. To the extent such costs and expenses payable by Tenant cannot be charged directly to, and paid by, Tenant, such costs and expenses shall bepaid by Landlord but reimbursed by Tenant as Additional Rent.4.2Definitions of Key Terms Relating to Additional Rent. As used in this Article 4, the following terms shall have the meaningshereinafter set forth:4.2.1Intentionally Deleted.4.2.2"Direct Expenses" shall mean "Operating Expenses" and "Tax Expenses."4.2.3"Expense Year" shall mean each calendar year in which any portion of the Lease Term falls, through and including thecalendar year in which the Lease Term expires, provided that Landlord, upon notice to Tenant, may change the Expense Year from time to time to any othertwelve (12) consecutive month period, and, in the event of any such change, Tenant's Share of Direct Expenses shall be equitably adjusted for any ExpenseYear involved in any such change.4.2.4"Operating Expenses" shall mean all expenses, costs and amounts of every kind and nature which Landlord pays oraccrues during any Expense Year because of or in connection with the ownership, management, maintenance, security, repair, replacement, restoration oroperation of the Project, or any portion thereof. Without limiting the generality of the foregoing, Operating Expenses shall specifically include any and all ofthe following: (i) the cost of supplying all utilities (excluding any utilities directly payable by Tenant pursuant to Article 6 or by another tenant or occupantof the Project), the cost of operating, repairing, maintaining, and renovating the utility, telephone, mechanical, sanitary, storm drainage, and elevator systems,and the cost of maintenance and service contracts in connection therewith; (ii) the cost of licenses, certificates, permits and inspections and the cost ofcontesting any governmental enactments which may increase Operating Expenses, and the costs incurred in connection with a governmentally mandatedtransportation system management program or similar program; (iii) premiums for insurance required to be carried by Landlord with respect to the Project andPremises under this Lease, and reasonable and customary deductible amounts under such insurance policies not exceeding deductible amounts generallyobtained by owners of Comparable Buildings (and if such deductible amounts are in excess of $75,000.00 and are used to fund capital expenditures, thedeductibles shall be amortized over the useful life of the capital expenditure as Landlord shall reasonably determine in accordance with sound real estatemanagement and accounting practices consistently applied by owners of Comparable Buildings); (iv) the cost of landscaping, relamping, and all supplies,tools, equipment and materials used in the operation, repair and maintenance of the Project, or any portion thereof; (v) the cost of parking area operation,repair, restoration, and maintenance; (vi) subject to item (s) below, fees and other costs, including management and/or incentive fees, consulting fees, legalfees and accounting fees, of all contractors and consultants in connection with the management, operation, maintenance and repair of the Project; (vii)subject to item (m) below the fair rental value of any management office space; (viii) subject to item (f), below, wages, salaries and other compensation andbenefits, including taxes levied thereon, of all persons engaged in the operation, maintenance and security of the Project; (ix) costs under any instrumentpertaining to the sharing of costs by the Project, but only to the extent that such cost sharing is non-discriminatory and commercially reasonable; (x) subjectto item (xiii) below, operation, repair, maintenance and replacement of all systems and equipment and components thereof of the Project; (xi) the cost ofjanitorial, alarm, security and other services, replacement of wall and floor coverings, ceiling tiles and fixtures in Common Areas, maintenance andreplacement of curbs and walkways, repair792986.06/WLA186772-00003/2-28-19/gjn/gjn-8- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  to roofs (including roof membrane) and re-roofing (subject to amortization (including interest on the amortized cost at a commercially reasonable interestrate) over the useful life of the new roof as Landlord shall reasonably determine in accordance with sound real estate management and accounting practicesconsistently applied by owners of Comparable Buildings); (xii) amortization (including commercially reasonable interest on the unamortized cost) over suchperiod of time as Landlord shall reasonably determine in accordance with sound real estate management and accounting practices consistently applied byowners of Comparable Buildings, of the cost of acquiring or the rental expense of personal property used in the maintenance, operation and repair of theProject, or any portion thereof; (xiii) the cost of capital improvements or other costs incurred in connection with the Project (A) which are intended to effecteconomies in the operation or maintenance of the Project, or any portion thereof, or to reduce current or future Operating Expenses or to enhance the safety orsecurity of the Project or its occupants, in each case only to the extent of the cost savings reasonably anticipated to result therefrom, (B) that are required tocomply with mandatory conservation programs, (C) that are required under any Applicable Law first enacted or enforced after the Lease CommencementDate, or (D) which are repairs, replacements or modifications to the Building Systems (as defined in Section 7.1, below); provided, however, that ifany such cost described in (A), (B), (C) or (D) above is a capital expenditure, such cost shall be amortized (including interest on the amortized cost at acommercially reasonable interest rate) over the useful life of the applicable capital item as Landlord shall reasonably determine in accordance with sound realestate management and accounting practices consistently applied by owners of Comparable Buildings; (xiv) costs, fees, charges or assessments imposed by,or resulting from any mandate imposed on Landlord by, any federal, state or local government for fire and police protection, trash removal, communityservices, or other services which do not constitute "Tax Expenses" as that term is defined in Section 4.2.5, below; provided, however, that if any such costdescribed in this subsection (xiv) is a capital expenditure, such cost shall be amortized (including interest on the amortized cost at a commercially reasonableinterest rate) over the useful life of the applicable capital item as Landlord shall reasonably determine in accordance with sound real estate management andaccounting practices consistently applied by owners of Comparable Buildings, and (xv) payments under any easement, license, operating agreement,declaration, restrictive covenant, or instrument pertaining to the sharing of costs by the Building, including, without limitation, any covenants, conditionsand restrictions affecting the property, and reciprocal easement agreements affecting the property, any parking licenses, and any agreements with transitagencies affecting the Property (collectively, "Underlying Documents"), provided the allocation of such costs is made on a commercially reasonable andnon-discriminatory basis. Landlord shall not collect more than one hundred percent of any Operating Expense or any Operating Expense more thanonce. Notwithstanding the foregoing, for purposes of this Lease, Operating Expenses shall not, however, include:(a)costs, including legal fees, space planners' fees, advertising and promotional expenses (except as otherwise setforth above), and brokerage fees incurred in connection with the original construction or development or to correct any defect in the originalconstruction or development of the Project, or original or future leasing of the Project, and costs, including permit, license and inspection costs,incurred with respect to the installation of tenant improvements made for tenants occupying space in the Project or incurred in renovating orotherwise improving, decorating, painting or redecorating vacant space for tenants or other occupants of the Project (excluding, however, suchcosts relating to any Common Areas of the Project or parking facilities that generally benefit all tenants);(b)except as set forth in items (xii), (xiii), and (xiv) above, depreciation, interest and principal payments onmortgages and other debt costs, if any, penalties and interest and costs of capital expenditures, improvements, repairs or alterations;(c)costs for which the Landlord is entitled to be reimbursed by any tenant or occupant of the Project or byinsurance by its carrier (or would be subject to reimbursement in the event Landlord fails to carry the insurance coverage required under thisLease) or any tenant's carrier or by anyone else, and electric power or other utility costs for which any tenant directly contracts with the localpublic service company;(d)any bad debt loss, rent loss, or reserves for bad debts or rent loss or other reserves of any kind;792986.06/WLA186772-00003/2-28-19/gjn/gjn-9- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  (e)costs associated with the operation of the business of the partnership or entity which constitutes the Landlord,as the same are distinguished from the costs of operation of the Project (which shall specifically include, but not be limited to, accounting costsassociated with the operation of the Project). Costs associated with the operation of the business of the partnership or entity which constitutes theLandlord include costs of partnership accounting and legal matters, costs of defending any lawsuits with any mortgagee (except as the actions ofthe Tenant may be in issue), costs of selling, syndicating, financing, mortgaging or hypothecating any of the Landlord's interest in the Project,and costs incurred in connection with any disputes between Landlord and its employees, between Landlord and Project management, or betweenLandlord and other tenants or occupants and costs incurred due to a violation by Landlord of the terms and conditions of any lease of space inthe Project;(f)the wages and benefits of any employee who does not devote substantially all of his or her employed time tothe Project unless such wages and benefits are prorated to reflect time spent on operating and managing the Project vis-a-vis time spent on mattersunrelated to operating and managing the Project; provided, that in no event shall Operating Expenses for purposes of this Lease include wagesand/or benefits attributable to personnel above the level of Project manager;(g)amount paid as ground rental for the Project by the Landlord;(h)except for a Project management fee to the extent allowed pursuant to item (s) below, overhead and profitincrement paid to the Landlord or to subsidiaries or affiliates of the Landlord for services in the Project to the extent the same exceeds the costs ofsuch services rendered by qualified, first-class unaffiliated third parties on a competitive basis;(i)any compensation paid to clerks, attendants or other persons in commercial concessions operated by theLandlord, provided that any compensation paid to any concierge at the Project shall be includable as an Operating Expense;(j)rentals and other related expenses incurred in leasing air conditioning systems, elevators or other equipmentwhich if purchased the cost of which would be excluded from Operating Expenses as a capital cost, except equipment not affixed to the Projectwhich is used in providing engineering, janitorial or similar services and, further excepting from this exclusion such equipment rented or leasedto remedy or ameliorate an emergency condition in the Project;(k)all items and services for which Tenant or any other tenant in the Project is obligated to reimburse Landlordor which Landlord provides selectively to one or more tenants (other than Tenant) without reimbursement;(l)any costs expressly excluded from Operating Expenses elsewhere in this Lease;(m)rent for any office space occupied by Project management personnel to the extent the size or rental rate ofsuch office space exceeds the size or fair market rental value of office space occupied by management personnel of the Comparable Buildings,with adjustment where appropriate for the size of the applicable project;(n)costs arising from the negligence or willful misconduct of Landlord or its agents, employees, contractors orproviders of materials or services; and(o)costs incurred to test, survey, remove, remedy, contain, or treat any “Hazardous Materials”, as defined inSection 5.3.1.1 below, existing in the Building or on or about the Project as of the Lease Commencement Date or thereafter brought into theBuilding or onto or about the Project after the Lease Commencement Date by Landlord or any other tenant of the Project or by any party otherthan Tenant or Tenant’s Agents;792986.06/WLA186772-00003/2-28-19/gjn/gjn-10- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  (p)costs of repairs or other work occasioned by fire, windstorm or other casualty (other than those amountswithin the deductible limits of insurance policies actually carried by Landlord, which amounts shall be includable as Operating Expenses so longas such deductibles are within the generally prevailing range of deductibles to policies carried by landlords of the Comparable Buildings) whichare covered by Landlord’s insurance policies or would be covered if Landlord had maintained insurance in accordance with this Lease;(q)costs incurred in connection with any major change in the Project, such as adding or deleting buildings orfloors or reconfiguring the parking facilities or other Common Areas;(r)fines, penalties and interest resulting from late payment by Landlord; and(s)fees payable by Landlord for management of the Project in excess of three percent (3%) (the “ ManagementFee Cap” ) of Landlord’s gross rental revenues from the Project;(t)costs incurred to comply with Landlord’s representations and warranties under this Lease or the Tenant WorkLetter, to comply with Landlord’s obligations under the Tenant Work Letter, or to deliver the Premises in the Delivery Condition;(u)costs to remedy any violation of any Underlying Document or any Applicable Law that exists as of the LeaseCommencement Date (and the inclusion of the phrase “to the extent required to allow the legal occupancy of the Premises” in the second to lastsentence of Section 1.1.1 above shall not operate as a waiver with respect to this exclusion); and(v)costs of replacing, as opposed to the routine repair and maintenance of the Building Structure (which shall beincludable in Operating Expenses), the Building Structure or any component thereof; provided that re-roofing shall be includable pursuant to theterms of Section 4.2.4(xi).4.2.5Taxes.4.2.5.1"Tax Expenses" shall mean all federal, state, county, or local governmental or municipal taxes, fees,charges or other impositions of every kind and nature, whether general, special, ordinary or extraordinary (including, without limitation, real estate taxes,general and special assessments, transit taxes, leasehold taxes or taxes based upon the receipt of rent, including gross receipts or sales taxes applicable to thereceipt of rent, unless required to be paid by Tenant, personal property taxes imposed upon the fixtures, machinery, equipment, apparatus, systems andequipment, appurtenances, furniture and other personal property used in connection with the Project, or any portion thereof), which shall be paid or accruedduring any Expense Year (without regard to any different fiscal year used by such governmental or municipal authority) because of or in connection with theownership, leasing and operation of the Project, or any portion thereof.4.2.5.2Tax Expenses shall include, without limitation: (i) Any tax on the rent, right to rent or other income fromthe Project, or any portion thereof, or as against the business of leasing the Project, or any portion thereof; (ii) Any assessment, tax, fee, levy or charge inaddition to, or in substitution, partially or totally, of any assessment, tax, fee, levy or charge previously included within the definition of real property tax;(iii) Any assessment, tax, fee, levy, or charge allocable to or measured by the area of the Premises or the Rent payable hereunder, including, withoutlimitation, any business or gross income tax or excise tax with respect to the receipt of such rent, or upon or with respect to the possession, leasing, operating,management, maintenance, alteration, repair, use or occupancy by Tenant of the Premises, or any portion thereof; and (iv) Any assessment, tax, fee, levy orcharge, upon this transaction or any document to which Tenant is a party, creating or transferring an interest or an estate in the Premises or the improvementsthereon.4.2.5.3Any reasonable costs and expenses (including, without limitation, reasonable attorneys' and consultants'fees) incurred in attempting to protest, reduce or minimize Tax Expenses shall be included in Tax Expenses in the Expense Year such expenses areincurred. Tax refunds shall be credited against Tax Expenses and refunded to Tenant regardless of when received, based on the Expense Year to which therefund is applicable,792986.06/WLA186772-00003/2-28-19/gjn/gjn-11- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  provided that in no event shall the amount to be refunded to Tenant for any such Expense Year exceed the total amount paid by Tenant as Additional Rentunder this Article 4 for such Expense Year. If Tax Expenses for any period during the Lease Term or any extension thereof are increased after payment thereoffor any reason, including, without limitation, error or reassessment by applicable governmental or municipal authorities, Tenant shall pay Landlord upondemand Tenant's Share of any such increased Tax Expenses. Notwithstanding anything to the contrary contained in this Section 4.2.5, there shall beexcluded from Tax Expenses (i) all excess profits taxes, franchise taxes, gift taxes, capital stock taxes, inheritance and succession taxes, estate taxes, federaland state income taxes, and other taxes to the extent applicable to Landlord's net income (as opposed to rents, receipts or income attributable to operations atthe Project), (ii) any items included as Operating Expenses, (iii) any items paid by Tenant under Section 4.5 of this Lease, and (iv) any penalties or feesarising from Landlord’s late payment of Tax Expenses.4.2.5.4At Tenant's request, and provided that it is then deemed advisable by Landlord in the exercise ofLandlord’ s reasonable business judgment (i.e., Landlord has a reasonable expectation of success of such appeal), Landlord shall bring or cause to be broughtan application or proceeding for reduction of the assessed valuation of the Building or Project, as applicable, in order to reduce Tax Expenses.4.2.6"Tenant's Share" shall mean the percentage set forth in Section 6 of the Summary. 4.3Allocation of Direct Expenses. The parties acknowledge that if at any time in the future the Building is a part of a multi-buildingproject, the costs and expenses incurred in connection with the Project (i.e., the Direct Expenses) shall be shared between the Building and the otherbuildings in the Project in accordance with this Section 4.3. Accordingly, as set forth in Section 4.2 above, Direct Expenses (which consist of OperatingExpenses and Tax Expenses) are determined annually for the Project as a whole, and a portion of the Direct Expenses, which portion shall be reasonablydetermined by Landlord on an equitable basis, shall be allocated to the Building (as opposed to any other future buildings in the Project). Such portion ofDirect Expenses allocated to the Building shall include all Direct Expenses attributable solely to the Building and an equitable pro-rata portion of the DirectExpenses attributable to the Project as a whole, and shall not include Direct Expenses attributable solely to other buildings in the Project.4.4Calculation and Payment of Additional Rent. Tenant shall pay to Landlord, in the manner set forth in Section 4.4.1, below, and asAdditional Rent, Tenant's Share of Direct Expenses for each Expense Year.4.4.1Statement of Actual Direct Expenses and Payment by Tenant. Landlord shall give to Tenant following the end ofeach Expense Year, a statement (the "Statement") which shall set forth in reasonable itemized detail the Direct Expenses incurred or accrued for suchpreceding Expense Year, and which shall indicate the amount of Tenant's Share of Direct Expenses. Landlord shall deliver such Statement to Tenant on orbefore June 1 following the end of the Expense Year to which such Statement relates. Upon receipt of the Statement for each Expense Year commencing orending during the Lease Term, Tenant shall pay, with its next installment of Base Rent due, the full amount of Tenant's Share of Direct Expenses for suchExpense Year, less the amounts, if any, paid during such Expense Year as "Estimated Direct Expenses," as that term is defined in Section 4.4.2, below, and ifTenant paid more as Estimated Direct Expenses than the actual Tenant's Share of Direct Expenses, Tenant shall receive a credit in the amount of Tenant'soverpayment against Rent next due under this Lease. The failure of Landlord to timely furnish the Statement for any Expense Year shall not prejudiceLandlord or Tenant from enforcing its rights under this Article 4. Even though the Lease Term has expired and Tenant has vacated the Premises, when thefinal determination is made of Tenant's Share of Direct Expenses for the Expense Year in which this Lease terminates, Tenant shall within thirty (30) daysafter receipt of such final determination pay to Landlord such amount, and if Tenant paid more as Estimated Direct Expenses than the actual Tenant's Share ofDirect Expenses, Landlord shall, within thirty (30) days, deliver a check payable to Tenant in the amount of the overpayment. The provisions of thisSection 4.4.1 shall survive the expiration or earlier termination of the Lease Term. Notwithstanding the immediately preceding sentences, Tenant shall notbe responsible for Tenant’s Share of any Direct Expenses (other than Tax Expenses) attributable to any Expense Year which are first billed to Tenant morethan eighteen (18) months after the earlier of the expiration of the applicable Expense Year or the Lease Expiration Date, and Tenant shall not be responsiblefor Tenant’s Share of any Tax Expenses attributable to any Expense Year which are first billed to Tenant more than thirty-six (36) months after the earlier ofthe expiration of the applicable Expense Year or the Lease Expiration Date.792986.06/WLA186772-00003/2-28-19/gjn/gjn-12- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  4.4.2Statement of Estimated Direct Expenses. In addition, Landlord shall give Tenant a yearly expense estimate statement(the "Estimate Statement") which shall set forth Landlord's reasonable estimate (the "Estimate") of what the total amount of Direct Expenses for the then-current Expense Year shall be and the estimated Tenant's Share of Direct Expenses (the "Estimated Direct Expenses"). Landlord shall deliver such EstimateStatement to Tenant on or before June 1 of the Expense Year to which such Estimate Statement relates. The failure of Landlord to timely furnish the EstimateStatement for any Expense Year shall not preclude Landlord from enforcing its rights to collect any Estimated Direct Expenses under this Article 4, nor shallLandlord be prohibited from revising any Estimate Statement or Estimated Direct Expenses theretofore delivered to the extent necessary. Thereafter, Tenantshall pay, with its next installment of Base Rent due, a fraction of the Estimated Direct Expenses for the then-current Expense Year (reduced by any amountspaid pursuant to the last sentence of this Section 4.4.2). Such fraction shall have as its numerator the number of months which have elapsed in such currentExpense Year, including the month of such payment, and twelve (12) as its denominator. Until a new Estimate Statement is furnished (which Landlord shallhave the right to deliver to Tenant at any time), Tenant shall pay monthly, with the monthly Base Rent installments, an amount equal to one-twelfth (1/12) ofthe total Estimated Direct Expenses set forth in the previous Estimate Statement delivered by Landlord to Tenant. 4.5Taxes and Other Charges for Which Tenant Is Directly Responsible. Tenant shall be liable for and shall pay beforedelinquency, taxes levied against Tenant's equipment, furniture, fixtures and any other personal property located in or about the Premises. If any such taxeson Tenant's equipment, furniture, fixtures and any other personal property are levied against Landlord or Landlord's property or if the assessed value ofLandlord's property is increased by the inclusion therein of a value placed upon such equipment, furniture, fixtures or any other personal property and ifLandlord pays the taxes based upon such increased assessment, which Landlord shall have the right to do regardless of the validity thereof but only underproper protest if requested by Tenant, Tenant shall upon demand repay to Landlord the taxes so levied against Landlord or the proportion of such taxesresulting from such increase in the assessment, as the case may be.4.6Landlord's Books and Records. Within one hundred eighty (180) days after receipt by Tenant of a Statement, if Tenant disputes theamount of Additional Rent set forth in the Statement, a member of Tenant's finance department, or an independent certified public accountant (whichaccountant is a member of a nationally or regionally recognized accounting firm and is not working on a contingency fee basis) ("Tenant's Accountant"),designated and paid for by Tenant, may, after reasonable notice to Landlord and at reasonable times, inspect Landlord's records with respect to the Statementat Landlord's offices in Northern California, provided that there is no existing monetary Event of Default and Tenant has paid all amounts required to be paidunder the applicable Estimate Statement and Statement, as the case may be. In connection with such inspection, Tenant and Tenant's agents must agree inadvance to follow Landlord's reasonable rules and procedures regarding inspections of Landlord's records, and shall execute a commercially reasonableconfidentiality agreement regarding such inspection. Tenant's failure to dispute the amount of Additional Rent set forth in any Statement within onehundred eighty (180) days of Tenant's receipt of such Statement shall be deemed to be Tenant's approval of such Statement and Tenant, thereafter, waives theright or ability to dispute the amounts set forth in such Statement. If after such inspection, Tenant still disputes such Additional Rent, a determination as tothe proper amount shall be made, at Tenant's expense, by an independent certified public accountant (the "Accountant") selected by Landlord and subject toTenant's reasonable approval; provided that if such Accountant determines that Direct Expenses were overstated by five percent (5%) or more, then the costof the Accountant and the cost of such determination shall be paid for by Landlord, and Landlord shall reimburse Tenant for the cost of the Tenant'sAccountant (provided that such cost shall be a reasonable market cost for such services). If such inspection determines that Tenant has overpaid any amountson account of Direct Expenses for such Expense Year, Landlord shall refund to Tenant the amount of such overpayment within thirty (30) days after theamount thereof is determined. Tenant hereby acknowledges that Tenant's sole right to inspect Landlord's books and records and to contest the amount ofDirect Expenses payable by Tenant shall be as set forth in this Section 4.6, and Tenant hereby waives any and all other rights pursuant to Applicable Law toinspect such books and records and/or to contest the amount of Direct Expenses payable by Tenant.5.USE OF PREMISES5.1Permitted Use. Tenant shall use the Premises solely for the Permitted Use set forth in Section 7 of the Summary and Tenant shall notuse or permit the Premises or the Project to be used for any other purpose or792986.06/WLA186772-00003/2-28-19/gjn/gjn-13- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  purposes whatsoever without the prior written consent of Landlord, which may be withheld in Landlord's sole discretion. 5.2Prohibited Uses. Tenant further covenants and agrees that Tenant shall not use, or suffer or permit any person or persons to use, thePremises or any part thereof for any use or purpose in violation of Applicable Laws. Landlord shall have the right to impose reasonable and customary non-discriminatory rules and regulations regarding the use of the Project, as reasonably deemed necessary by Landlord with respect to the orderly operation of theProject, and Tenant shall comply with such reasonable rules and regulations provided the same are provided to Tenant in writing. In the event of any conflictbetween the rules and regulations and the other provisions of this Lease, the terms of this Lease shall control. Tenant shall not do or permit anything to bedone in or about the Premises which will in any way damage the reputation of the Project or obstruct or interfere with the rights of other tenants or occupantsof the Building, or injure them or use or allow the Premises to be used for any unlawful purpose, nor shall Tenant cause, maintain or permit any nuisance in,on or about the Premises. Tenant shall comply with, and Tenant's rights and obligations under the Lease and Tenant's use of the Premises shall be subject andsubordinate to, all recorded easements, covenants, conditions, and restrictions now or hereafter affecting the Project. Landlord hereby confirms that as of thedate of this Lease there are no recorded easements, covenants, conditions, and restrictions affecting the Project. Tenant shall only be required to comply withany future recorded easements, covenants, conditions, and restrictions affecting the Project provided the same do not materially and adversely affect Tenant’srights (including parking rights) under this Lease or use of or access to the Premises for the Permitted Use or materially increase Tenant’s obligations underthis Lease. 5.3Hazardous Materials. 5.3.1Tenant's Obligations.5.3.1.1Prohibitions. As a material inducement to Landlord to enter into this Lease with Tenant, Tenant hasfully and accurately, to Tenant’s knowledge as of the date of its signature thereon, completed Landlord’s Pre-Leasing Environmental Exposure Questionnaire(the “Environmental Questionnaire”), which is attached as Exhibit E and identifies the “Hazardous Materials,” as that term is defined below, that Tenantreasonably anticipates to be used at the Premises and any related environmental permits that may be required. Tenant agrees that neither Tenant nor Tenant’semployees, contractors and subcontractors of any tier, entities with a contractual relationship with Tenant (other than Landlord), or any entity acting as anagent or sub-agent of Tenant (collectively, "Tenant's Agents") will produce, use, store or generate any Hazardous Materials, on, under or about the Premisesin violation of Environmental Laws, nor cause or permit any Hazardous Material to be brought upon, placed, stored, manufactured, generated, blended,handled, recycled, used or "Released," as that term is defined below, on, in, under or about the Premises in violation of Environmental Laws. Upon Landlord'swritten request (but no more than once each Lease Year), or in the event of any material change in Tenant's use of Hazardous Materials resulting in a newclass or category of Hazardous Materials being used in the Premises from that set forth in the Environmental Questionnaire then in place (i.e., changes in nonHazardous Materials or reasonable changes to the amounts or types of Hazardous Materials in the same category are exempt), Tenant shall deliver toLandlord an updated Environmental Questionnaire. Landlord’s prior written consent shall be required to any Hazardous Materials use for the Premises that isnot described on the Environmental Questionnaire, to the extent such use would result in a new class or category of Hazardous Materials being used in thePremises, such additional use shall be subject to Landlord's prior consent, which may be withheld in Landlord’s reasonable discretion. For purposes of thisLease, "Hazardous Materials" means all flammable explosives, petroleum and petroleum products, waste oil, radon, radioactive materials, toxic pollutants,asbestos, polychlorinated biphenyls (“PCBs”), medical waste, chemicals known to cause cancer or reproductive toxicity, pollutants, contaminants, hazardouswastes, toxic substances or related materials, including without limitation any chemical, element, compound, mixture, solution, substance, object, waste orany combination thereof, which is or may be hazardous to human health, safety or to the environment due to its radioactivity, ignitability, corrosiveness,reactivity, explosiveness, toxicity, carcinogenicity, infectiousness or other harmful or potentially harmful properties or effects, or defined as, regulated as orincluded in, the definition of “hazardous substances,” “hazardous wastes,” “hazardous materials,” or “toxic substances” under any Environmental Laws. Theterm “Hazardous Materials” for purposes of this Lease shall also include any mold, fungus or spores, whether or not the same is defined, listed, or otherwiseclassified as a “hazardous material” under any Environmental Laws, if such mold, fungus or spores may pose a risk to human health or the environment ornegatively impact the value of the792986.06/WLA186772-00003/2-28-19/gjn/gjn-14- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Premises. For purposes of this Lease, "Release" or "Released" or "Releases" shall mean any release, deposit, discharge, emission, leaking, spilling, seeping,migrating, injecting, pumping, pouring, emptying, escaping, dumping, disposing, or other movement of Hazardous Materials into the environment inviolation of Environmental Laws.5.3.1.2Notices to Landlord. Tenant shall notify Landlord in writing as soon as possible but in no event laterthan five (5) days after (i) Tenant becomes aware of the occurrence of any actual, alleged or threatened Release of any Hazardous Material caused by Tenantor Tenant's Agents in, on, under, from, about or in the vicinity of the Premises (whether past or present), regardless of the quantity of any such Release, or(ii) Tenant becomes aware of any regulatory actions, inquiries, inspections, investigations, directives, or any cleanup, compliance, enforcement or abatementproceedings (including any threatened or contemplated investigations or proceedings) relating to Releases of Hazardous Materials at the Premises, or(iii) Tenant becomes aware of any claims by any person or entity relating to any Release of Hazardous Materials in, on, under, from, about or in the vicinity ofthe Premises, whether relating to damage, contribution, cost recovery, compensation, loss or injury. Collectively, the matters set forth in clauses (i), (ii) and(iii) above are hereinafter referred to as “Hazardous Materials Claims”. In the event Landlord has reasonable grounds to believe that Tenant has notprovided the required notice of a Hazardous Materials Claim, Landlord shall have the right to deliver a written notice to Tenant inquiring as to the status ofany Hazardous Materials Claim and Tenant shall promptly respond to such written request with the current status of any Hazardous Materials Claimsimpacting the Premises. Tenant shall promptly forward to Landlord copies of all orders, notices, permits, applications and other written communications andreports served upon Tenant or generated by or for Tenant in connection with any Hazardous Materials Claims. Additionally, Tenant shall promptly adviseLandlord in writing of Tenant’s discovery of any occurrence or condition on, in, under or about the Premises that could subject Tenant or Landlord to anymaterial liability under any Environmental Laws. Tenant shall not enter into any legal proceeding or other action, settlement, consent decree or othercompromise with respect to any Hazardous Materials Claims without first notifying Landlord of Tenant’s intention to do so and affording Landlord theopportunity to join and participate, as a party if Landlord so elects, in such proceedings and in no event shall Tenant enter into any agreements which arebinding on Landlord or the Premises without Landlord’s prior written consent. If Landlord opts to join in such proceedings, Landlord shall not enter into anyagreements which are binding on Tenant without Tenant’s prior written consent. Landlord shall have the right to appear at and participate in, any and alllegal or other administrative proceedings concerning any Hazardous Materials Claim. For purposes of this Lease, “Environmental Laws” means allapplicable present and future laws relating to the protection of human health, safety, wildlife or the environment, including, without limitation, (i) allrequirements pertaining to reporting, licensing, permitting, investigation and/or remediation of emissions, discharges, Releases, or threatened Releases ofHazardous Materials, whether solid, liquid, or gaseous in nature, into the air, surface water, groundwater, or land, or relating to the manufacture, processing,distribution, use, treatment, storage, disposal, transport, or handling of Hazardous Materials; and (ii) all requirements pertaining to the health and safety ofemployees or the public. Environmental Laws include, but are not limited to, the Comprehensive Environmental Response, Compensation and Liability Actof 1980, 42 USC § 9601, et seq., the Hazardous Materials Transportation Authorization Act of 1994, 49 USC § 5101, et seq., the Solid Waste Disposal Act, asamended by the Resource Conservation and Recovery Act of 1976, and Hazardous and Solid Waste Amendments of 1984, 42 USC § 6901, et seq., theFederal Water Pollution Control Act, as amended by the Clean Water Act of 1977, 33 USC § 1251, et seq., the Clean Air Act of 1966, 42 USC § 7401, et seq.,the Toxic Substances Control Act of 1976, 15 USC § 2601, et seq., the Safe Drinking Water Act of 1974, 42 USC §§ 300f through 300j, the OccupationalSafety and Health Act of 1970, as amended, 29 USC § 651 et seq., the Oil Pollution Act of 1990, 33 USC § 2701 et seq., the Emergency Planning andCommunity Right-To-Know Act of 1986, 42 USC § 11001 et seq., the National Environmental Policy Act of 1969, 42 USC § 4321 et seq., the FederalInsecticide, Fungicide and Rodenticide Act of 1947, 7 USC § 136 et seq., California Carpenter-Presley-Tanner Hazardous Substance Account Act, CaliforniaHealth & Safety Code §§ 25300 et seq., Hazardous Materials Release Response Plans and Inventory Act, California Health & Safety Code, §§ 25500 et seq.,Underground Storage of Hazardous Substances provisions, California Health & Safety Code, §§ 25280 et seq., California Hazardous Waste Control Law,California Health & Safety Code, §§ 25100 et seq., and any other state or local law counterparts, as amended, as such applicable laws, are in effect as of theLease Commencement Date, or thereafter adopted, published, or promulgated.5.3.1.3Releases of Hazardous Materials. If any Release of any Hazardous Material in, on, under, from or aboutthe Premises shall occur at any time during the Lease Term caused by Tenant or Tenant's Agents, in addition to notifying Landlord as specified above,Tenant, at its own sole cost and expense, shall (i) promptly comply with any and all reporting requirements imposed pursuant to any and all EnvironmentalLaws,792986.06/WLA186772-00003/2-28-19/gjn/gjn-15- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  (ii) provide a written notification to Landlord indicating that Tenant has complied with all applicable reporting requirements, and (iii) take any and allnecessary investigation, corrective and remedial action in accordance with any and all applicable Environmental Laws, all in accordance with the provisionsand requirements of this Section 5.3, including, without limitation, Section 5.3.4. 5.3.1.4Indemnification. 5.3.1.4.1In General. Without limiting in any way Tenant’s obligations under any other provisionof this Lease, Tenant shall be solely responsible for and shall protect, defend, indemnify and hold the Landlord Parties harmless from and againstany and all claims, judgments, losses, damages, costs, expenses, penalties, enforcement actions, taxes, fines, remedial actions, liabilities(including, without limitation, reasonable attorneys’ fees, litigation, arbitration and administrative proceeding costs, expert and consultant feesand laboratory costs) and sums paid in settlement of claims, but excluding any consequential or special damages, which arise during or after theLease Term, whether foreseeable or unforeseeable, to the extent arising out of or attributable to the Release of Hazardous Materials in, on, underor about the Premises by Tenant or Tenant's Agents in violation of Environmental Laws.5.3.1.4.2Limitations. Notwithstanding anything in Section 5.3.1.4, above, to the contrary, Tenant'sindemnity of Landlord as set forth in Section 5.3.1.4, above, shall not be applicable to claims based upon Hazardous Materials not Released byTenant or Tenant's Agents. 5.3.1.4.3Landlord Indemnity. Under no circumstance shall Tenant be liable for, and Landlord shallindemnify, defend, protect and hold the Tenant Parties harmless from and against any and all claims, judgments, losses, damages, costs, expenses,penalties, enforcement actions, taxes, fines, remedial actions, liabilities (including, without limitation, reasonable attorneys’ fees, litigation,arbitration and administrative proceeding costs, expert and consultant fees and laboratory costs) and sums paid in settlement of claims, butexcluding any consequential or special damages, which arise during or after the Lease Term, whether foreseeable or unforeseeable, to the extentarising out of or attributable to any Hazardous Materials that exist in, on or about the Project as of the Lease Commencement Date or that existafter the expiration or termination of this Lease except to the extent such Hazardous Materials are the responsibility of Tenant in accordance withthis Section 5.3, or the Release of Hazardous Materials in, on, under or about the Project by Landlord or any Landlord Parties in violation ofEnvironmental Laws. Landlord will provide Tenant with any Hazardous Material reports relating to the Building or Project that Landlord has inits possession, or control. The provision of such reports shall be for informational purposes only, and Landlord does not make any representationor warranty as to the correctness or completeness of any such reports.5.3.1.5Compliance with Environmental Laws. Without limiting the generality of Tenant’s obligation tocomply with applicable laws as otherwise provided in this Lease, Tenant shall, at its sole cost and expense, comply with all Environmental Laws related tothe use of Hazardous Materials by Tenant and Tenant’s Agents. Tenant shall obtain and maintain any and all necessary permits, licenses, certifications andapprovals appropriate or required for the use, handling, storage, and disposal of any Hazardous Materials used, stored, generated, transported, handled,blended, or recycled by Tenant on the Premises. Landlord shall have a continuing right, without obligation, to require Tenant to obtain, and to review andinspect any and all such permits, licenses, certifications and approvals, together with copies of any and all Hazardous Materials management plans andprograms required by Environmental Laws, any and all Hazardous Materials risk management and pollution prevention programs required by EnvironmentalLaws, and any and all Hazardous Materials emergency response and employee training programs respecting Tenant’s use of Hazardous Materials. Uponrequest of Landlord (but no more than once every Lease Year, unless Landlord shall have reasonable grounds to believe that Tenant is not in compliance withits covenants under this Section 5.3), Tenant shall deliver to Landlord a notice certifying to Tenant's knowledge Tenant's compliance with all EnvironmentalLaws and the terms of this Section 5.3.5.3.2Assurance of Performance.5.3.2.1Environmental Assessments In General. In the event Landlord has a reasonable basis for determiningthat Tenant has caused a Release of Hazardous Materials in violation of Environmental Laws,792986.06/WLA186772-00003/2-28-19/gjn/gjn-16- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Landlord may, but shall not be required to, engage from time to time such contractors as Landlord reasonably determines to be appropriate (and which arereasonably acceptable to Tenant) to perform environmental assessments of a scope reasonably determined by Landlord (an "Environmental Assessment") toevaluate Tenant’s compliance with the requirements of this Lease with respect to any Release of Hazardous Materials. The environmental assessmentconducted by Landlord’s consultant shall not unreasonably interfere with Tenant’s operations at the Premises. Landlord shall require its consultant toprovide insurance against claims, damages, or costs arising from bodily injury or property damage caused to Tenant or the Premises by Landlord’sconsultant. The Environmental Assessment shall not include access to areas of Tenant’s operations that are used for vivarium purposes or are protected asconfidential business information or contain operations or processes that are protected under intellectual property rights, such as, but not limited to, tradesecrets.5.3.2.2Costs of Environmental Assessments. All costs and expenses incurred by Landlord in connection withany such Environmental Assessment initially shall be paid by Landlord; provided that if any such Environmental Assessment demonstrates that Tenant hascaused a Release of Hazardous Materials at or from the Premises, then all of the reasonable, out-of-pocket costs and expenses of such EnvironmentalAssessment shall be reimbursed by Tenant as Additional Rent within thirty (30) days after receipt of written demand therefor.5.3.3Tenant’s Obligations upon Surrender. At the expiration or earlier termination of the Lease Term, Tenant, at Tenant’ssole cost and expense, shall: (i) cause a Phase I environmental assessment to be conducted in general conformance with ASTM Standard E 1527-13 or thenapplicable standard (a "Phase I") of the Premises to be conducted in accordance with Section 15.3; (ii) cause all Hazardous Materials brought onto thePremises by Tenant or Tenant's Agents to be removed from the Premises and disposed of in accordance with all Environmental Laws and cause all HazardousMaterials brought onto the Premises by Tenant or Tenant's Agents to be removed as necessary to allow the Premises to be used for the purposes allowed as ofthe date of this Lease; and (iii) cause to be removed all containers installed or used by Tenant or Tenant’s Agents to store any Hazardous Materials on thePremises, and cause to be repaired any damage to the Premises caused by such removal.5.3.4Clean-up.5.3.4.1Environmental Reports; Clean-Up. If any written report containing results of any EnvironmentalAssessment (an “Environmental Report”) shall indicate (i) that Tenant or Tenant’s Agents caused a Release of Hazardous Materials at the Premises, whichRelease of Hazardous Materials requires an investigation, characterization, monitoring, assessment, repair, closure, remediation, removal, or other clean-upunder Environmental Laws (the “Clean-up"), Tenant shall promptly prepare and submit to Landlord within sixty (60) days after receipt of the EnvironmentalReport, a comprehensive plan, subject to Landlord’s reasonable review and comment, which review and comment Landlord shall promptly conduct andprovide to Tenant specifying the actions to be taken by Tenant under Environmental Laws to perform the Clean-up so that all Hazardous Materials broughtonto the Premises by Tenant or Tenant's Agents are removed. Upon Landlord’s approval of the Clean-up plan, which approval shall not be unreasonablywithheld or delayed, Tenant shall, at Tenant’s sole cost and expense, without limitation on any rights and remedies of Landlord under this Lease, promptlyimplement such plan with a consultant selected by Tenant and reasonably acceptable to Landlord and proceed to Clean-Up Hazardous Materials Released byTenant or Tenant’s Agents, in accordance with Environmental Laws. If Tenant fails to complete the Clean-up in accordance with Environmental Laws withinthe designated time period to complete the Clean-up, or fails to meet any interim milestones with respect to such Clean-up, then Landlord shall have theright, but not the obligation, and without waiving any other rights under this Lease, after written notice to Tenant and providing a reasonable time period forTenant to cure, to carry out such Clean-up required under Environmental Laws, and tender an indemnification claim to Tenant under Section 5.3.1.4.1 of thisLease.5.3.4.2No Rent Abatement. Tenant shall continue to pay all Rent due or accruing under this Lease during anyClean-up, and shall not be entitled to any reduction, offset or deferral of any Base Rent or Additional Rent due or accruing under this Lease during any suchClean-up. 5.3.4.3Surrender of Premises. Tenant shall complete any Clean-up to the extent feasible prior to surrender ofthe Premises upon the expiration or earlier termination of this Lease. Tenant shall obtain and deliver to Landlord a letter or other written determination fromthe overseeing governmental authority confirming792986.06/WLA186772-00003/2-28-19/gjn/gjn-17- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  that the Clean-up has been completed in accordance with all requirements of such governmental authority and that no further response action of any kind isrequired for the commercial/industrial use of the Premises reasonably consistent with the Permitted Use (“Closure Letter”). Upon the expiration or earliertermination of this Lease, Tenant shall also be obligated to close all permits obtained in connection with Hazardous Materials used by Tenant or Tenant’sAgents in accordance with Environmental Laws.5.3.4.4Failure to Timely Clean-Up. Should any Clean-up for which Tenant is responsible not be completed, orshould Tenant not receive the Closure Letter and any governmental approvals required under Environmental Laws in conjunction with such Clean-up priorto the expiration or earlier termination of this Lease, then, commencing on the later of the termination of this Lease and three (3) business days afterLandlord's delivery of notice of such failure and that it elects to treat such failure as a holdover, Tenant shall be liable to Landlord as a holdover tenant (asmore particularly provided in Article 16) until Tenant has fully complied with its obligations under this Section 5.3; provided, however, that Tenant shall beconsidered a holdover tenant only for the time that Hazardous Materials subject to Clean-up for which Tenant is responsible prevent the occupancy of thePremises in accordance with the San Francisco Bay Regional Water Quality Control Board’s, the California Department of Toxic Substances Control’s or theSan Mateo County Environmental Health Services risk-based screening levels for commercial use.5.3.5Confidentiality. Unless compelled to do so by Applicable Law, valid order of a court or judicial or administrativeprocess, Tenant agrees that Tenant shall not disclose, discuss, disseminate or copy any information, data, findings, communications, conclusions and reportsregarding the environmental condition of the Premises to any Person (other than Tenant’s consultants, attorneys, property managers, employees, shareholders,subtenants and assignees that have a need to know such information), including any governmental authority, without the prior written consent ofLandlord. In the event Tenant reasonably believes that disclosure is compelled by applicable law, it shall provide Landlord ten (10) days’ advance notice ofdisclosure of confidential information so that Landlord may attempt to obtain a protective order. Tenant may additionally release such information to bonafide prospective purchasers or lenders, subject to any such parties’ written agreement to be bound by the terms of this Section 5.3.5.3.6Copies of Environmental Reports. Within thirty (30) days of receipt thereof, Tenant shall provide Landlord with acopy of any and all environmental assessments, audits, studies and reports regarding Tenant’s activities with respect to a Release of Hazardous Materials atthe Premises, or ground water beneath the Land, or the environmental condition or Clean-up thereof. Tenant shall be obligated to provide Landlord with acopy of such materials without regard to whether such materials are generated by Tenant or prepared for Tenant, or how Tenant comes into possession of suchmaterials.5.3.7Intentionally Omitted. 5.3.8Signs, Response Plans, Etc. Tenant shall be responsible for posting on the Premises any signs required underapplicable Environmental Laws with respect to the use of Hazardous Materials by Tenant or Tenant’s Agents. Tenant shall also complete and file anybusiness response plans or inventories required by any Environmental Laws. Tenant shall concurrently file a copy of any such business response plan orinventory with Landlord.5.3.9Survival. Each covenant, agreement, representation, warranty and indemnification made by Tenant and Landlord setforth in this Section 5.3 shall survive the expiration or earlier termination of this Lease and shall remain effective until all of its obligations under this Section5.3 have been completely performed and satisfied.6.SERVICES AND UTILITIES6.1In General. From and after the Lease Commencement Date, Tenant will be responsible, at its sole cost and expense, for thefurnishing of all services and utilities to the Premises, including, but not limited to heating, ventilation and air‑conditioning, electricity, water, telephone,janitorial and interior Building security services.792986.06/WLA186772-00003/2-28-19/gjn/gjn-18- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  6.1.1All utilities (including electricity, gas, sewer and water) are separately metered or sub-metered to the Premises. After theLease Commencement Date such utilities that are separately metered shall be contracted for and paid directly by Tenant to the applicable utility provider andwith respect to such utilities to the Building that are sub-metered (instead of separately metered) to the Premises, then Tenant shall pay to Landlord, withinthirty (30) days after billing, an equitable portion of the Building utility costs, based on Tenant's proportionate use thereof and the readings from such sub-meter.6.1.2Landlord shall not provide janitorial services for the interior of the Premises. Tenant shall be solely responsible forperforming all janitorial services and other cleaning of the Premises, all in compliance with Applicable Laws. The janitorial and cleaning of the Premisesshall be adequate to maintain the Premises in a manner consistent with Comparable Buildings. Tenant shall cooperate fully with Landlord at all times and abide by all regulations and requirements that Landlord may reasonably prescribe forthe proper functioning and protection of the HVAC, electrical, mechanical and plumbing systems. Provided that Landlord agrees to provide and maintainand keep in continuous service utility connections to the Building, including electricity, water and sewage connections, Landlord shall have no obligationto provide any services or utilities to the Building, including, but not limited to heating, ventilation and air‑conditioning, electricity, water, telephone,janitorial and interior Building security services. 6.2Interruption of Use. Tenant agrees that Landlord shall not be liable for damages, by abatement of Rent or otherwise, for failure tofurnish or delay in furnishing any service (including telephone and telecommunication services), or for any diminution in the quality or quantity thereof,when such failure or delay or diminution is occasioned, in whole or in part, by breakage, repairs, replacements, or improvements, by any strike, lockout orother labor trouble, by inability to secure electricity, gas, water, or other fuel at the Building or Project after reasonable effort to do so, by any riot or otherdangerous condition, emergency, accident or casualty whatsoever, by act or default of Tenant or other parties, or by any other cause; and such failures ordelays or diminution shall never be deemed to constitute an eviction or disturbance of Tenant's use and possession of the Premises or relieve Tenant frompaying Rent or performing any of its obligations under this Lease. Furthermore, Landlord shall not be liable under any circumstances for a loss of, or injuryto, property or for injury to, or interference with, Tenant's business, including, without limitation, loss of profits, however occurring, through or in connectionwith or incidental to a failure to furnish any of the services or utilities as set forth in this Article 6.6.3Energy Performance Disclosure Information. Tenant hereby acknowledges that at some time after the date of this Lease Landlordmay be required to disclose certain information concerning the energy performance of the Building pursuant to California Public Resources Code Section25402.10 and the regulations adopted pursuant thereto (collectively the “Energy Disclosure Requirements”). If and to the extent Landlord is required inthe future under the Energy Disclosure Requirements to disclose information concerning Tenant’s energy usage to certain third parties, including, withoutlimitation, prospective purchasers, lenders and tenants of the Building (the “Tenant Energy Use Disclosure”), Tenant hereby (A) consents to all such TenantEnergy Use Disclosures made by Landlord in accordance with the Energy Disclosure Requirements, and (B) acknowledges that Landlord shall not berequired to notify Tenant of any Tenant Energy Use Disclosure. The terms of this Section 6.3 shall survive the expiration or earlier termination of this Leasefor a period of one (1) year.6.4Tenant’s Emergency Generator. In the event Tenant wishes to install a separate generator (i.e., in addition to the existingemergency generator) to provide back-up generator services to the Premises, subject to the receipt of all necessary approvals from the applicablegovernmental authority, Tenant, at Tenant's sole cost and expense, shall have the right to install a back-up generator in the Premises, or outside the Premisesin the location reasonably designated by Landlord (subject to the same being approved by the city), as an Alteration (in which case such installation shall begoverned by the terms of Article 8) (the "Tenant Generator"). Such Tenant Generator shall be installed pursuant to plans and specifications approved byLandlord, which approval shall not be unreasonably withheld, conditioned or delayed. Tenant acknowledges that Landlord has not made any representationregarding the receipt of approvals for the Tenant Generator, and if Tenant is unable for any reason to receive such approvals, Landlord shall not be liable forany damages resulting therefrom. In the event such Tenant Generator is installed, then during the Lease Term, Tenant shall maintain such Tenant Generatorat Tenant's sole cost and expense. Notwithstanding the foregoing, Landlord shall not be liable for any damages whatsoever resulting from any failure in792986.06/WLA186772-00003/2-28-19/gjn/gjn-19- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  operation of the Tenant Generator, or the failure of the Tenant Generator to provide suitable or adequate back-up power to the Premises, including but notlimited to, loss of profits, loss of rents or other revenues, loss of business opportunity, loss of goodwill or loss of use, in each case, however occurring, or lossto inventory, scientific research, scientific experiments, laboratory animals, products, specimens, samples, and/or scientific, business, accounting and otherrecords of every kind and description kept at the Premises and any and all income derived or derivable therefrom. Tenant's obligations with respect to thePremises, including the insurance and indemnification obligations contained in Article 10, below, shall apply to Tenant's use of the Tenant Generator andTenant shall carry industry standard Boiler and machinery insurance covering the Tenant Generator. Tenant shall maintain all required permits in connectionwith the Tenant Generator throughout the Lease Term. If installed, at Landlord's election prior to the expiration or earlier termination of this Lease, Tenantshall either (A) leave the Tenant Generator in place, in which event Tenant shall surrender the Generator (and shall transfer to Landlord all permits maintainedby Tenant in connection with the Generator during the Lease Term) concurrent with the surrender of the Premises to Landlord as required hereunder in goodoperating and working order, reasonable wear and tear and damage by casualty excepted, with all permits current, or (B) remove the Tenant Generator prior tothe expiration or earlier termination of this Lease, and repair all damage to the Building and Premises resulting from such removal, at Tenant's sole cost andexpense. In the event that Landlord fails to expressly elect to have the Tenant Generator removed upon the expiration or earlier termination of this Lease,then Landlord shall be deemed to have elected to have such Tenant Generator left in place. 6.5Rooftop Rights. Provided that Tenant is then in occupancy of any portion of the Premises, then in accordance with, and subject to,the terms and conditions set forth in Article 8, and this Section 6.5, Tenant shall have the right to install and maintain, at Tenant's sole cost and expense butwithout the payment of any additional rent or fee, one (1) satellite dish/antennae on the roof of the Building (and reasonable equipment and cabling relatedthereto), for receiving or transmitting signals or broadcasts servicing the business conducted by Tenant from within the Premises (all such equipment isdefined collectively as the "Telecommunications Equipment"). Landlord makes no representations or warranties whatsoever with respect to the condition ofthe roof of the Building, or the fitness or suitability of the roof of the Building for the installation, maintenance and operation of the TelecommunicationsEquipment, including, without limitation, with respect to the quality and clarity of any receptions and transmissions to or from the TelecommunicationsEquipment and the presence of any interference with such signals whether emanating from the Building or otherwise. The dimensions, physical appearanceand the weight of the Telecommunications Equipment shall be subject to Landlord's reasonable approval, the location of any such installation of theTelecommunications Equipment shall be designated by Landlord subject to Tenant's reasonable approval and Landlord may require Tenant to installscreening around such Telecommunications Equipment, at Tenant's sole cost and expense, as reasonably designated by Landlord. Tenant shall maintainsuch Telecommunications Equipment, at Tenant's sole cost and expense. In the event Tenant elects to exercise its right to install the TelecommunicationsEquipment, then Tenant shall give Landlord prior notice thereof. Tenant shall reimburse to Landlord any reasonable, out-of-pocket third party costsreasonably incurred by Landlord in approving such Telecommunications Equipment. Tenant shall remove such Telecommunications Equipment upon theexpiration or earlier termination of this Lease, or, in the event Tenant no longer occupies any portion of the Premises, then upon the termination of Tenant'srights under this Section 6.5, and shall repair any damage to the affected portion of the rooftop and the Premises caused thereby. Such TelecommunicationsEquipment shall be installed pursuant to plans and specifications approved by Landlord (specifically including, without limitation, all mounting andwaterproofing details), which approval will not be unreasonably withheld, conditioned, or delayed. Notwithstanding any such review or approval byLandlord, Tenant shall remain solely liable for any damage to any portion of the roof or roof membrane, specifically including any penetrations, inconnection with Tenant's installation, use, maintenance and/or repair of such Telecommunications Equipment, and Landlord shall have no liabilitytherewith. Such Telecommunications equipment shall, in all instances, comply with Applicable Laws. Tenant shall not be entitled to license itsTelecommunications Equipment to any unrelated third party, nor shall Tenant be permitted to receive any revenues, fees or any other consideration for theuse of such Telecommunications Equipment by an unrelated third party. Tenant's right to install such Telecommunication Equipment shall be non-exclusive, and Tenant hereby expressly acknowledges Landlord's continued right (i) to itself utilize any rooftop space, and (ii) to re-sell, license or lease anyrooftop space to an unaffiliated third party; provided, however, such Landlord (or third-party) use shall not materially interfere with (or preclude theinstallation of) Tenant's Telecommunications Equipment.792986.06/WLA186772-00003/2-28-19/gjn/gjn-20- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  7.REPAIRS7.1Tenant Repair Obligations. Tenant shall, throughout the Term, at its sole cost and expense, maintain, repair, and replace asrequired, the Premises and Building and every part thereof in a good standard of maintenance, repair and replacement as required, and in good and sanitarycondition, all in accordance with the standards of Comparable Buildings, except for Landlord Repair Obligations and except for any damage by casualtywhich is not Tenant’s obligation to repair pursuant to Article 11 below, whether or not such maintenance, repair or replacement is required in order to complywith Applicable Laws ("Tenant's Repair Obligations"), including, without limitation, the following: (1) glass, windows, window frames, window casements(including the repairing, resealing, cleaning and replacing of both interior and exterior windows) and skylights; (2) interior and exterior doors, door framesand door closers; (3) interior lighting (including, without limitation, light bulbs and ballasts); (4) the plumbing, sewer, drainage, electrical, fire protection,elevator, escalator, life safety and security systems and equipment, existing heating, ventilation and air-conditioning systems, and all other mechanical,electrical and communications systems and equipment (collectively, the "Building Systems"), including without limitation (i) any specialty or supplementalBuilding Systems installed by or for Tenant and (ii) all electrical facilities and equipment, including lighting fixtures, lamps, fans and any exhaust equipmentand systems, electrical motors and all other appliances and equipment of every kind and nature located in, upon or about the Premises; (5) allcommunications systems serving the Premises; (6) all of Tenant's security systems in or about or serving the Premises; (7) Tenant's signage; and (8) interiordemising walls and partitions (including painting and wall coverings), equipment, floors, and any roll-up doors, ramps and dock equipment. Tenant’s RepairObligations also includes the routine maintenance of the load bearing and exterior walls of the Building, including, without limitation, any painting, sealing,patching and waterproofing of such walls. Tenant shall additionally be responsible, at Tenant’s sole cost and expense, to furnish all expendables, includinglight bulbs, paper goods and soaps, used in the Premises, and, to the extent that Landlord notifies Tenant in writing of its intention to no longer arrange forsuch monitoring, cause the fire alarm systems serving the Premises to be monitored by a monitoring or protective services firm approved by Landlord inwriting. Landlord hereby assigns to Tenant all warranties and guaranties, if any, in existence with respect to the items which are Tenant’s obligation to repairand maintain pursuant to this Section 7.1, which assignment shall be on a non-exclusive basis such that the warranties and guaranties may be enforced byTenant and/or Landlord, and Landlord shall cooperate with Tenant in a commercially reasonable manner to assist in enforcing all such warranties andguaranties for the benefit of Tenant.7.2Service Contracts. All Building Systems, including HVAC, elevators, main electrical, plumbing and fire/life-safety systems, shall bemaintained, and repaired by Tenant (with Landlord being responsible for replacement of the Building Systems pursuant to Section 7.4 below, provided thatTenant hereby agrees that replacement of a component part of a Building System which does not exceed $10,000.00 shall be deemed a repair for whichTenant shall be responsible hereunder and not a replacement of the applicable Building System) (i) in a commercially reasonable good and serviceablecondition, (ii) in accordance with any applicable manufacturer specifications relating to any particular component of such Building Systems, (iii) inaccordance with Applicable Laws. Tenant shall contract with a qualified, experienced professional third party service companies (a "ServiceContract"). Tenant shall regularly, in accordance with commercially reasonable standards, generate and maintain preventive maintenance records relating toeach Building’s mechanical and main electrical systems, including life safety, elevators and the central plant (“Preventative Maintenance Records”). Inaddition, upon Landlord’s written request, Tenant shall deliver a copy of all current Service Contracts to Landlord and/or a copy of the PreventativeMaintenance Records.7.3Landlord's Right to Perform Tenant's Repair Obligations. Tenant shall notify Landlord in writing at least ten (10) business daysprior to performing any Tenant's Repair Obligations which may have a material, adverse affect on the Building Systems or which is reasonably anticipated tocost more than $100,000.00. Upon receipt of such notice from Tenant, Landlord shall have the right to either (i) perform such material Tenant's RepairObligation by delivering notice of such election to Tenant within ten (10) business days following receipt of Tenant's notice, and Tenant shall pay Landlordthe cost thereof (including Landlord's reasonable out-of-pocket costs incurred in connection therewith) within thirty (30) days after receipt of an invoicetherefor, or (ii) require Tenant to perform such Tenant's Repair Obligation at Tenant's sole cost and expense. If Tenant fails to perform any Tenant's RepairObligation within a reasonable period of time, given the circumstances, after receipt of written notice from Landlord of the need for such repairs, but in anyevent not later than thirty (30) days after receipt of said notice (unless Tenant’s792986.06/WLA186772-00003/2-28-19/gjn/gjn-21- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  obligation cannot reasonably be performed within thirty (30) days, in which event Tenant shall be allowed additional time as is reasonably necessary toperform the obligation so long as Tenant begins performance within the initial thirty (30) days and diligently pursues performance to completion), or, in theevent of an “Emergency”, as defined in Section 7.5 below, not later than two (2) business days after receipt of such notice, then Landlord may, but need not,following delivery of notice to Tenant of such election, make such Tenant’s Repair Obligation, and Tenant shall pay Landlord the cost thereof (includingLandlord’s reasonable out-of-pocket costs incurred in connection therewith) within thirty (30) days after receipt of an invoice therefor.7.4Landlord Repair Obligations. Landlord shall be responsible for repairing, maintaining and replacing as required, in a goodstandard of maintenance, repair and replacement as required, and in a good and sanitary condition, all in accordance with the standards of ComparableBuildings, whether or not such maintenance, repair or replacement is required in order to comply with Applicable Laws, the exterior walls, foundation androof (including roof membrane) of the Building and the structural portions of all floors of the Building (collectively, the "Building Structure"), and allunderground utilities and for replacing, as required, the Building Systems, except to the extent that such repairs are required due to the negligence or willfulmisconduct of Tenant (the "Landlord Repair Obligation"); provided, however, that if such repairs or maintenance are due to the negligence or willfulmisconduct of Tenant, Landlord shall nevertheless make such repairs at Tenant's expense, or, if covered by Landlord's insurance, Tenant shall only beobligated to pay any commercially reasonable deductible in connection therewith. Costs expended by Landlord in connection with the Landlord RepairObligations shall be included in Operating Expenses to the extent allowed pursuant to the terms of Section 4.2.4 above. Landlord shall comply with theterms of Article 27 of this Lease in connection with any entry to the Premises necessary to complete Landlord Repair Obligations.7.5Tenant's Right to Make Repairs. Notwithstanding any provision to the contrary contained in this Lease, if Tenant provides writtennotice to Landlord of an event or circumstance which requires the action of Landlord under this Lease with respect to repair and/or maintenance required inthe Premises, including repairs to the portions of the Building located within the Premises that are Landlord’s responsibility under Section 7.4 (the “BaseBuilding”), which event or circumstance with respect to the Base Building materially and adversely affects Tenant’s use of or access to the Premises or theconduct of Tenant’s business from the Premises, and Landlord fails to perform such corrective action within a reasonable period of time, given thecircumstances, after the receipt of such notice, but in any event not later than thirty (30) days after receipt of said notice (unless Landlord’s obligation cannotreasonably be performed within thirty (30) days, in which event Landlord shall be allowed additional time as is reasonably necessary to perform theobligation so long as Landlord begins performance within the initial thirty (30) days and diligently pursues performance to completion), or, in the event of anEmergency (as defined below), not later than two (2) business days after receipt of such notice, then Tenant shall have the right to undertake such actions asmay be reasonably necessary to make such repairs if Landlord thereafter fails to commence corrective action within five (5) business days followingLandlord's receipt of a second written notice from Tenant specifying that Tenant will undertake such actions if Landlord fails to timely do so (provided thatsuch second notice shall include the following language in bold, capitalized text: "IF LANDLORD FAILS TO COMMENCE THE REPAIRSDESCRIBED IN THIS LETTER WITHIN FIVE (5) BUSINESS DAYS FROM LANDLORD'S RECEIPT OF THIS LETTER, TENANT WILLPERFORM SUCH REPAIRS AT LANDLORD'S EXPENSE"; provided, however, that in no event shall Tenant undertake any actions that could materiallyand adversely affect the Base Building. Notwithstanding the foregoing, in the event of an Emergency, no second written notice shall be required as long asTenant advises Landlord in the first written notice of Tenant's intent to perform such Emergency repairs if Landlord does not commence the same within suchtwo (2) business day period, utilizing the language required in second notices (but replacing “FIVE (5) BUSINESS DAYS” with “TWO (2) BUSINESSDAYS”). If such action was required under the terms of this Lease to be taken by Landlord and was not commenced by Landlord within such five (5) businessday period (or within two (2) business days after the initial notice in the event of an Emergency) and thereafter diligently pursued to completion, then Tenantshall be entitled to prompt reimbursement by Landlord of the reasonable out-of-pocket third-party costs and expenses actually incurred by Tenant in takingsuch action. If Tenant undertakes such corrective actions pursuant to this Section 7.3, then (a) the insurance and indemnity provisions set forth in this Leaseshall apply to Tenant's performance of such corrective actions, (b) Tenant shall proceed in accordance with all applicable laws, (c) Tenant shall retain toperform such corrective actions only such reputable contractors and suppliers as are duly licensed and qualified, (d) Tenant shall effect such repairs in a goodand workmanlike and commercially reasonable manner, (e) Tenant shall use new or like new materials, and (f) Tenant shall take reasonable efforts tominimize any material interference or impact on the other tenants and occupants of the Building. Promptly following792986.06/WLA186772-00003/2-28-19/gjn/gjn-22- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  completion of any work taken by Tenant pursuant to the terms of this Section 7.5, Tenant shall deliver a detailed invoice of the work completed, the materialsused and the costs relating thereto, and within forty-five (45) days after receipt of such invoice Landlord shall reimburse Tenant the amounts expended byTenant in connection with such work, provided that Landlord shall have the right to reasonably object if Landlord claims that such action did not have to betaken by Landlord pursuant to the terms of this Lease or that the charges are excessive (in which case Landlord shall pay within forty-five (45) days afterreceipt of the invoice the amount it contends would not have been excessive). If Landlord does not reimburse Tenant such amount within forty-five (45) daysafter receipt of such invoice or deliver a written objection to Tenant within forty-five (45) days after receipt of such invoice, then Tenant shall be entitled todeliver a reminder notice to Landlord with respect to such reimbursement obligation, and in the event Landlord fails to pay or provide a written objectionwithin ten (10) days following receipt of the reminder notice, Tenant may deduct from Rent payable by Tenant under this Lease the amount set forth in suchinvoice. If, however, Landlord delivers to Tenant, within forty-five (45) days after receipt of Tenant’s invoice (or within ten (10) days following receipt of areminder notice), a written objection to the payment of such invoice, setting forth with reasonable particularity Landlord’s reasons for its claim that suchaction did not have to be taken by Landlord pursuant to the terms of this Lease or that the charges are excessive, then Tenant shall not then be entitled tosuch deduction from Rent, and Tenant may institute legal proceedings against Landlord to collect the amount set forth in the subject invoice or pursue anyother remedies under this Lease based upon a default by Landlord. If Tenant receives a final judgment against Landlord (whether by virtue of Landlord’sfailure to appeal or unsuccessful appeal of such judgment), Tenant may offset and deduct the amount of the judgment (including all fees, expenses andreasonable attorneys' fees actually incurred by Tenant in connection with such legal proceedings, to the extent included in such judgment), from the Rentnext due and owing under this Lease. For purposes of this Section 7.5, an "Emergency" shall mean an event threatening immediate and material danger topeople located in the Building or immediate, material damage to the Building, Base Building, the Tenant Improvements or Alterations, or creating a realisticpossibility of an immediate and material interference with, or immediate and material interruption of a material aspect of Tenant's business operations.8.ADDITIONS AND ALTERATIONS8.1Landlord's Consent to Alterations. Tenant may not make any improvements, alterations, additions or changes to the Premises orany mechanical, plumbing or HVAC facilities or systems pertaining to the Premises (collectively, the "Alterations") without first procuring the prior writtenconsent of Landlord to such Alterations, which consent shall be requested by Tenant not less than thirty (30) days prior to the commencement thereof, andwhich consent shall not be unreasonably withheld or conditioned by Landlord, provided it shall be deemed reasonable for Landlord to withhold its consentto any Alteration which adversely affects the structural portions or the Building Systems or is visible from the exterior of the Building. Notwithstanding theforegoing, Tenant shall be permitted to make Alterations following ten (10) business days' notice to Landlord, but without Landlord's consent, to the extentthat such Alterations (i) do not adversely affect the Building Systems, (ii) are not visible from the exterior of the Building, and (iii) cost less than $100,000.00for a particular job of work. The construction of the initial improvements to the Premises shall be governed by the terms of the Tenant Work Letter and notthe terms of this Article 8. The term “Alterations” do not include maintenance or repair required in connection with Tenant’s Repair Obligations, which shallbe governed by Section 7.1, above.8.2Manner of Construction. Landlord may impose, as a condition of its consent to any and all Alterations of the Premises or about thePremises, such requirements as Landlord in its reasonable discretion may deem desirable, including, but not limited to, the requirement that upon Landlord'swritten request made at the time of Landlord’s consent to such Alterations, Tenant shall, at Tenant's expense, remove such Alterations upon the expiration orany early termination of the Lease Term, only if such Alterations are Specialty Improvements. Landlord's determination with respect to removal of any suchSpecialty Improvements shall include the extent to which Landlord shall require Tenant to perform any work to return the affected portion of the Premises tothe condition existing prior to such Specialty Improvement, reasonable wear and tear excepted. For the avoidance of doubt, Tenant shall only be responsiblefor removing Specialty Improvements (hereafter defined), if at the time of its consent to such Specialty Improvements, Landlord advises in writing in itsconsent that Tenant is obligated to remove such Specialty Improvements at the expiration of the Term. “Specialty Improvements” means, collectively, anyalterations, additions or improvements to the Premises which are not typical alterations, additions or improvements found in Comparable Buildings. Tenantshall not be required to remove any other Alterations at surrender of the Premises. 792986.06/WLA186772-00003/2-28-19/gjn/gjn-23- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Tenant shall construct such Alterations and perform such repairs in a good and workmanlike manner, in conformance with Applicable Laws and pursuant to avalid building permit, issued by the city in which the Building is located (or other applicable governmental authority). Tenant shall not use (and uponnotice from Landlord shall cease using) contractors, services, workmen, labor, materials or equipment that, in Landlord's reasonable judgment, would disturblabor harmony with the workforce or trades engaged in performing other work, labor or services in or about the Building or the Common Areas. Uponcompletion of any Alterations which are subject to Landlord’s consent under this Article 8, Tenant shall deliver to Landlord final lien waivers from allcontractors, and material subcontractors who performed such work to the extent required by Applicable Law. In addition to Tenant's obligations underArticle 9 of this Lease, to the extent required by Applicable Law, upon completion of any Alterations, Tenant agrees to cause a Notice of Completion to berecorded in the office of the Recorder of the County of San Mateo in accordance with Section 3093 of the Civil Code of the State of California or anysuccessor statute. Upon written request, Tenant shall deliver to the Project construction manager a reproducible copy of any "as built" drawings of theAlterations as well as all permits, approvals and other documents issued by any governmental agency in connection with the Alterations.8.3Payment for Improvements. If Tenant requests that any Alterations be completed by Landlord, and Landlord agrees, Tenant shallpay to Landlord an amount equal to five percent (5%) of the hard cost of such work to compensate Landlord for all overhead, general conditions, fees andother costs and expenses arising from Landlord's involvement with such work. If Tenant does not order any work directly from Landlord, Tenant shallreimburse Landlord for Landlord's reasonable, actual, out-of-pocket costs and expenses actually incurred in connection with Landlord's review of such work.8.4Construction Insurance. In addition to the requirements of Article 10 of this Lease, in the event that Tenant makes any Alterations,prior to the commencement of such Alterations, Tenant shall provide Landlord with evidence that Tenant or its general contractor carries "Builder's All Risk"insurance in an amount reasonably approved by Landlord covering the construction of such Alterations, it being understood and agreed that all of suchAlterations shall be insured by Tenant pursuant to Article 10 of this Lease immediately upon completion thereof. In addition, Tenant's contractors andsubcontractors shall be required to carry (i) Commercial General Liability Insurance in an amount reasonably approved by Landlord, with Landlord, and, atLandlord's option, Landlord's property manager and project manager, as additional insureds in an amount reasonably approved by Landlord, and otherwise inaccordance with the requirements of Article 10 of this Lease, and (ii) workers compensation insurance with a waiver of subrogation in favor of Landlord. Inconnection with Alterations with a cost in excess of $500,000, Landlord may, in its discretion, require Tenant to obtain a lien and completion bond or somealternate form of security satisfactory to Landlord in an amount sufficient to ensure the lien-free completion of such Alterations and naming Landlord as a co-obligee.8.5Landlord's Property. All Alterations, improvements, fixtures, equipment and/or appurtenances which are permanently affixed to thePremises or which tie into the Building Systems installed in, on or about the Premises by or on behalf of Tenant, from time to time, shall be at the sole cost ofTenant and shall be and become the property of Landlord and remain in place at the Premises following the expiration or earlier termination of thisLease. Notwithstanding the foregoing, pursuant to Section 8.2 above, Landlord may, by written notice to Tenant at the time of its approval of workingdrawings, require Tenant, at Tenant's expense, to remove any Specialty Improvements within the Premises and to repair any damage to the Premises andBuilding caused by such removal and, if applicable pursuant to Section 8.2 above, return the affected portion of the Premises to the condition existing priorto such Specialty Improvement, reasonable wear and tear excepted. If Tenant fails to complete such removal and/or to repair any damage caused by theremoval of Specialty Improvements in the Premises and return the affected portion of the Premises to the condition existing prior to such SpecialtyImprovement (reasonable wear and tear excepted), Landlord may do so and may charge the reasonable cost thereof to Tenant. Tenant hereby protects,defends, indemnifies and holds Landlord harmless from any liability, cost, obligation, expense or claim of lien in any manner relating to the installation,placement, removal (in the case of Specialty Improvements designated for removal pursuant to Section 8.2 above) or financing of any such Alterations,improvements, fixtures and/or equipment which are permanently affixed to the Premises or which tie into the Building Systems installed in, on or about thePremises by or on behalf of Tenant, which obligations of Tenant shall survive the expiration or earlier termination of this Lease. Notwithstanding anythingto the contrary set forth in this Lease, upon the expiration of the Lease Term, or upon any earlier termination of this Lease, Tenant shall have no obligation toremove from the Premises (i) any of the Tenant Improvements initially constructed pursuant to the terms of the Tenant Work Letter or any otherimprovements,792986.06/WLA186772-00003/2-28-19/gjn/gjn-24- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  fixtures, equipment and/or appurtenances existing in, on or about the Premises as of the date Landlord delivers possession of the Premises to Tenant, (ii) anyAlterations which are not subject to Landlord’s consent under this Article 8, or (iii) any Alterations (including any Specialty Improvements) which are notSpecialty Improvements designated to be removed by Landlord pursuant to Section 8.2.9.COVENANT AGAINST LIENS Tenant shall keep the Project and Premises free from any liens or encumbrances arising out of the work performed,materials furnished or obligations incurred by or on behalf of Tenant, and shall protect, defend, indemnify and hold Landlord harmless from and against anyclaims, liabilities, judgments or costs (including, without limitation, reasonable attorneys' fees and costs) arising out of same or in connectiontherewith. Tenant shall give Landlord notice at least twenty (20) days prior to the commencement of any such work on the Premises (or such additional timeas may be necessary under Applicable Laws) to afford Landlord the opportunity of posting and recording appropriate notices of non-responsibility (to theextent applicable pursuant to then Applicable Laws). Tenant shall remove any such lien or encumbrance by bond or otherwise within ten (10) business daysafter written notice by Landlord, and if Tenant shall fail to do so, Landlord may pay the amount necessary to remove such lien or encumbrance, without beingresponsible for investigating the validity thereof. 10.INSURANCE10.1Indemnification and Waiver. Except to the extent due to the negligence, willful misconduct or violation of this Lease byLandlord or the Landlord Parties, Tenant hereby assumes all risk of damage to property or injury to persons in, upon or about the Premises from any causewhatsoever and agrees that Landlord, its partners, subpartners and their respective officers, agents, servants, employees, lenders, any property manager andindependent contractors (individually, a “Landlord Party” and collectively, "Landlord Parties") shall not be liable for, and are hereby released from anyresponsibility for, any damage either to person or property or resulting from the loss of use thereof, which damage is sustained by Tenant or by other personsclaiming through Tenant. Except to the extent due to the negligence, willful misconduct or violation of this Lease by Landlord or any Landlord Party,Tenant shall indemnify, defend, protect, and hold harmless the Landlord Parties from any and all claims, loss, cost, damage, injury, expense and liability(including without limitation court costs and reasonable attorneys' fees) incurred in connection with or arising from any cause in, on or about the Premises,any acts, omissions or negligence of Tenant or of any person claiming by, through or under Tenant, or of the contractors, agents, servants, employees,invitees, guests or licensees of Tenant or any such person, in, on or about the Project or any breach of the terms of this Lease. Notwithstanding anything tothe contrary in this Lease, Landlord shall not be released or indemnified from, and shall indemnify, defend, protect and hold harmless Tenant, its agents,officers and employees, from, all losses, damages, liabilities, demands, claims, actions, attorneys’ fees, costs and expenses arising from the negligence orwillful misconduct of Landlord or its agents, contractors, employees, licensees or invitees, or a violation of Landlord’s obligations or representations underthis Lease, or resulting from the negligent or wrongful actions or omissions of Landlord or the Landlord Parties in, on or about the Common Areas, all exceptto the extent due to the negligence, willful misconduct or violation of this Lease by Tenant or its agents, contractors, employees, licensees or invitees. Theprovisions of this Section 10.1 shall survive the expiration or sooner termination of this Lease with respect to any claims or liability arising in connectionwith any event occurring prior to such expiration or termination. 10.2Landlord's Insurance; Tenant's Compliance With Landlord's Property Insurance. Landlord shall insure the Building TenantImprovements and any Alterations during the Lease Term against loss or damage under an "all risk" property insurance policy on a full replacement costbasis, with reasonable and customary deductible amounts not exceeding deductible amounts generally obtained by owners of Comparable Buildings. Suchcoverage shall be in such amounts, from such companies, and on such other terms and conditions, as Landlord may from time to time reasonablydetermine. Additionally, at the option of Landlord, such insurance coverage may include the risks of earthquakes and/or flood damage and additionalhazards, a rental loss endorsement and one or more loss payee endorsements in favor of the holders of any mortgages or deeds of trust encumbering theinterest of Landlord in the Building or the ground or underlying lessors of the Building, or any portion thereof. The costs of such insurance shall be includedin Operating Expenses, subject to the terms of Section 4.2.4. Tenant shall, at Tenant's expense, comply with all insurance company requirements pertainingto the use of the Premises. If Tenant's conduct or use of the Premises causes any increase in the premium for such insurance policies then Tenant shallreimburse Landlord for any such increase. Tenant, at Tenant's expense, shall comply with all rules, orders, regulations or requirements of the AmericanInsurance Association (formerly the National Board of Fire Underwriters) and with any similar body. 792986.06/WLA186772-00003/2-28-19/gjn/gjn-25- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Tenant shall also provide Landlord and Landlord’s insurer(s) with such information regarding the use of the Premises and any damage to the Premises as theymay require in connection with the placement of insurance for the Premises or the adjusting of any losses to the Premises. Notwithstanding anything to thecontrary in this Lease, Tenant shall not be required to comply with or cause the Premises to comply with any laws, rules, regulations or insurancerequirements requiring the construction of alterations unless such compliance is necessitated solely due to Tenant's particular use of the Premises. Landlordshall also keep in full force and effect a policy of Commercial General Liability Insurance protecting Landlord against claims for bodily injury and propertydamage arising out of Landlord’s ownership, use, occupancy or maintenance of the Building and the Common Areas. Such insurance shall be on anoccurrence basis and shall include limits of liability not less than those required of Tenant under Section 10.3 and name Tenant as an additional insured.10.3Tenant's Insurance. Tenant shall maintain the following coverages in the following amounts.10.3.1Commercial General Liability Insurance on an occurrence form covering the insured against claims of bodily injury,personal injury and property damage (including loss of use thereof) arising out of Tenant's operations, and contractual liabilities including a contractualcoverage, and including products and completed operations coverage, for limits of liability on a per location basis of not less than: Bodily Injury andProperty Damage Liability$5,000,000 each occurrence$5,000,000 annual aggregatePersonal Injury Liability$3,000,000 each occurrence$3,000,000 annual aggregate10.3.2Property Insurance covering all office furniture, business and trade fixtures, office equipment, free-standing cabinetwork, movable partitions, merchandise and all other items of Tenant's property on the Premises installed by, for, or at the expense of Tenant. Such insuranceshall be written on special form policies, for the full replacement cost value (subject to reasonable deductible amounts) new without deduction fordepreciation of the covered items and in amounts that meet any co-insurance clauses of the policies of insurance and shall include coverage for damage orother loss caused by fire or other peril including, but not limited to, vandalism and malicious mischief, theft, water damage, including sprinkler leakage,bursting or stoppage of pipes, and explosion.10.3.3Business Income Interruption for six (6) months including Extra Expense insurance in such amounts as will reimburseTenant for actual direct or indirect loss of earnings attributable to the risks outlined in Section 10.3.2 above.10.3.4Worker's Compensation and Employer's Liability or other similar insurance pursuant to all applicable state and localstatutes and regulations. The policy shall include a waiver of subrogation in favor of Landlord, its employees, Lenders and any property manager or partners.10.4Form of Policies. The minimum limits of policies of insurance required of Tenant under this Lease shall in no event limit theliability of Tenant under this Lease. Such insurance shall (i) name Landlord, its subsidiaries and affiliates, its property manager (if any) and any other partythe Landlord so specifies, as an additional insured or loss payee, as applicable, including Landlord's managing agent, if any; (ii) be issued by an insurancecompany having a rating of not less than A-:VII in Best's Insurance Guide or which is otherwise acceptable to Landlord and authorized to do business in theState of California; (iv) be primary insurance as to all claims thereunder and provide that any insurance carried by Landlord is excess and is non-contributingwith any insurance required of Tenant; and (v) be in form and content reasonably acceptable to Landlord. Tenant shall promptly provide written notice ofcancellation received by Tenant from its insurer. Tenant shall deliver certificates of said policies to Landlord on or before the Lease Commencement Dateand at least ten (10) days before the expiration dates thereof. In the event Tenant shall fail to procure such insurance, or to deliver such certificate, and suchfailure continues for ten (10) days after written notice thereof from Landlord Tenant, Landlord may, at its option, procure such policies for the account ofTenant, and the cost thereof shall be paid to Landlord within thirty (30) days after delivery to Tenant of bills therefor.792986.06/WLA186772-00003/2-28-19/gjn/gjn-26- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  10.5Subrogation. Landlord and Tenant hereby agree to look solely to, and seek recovery only from, their respective insurance carriersin the event of a property or business interruption loss to the extent that such coverage is agreed to be provided hereunder. The parties each hereby waive allrights and claims against each other for such losses, and waive all rights of subrogation of their respective insurers, provided such waiver of subrogation shallnot affect the right to the insured to recover thereunder. The parties agree that their respective insurance policies do now, or shall, contain the waiver ofsubrogation.10.6Additional Insurance Obligations. Tenant shall carry and maintain during the entire Lease Term, at Tenant's sole cost and expense,increased amounts of the insurance required to be carried by Tenant pursuant to this Article 10 and such other reasonable types of insurance coverage and insuch reasonable amounts covering the Premises and Tenant's operations therein, as may be reasonably requested by Landlord or Landlord's lender, but in noevent in excess of the amounts and types of insurance then being required by prudent owners of Comparable Buildings and Tenant shall only be obligated tomodify coverage once every five (5) years.11.DAMAGE AND DESTRUCTION11.1Repair of Damage to Premises by Landlord. Tenant shall promptly notify Landlord of any damage to the Premises resulting fromfire or any other casualty. If the Premises or any Common Areas serving or providing access to the Premises shall be damaged by fire or other casualty,Landlord shall notify Tenant within sixty (60) days after the date of the damage whether Landlord will restore the Premises and Common Areas and, inLandlord’s reasonable judgment, the time period within which the restoration can be completed. If Landlord elects to restore Premises and Common Areas,Landlord shall promptly and diligently, subject to reasonable delays for insurance adjustment or other matters beyond Landlord's reasonable control, andsubject to all other terms of this Article 11, restore the Premises and such Common Areas pursuant to plans and specifications reasonably approved byTenant. Such restoration shall be to substantially the same condition of the Premises and the Common Areas prior to the casualty, except for modificationsrequired by zoning and building codes and other laws or any other modifications to the Common Areas deemed desirable by Landlord, which are consistentwith the character of the Project, provided that access to the Premises and the parking facilities serving the Project shall not be materially impaired.Landlord’s repair obligations shall include the Tenant Improvements and Tenant’s Alterations installed in the Premises. Landlord shall not be liable for anyinconvenience or annoyance to Tenant or its visitors, or injury to Tenant's business resulting in any way from such damage or the repair thereof; providedhowever, that if such fire or other casualty shall have damaged the Premises or Common Areas necessary to Tenant's occupancy, and the damaged portions ofthe Premises are not occupied by Tenant as a result thereof, then during the time and to the extent the Premises are unfit for occupancy, the Rent shall beabated in proportion to the ratio that the amount of rentable square feet of the Premises which is unfit for occupancy for the purposes permitted under thisLease bears to the total rentable square feet of the Premises. 11.2Landlord's Option to Repair. Notwithstanding the terms of Section 11.1, Landlord may elect not to rebuild and/or restore thePremises, Building and/or Project, and instead terminate this Lease, by notifying Tenant in writing of such termination within sixty (60) days after the date ofthe damage, such notice to include a termination date giving Tenant sixty (60) days to vacate the Premises, but Landlord may so elect only if the Buildingshall be damaged by fire or other casualty or cause, and one or more of the following conditions is present: (i) in Landlord's reasonable judgment, repairscannot reasonably be completed within one (1) year after the date of the damage (when such repairs are made without the payment of overtime or otherpremiums); (ii) the damage is due to a risk that Landlord is not required to insure under this Lease (and does not actually insure), and the cost of restorationexceed ten percent (10%) of the replacement cost of the Building (unless Tenant agrees to pay any uninsured amount in excess of such ten percent (10%)); or(iii) the damage occurs during the last twelve (12) months of the Lease Term and will take more than sixty (60) days to restore. 11.3Tenant’s Option to Terminate. Notwithstanding anything to the contrary in Section 11.1 or 11.2, if (a) the damage occurs duringthe last twelve (12) months of the Lease Term, and will take more than sixty (60) days to restore, or (b) in the reasonable judgment of Landlord, the repairscannot be completed within eight (8) months days after the date of the damage (or are not in fact completed within nine (9) months after the date of thedamage), Tenant may elect, no earlier than sixty (60) days after the date of the damage and not later than sixty (60) days after Tenant’s receipt of Landlord’snotice of the repair period, or within thirty (30) days after such repairs are not timely completed,792986.06/WLA186772-00003/2-28-19/gjn/gjn-27- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  to terminate this Lease by written notice to Landlord effective as of the date specified in the notice, which date shall not be less than thirty (30) days nor morethan sixty (60) days after the date such notice is given by Tenant. 11.4Waiver of Statutory Provisions. The provisions of this Lease, including this Article 11, constitute an express agreement betweenLandlord and Tenant with respect to any and all damage to, or destruction of, all or any part of the Premises, the Building or the Project, and any statute orregulation of the State of California, including, without limitation, Sections 1932(2) and 1933(4) of the California Civil Code, with respect to any rights orobligations concerning damage or destruction in the absence of an express agreement between the parties, and any other statute or regulation, now orhereafter in effect, shall have no application to this Lease or any damage or destruction to all or any part of the Premises, the Building or the Project.12.NONWAIVER No provision of this Lease shall be deemed waived by either party hereto unless expressly waived in a writing signed thereby. Thewaiver by either party hereto of any breach of any term, covenant or condition herein contained shall not be deemed to be a waiver of any subsequent breachof same or any other term, covenant or condition herein contained. The subsequent acceptance of Rent hereunder by Landlord shall not be deemed to be awaiver of any preceding breach by Tenant of any term, covenant or condition of this Lease, other than the failure of Tenant to pay the particular Rent soaccepted, regardless of Landlord's knowledge of such preceding breach at the time of acceptance of such Rent. No acceptance of a lesser amount than theRent herein stipulated shall be deemed a waiver of Landlord's right to receive the full amount due, nor shall any endorsement or statement on any check orpayment or any letter accompanying such check or payment be deemed an accord and satisfaction, and Landlord may accept such check or payment withoutprejudice to Landlord's right to recover the full amount due. No receipt of monies by Landlord from Tenant after the termination of this Lease shall in anyway alter the length of the Lease Term or of Tenant's right of possession hereunder, or after the giving of any notice shall reinstate, continue or extend theLease Term or affect any notice given Tenant prior to the receipt of such monies, it being agreed that after the service of notice or the commencement of asuit, or after final judgment for possession of the Premises, Landlord may receive and collect any Rent due, and the payment of said Rent shall not waive oraffect said notice, suit or judgment.13.CONDEMNATION If the whole or any material part of the Premises, Building or Project shall be taken by power of eminent domain or condemned byany competent authority for any public or quasi-public use or purpose, or if any adjacent property or street shall be so taken or condemned, or reconfigured orvacated by such authority in such manner as to require the use, reconstruction or remodeling of any part of the Premises, Building or Project, or if Landlordshall grant a deed or other instrument in lieu of such taking by eminent domain or condemnation, Landlord shall have the option to terminate this Leaseeffective as of the date possession is required to be surrendered to the authority. If more than ten percent (10%) of the rentable square feet of the Premises istaken, or if access to the Premises is substantially impaired, in each case for a period in excess of ninety (90) days, Tenant shall have the option to terminatethis Lease effective as of the date possession is required to be surrendered to the authority. Tenant shall not because of such taking assert any claim againstLandlord or the authority for any compensation because of such taking and Landlord shall be entitled to the entire award or payment in connectiontherewith, except that Tenant shall have the right to file any separate claim available to Tenant for any taking of Tenant's personal property and fixturesbelonging to Tenant and removable by Tenant upon expiration of the Lease Term pursuant to the terms of this Lease, and for moving expenses, so long assuch claims do not diminish the award available to Landlord, its ground lessor with respect to the Building or Project or its mortgagee, and such claim ispayable separately to Tenant. All Rent shall be apportioned as of the date of such termination. If any part of the Premises shall be taken, and this Leaseshall not be so terminated, the Rent shall be proportionately abated. Tenant hereby waives any and all rights it might otherwise have pursuant toSection 1265.130 of The California Code of Civil Procedure. Notwithstanding anything to the contrary contained in this Article 13, in the event of atemporary taking of all or any portion of the Premises for a period of one hundred and eighty (180) days or less, then this Lease shall not terminate but theBase Rent and the Additional Rent shall be abated for the period of such taking in proportion to the ratio that the amount of rentable square feet of thePremises taken bears to the total rentable square feet of the Premises. Landlord shall be entitled to receive the entire award made in connection with any suchtemporary taking.14.ASSIGNMENT AND SUBLETTING14.1Transfers. Except as permitted in Section 14.8 below, Tenant shall not, without the prior written consent of Landlord, assign,mortgage, pledge, hypothecate, encumber, or permit any lien to attach to, or otherwise792986.06/WLA186772-00003/2-28-19/gjn/gjn-28- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  transfer, this Lease or any interest hereunder, permit any assignment, or other transfer of this Lease or any interest hereunder by operation of law, sublet thePremises or any part thereof, or enter into any license or concession agreements or otherwise permit the occupancy or use of the Premises or any part thereofby any persons other than Tenant and its employees, agents and contractors (all of the foregoing are hereinafter sometimes referred to collectively as"Transfers" and any person to whom any Transfer is made or sought to be made is hereinafter sometimes referred to as a "Transferee"). If Tenant desiresLandlord's consent to any Transfer, Tenant shall notify Landlord in writing, which notice (the "Transfer Notice") shall include (i) the proposed effective dateof the Transfer, which shall not be less than twenty (20) days nor more than one hundred eighty (180) days after the date of delivery of the Transfer Notice, (ii)a description of the portion of the Premises to be transferred (the "Subject Space"), (iii) the material terms of the proposed Transfer and the considerationtherefor, including calculation of the "Transfer Premium", as that term is defined in Section 14.3 below, in connection with such Transfer, the name andaddress of the proposed Transferee, and a copy of all existing executed and/or proposed documentation pertaining to the proposed Transfer, (iv) currentfinancial statements of the proposed Transferee certified by an officer, partner or owner thereof, and (v) any other information pertaining to the proposedTransfer reasonably requested by Landlord within ten (10) business days after its receipt of the Transfer Notice which will enable Landlord to determine thefinancial responsibility, character, and reputation of the proposed Transferee, nature of such Transferee's business and proposed use of the SubjectSpace. Any Transfer made without Landlord's prior written consent shall, at Landlord's option, be null, void and of no effect, and shall, at Landlord's option,constitute a default by Tenant under this Lease. Whether or not Landlord consents to any proposed Transfer, Tenant shall pay Landlord's reasonable reviewand processing fees, as well as any reasonable professional fees (including, without limitation, attorneys', accountants', architects', engineers' and consultants'fees) incurred by Landlord (not to exceed $3,500 in the aggregate for any particular Transfer), within thirty (30) days after written request by Landlord.14.2Landlord's Consent. Landlord shall not unreasonably withhold, condition or delay its consent to any proposed Transfer of theSubject Space to the Transferee on the terms specified in the Transfer Notice, and shall respond within twenty (20) days following the receipt of a TransferNotice and all information required by the terms of Section 14.1 above. If Landlord fails to respond within such twenty (20) day period, then Tenant maysend Landlord a reminder notice setting forth such failure containing the following sentence at the top of such notice in bold, capitalized font at least twelve(12) points in size: "LANDLORD'S FAILURE TO RESPOND TO THIS NOTICE WITHIN FIVE (5) BUSINESS DAYS SHALL RESULT IN LANDLORD'SDEEMED APPROVAL OF TENANT'S REQUEST FOR TRANSFER" (the "Transfer Reminder Notice"). Any such Transfer Reminder Notice shall include acomplete copy of Tenant's Transfer Notice. If Landlord fails to respond within five (5) business days after receipt of a Transfer Reminder Notice, then Tenant’s Transfer for which Tenant requested Landlord's approval shall be deemed approved by Landlord. Without limitation as to other reasonable grounds forwithholding consent, the parties hereby agree that it shall be reasonable under this Lease and under any Applicable Law for Landlord to withhold consent toany proposed Transfer where one or more of the following apply:14.2.1The Transferee is of a character or reputation or engaged in a business which is not consistent with the quality of theBuilding or the Project;14.2.2The Transferee is either a governmental agency or instrumentality thereof;14.2.3The Transferee is not a party of reasonable financial worth and/or financial stability in light of the responsibilities tobe undertaken in connection with the Transfer on the date consent is requested; or14.2.4The proposed Transfer would cause a violation of another lease for space in the Project, or would give an occupant ofthe Project a right to cancel its lease.If Landlord consents or is deemed to have consented to any Transfer pursuant to the terms of this Section 14.2 (and does not exercise anyrecapture rights Landlord may have under Section 14.4 of this Lease), Tenant may within six (6) months after Landlord's consent, but not later than theexpiration of said six-month period, enter into such Transfer of the Premises or portion thereof, upon substantially the same terms and conditions as are setforth in the Transfer Notice furnished by Tenant to Landlord pursuant to Section 14.1 of this Lease, provided that if there are any material changes in theterms and conditions from those specified in the Transfer Notice such that Landlord would initially have been entitled to refuse its consent to such Transferunder this Section 14.2, Tenant shall again submit792986.06/WLA186772-00003/2-28-19/gjn/gjn-29- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  the Transfer to Landlord for its approval and other action under this Article 14 (including Landlord's right of recapture, if any, under Section 14.4 of thisLease). Notwithstanding anything to the contrary in this Lease, if Tenant or any proposed Transferee claims that Landlord has unreasonably withheld ordelayed its consent under Section 14.2 or otherwise has breached or acted unreasonably under this Article 14, their sole remedies shall be a suit for contractdamages (other than damages for injury to, or interference with, Tenant's business including, without limitation, loss of profits, however occurring) ordeclaratory judgment and an injunction for the relief sought, and Tenant hereby waives all other remedies, including, without limitation, any right at law orequity to terminate this Lease, on its own behalf and, to the extent permitted under all Applicable Laws, on behalf of the proposed Transferee.14.3Transfer Premium. If Landlord consents to a Transfer, as a condition thereto which the parties hereby agree is reasonable, Tenantshall pay to Landlord fifty percent (50%) of any "Transfer Premium," as that term is defined in this Section 14.3, received by Tenant from suchTransferee. "Transfer Premium" shall mean all rent, additional rent or other consideration payable by such Transferee in connection with the Transfer inexcess of the Rent and Additional Rent payable by Tenant under this Lease during the term of the Transfer on a per rentable square foot basis if less than allof the Premises is transferred, and after deduction of (i) any costs of improvements made to the Subject Space in connection with such Transfer, (ii) brokeragecommissions paid in connection with such Transfer, (iii) reasonable legal fees incurred in connection with such Transfer, (iv) any free base rent or otherconcessions reasonably provided to the Transferee, and (v) any fees paid to Landlord under Section 14.1. "Transfer Premium" shall also include, but not belimited to, key money, bonus money or other cash consideration paid by Transferee to Tenant in connection with such Transfer, and any payment in excess offair market value for services rendered by Tenant to Transferee or for assets, fixtures, inventory, equipment, or furniture transferred by Tenant to Transferee inconnection with such Transfer. The determination of the amount of Landlord's applicable share of the Transfer Premium shall be made on a monthly basis asrent or other consideration is received by Tenant under the Transfer. 14.4Landlord's Option as to Subject Space. Notwithstanding anything to the contrary contained in this Article 14, in the event Tenantcontemplates a Transfer which, together with all prior Transfers then remaining in effect, would cause more than fifty percent (50%) of the Premises to beTransferred for more than fifty percent (50%) of the then remaining Lease Term (taking into account any extension of the Lease Term which has irrevocablybeen exercised by Tenant), Tenant shall give Landlord notice (the "Intention to Transfer Notice") of such contemplated Transfer (whether or not thecontemplated Transferee or the terms of such contemplated Transfer have been determined). The Intention to Transfer Notice shall specify the portion of andamount of rentable square feet of the Premises which Tenant intends to Transfer (the "Contemplated Transfer Space"), the contemplated date ofcommencement of the Contemplated Transfer (the "Contemplated Effective Date"), and the contemplated length of the term of such contemplated Transfer,and shall specify that such Intention to Transfer Notice is delivered to Landlord pursuant to this Section 14.4 in order to allow Landlord to elect to recapturethe Contemplated Transfer Space. Thereafter, Landlord shall have the option, by giving written notice to Tenant within ten (10) business days after receipt ofany Intention to Transfer Notice, to recapture the Contemplated Transfer Space. Such recapture shall cancel and terminate this Lease with respect to suchContemplated Transfer Space as of the Contemplated Effective Date. In the event of a recapture by Landlord, if this Lease shall be canceled with respect toless than the entire Premises, Landlord shall be responsible at its cost for demising the recaptured space from the remainder of the Premises, the Rent reservedherein shall be prorated on the basis of the number of rentable square feet retained by Tenant in proportion to the number of rentable square feet contained inthe Premises, and this Lease as so amended shall continue thereafter in full force and effect, and upon request of either party, the parties shall execute writtenconfirmation of the same. If Landlord declines, or fails to elect in a timely manner, to recapture such Contemplated Transfer Space under this Section 14.4,then, subject to the other terms of this Article 14, for a period of nine (9) months (the "Nine Month Period") commencing on the last day of such thirty (30)day period, Landlord shall not have any right to recapture the Contemplated Transfer Space with respect to any Transfer subject to Landlord’s recapture rightmade during the Nine Month Period, provided that any such Transfer is substantially on the terms set forth in the Intention to Transfer Notice, and providedfurther that any such Transfer shall be subject to the remaining terms of this Article 14. If such a Transfer is not so consummated within the Nine MonthPeriod (or if a Transfer is so consummated, then upon the expiration of the term of any Transfer of such Contemplated Transfer Space consummated withinsuch Nine Month Period), Tenant shall again be required to submit a new Intention to Transfer Notice to Landlord with respect any contemplated Transfer, asprovided above in this Section 14.4.792986.06/WLA186772-00003/2-28-19/gjn/gjn-30- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  14.5Effect of Transfer. If Landlord consents to a Transfer, (i) the terms and conditions of this Lease shall in no way be deemed to havebeen waived or modified, (ii) such consent shall not be deemed consent to any further Transfer by either Tenant or a Transferee, (iii) Tenant shall deliver toLandlord, promptly after execution, an original executed copy of all documentation pertaining to the Transfer in form reasonably acceptable to Landlord, (iv)Tenant shall furnish upon Landlord's request a complete statement, certified by a person which has the authority within Tenant's organization to certify thesame, setting forth in detail the computation of any Transfer Premium Tenant has derived and shall derive from such Transfer, and (v) no Transfer relating tothis Lease or agreement entered into with respect thereto, whether with or without Landlord's consent, shall relieve Tenant or any guarantor of the Lease fromany liability under this Lease, including, without limitation, in connection with the Subject Space. If Landlord has a reasonable basis for determining thatTenant has understated the Transfer Premium, Landlord or its authorized representatives shall have the right at all reasonable times upon reasonableadvanced notice to audit the books, records and papers of Tenant relating to any Transfer, and shall have the right to make copies thereof. If the TransferPremium respecting any Transfer shall be found understated, Tenant shall, within thirty (30) days after demand, pay the deficiency, and if understated bymore than five percent (5%), Tenant shall pay Landlord's reasonable, out-of-pocket costs of such audit.14.6Additional Transfers. For purposes of this Lease, the term "Transfer" shall also include (i) if Tenant is a partnership, thewithdrawal or change, voluntary, involuntary or by operation of law, of more than fifty percent (50%) of the partners, or transfer of more than fifty percent(50%) of partnership interests, within a twelve (12)-month period, or the dissolution of the partnership without immediate reconstitution thereof, and (ii) ifTenant is a closely held corporation (i.e., whose stock is not publicly held and not traded through an exchange or over the counter), (A) the dissolution,merger, consolidation or other reorganization of Tenant or (B) the sale or other transfer of an aggregate of more than fifty percent (50%) of the voting sharesof Tenant (other than to immediate family members by reason of gift or death), within a twelve (12)-month period, or (C) the sale, mortgage, hypothecation orpledge of an aggregate of more than fifty percent (50%) of the value of the unencumbered assets of Tenant within a twelve (12)-month period.14.7Occurrence of Default. Any Transfer hereunder shall be subordinate and subject to the provisions of this Lease, and if this Leaseshall be terminated during the term of any Transfer, Landlord shall have the right to: (i) treat such Transfer as cancelled and repossess the Subject Space byany lawful means, or (ii) require that such Transferee attorn to and recognize Landlord as its landlord under any such Transfer. If Tenant shall be in defaultunder this Lease beyond applicable notice and cure periods, Landlord is hereby irrevocably authorized, as Tenant's agent and attorney-in-fact, to direct anyTransferee to make all payments under or in connection with the Transfer directly to Landlord (which Landlord shall apply towards Tenant's obligationsunder this Lease) until such default is cured. Such Transferee shall rely on any representation by Landlord that Tenant is in default hereunder, without anyneed for confirmation thereof by Tenant. Upon any assignment, the assignee shall assume in writing all obligations and covenants of Tenant thereafter to beperformed or observed under this Lease. No collection or acceptance of rent by Landlord from any Transferee shall be deemed a waiver of any provision ofthis Article 14 or the approval of any Transferee or a release of Tenant from any obligation under this Lease, whether theretofore or thereafter accruing. In noevent shall Landlord's enforcement of any provision of this Lease against any Transferee be deemed a waiver of Landlord's right to enforce any term of thisLease against Tenant or any other person. If Tenant's obligations hereunder have been guaranteed, Landlord's consent to any Transfer shall not be effectiveunless the guarantor also consents to such Transfer.14.8Non-Transfers. Notwithstanding anything to the contrary contained in this Article 14, (i) an assignment or subletting of all or aportion of the Premises to an affiliate of Tenant (an entity that is controlled by, controls, or is under common control with, Tenant), (ii) an assignment of thePremises to an entity that acquires all or substantially all of the assets or interests (partnership, stock or other) of Tenant, or (iii) an assignment of the Premisesto an entity that is the resulting entity of a merger or consolidation of Tenant with another entity (each, a "Permitted Transferee"), shall not be deemed aTransfer under this Article 14 (and for the avoidance of doubt, Sections 14.2, 14.3 and 14.4. shall not apply to such transaction), provided that (A) Tenantnotifies Landlord of any such assignment or sublease and promptly supplies Landlord with any documents or information requested by Landlord regardingsuch assignment or sublease or such affiliate, (B) such assignment or sublease is not a subterfuge by Tenant to avoid its obligations under this Lease, and (C) such Permitted Transferee described in subpart (ii) or (iii) above in connection with an assignment shall have a tangible net worth (not including goodwill asan asset) computed in accordance with792986.06/WLA186772-00003/2-28-19/gjn/gjn-31- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  generally accepted accounting principles ("Net Worth") at least equal to $150,000,000.00. An assignee of Tenant's entire interest that is also a PermittedTransferee may also be known as a "Permitted Assignee". "Control," as used in this Section 14.8, shall mean the ownership, directly or indirectly, of at leastfifty-one percent (51%) of the voting securities of, or possession of the right to vote, in the ordinary direction of its affairs, of at least fifty-one percent (51%)of the voting interest in, any person or entity. No such permitted assignment or subletting shall serve to release Tenant from any of its obligations under thisLease.15.SURRENDER OF PREMISES; OWNERSHIP AND REMOVAL OF TRADE FIXTURES15.1Surrender of Premises. No act or thing done by Landlord or any agent or employee of Landlord during the Lease Term shall bedeemed to constitute an acceptance by Landlord of a surrender of the Premises unless such intent is specifically acknowledged in writing by Landlord. Thedelivery of keys to the Premises to Landlord or any agent or employee of Landlord shall not constitute a surrender of the Premises or effect a termination ofthis Lease, whether or not the keys are thereafter retained by Landlord, and notwithstanding such delivery Tenant shall be entitled to the return of such keysat any reasonable time upon request until this Lease shall have been properly terminated. The voluntary or other surrender of this Lease by Tenant, whetheraccepted by Landlord or not, or a mutual termination hereof, shall not work a merger, and at the option of Landlord shall operate as an assignment toLandlord of all subleases or subtenancies affecting the Premises or terminate any or all such sublessees or subtenancies.15.2Removal of Tenant Property by Tenant. Upon the expiration of the Lease Term, or upon any earlier termination of this Lease,Tenant shall, subject to the provisions of this Article 15, quit and surrender possession of the Premises to Landlord in as good order and condition as whenTenant took possession and as thereafter improved by Landlord and/or Tenant, reasonable wear and tear, damage by casualty and repairs which arespecifically made the responsibility of Landlord hereunder excepted. Upon such expiration or termination, Tenant shall, without expense to Landlord,remove or cause to be removed from the Premises all debris and rubbish, and such items of furniture, equipment, free-standing cabinet work, movablepartitions and other articles of personal property owned by Tenant or installed or placed by Tenant at its expense in the Premises, and such similar articles ofany other persons claiming under Tenant, as Landlord may, in its sole discretion, require to be removed, and Tenant shall repair at its own expense all damageto the Premises and Building resulting from such removal.15.3Environmental Assessment. In connection with its surrender of the Premises, Tenant shall submit to Landlord, at least one hundredtwenty (120) days prior to the expiration date of this Lease (or in the event of an earlier termination of this Lease, as soon as reasonably possible followingsuch termination), a Phase I of the Premises by a competent and experienced environmental engineer or engineering firm selected by Tenant and reasonablysatisfactory to Landlord (pursuant to a contract approved by Landlord and providing that Landlord can rely on the Phase I), which (i) evidences that thePremises are in a clean and safe condition and free and clear of any Hazardous Materials in violation of Environmental Laws; and (ii) includes a review of thePremises by an environmental consultant for asbestos, mold, fungus, spores, and other moisture conditions, on-site chemical use, and lead-based paint. Ifsuch Phase I reveals that Clean-up is required under any Environmental Laws, Tenant shall submit a remediation plan prepared by a recognizedenvironmental consultant and shall be responsible for all costs of Clean-up, as more particularly provided in Section 5.3, above.16.HOLDING OVER If Tenant holds over after the expiration of the Lease Term or earlier termination thereof, with the express or implied consent ofLandlord, such tenancy shall be from month-to-month only, and shall not constitute a renewal hereof or an extension for any further term. If Tenant holdsover after the expiration of the Lease Term of earlier termination thereof, without the express or implied consent of Landlord, such tenancy shall be deemed tobe a tenancy by sufferance only, and shall not constitute a renewal hereof or an extension for any further term. In either case, Base Rent shall be payable at amonthly rate equal to 150% of the Base Rent applicable during the last rental period of the Lease Term under this Lease. Such month-to-month tenancy ortenancy by sufferance, as the case may be, shall be subject to every other applicable term, covenant and agreement contained herein. Nothing contained inthis Article 16 shall be construed as consent by Landlord to any holding over by Tenant, and Landlord expressly reserves the right to require Tenant tosurrender possession of the Premises to Landlord as provided in this Lease upon the expiration or other termination of this Lease. The provisions of thisArticle 16 shall not be deemed to limit or constitute a waiver of any other rights or remedies of Landlord provided herein or at law. If Tenant fails to792986.06/WLA186772-00003/2-28-19/gjn/gjn-32- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  surrender the Premises within thirty (30) days following the termination or expiration of this Lease, in addition to any other liabilities to Landlord accruingtherefrom, Tenant shall protect, defend, indemnify and hold Landlord harmless from all loss, costs (including reasonable attorneys' fees) and liabilityresulting from such failure, including, without limiting the generality of the foregoing, any claims made by any succeeding tenant founded upon such failureto surrender and any lost profits to Landlord resulting therefrom.17.ESTOPPEL CERTIFICATES Within ten (10) business days following a request in writing by Landlord, Tenant shall execute and deliver to Landlordan estoppel certificate, which, as submitted by Landlord, shall be substantially in the form of Exhibit D, attached hereto (or such other customary form as maybe reasonably required by any prospective mortgagee or purchaser of the Project, or any portion thereof), indicating therein any exceptions thereto that mayexist at that time, and shall also contain any other factual information concerning this Lease reasonably requested by Landlord or Landlord's mortgagee orprospective mortgagee. Any such certificate may be relied upon by any prospective mortgagee or purchaser of all or any portion of the Project. At any timeduring the Lease Term (but not more than once in any calendar year unless in connection with the sale or proposed sale, or the financing/refinancing, of theProject or any portion thereof, upon a default by Tenant beyond any applicable notice and cure period expressly set forth in this Lease, or upon the filing ofbankruptcy by Tenant), Landlord may require Tenant to provide Landlord with a current financial statement and financial statements of the two (2) yearsprior to the current financial statement year. Such statements shall be prepared in accordance with generally accepted accounting principles and, if such isthe normal practice of Tenant, shall be audited by an independent certified public accountant. Landlord shall hold such statementsconfidential. Notwithstanding the foregoing, in the event that (i) stock in the entity which constitutes Tenant under this Lease or the entity that controlsTenant is publicly traded on NASDAQ or a national stock exchange and Tenant’s financials are therefore publicly available, and (ii) Tenant has its own,separate and distinct 10K and 10Q filing requirements (as opposed joint or cumulative filings with an entity that controls Tenant or with entities which areotherwise affiliates of Tenant), then Tenant's obligation to provide Landlord with any financial statements hereunder shall be deemed satisfied. Failure ofTenant to timely execute and deliver such estoppel certificate, which failure continues for two (2) business days after a second request therefor in writing fromLandlord to Tenant, shall constitute an acceptance of the Premises and an acknowledgment by Tenant that statements included in the estoppel certificate aretrue and correct, without exception.18.SUBORDINATION Landlord hereby represents and warrants to Tenant that as of the date of this Lease the Project is not subject to any ground lease,or to the lien of any mortgage or deed of trust. Subject to the terms of this Article 18, this Lease shall be subject and subordinate to all future ground orunderlying leases of the Building or Project and to the lien of any mortgage, trust deed or other encumbrances hereafter in force against the Building orProject or any part thereof, if any, and to all renewals, extensions, modifications, consolidations and replacements thereof, and to all advances made orhereafter to be made upon the security of such mortgages or trust deeds, unless the holders of such mortgages, trust deeds or other encumbrances, or thelessors under such ground lease or underlying leases, require in writing that this Lease be superior thereto. The subordination of this Lease to any such futureground or underlying leases of the Building or Project or to the lien of any mortgage, trust deed or other encumbrances, shall be subject to and conditionedupon Tenant's receipt of a commercially reasonable subordination, non-disturbance, and attornment agreement in favor of Tenant. Tenant covenants andagrees in the event any proceedings are brought for the foreclosure of any such mortgage or deed in lieu thereof (or if any ground lease is terminated), toattorn, without any deductions or set-offs whatsoever, to the lienholder or purchaser or any successors thereto upon any such foreclosure sale or deed in lieuthereof (or to the ground lessor), if so requested to do so by such purchaser or lienholder or ground lessor, and to recognize such purchaser or lienholder orground lessor as the lessor under this Lease, provided such lienholder or purchaser or ground lessor shall agree to accept this Lease and not disturb Tenant'soccupancy, so long as Tenant timely pays the rent and observes and performs the terms, covenants and conditions of this Lease to be observed and performedby Tenant. Landlord's interest herein may be assigned as security at any time to any lienholder. Tenant shall, within ten (10) business days of request byLandlord, execute such further commercially reasonable instruments or assurances consistent with this Article 18 as Landlord may reasonably deem necessaryto evidence or confirm the subordination or superiority of this Lease to any such mortgages, trust deeds, ground leases or underlying leases. Tenant waivesthe provisions of any current or future statute, rule or law which may give or purport to give Tenant any right or election to terminate or otherwise adverselyaffect this Lease and the obligations of the Tenant hereunder in the event of any foreclosure proceeding or sale.792986.06/WLA186772-00003/2-28-19/gjn/gjn-33- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  19.DEFAULTS; REMEDIES19.1Events of Default. The occurrence of any of the following shall constitute a default of this Lease by Tenant:19.1.1Any failure by Tenant to pay any Rent or any other charge required to be paid under this Lease, or any part thereof,when due unless such failure is cured within five (5) business days after written notice thereof from Landlord to Tenant; or19.1.2Any failure by Tenant to observe or perform any other provision, covenant or condition of this Lease to be observedor performed by Tenant where such failure continues for thirty (30) days after written notice thereof from Landlord to Tenant specifying in detail Tenant’sfailure to perform; provided that if the nature of such default is such that the same cannot reasonably be cured within a thirty (30) day period, Tenant shall notbe deemed to be in default if it diligently commences such cure within such period and thereafter diligently proceeds to rectify and cure such default; or19.1.3Abandonment (as defined by Applicable Laws) of all or a substantial portion of the Premises by Tenant while Tenantis in default under this Lease; or19.1.4The failure by Tenant to observe or perform according to the provisions of Sections 5.1 and 5.2, and Articles 14, 17 or18 of this Lease where such failure continues for more than five (5) business days after written notice thereof from Landlord to Tenant .The notice periods provided herein are in lieu of, and not in addition to, any notice periods provided by law. 19.2Remedies Upon Default. Upon the occurrence of any event of default by Tenant, Landlord shall have, in addition to any otherremedies available to Landlord at law or in equity (all of which remedies shall be distinct, separate and cumulative), the option to pursue any one or more ofthe following remedies, each and all of which shall be cumulative and nonexclusive, without any notice or demand whatsoever.19.2.1Terminate this Lease, in which event Tenant shall immediately surrender the Premises to Landlord, and if Tenant failsto do so, Landlord may, without prejudice to any other remedy which it may have for possession or arrearages in rent, enter upon and take possession of thePremises and expel or remove Tenant and any other person who may be occupying the Premises or any part thereof, without being liable for prosecution orany claim or damages therefor; and Landlord may recover from Tenant the following:(i)The worth at the time of award of the unpaid rent which has been earned at the time of such termination; plus(ii)The worth at the time of award of the amount by which the unpaid rent which would have been earned aftertermination until the time of award exceeds the amount of such rental loss that Tenant proves could have been reasonably avoided; plus(iii)The worth at the time of award of the amount by which the unpaid rent for the balance of the Lease Termafter the time of award exceeds the amount of such rental loss that Tenant proves could have been reasonably avoided; plus(iv)Any other amount necessary to compensate Landlord for all the detriment proximately caused by Tenant'sfailure to perform its obligations under this Lease or which in the ordinary course of things would be likely to result therefrom, specificallyincluding but not limited to, brokerage commissions and advertising expenses incurred, expenses of remodeling the Premises or any portionthereof for a new tenant, whether for the same or a different use, and any special concessions made to obtain a new tenant; and792986.06/WLA186772-00003/2-28-19/gjn/gjn-34- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  (v)At Landlord's election, such other amounts in addition to or in lieu of the foregoing as may be permitted fromtime to time by Applicable Law.The term "rent" as used in this Section 19.2 shall be deemed to be and to mean all sums of every nature required to be paid by Tenant pursuant tothe terms of this Lease, whether to Landlord or to others. As used in Sections 19.2.1(i) and (ii), above, the "worth at the time of award" shall be computed byallowing interest at the rate set forth in Article 25 of this Lease, but in no case greater than the maximum amount of such interest permitted by law. As used inSection 19.2.1(iii) above, the "worth at the time of award" shall be computed by discounting such amount at the discount rate of the Federal Reserve Bankof San Francisco at the time of award plus one percent (1%). 19.2.2Landlord shall have the remedy described in California Civil Code Section 1951.4 (lessor may continue lease in effectafter lessee's breach and abandonment and recover rent as it becomes due, if lessee has the right to sublet or assign, subject only to reasonablelimitations). Accordingly, if Landlord does not elect to terminate this Lease on account of any default by Tenant, Landlord may, from time to time, withoutterminating this Lease, enforce all of its rights and remedies under this Lease, including the right to recover all rent as it becomes due.19.2.3Landlord shall at all times have the rights and remedies (which shall be cumulative with each other and cumulativeand in addition to those rights and remedies available under Sections 19.2.1 and 19.2.2, above, or any law or other provision of this Lease), without priordemand or notice except as required by Applicable Law, to seek any declaratory, injunctive or other equitable relief, and specifically enforce this Lease, orrestrain or enjoin a violation or breach of any provision hereof. 19.3Subleases of Tenant. If Landlord elects to terminate this Lease on account of any default by Tenant, as set forth in this Article 19,Landlord shall have the right to terminate any and all subleases, licenses, concessions or other consensual arrangements for possession entered into by Tenantand affecting the Premises or may, in Landlord's sole discretion, succeed to Tenant's interest in such subleases, licenses, concessions or arrangements. In theevent of Landlord's election to succeed to Tenant's interest in any such subleases, licenses, concessions or arrangements, Tenant shall, as of the date of noticeby Landlord of such election, have no further right to or interest in the rent or other consideration receivable thereunder. 19.4Efforts to Relet. No re-entry or repossession, repairs, maintenance, changes, alterations and additions, reletting, appointment of areceiver to protect Landlord's interests hereunder, or any other action or omission by Landlord shall be construed as an election by Landlord to terminate thisLease or Tenant's right to possession, or to accept a surrender of the Premises, nor shall same operate to release Tenant in whole or in part from any of Tenant'sobligations hereunder, unless express written notice of such intention is sent by Landlord to Tenant. Tenant hereby irrevocably waives any right otherwiseavailable under any law to redeem or reinstate this Lease.19.5Landlord Default.19.5.1In General. Notwithstanding anything to the contrary set forth in this Lease, Landlord shall not be in default in theperformance of any obligation required to be performed by Landlord pursuant to this Lease unless Landlord fails to perform such obligation within thirty (30)days after written notice thereof from Tenant to Landlord specifying in detail Landlord's failure to perform; provided, however, if the nature of Landlord'sobligation is such that the same cannot reasonably be cured within a thirty (30) day period, then Landlord shall not be in default under this Lease if it shalldiligently commence such cure within such thirty (30) day period and thereafter diligently pursue the same to completion. Upon any such default byLandlord under this Lease, Tenant may, except as otherwise specifically provided in this Lease to the contrary, exercise any of its rights provided under thisLease at law or in equity.19.5.2Abatement of Rent. In the event that Tenant is prevented from using, and does not use, the Premises or any portionthereof, as a result of (i) any repair, maintenance or alteration performed by Landlord which is required due to Landlord’s negligence, willful misconduct orbreach of this Lease or which is negligently performed by Landlord, (ii) any failure to perform any repair, maintenance or alteration required by this Leaseand which is reasonably within the control of Landlord to correct, or (iii) any failure to provide services, utilities or access to the Premises as required by thisLease and which is reasonably within the control of Landlord to correct (and except792986.06/WLA186772-00003/2-28-19/gjn/gjn-35- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  to the extent such failure is caused by the action or inaction of Tenant) (any such set of circumstances as set forth in items (i), (ii) or (iii), above, to be knownas an "Abatement Event"), then Tenant shall give Landlord notice of such Abatement Event, and if such Abatement Event continues for five (5) consecutivebusiness days after Landlord's receipt of any such notice (the "Eligibility Period"), then the Base Rent, Tenant's Share of Direct Expenses, and Tenant'sobligation, if any, to pay for parking (to the extent not utilized by Tenant) shall be abated or reduced, as the case may be, after expiration of the EligibilityPeriod for such time that Tenant continues to be so prevented from using, and does not use for the normal conduct of Tenant's business, the Premises or aportion thereof, in the proportion that the rentable area of the portion of the Premises that Tenant is prevented from using, and does not use, bears to the totalrentable area of the Premises; provided, however, in the event that Tenant is prevented from using, and does not use, a portion of the Premises for a period oftime in excess of the Eligibility Period and the remaining portion of the Premises is not sufficient to allow Tenant to effectively conduct its business therein,and if Tenant does not effectively conduct its business from such remaining portion, then for such time after expiration of the Eligibility Period during whichTenant is so prevented from effectively conducting its business therein, the Base Rent and Tenant's Share of Direct Expenses for the entire Premises andTenant's obligation to pay for parking, if any, shall be abated for such time as Tenant continues to be so prevented from using, and does not use, thePremises. If, however, Tenant reoccupies any portion of the Premises during such period, the Rent allocable to such reoccupied portion, based on theproportion that the rentable area of such reoccupied portion of the Premises bears to the total rentable area of the Premises, shall be payable by Tenant fromthe date Tenant reoccupies such portion of the Premises. In addition, if, as a result of an Abatement Event, Tenant is prevented from using, and does not use,the Premises or any portion thereof for a continuous period of seventy five (75) days, then Tenant shall have the right to terminate this Lease upon ten (10)days’ written notice to Landlord, in which event this Lease shall terminate upon the expiration of such ten (10) day period unless such use is restored withinsuch ten (10) day period. In the event of any Abatement Event, Landlord shall diligently pursue the remedy of the same as promptly as possible. To theextent an Abatement Event is caused by an event covered by Articles 11 or 13 of this Lease, then Tenant's right to abate rent shall be governed by the termsof such Article 11 or 13, as applicable, and the Eligibility Period shall not be applicable thereto. Except as provided in this Section 19.5.2, nothingcontained herein shall be interpreted to mean that Tenant is excused from paying Rent due hereunder.20.COVENANT OF QUIET ENJOYMENT Landlord covenants that Tenant, on paying the Rent, charges for services and other payments herein reservedand on keeping, observing and performing all the other terms, covenants, conditions, provisions and agreements herein contained on the part of Tenant to bekept, observed and performed, shall, during the Lease Term, peaceably and quietly have, hold and enjoy the Premises subject to the terms, covenants,conditions, provisions and agreements hereof without interference by any persons lawfully claiming by or through Landlord. The foregoing covenant is inlieu of any other covenant express or implied.21.LETTER OF CREDIT21.1Delivery of Letter of Credit. Tenant shall deliver to Landlord, concurrently with Tenant's execution of this Lease, anunconditional, clean, irrevocable letter of credit (the "L‑C") in the amount set forth in Section 8 of the Lease Summary (the "L‑C Amount"), which L‑C shallbe issued by a money-center, solvent and nationally recognized bank (a bank which accepts deposits, maintains accounts, has a local San Francisco Bay Areaoffice which will negotiate a letter of credit, and whose deposits are insured by the FDIC) reasonably acceptable to Landlord (such approved, issuing bankbeing referred to herein as the "Bank"), which Bank must have a rating from Standard and Poors Corporation of A- or better (or any equivalent rating theretofrom any successor or substitute rating service selected by Lessor) and a letter of credit issuer rating from Moody’s Investor Service of A3 or better (or anyequivalent rating thereto from any successor rating agency thereto)) (collectively, the “Bank’s Credit Rating Threshold”), and which L‑C shall besubstantially in the form of Exhibit F, attached hereto or such other form as is reasonably acceptable to Landlord. Tenant shall pay all expenses, pointsand/or fees incurred by Tenant in obtaining the L‑C. The L‑C shall (i) be "callable" at sight, irrevocable and unconditional, (ii) be maintained in effect,whether through renewal or extension, for the period commencing on the date of this Lease and continuing until the date (the "L‑C Expiration Date") that isno less than ninety-five (95) days after the expiration of the Lease Term as the same may be extended, and Tenant shall deliver a new L‑C or certificate ofrenewal or extension to Landlord at least thirty (30) days prior to the expiration of the L‑C then held by Landlord, without any action whatsoever on the partof Landlord, (iii) be fully assignable by Landlord, its successors and assigns, (iv) permit partial draws and multiple presentations and drawings, and (v) beotherwise subject to the Uniform Customs and Practices for Documentary792986.06/WLA186772-00003/2-28-19/gjn/gjn-36- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Credits (1993-Rev), International Chamber of Commerce Publication #500, or the International Standby Practices-ISP 98, International Chamber ofCommerce Publication #590. Landlord, or its then managing agent, shall have the right to draw down an amount up to the face amount of the L‑C if any ofthe following shall have occurred or be applicable: (A) such amount is due to Landlord under the terms and conditions of this Lease, and has not been paidwithin applicable notice and cure periods (or, if Landlord is prevented by Applicable Law from providing notice, within the period for payment set forth inthe Lease), or (B) Tenant has filed a voluntary petition under the U. S. Bankruptcy Code or any state bankruptcy code (collectively, "Bankruptcy Code"), or(C) an involuntary petition has been filed against Tenant under the Bankruptcy Code that is not dismissed within thirty (30) days, or (D) the Lease has beenrejected, or is deemed rejected, under Section 365 of the U.S. Bankruptcy Code, following the filing of a voluntary petition by Tenant under the BankruptcyCode, or the filing of an involuntary petition against Tenant under the Bankruptcy Code, or (E) the Bank has notified Landlord that the L‑C will not berenewed or extended through the L‑C Expiration Date, and Tenant has not provided a replacement L-C that satisfies the requirements of this Lease at leastthirty (30) days prior to such expiration, or (F) Tenant is placed into receivership or conservatorship, or becomes subject to similar proceedings under Federalor State law, or (G) Tenant executes an assignment for the benefit of creditors, or (H) if any of the Bank's Fitch Ratings (or other comparable ratings to theextent the Fitch Ratings are no longer available) have been reduced below the Bank's Credit Rating Threshold, and Tenant has failed to provide Landlordwith a replacement letter of credit, conforming in all respects to the requirements of this Article 21 (including, but not limited to, the requirements placed onthe issuing Bank more particularly set forth in this Section 21.1 above), in the amount of the applicable L‑C Amount, within ten (10) days followingLandlord’s written demand therefor (with no other notice or cure or grace period being applicable thereto, notwithstanding anything in this Lease to thecontrary) (each of the foregoing being an "L‑C Draw Event"). The L‑C shall be honored by the Bank regardless of whether Tenant disputes Landlord's rightto draw upon the L‑C. In addition, in the event the Bank is placed into receivership or conservatorship by the Federal Deposit Insurance Corporation or anysuccessor or similar entity, then, effective as of the date such receivership or conservatorship occurs, said L‑C shall be deemed to fail to meet the requirementsof this Article 21, and, within ten (10) days following Landlord's written notice to Tenant of such receivership or conservatorship (the "L‑C FDICReplacement Notice"), Tenant shall replace such L‑C with a substitute letter of credit from a different issuer (which issuer shall meet or exceed the Bank'sCredit Rating Threshold and shall otherwise be acceptable to Landlord in its reasonable discretion) and that complies in all respects with the requirements ofthis Article 21. If Tenant fails to replace such L‑C with such conforming, substitute letter of credit pursuant to the terms and conditions of this Section 21.1,then, notwithstanding anything in this Lease to the contrary, Landlord shall have the right to declare Tenant in default of this Lease for which there shall beno notice or grace or cure periods being applicable thereto (other than the aforesaid ten (10) day period). Tenant shall be responsible for the payment of anyand all Tenant’s and Bank’s costs incurred with the review of any replacement L‑C, which replacement is required pursuant to this Section or is otherwiserequested by Tenant. In the event of an assignment by Tenant of its interest in the Lease (and irrespective of whether Landlord's consent is required for suchassignment), the acceptance of any replacement or substitute letter of credit by Landlord from the assignee shall be subject to Landlord's prior writtenapproval, in Landlord's reasonable discretion, and the actual, reasonable out-of-pocket attorney's fees incurred by Landlord in connection with suchdetermination shall be payable by Tenant to Landlord within thirty (30) days of billing.21.2Application of L‑C. Tenant hereby acknowledges and agrees that Landlord is entering into this Lease in material reliance upon theability of Landlord to draw upon the L‑C upon the occurrence of any L‑C Draw Event. In the event of any L‑C Draw Event, Landlord may, but withoutobligation to do so, and without notice to Tenant (except in connection with an L-C Draw Event under Section 21.1(H) above), draw upon the L‑C, in part orin whole, in the amount necessary to cure any such L-C Draw Event and/or to compensate Landlord for any and all damages of any kind or nature sustainedor which Landlord reasonably estimates that it will sustain resulting from Tenant's breach or default of the Lease or other L-C Draw Event and/or tocompensate Landlord for any and all damages arising out of, or incurred in connection with, the termination of this Lease, including, without limitation,those specifically identified in Section 1951.2 of the California Civil Code. The use, application or retention of the L‑C, or any portion thereof, by Landlordshall not prevent Landlord from exercising any other right or remedy provided by this Lease or by any Applicable Law, it being intended that Landlord shallnot first be required to proceed against the L‑C, and such L‑C shall not operate as a limitation on any recovery to which Landlord may otherwise beentitled. Tenant agrees and acknowledges that (i) the L‑C constitutes a separate and independent contract between Landlord and the Bank, (ii) Tenant is nota third party beneficiary of such contract, (iii) Tenant has no property interest whatsoever in the L‑C or the proceeds thereof, and (iv) in the event Tenantbecomes a debtor under any chapter of the792986.06/WLA186772-00003/2-28-19/gjn/gjn-37- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Bankruptcy Code, Tenant is placed into receivership or conservatorship, and/or there is an event of a receivership, conservatorship or a bankruptcy filing by,or on behalf of, Tenant, neither Tenant, any trustee, nor Tenant's bankruptcy estate shall have any right to restrict or limit Landlord's claim and/or rights to theL‑C and/or the proceeds thereof by application of Section 502(b)(6) of the U. S. Bankruptcy Code or otherwise.21.3Maintenance of L-C by Tenant. If, as a result of any drawing by Landlord of all or any portion of the L-C in accordance with theterms of this Article 21, the amount of the L-C shall be less than the L-C Amount, Tenant shall, within five (5) business days thereafter, provide Landlord withadditional letter(s) of credit in an amount equal to the deficiency, and any such additional letter(s) of credit shall comply with all of the provisions of thisArticle 21. Tenant further covenants and warrants that it will neither assign nor encumber the L-C or any part thereof and that neither Landlord nor itssuccessors or assigns will be bound by any such assignment, encumbrance, attempted assignment or attempted encumbrance. Without limiting the generalityof the foregoing, if the L-C expires earlier than the L‑C Expiration Date, Landlord will accept a renewal thereof (such renewal letter of credit to be in effectand delivered to Landlord, as applicable, not later than thirty (30) days prior to the expiration of the L-C), which shall be irrevocable and automaticallyrenewable as above provided through the L‑C Expiration Date upon the same terms as the expiring L‑C or such other terms as may be acceptable to Landlordin its sole discretion. If Tenant exercises its option to extend the Lease Term pursuant to Section 2.2 of this Lease then, unless the parties have agreedotherwise in writing, not later than thirty (30) days prior to the commencement of the Option Term, Tenant shall deliver to Landlord a new L C or certificateof renewal or extension evidencing the L-C Expiration Date as thirty (30) days after the expiration of the Option Term. However, if the L‑C is not timelyrenewed, or if Tenant fails to maintain the L‑C in the amount and in accordance with the terms set forth in this Article 21, Landlord shall have the right topresent the L‑C to the Bank in accordance with the terms of this Article 21, and the proceeds of the L-C may be applied by Landlord against any Rentpayable by Tenant under this Lease that is not paid when due and/or to pay for all losses and damages that Landlord has suffered or that Landlord reasonablyestimates that it will suffer as a result of any breach or default by Tenant under this Lease. In the event Landlord elects to exercise its rights as providedabove, (I) any unused proceeds shall constitute the property of Landlord (and not Tenant’s property or, in the event of a receivership, conservatorship, or abankruptcy filing by, or on behalf of, Tenant, property of such receivership, conservatorship or Tenant’s bankruptcy estate) and need not be segregated fromLandlord’s other assets, and (II) Landlord agrees to pay to Tenant within thirty (30) days after the L‑C Expiration Date the amount of any proceeds of the L-Creceived by Landlord and not applied against any Rent payable by Tenant under this Lease that was not paid when due or used to pay for any losses and/ordamages suffered by Landlord (or reasonably estimated by Landlord that it will suffer) as a result of any breach or default by Tenant under this Lease;provided, however, that if prior to the L‑C Expiration Date a voluntary petition is filed by Tenant, or an involuntary petition is filed against Tenant by any ofTenant’s creditors, under the Bankruptcy Code, then Landlord shall not be obligated to make such payment in the amount of the unused L-C proceeds untileither all preference issues relating to payments under this Lease have been resolved in such bankruptcy or reorganization case or such bankruptcy orreorganization case has been dismissed. If Landlord draws on the L-C due to Tenant’s failure to timely renew or provide a replacement L-C, such failure shallnot be considered a default under this Lease and Landlord shall return such cash proceeds upon Tenant’s presentation of a replacement L-C that satisfies therequirements of this Lease, subject to reasonable satisfaction of any preference risk to Landlord.21.4Transfer and Encumbrance. The L-C shall also provide that Landlord may, at any time and without notice to Tenant and withoutfirst obtaining Tenant's consent thereto, transfer (one or more times) its interest in and to the L-C to another party, person or entity in connection with theassignment by Landlord of its rights and interests in and to this Lease. In the event of a transfer of Landlord's interest in under this Lease, and upon thetransferee’s written assumption of Landlord’s obligations under this Lease (including with respect to the L-C), Landlord shall transfer the L-C to the transfereeand thereupon Landlord shall, without any further agreement between the parties, be released by Tenant from all liability therefor, and it is agreed that theprovisions hereof shall apply to every transfer or assignment of the whole of said L-C to a new landlord. In connection with any such transfer of the L-C byLandlord, Tenant shall, at Tenant's sole cost and expense, execute and submit to the Bank such commercially reasonable applications, documents andinstruments as may be necessary to effectuate such transfer and, Tenant shall be responsible for paying the Bank's transfer and processing fees in connectiontherewith; provided that, Landlord shall have the right (in its sole discretion), but not the obligation, to pay such fees on behalf of Tenant, in which caseTenant shall reimburse Landlord within thirty (30) days after Tenant's receipt of an invoice from Landlord therefor.792986.06/WLA186772-00003/2-28-19/gjn/gjn-38- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  21.5L-C Not a Security Deposit. Landlord and Tenant (1) acknowledge and agree that in no event or circumstance shall the L‑C or anyrenewal thereof or substitute therefor or any proceeds thereof be deemed to be or treated as a “security deposit” under any law applicable to security depositsin the commercial context, including, but not limited to, Section 1950.7 of the California Civil Code, as such Section now exists or as it may be hereafteramended or succeeded (the “Security Deposit Laws”), (2) acknowledge and agree that the L‑C (including any renewal thereof or substitute therefor or anyproceeds thereof) is not intended to serve as a security deposit, and the Security Deposit Laws shall have no applicability or relevancy thereto, and (3) waiveany and all rights, duties and obligations that any such party may now, or in the future will, have relating to or arising from the Security DepositLaws. Tenant hereby irrevocably waives and relinquishes the provisions of Section 1950.7 of the California Civil Code and any successor statute, and allother provisions of law, now or hereafter in effect, which (x) establish the time frame by which a landlord must refund a security deposit under a lease, and/or(y) provide that a landlord may claim from a security deposit only those sums reasonably necessary to remedy defaults in the payment of rent, to repairdamage caused by a tenant or to clean the premises, it being agreed that Landlord may, in addition, claim those sums specified in this Article 21 and/or thosesums reasonably necessary to (a) compensate Landlord for any loss or damage caused by Tenant's breach of this Lease, including any damages Landlordsuffers following termination of this Lease, and/or (b) compensate Landlord for any and all damages arising out of, or incurred in connection with, thetermination of this Lease, including, without limitation, those specifically identified in Section 1951.2 of the California Civil Code. Tenant agrees not tointerfere in any way with any payment to Landlord of the proceeds of the L-C, either prior to or following a "draw" by Landlord of all or any portion of the L-C, regardless of whether any dispute exists between Tenant and Landlord as to Landlord's right to draw down all or any portion of the L-C. No condition orterm of this Lease shall be deemed to render the L‑C conditional and thereby afford the Bank a justification for failing to honor a drawing upon such L-C in atimely manner. Tenant shall not request or instruct the Bank of any L‑C to refrain from paying sight draft(s) drawn under such L‑C.21.6Remedy for Improper Drafts. Tenant's sole remedy in connection with the improper presentment or payment of sight drafts drawnunder any L‑C shall be the right to obtain from Landlord a refund of the amount of any sight draft(s) that were improperly presented or the proceeds of whichwere misapplied, and reasonable actual out-of-pocket attorneys' fees, provided that at the time of such refund, Tenant increases the amount of such L‑C to theamount (if any) then required under the applicable provisions of this Lease. Tenant acknowledges that the presentment of sight drafts drawn under any L‑C,or the Bank's payment of sight drafts drawn under such L‑C, could not under any circumstances cause Tenant injury that could not be remedied by an awardof money damages, and that the recovery of money damages would be an adequate remedy therefor. In the event Tenant shall be entitled to a refund asaforesaid and Landlord shall fail to make such payment within ten (10) business days after demand, Tenant shall have the right to deduct the amount thereoffrom the next installment(s) of Base Rent.22.COMMUNICATIONS AND COMPUTER LINE Tenant may install, maintain, replace, remove or use any communications or computer wires andcables serving the Premises (collectively, the "Lines"), provided that Tenant shall use an experienced and qualified contractor reasonably approved in writingby Landlord, and comply with all of the other provisions of Articles 7 and 8 of this Lease. Tenant shall pay all costs in connection therewith. Tenant shallhave no obligation to remove any Lines installed by Tenant located in or serving the Premises upon the expiration or earlier termination of this Lease.23.SIGNS23.1Exterior Signage. Tenant, at its sole cost and expense, may install (i) its prorata share of identification signage on the existingmonument sign located at the Project, and (ii) at the entrance to the Building, and on the exterior of the Building (collectively, "Tenant Signage"); provided,however, in no event shall Tenant's Signage include an "Objectionable Name," as that term is defined in Section 23.2 of this Lease. All such signage shall besubject to Tenant's obtaining all required governmental approvals. All permitted signs shall be maintained by Tenant at its expense in a good and safecondition and appearance. Upon the expiration or earlier termination of this Lease, Tenant shall remove all of its signs at Tenant's sole cost andexpense. The graphics, materials, color, design, lettering, lighting, size, illumination, specifications and exact location of Tenant's Signage (collectively, the"Sign Specifications") shall be subject to the prior written approval of Landlord, which approval shall not be unreasonably withheld, conditioned or delayed,and shall be consistent and compatible with the quality and nature of the Project. Tenant hereby acknowledges that, notwithstanding Landlord's approval ofTenant's Signage, Landlord has made no representation or warranty to792986.06/WLA186772-00003/2-28-19/gjn/gjn-39- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Tenant with respect to the probability of obtaining all necessary governmental approvals and permits for Tenant's Signage. In the event Tenant does notreceive the necessary governmental approvals and permits for Tenant's Signage, Tenant's and Landlord's rights and obligations under the remaining TCCs ofthis Lease shall be unaffected. 23.2Objectionable Name. Tenant's Signage shall not include a name or logo which relates to an entity which is of a character orreputation, or is associated with a political faction or orientation, which as reasonably determined by Landlord is inconsistent with the quality of the Project,or which would otherwise reasonably offend a landlord of the Comparable Buildings (an "Objectionable Name"). Landlord hereby agrees that the followingname, or any reasonable derivation thereof, is not an Objectionable Name: "Unity Biotechnology."23.3Prohibited Signage and Other Items. Any signs, notices, logos, pictures, names or advertisements visible from the exterior of thePremises or Building which are installed and that have not been separately approved by Landlord may be removed without notice by Landlord at the soleexpense of Tenant. Any signs, window coverings, or blinds (even if the same are located behind the Landlord-approved window coverings for the Building),or other items visible from the exterior of the Premises or Building, shall be subject to the prior approval of Landlord, in its reasonable discretion.23.4Termination of Right to Tenant's Signage. The rights contained in this Article 23 shall be personal to Original Tenant and anyTransferee approved or deemed approved by Landlord under Article 14 or any transferee under a transaction not subject to Landlord’s consent under Article14, and may only be exercised and maintained by such parties (and not any other assignee, sublessee or other transferee of the Original Tenant's interest inthis Lease) to the extent (x) they are not in default under this Lease (beyond any applicable notice and cure period) and (y) with respect to any signage on theexterior of the Building, if they lease at least fifty percent (50%) of the rentable square footage of the Building.24.COMPLIANCE WITH LAW Landlord shall promptly comply with and be responsible, at its sole cost and expense, except to the extent permitted to beincluded in Operating Expenses pursuant to Section 4.2.4 above, to comply with all Applicable Laws with respect to the Base Building and Common Areas,and Landlord shall make all alterations to the Base Building and Common Areas as are required to comply with Applicable Laws (but subject to possiblereimbursement by Tenant pursuant to the terms hereof). Tenant shall not do anything or suffer anything to be done in or about the Premises or the Projectwhich will in any way conflict with any law, statute, ordinance, code or other governmental rule, regulation or requirement now in force or which mayhereafter be enacted or promulgated (collectively, "Applicable Laws"). After the Lease Commencement Date, at its sole cost and expense, Tenant shallpromptly comply with all such Applicable Laws with respect to the Premises, and Tenant shall make all alterations to the Premises as are required to complywith Applicable Laws. The judgment of any court of competent jurisdiction or the admission of Tenant in any judicial action, regardless of whether Landlordis a party thereto, that Tenant has violated any of said Applicable Laws, shall be conclusive of that fact as between Landlord and Tenant. Notwithstandingthe foregoing, to the extent Landlord's compliance obligations set forth in the first sentence of this Article 24 (a) are triggered by Alterations which areSpecialty Improvements made by Tenant to the Premises after completion of the Tenant Improvements (with the parties acknowledging that responsibility forcompliance with Applicable Laws regarding or triggered by the Tenant Improvements is Landlord’s responsibility pursuant to Exhibit B and is not governedby this Article 24) or by Tenant's particular manner of use of the Premises (as distinguished from the Permitted Use), and (b) are not to correct violations ofApplicable Law existing as of the Lease Commencement Date (any such compliance obligations satisfying the criteria in subsections (a), and (b), the “TenantReimbursable Obligations”), Tenant shall reimburse Landlord for the cost incurred by Landlord for the Tenant Reimbursable Obligations within thirty (30)days after receipt of an invoice from Landlord. For purposes of Section 1938 of the California Civil Code, Landlord hereby discloses to Tenant, and Tenanthereby acknowledges, that as of the date of this Lease the Project, Building and Premises have not undergone inspection by a Certified Access Specialist(CASp). As required by Section 1938(e) of the California Civil Code, Landlord hereby states as follows: "A Certified Access Specialist (CASp) can inspectthe subject premises and determine whether the subject premises comply with all of the applicable construction-related accessibility standards under statelaw. Although state law does not require a CASp inspection of the subject premises, the commercial property owner or lessor may not prohibit the lessee ortenant from obtaining a CASp inspection of the subject premises for the occupancy or potential occupancy of the lessee or tenant, if requested by the lesseeor tenant. The parties shall mutually agree on the arrangements for the time and manner of the CASp inspection, the payment of the fee for the CASpinspection, and the cost of making792986.06/WLA186772-00003/2-28-19/gjn/gjn-40- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  any repairs necessary to correct violations of construction-related accessibility standards within the premises." In furtherance of the foregoing, Landlord andTenant hereby agree as follows: (a) any CASp inspection requested by Tenant shall be conducted, at Tenant's sole cost and expense, by a CASp reasonablyapproved in advance by Landlord; and (b) Tenant, at its cost, is responsible for making any repairs or modifications within the Premises to correct violationsof construction-related accessibility standards identified by any such CASp inspection requested by Tenant. 25.LATE CHARGES If any installment of Rent or any other sum due from Tenant shall not be received by Landlord or Landlord's designee within five (5)business days after Tenant's receipt of written notice from Landlord that said amount is due, then Tenant shall pay to Landlord a late charge equal to fourpercent (4%) of the overdue amount plus any reasonable attorneys' fees incurred by Landlord by reason of Tenant's failure to pay Rent and/or other chargeswhen due hereunder; provided, however, with regard to the first such failure in any twelve (12) month period, Landlord will waive such late charge andattorneys’ fees to the extent Tenant cures such failure within five (5) business days following Tenant's receipt of written notice from Landlord that the samewas not received when due. The late charge shall be deemed Additional Rent and the right to require it shall be in addition to all of Landlord's other rightsand remedies hereunder or at law and shall not be construed as liquidated damages or as limiting Landlord's remedies in any manner. In addition to the latecharge described above, any Rent or other amounts owing hereunder which are not paid within ten (10) days after the date they are due shall bear interestfrom the date when due until paid at a rate per annum equal to the lesser of (i) the annual "Bank Prime Loan" rate cited in the Federal Reserve StatisticalRelease Publication G.13(415), published on the first Tuesday of each calendar month (or such other comparable index as Landlord and Tenant shallreasonably agree upon if such rate ceases to be published) plus three (3) percentage points, and (ii) the highest rate permitted by Applicable Law.26.LANDLORD'S RIGHT TO CURE DEFAULT; PAYMENTS BY TENANT26.1Landlord's Cure. All covenants and agreements to be kept or performed by Tenant under this Lease shall be performed by Tenantat Tenant's sole cost and expense and without any reduction of Rent, except to the extent, if any, otherwise expressly provided herein. If Tenant shall fail toperform any obligation under this Lease, and such failure shall continue in excess of the time allowed under Section 19.1.2, above, unless a specific timeperiod is otherwise stated in this Lease, Landlord may, but shall not be obligated to, make any such payment or perform any such act on Tenant's part withoutwaiving its rights based upon any default of Tenant and without releasing Tenant from any obligations hereunder.26.2Tenant's Reimbursement. Except as may be specifically provided to the contrary in this Lease, Tenant shall pay to Landlord,within thirty (30) days after delivery by Landlord to Tenant of statements therefor: (i) sums equal to expenditures reasonably made and obligations incurredby Landlord in connection with the remedying by Landlord of Tenant's defaults pursuant to the provisions of Section 26.1; and (ii) sums equal to all losses,costs, liabilities, damages and expenses finally adjudicated and for which Tenant is responsible under Article 10 of this Lease. Tenant's obligations underthis Section 26.2 shall survive the expiration or sooner termination of the Lease Term.27.ENTRY BY LANDLORD Landlord reserves the right, upon not less than one (1) business day's prior notice to Tenant (except in the case of anEmergency) to enter the Premises at all reasonable times to (i) inspect them; (ii) show the Premises to prospective purchasers, or to current or prospectivemortgagees, ground or underlying lessors or insurers or, during the last nine (9) months of the Lease Term, to prospective tenants; (iii) post notices ofnonresponsibility (to the extent applicable pursuant to then Applicable Law); or (iv) alter, improve or repair the Premises or the Building, or for structuralalterations, repairs or improvements to the Building or the Building's systems and equipment, in each case as authorized under this Lease. Landlord maymake any such entries without the abatement of Rent, except as otherwise provided in this Lease, and may take such reasonable steps as required toaccomplish the stated purposes. In an Emergency, Landlord shall have the right to use any means that Landlord may deem proper to open the doors in and tothe Premises. Any entry into the Premises by Landlord in the manner hereinbefore described shall not be deemed to be a forcible or unlawful entry into, or adetainer of, the Premises, or an actual or constructive eviction of Tenant from any portion of the Premises. Landlord shall use commercially reasonableefforts to minimize any interference with Tenant's use of or access to the Premises or business operations in connection with any such entry and shall complywith Tenant’s reasonable security measures, including that Tenant may require that Landlord be accompanied by an employee of Tenant during any suchentry into the Premises by792986.06/WLA186772-00003/2-28-19/gjn/gjn-41- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Landlord (except in the event of an Emergency in which case no escort shall be required); provided, however, that in no event shall the unavailability of suchescort at the time that Landlord is permitted to enter the Premises delay Landlord's entry into the Premises as permitted hereunder. Without limiting theforegoing, except in an Emergency, Landlord shall not enter into any portion of the Premises used for vivarium purposes or enter into any portion of thePremises identified to Landlord as an area containing sensitive business information unless accompanied by a representative of Tenant. Landlord shall holdconfidential any information regarding Tenant’s business that it may learn as a result of any such entry.28.TENANT PARKING Without additional charge, throughout the Lease Term, Tenant shall have the right to use the amount of parking set forth inSection 9 of the Summary, in the on-site parking facility (or facilities) which serve the Project. Tenant shall abide by all reasonable and non-discriminatoryrules and regulations which are prescribed from time to time and either posted at the parking facility or provided to Tenant in writing for the orderlyoperation and use of the parking facility where the parking passes are located (including any sticker or other identification system established by Landlordand the prohibition of vehicle repair and maintenance activities in the parking facilities), and shall cooperate in seeing that Tenant's employees and visitorsalso comply with such rules and regulations. Tenant's use of the Project parking facility shall be at Tenant's sole risk and Tenant acknowledges and agreesthat Landlord shall have no liability whatsoever for damage to the vehicles of Tenant, its employees and/or visitors, or for other personal injury or propertydamage or theft relating to or connected with the parking rights granted herein or any of Tenant's, its employees' and/or visitors' use of the parking facilities,except to the extent caused by the negligence or willful misconduct of Landlord or its agents, employees or contractors. 29.MISCELLANEOUS PROVISIONS29.1Terms; Captions. The words "Landlord" and "Tenant" as used herein shall include the plural as well as the singular. Thenecessary grammatical changes required to make the provisions hereof apply either to corporations or partnerships or individuals, men or women, as the casemay require, shall in all cases be assumed as though in each case fully expressed. The captions of Articles and Sections are for convenience only and shallnot be deemed to limit, construe, affect or alter the meaning of such Articles and Sections.29.2Binding Effect. Subject to all other provisions of this Lease, each of the covenants, conditions and provisions of this Lease shallextend to and shall, as the case may require, bind or inure to the benefit not only of Landlord and of Tenant, but also of their respective heirs, personalrepresentatives, successors or assigns, provided this clause shall not permit any assignment by Tenant contrary to the provisions of Article 14 of this Lease.29.3No Air Rights. No rights to any view or to light or air over any property, whether belonging to Landlord or any other person, aregranted to Tenant by this Lease. If at any time any windows of the Premises are temporarily darkened or the light or view therefrom is temporarily obstructedby reason of any repairs, improvements, maintenance or cleaning in or about the Project, the same shall be without liability to Landlord and without anyreduction or diminution of Tenant's obligations under this Lease.29.4Modification of Lease. Should any current or prospective mortgagee or ground lessor for the Building or Project require amodification of this Lease, which modification will not cause an increased cost or expense to Tenant or in any other way materially and adversely change therights and obligations of Tenant hereunder, then and in such event, Tenant agrees that this Lease may be so modified and agrees to execute whatevercommercially reasonable documents are reasonably required therefor and to deliver the same to Landlord within ten (10) business days following a requesttherefor. At the request of Landlord or any mortgagee or ground lessor, Tenant agrees to execute a short form of Lease and deliver the same to Landlordwithin ten (10) business days following the request therefor.29.5Transfer of Landlord's Interest. Tenant acknowledges that Landlord has the right to transfer all or any portion of its interest in theProject or Building and in this Lease, and Tenant agrees that in the event of any such transfer, Landlord shall automatically be released from all liabilityunder this Lease and Tenant agrees to look solely to such transferee for the performance of Landlord's obligations hereunder after the date of transfer and suchtransferee shall be deemed to have fully assumed and be liable for all obligations of this Lease to be performed by Landlord, including the return of anySecurity Deposit, and Tenant shall attorn to such transferee.792986.06/WLA186772-00003/2-28-19/gjn/gjn-42- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  29.6Prohibition Against Recording. Except as provided in Section 29.4 of this Lease, neither this Lease, nor any memorandum,affidavit or other writing with respect thereto, shall be recorded by Tenant or by anyone acting through, under or on behalf of Tenant.29.7Landlord's Title. Landlord's title is and always shall be paramount to the title of Tenant. Nothing herein contained shall empowerTenant to do any act which can, shall or may encumber the title of Landlord.29.8Relationship of Parties. Nothing contained in this Lease shall be deemed or construed by the parties hereto or by any third party tocreate the relationship of principal and agent, partnership, joint venturer or any association between Landlord and Tenant.29.9Application of Payments. Landlord shall have the right to apply payments received from Tenant pursuant to this Lease, regardlessof Tenant's designation of such payments, to satisfy any obligations of Tenant that are then due and payable hereunder, in such order and amounts asLandlord, in its sole discretion, may elect.29.10Time of Essence. Time is of the essence with respect to the performance of every provision of this Lease in which time ofperformance is a factor.29.11Partial Invalidity. If any term, provision or condition contained in this Lease shall, to any extent, be invalid or unenforceable, theremainder of this Lease, or the application of such term, provision or condition to persons or circumstances other than those with respect to which it is invalidor unenforceable, shall not be affected thereby, and each and every other term, provision and condition of this Lease shall be valid and enforceable to thefullest extent possible permitted by law.29.12No Warranty. In executing and delivering this Lease, Tenant has not relied on any representations, including, but not limited to,any representation as to the amount of any item comprising Additional Rent or the amount of the Additional Rent in the aggregate or that Landlord isfurnishing the same services to other tenants, at all, on the same level or on the same basis, or any warranty or any statement of Landlord which is not set forthherein or in one or more of the exhibits attached hereto.29.13Landlord Exculpation. The liability of Landlord or the Landlord Parties to Tenant for any default by Landlord under this Leaseor arising in connection herewith or with Landlord's operation, management, leasing, repair, renovation, alteration or any other matter relating to the Projector the Premises shall be limited solely and exclusively to an amount which is equal to the interest of Landlord in the Project (including any rental, insurance,sale and/or condemnation proceeds derived therefrom). Neither Landlord, nor any of the Landlord Parties shall have any personal liability therefor, andTenant hereby expressly waives and releases such personal liability on behalf of itself and all persons claiming by, through or under Tenant. The limitationsof liability contained in this Section 29.13 shall inure to the benefit of Landlord's and the Landlord Parties' present and future partners, beneficiaries, officers,directors, trustees, shareholders, agents and employees, and their respective partners, heirs, successors and assigns. Under no circumstances shall any presentor future partner of Landlord (if Landlord is a partnership), or trustee or beneficiary (if Landlord or any partner of Landlord is a trust), have any liability for theperformance of Landlord's obligations under this Lease. Notwithstanding any contrary provision herein, neither Landlord nor the Landlord Parties shall beliable under any circumstances for injury or damage to, or interference with, Tenant's business, including but not limited to, loss of profits, loss of rents orother revenues, loss of business opportunity, loss of goodwill or loss of use, in each case, however occurring, or loss to inventory, scientific research,scientific experiments, laboratory animals, products, specimens, samples, and/or scientific, business, accounting and other records of every kind anddescription kept at the premises and any and all income derived or derivable therefrom; similarly, notwithstanding any contrary provision herein, except andthen only to the extent as set forth in Article 16 above, neither Tenant nor the Tenant Parties shall be liable under any circumstances for injury or damage to,or interference with, Landlord’s business, including but not limited to, loss of profits, loss of rents or other revenues, loss of business opportunity, loss ofgoodwill or loss of use, in each case, however occurring.29.14Entire Agreement. It is understood and acknowledged that there are no oral agreements between the parties hereto affecting thisLease and this Lease constitutes the parties' entire agreement with respect to the leasing of the Premises and supersedes and cancels any and all previousnegotiations, arrangements, brochures, agreements792986.06/WLA186772-00003/2-28-19/gjn/gjn-43- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  and understandings, if any, between the parties hereto or displayed by Landlord to Tenant with respect to the subject matter thereof, and none thereof shall beused to interpret or construe this Lease. None of the terms, covenants, conditions or provisions of this Lease can be modified, deleted or added to except inwriting signed by the parties hereto.29.15Right to Lease. Landlord reserves the absolute right to effect such other tenancies in the Project as Landlord in the exercise of itssole business judgment shall determine to best promote the interests of the Building or Project. Tenant does not rely on the fact, nor does Landlord represent,that any specific tenant or type or number of tenants shall, during the Lease Term, occupy any space in the Building or Project.29.16Force Majeure. Any prevention, delay or stoppage due to strikes, lockouts, labor disputes, acts of God, acts of war, terrorist acts,inability to obtain services, labor, or materials or reasonable substitutes therefor, governmental actions, civil commotions, fire or other casualty, and othercauses beyond the reasonable control of the party obligated to perform, except with respect to the obligations imposed with regard to Rent and other chargesto be paid by Landlord or Tenant pursuant to this Lease (collectively, a "Force Majeure"), notwithstanding anything to the contrary contained in this Lease,shall excuse the performance of such party for a period equal to any such prevention, delay or stoppage and, therefore, if this Lease specifies a time period forperformance of an obligation of either party, that time period shall be extended by the period of any delay in such party's performance caused by a ForceMajeure.29.17Waiver of Redemption by Tenant. Tenant hereby waives, for Tenant and for all those claiming under Tenant, any and all rightsnow or hereafter existing to redeem by order or judgment of any court or by any legal process or writ, Tenant's right of occupancy of the Premises after anytermination of this Lease.29.18Notices. All notices, demands, statements, designations, approvals or other communications (collectively, "Notices") given orrequired to be given by either party to the other hereunder or by law shall be in writing, shall be (A) sent by United States certified or registered mail, postageprepaid, return receipt requested ("Mail"), (B) transmitted by telecopy, if such telecopy is promptly followed by a Notice sent by Mail, (C) delivered by anationally recognized overnight courier, or (D) delivered personally. Any Notice shall be sent, transmitted, or delivered, as the case may be, to Tenant at theappropriate address set forth in Section 10 of the Summary, or to such other place as Tenant may from time to time designate in a Notice to Landlord, or toLandlord at the addresses set forth below, or to such other places as Landlord may from time to time designate in a Notice to Tenant. Any Notice will bedeemed given (i) three (3) days after the date it is posted if sent by Mail, (ii) the date the telecopy is transmitted, (iii) the date the overnight courier delivery ismade, or (iv) the date personal delivery is made. As of the date of this Lease, any Notices to Landlord must be sent, transmitted, or delivered, as the case maybe, to the following addresses:BAYSIDE AREA DEVELOPMENT, LLCc/o HCP Life Science Estatesc/o HCP, Inc.1920 Main Street, Suite 1200Irvine, CA 92614Attn: Legal Departmentwith a copy to:BAYSIDE AREA DEVELOPMENT, LLCc/o HCP Life Science Estates950 Tower Lane, Suite 1650Foster City, CA 94404 and792986.06/WLA186772-00003/2-28-19/gjn/gjn-44- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  Allen Matkins Leck Gamble Mallory & Natsis LLP1901 Avenue of the Stars, Suite 1800Los Angeles, California 90067Attention: Anton N. Natsis, Esq.29.19Joint and Several. If there is more than one tenant, the obligations imposed upon Tenant under this Lease shall be joint andseveral. 29.20Authority. If Tenant is a corporation, trust or partnership, each individual executing this Lease on behalf of Tenant herebyrepresents and warrants that Tenant is a duly formed and existing entity qualified to do business in the State of California and that Tenant has full right andauthority to execute and deliver this Lease and that each person signing on behalf of Tenant is authorized to do so. In such event, Tenant shall, within ten(10) days after execution of this Lease, deliver to Landlord satisfactory evidence of such authority and, if a corporation, upon demand by Landlord, alsodeliver to Landlord satisfactory evidence of (i) good standing in Tenant's state of incorporation and (ii) qualification to do business in the State of California.29.21Attorneys' Fees. In the event that either Landlord or Tenant should bring suit for the possession of the Premises, for the recoveryof any sum due under this Lease, or because of the breach of any provision of this Lease or for any other relief against the other, then all costs and expenses,including reasonable attorneys' fees, incurred by the prevailing party therein shall be paid by the other party, which obligation on the part of the other partyshall be deemed to have accrued on the date of the commencement of such action and shall be enforceable whether or not the action is prosecuted tojudgment.29.22Governing Law; WAIVER OF TRIAL BY JURY. This Lease shall be construed and enforced in accordance with the laws of theState of California. IN ANY ACTION OR PROCEEDING ARISING HEREFROM, LANDLORD AND TENANT HEREBY CONSENT TO (I) THEJURISDICTION OF ANY COMPETENT COURT WITHIN THE STATE OF CALIFORNIA, (II) SERVICE OF PROCESS BY ANY MEANS AUTHORIZED BYCALIFORNIA LAW, AND (III) IN THE INTEREST OF SAVING TIME AND EXPENSE, TRIAL WITHOUT A JURY IN ANY ACTION, PROCEEDING ORCOUNTERCLAIM BROUGHT BY EITHER OF THE PARTIES HERETO AGAINST THE OTHER OR THEIR SUCCESSORS IN RESPECT OF ANYMATTER ARISING OUT OF OR IN CONNECTION WITH THIS LEASE, THE RELATIONSHIP OF LANDLORD AND TENANT HEREUNDER, TENANT'SUSE OR OCCUPANCY OF THE PREMISES, AND/OR ANY CLAIM FOR INJURY OR DAMAGE, OR ANY EMERGENCY OR STATUTORY REMEDY. INTHE EVENT LANDLORD COMMENCES ANY SUMMARY PROCEEDINGS OR ACTION FOR NONPAYMENT OF BASE RENT OR ADDITIONAL RENT,TENANT SHALL NOT INTERPOSE ANY COUNTERCLAIM OF ANY NATURE OR DESCRIPTION (UNLESS SUCH COUNTERCLAIM SHALL BEMANDATORY) IN ANY SUCH PROCEEDING OR ACTION, BUT SHALL BE RELEGATED TO AN INDEPENDENT ACTION AT LAW.29.23Submission of Lease. Submission of this instrument for examination or signature by Tenant does not constitute a reservation of,option for or option to lease, and it is not effective as a lease or otherwise until execution and delivery by both Landlord and Tenant.29.24Brokers. Landlord and Tenant hereby warrant to each other that they have had no dealings with any real estate broker or agent inconnection with the negotiation of this Lease, excepting only the real estate brokers or agents specified in Section 12 of the Summary (the "Brokers"), andthat they know of no other real estate broker or agent who is entitled to a commission in connection with this Lease. Landlord shall be responsible for payinga commission to the Brokers in connection with this Lease pursuant to a separate agreement. Each party agrees to indemnify and defend the other partyagainst and hold the other party harmless from any and all claims, demands, losses, liabilities, lawsuits, judgments, costs and expenses (including withoutlimitation reasonable attorneys' fees) with respect to any leasing commission or equivalent compensation alleged to be owing on account of any dealingswith any real estate broker or agent, other than the Brokers, occurring by, through, or under the indemnifying party. The terms of this Section 29.24 shallsurvive the expiration or earlier termination of the Lease Term.29.25Independent Covenants. This Lease shall be construed as though the covenants herein between Landlord and Tenant areindependent and not dependent and Tenant hereby expressly waives the benefit of any statute792986.06/WLA186772-00003/2-28-19/gjn/gjn-45- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  to the contrary and agrees that if Landlord fails to perform its obligations set forth herein, Tenant shall not be entitled to make any repairs or perform any actshereunder at Landlord's expense or to any setoff of the Rent or other amounts owing hereunder against Landlord (except to the extent otherwise expresslyprovided in this Lease).29.26Project or Building Name, Address and Signage. Landlord shall have the right at any time to change the name and/or address ofthe Project or Building (and Landlord shall reimburse Tenant its reasonable out-of-pocket costs incurred as a result of such change) and, subject to Article 23above, to install, affix and maintain any and all signs on the exterior and on the interior of the Project or Building as Landlord may, in Landlord's solediscretion, desire. Tenant shall not use the name of the Project or Building or use pictures or illustrations of the Project or Building in advertising or otherpublicity or for any purpose other than as the address of the business to be conducted by Tenant in the Premises, without the prior written consent ofLandlord.29.27Counterparts. This Lease may be executed in counterparts with the same effect as if both parties hereto had executed the samedocument. Both counterparts shall be construed together and shall constitute a single lease.29.28Confidentiality. Landlord acknowledges that while this Lease is in effect, Landlord and its Representatives (as defined below)may have access to proprietary information or material non-public information about Tenant, a publicly traded company. Landlord and its Representativesshall not disclose such proprietary information or material non-public information about Tenant, provided that in no event shall any disclosure as required byApplicable Law, court order or a governmental agency, or to Landlord’s financial, legal, accounting consultants, lenders, assignees, purchasers, partners,members and investors be deemed a breach of the foregoing (provided Landlord shall communicate the confidential nature of such information). As usedherein, “Representatives” means the officers, directors, employees, agents, advisors, subcontractors, and consultants of a party and its affiliate.29.29Development of the Project. 29.29.1Subdivision. Landlord, at its sole cost and expense, reserves the right to subdivide all or a portion of the buildingsand Common Areas. Tenant agrees to execute and deliver, upon demand by Landlord and in the commercially reasonable form requested by Landlord, anyadditional documents needed to conform this Lease to the circumstances resulting from a subdivision and any all maps in connectiontherewith. Notwithstanding anything to the contrary set forth in this Lease, the separate ownership of any buildings and/or Common Areas by an entity otherthan Landlord shall not affect the calculation of Direct Expenses or Tenant's payment of Tenant's Share of Direct Expenses or materially and adverselychange the rights and obligations of Tenant hereunder.29.29.2Construction of Property and Other Improvements. Tenant acknowledges that portions of the Project may beunder construction by Landlord following Tenant's occupancy of the Premises, and that such construction may temporarily for a commercially reasonableperiod of time result in levels of noise, dust, obstruction of access, etc. which are in excess of that present in a fully constructed project. Landlord herebyagrees that Landlord shall perform all construction in a good and workmanlike manner, in accordance with all Applicable Laws, and further agrees to performany such construction in a manner reasonably calculated to minimize interference with Tenant's use of (including without limitation, Tenant’s vivariumoperations) or access to the Premises or the parking facilities serving the Project. Subject to the terms of Section 19.5 of this Lease, Tenant hereby waives anyand all rent offsets or claims of constructive eviction which may arise in connection with such construction performed in accordance with this Section29.29.2. Landlord shall provide not less than ten (10) business days’ prior written notice to Tenant of any construction that may impact Tenant’s use of oraccess to the Premises the parking facilities and accommodate reasonable requests of Tenant with respect to the same to delay the scheduling of or tominimize the impact of such construction on Tenant’s business operations at the Premises.. 29.30No Violation. Tenant hereby warrants and represents that neither its execution of nor performance under this Lease shall causeTenant to be in violation of any agreement, instrument, contract, law, rule or regulation by which Tenant is bound, and Tenant shall protect, defend,indemnify and hold Landlord harmless against any claims, demands, losses, damages, liabilities, costs and expenses, including, without limitation,reasonable attorneys' fees and costs, arising from Tenant's breach of this warranty and representation.792986.06/WLA186772-00003/2-28-19/gjn/gjn-46- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  29.31Transportation Management. Tenant shall fully comply with all present or future governmentally mandated programs intendedto manage parking, transportation or traffic in and around the Project and/or the Building, and in connection therewith, Tenant shall use commerciallyreasonable efforts to take responsible action for the transportation planning and management of all employees located at the Premises by working directlywith Landlord, any governmental transportation management organization or any other transportation-related committees or entities. Such programs mayinclude, without limitation: (i) restrictions on the number of peak-hour vehicle trips generated by Tenant; (ii) increased vehicle occupancy; (iii)implementation of an in-house ridesharing program and an employee transportation coordinator; (iv) working with employees and any Project, Building orarea-wide ridesharing program manager; (v) instituting employer-sponsored incentives (financial or in-kind) to encourage employees to rideshare; and (vi)utilizing flexible work shifts for employees.792986.06/WLA186772-00003/2-28-19/gjn/gjn-47- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  IN WITNESS WHEREOF, Landlord and Tenant have caused this Lease to be executed the day and date first above written. LANDLORD: BAYSIDE AREA DEVELOPMENT, LLC,a Delaware limited liability companyBy: Print NameIts: TENANT: UNITY BIOTECHNOLOGY, INC.,a Delaware corporationBy: Print NameIts: 792986.06/WLA186772-00003/2-28-19/gjn/gjn-48- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  EXHIBIT A285 EAST GRAND AVENUEOUTLINE OF PREMISES792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT A-1- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT A-2- Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  EXHIBIT A-1285 EAST GRAND AVENUEPROJECT SITE PLAN 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT A-1-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]  EXHIBIT B285 EAST GRAND AVENUETENANT WORK LETTER1.Defined Terms. As used in this Tenant Work Letter, the following capitalized terms have the following meanings:(a)Approved TI Plans: Plans and specifications prepared by the applicable Architect for the Tenant Improvements and approved byLandlord and Tenant in accordance with Paragraph 2 of this Tenant Work Letter, subject to further modification from time to time to the extentprovided in and in accordance with such Paragraph 2.(b)Architect: CAC Architects.(c)Tenant Change Request: See definition in Paragraph 2(c)(ii) hereof.(d)Final TI Working Drawings: See definition in Paragraph 2(a) hereof.(e)General Contractor: Landmark Builders. Tenant shall have no right to direct or control such General Contractor.(f)Landlord's TI Work: Any Tenant Improvements which Landlord is to construct or install pursuant to this Tenant Work Letter.(g)Project Manager. Project Management Advisors, Inc., or any other project manager designated by Landlord in itsreasonable discretion from time to time to act in a supervisory, oversight, project management or other similar capacity on behalf of Landlord inconnection with the design and/or construction of the Tenant Improvements and the oversight of the General Contractor.(h)Punch List Work: Minor corrections of construction or decoration details, and minor mechanical adjustments, that are required inorder to cause any applicable portion of the Tenant Improvements as constructed to conform to the Approved Plans in all material respects andthat do not materially interfere with Tenant's use or occupancy of the Building and the Premises.(i)Substantial Completion Certificate: See definition in Paragraph 3(a) hereof.(j)Tenant Delay: Any of the following types of delay in the completion of construction of Landlord's TI Work (but in each instance,only to the extent that any of the following has actually and proximately caused substantial completion of Landlord's TI Work to be delayed)beyond December 4, 2019:(i)Any delay resulting from Tenant's failure to furnish, in a timely manner, information reasonably requested by Landlord or byLandlord's Project Manager in connection with the design or construction of Landlord's TI Work, or from Tenant's failure to approve in a timelymanner any matters requiring approval by Tenant;(ii)Any delay resulting from Tenant Change Requests initiated by Tenant, including any delay resulting from the need to revise anydrawings or obtain further governmental approvals as a result of any such Tenant Change Request; or(iii)Any delay caused by Tenant (or Tenant's contractors, agents or employees) materially interfering with the performance of Landlord'sTI Work, provided that Landlord shall have given Tenant prompt notice of such material interference.792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT B-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  Landlord shall promptly notify Tenant in writing of any potential Tenant Delay and Tenant shall have two (2) business days after receipt ofLandlord’s notice to cure the same before it constitutes Tenant Delay. In addition, Landlord shall use commercially reasonable efforts to mitigate anypotential Tenant Delay.(k)Tenant Improvements: The improvements to or within the Building shown on the Approved Plans from time to time and to beconstructed by Landlord pursuant to the Lease and this Tenant Work Letter. The term "Tenant Improvements" does not include the improvementsexisting in the Building and Premises at the date of execution of the Lease.(l)Unavoidable Delays: Delays due to acts of God, acts of public agencies, labor disputes, strikes, fires, freight embargoes, inability(despite the exercise of due diligence) to obtain supplies, materials, fuels or permits, or other causes or contingencies (excluding financialinability) beyond the reasonable control of Landlord or Tenant, as applicable.(m)Capitalized terms not otherwise defined in this Tenant Work Letter shall have the definitions set forth in the Lease.2.Plans and Construction. Landlord and Tenant shall comply with the procedures set forth in this Paragraph 2 in preparing, deliveringand approving matters relating to the Tenant Improvements.(a)Approved Plans and Working Drawings for Tenant Improvements. Prior to the date of the Lease, Landlord and Tenant mutuallyapproved schematic plans and outline specifications for the Tenant Improvements prepared by the Architect (the “Approved Schematic Plans”),which Approved Schematic Plans are attached hereto as Schedule 2. Following the execution of this Lease, Tenant shall cause to be prepared,promptly and with reasonable diligence (assuming timely delivery by Landlord of any information and decisions required to be furnished ormade by Landlord in order to permit preparation of final working drawings, all of which information and decisions Landlord will deliverpromptly and with reasonable diligence), and delivered to Landlord for approval (which approval shall not be unreasonably withheld,conditioned or delayed by Landlord) final detailed working drawings and specifications for the Tenant Improvements, including (withoutlimitation) any applicable life safety, mechanical, electrical and plumbing working drawings and final architectural drawings (collectively,“Final TI Working Drawings”), which Final TI Working Drawings shall substantially conform to the Approved Schematic Plans. Upon receiptfrom Tenant of proposed Final TI Working Drawings, any other plans and specifications, or any revisions or resubmittals of any of the foregoing,as applicable, Landlord shall promptly and diligently (and in all events within 10 days after receipt in the case of an initial submittal of proposedFinal TI Working Drawings, and within 7 days after receipt in the case of any other plans and specifications or any revisions or resubmittals ofany of the foregoing) either approve such proposed Final TI Working Drawings or other plans and specifications, as applicable, or set forth inwriting with particularity any changes necessary to bring the aspects of such proposed Final TI Working Drawings or other plans andspecifications into a form which will be reasonably acceptable to Landlord. If Landlord fails to respond within such ten (10) day or seven (7) dayperiod, as applicable, then Tenant may send Landlord a reminder notice via email to Scott Bohn and Natalia De Michele setting forth such failure containing the following sentence at the top of such notice in bold, capitalized font at leasttwelve (12) points in size: "LANDLORD'S FAILURE TO RESPOND TO THIS NOTICE WITHIN TWO (2) BUSINESS DAYS SHALL RESULT INLANDLORD'S DEEMED APPROVAL OF TENANT'S FINAL TI WORKING DRAWINGS" (the "Tenant Improvements Reminder Notice"). Anysuch Tenant Improvements Reminder Notice shall include a complete copy of the Final TI Working Drawings. If Landlord fails to respond withintwo (2) business days after receipt of a Tenant Improvements Reminder Notice, then Tenant’s Final TI Working Drawings for which Tenantrequested Landlord's approval shall be deemed approved by Landlord. Upon approval of the Final TI Working Drawings by Landlord andTenant, the Final TI Working Drawings shall constitute the “Approved TI Plans,” superseding (to the extent of any inconsistencies) anyinconsistent features of the previously existing Approved Schematic Plans.(b)Cost of Improvements. “Cost of Improvement” shall mean, with respect to any item or component for which a cost must bedetermined in order to allocate such cost, or an increase in such cost, to Tenant pursuant to this Tenant Work Letter, the sum of the following(unless otherwise agreed in writing by Landlord and Tenant with respect to any specific item or component or any category of items orcomponents): (i) all sums paid to contractors or subcontractors for labor and materials furnished in connection with construction of such item or792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT B-2-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  component; (ii) all costs, expenses, payments, fees and charges (other than penalties) paid to or at the direction of any city, county orother governmental or quasi-governmental authority or agency which are required to be paid in order to obtain all necessary governmentalpermits, licenses, inspections and approvals relating to construction of such item or component; (iii) engineering and architectural fees forservices rendered in connection with the design and construction of such item or component (including, but not limited to, the TI Architect forsuch item or component and an electrical engineer, mechanical engineer and civil engineer, if applicable); (iv) sales and use taxes; (v) testing andinspection costs; (vi) the cost of power, water and other utility facilities and the cost of collection and removal of debris required in connectionwith construction of such item or component; (vii) costs for builder’s risk insurance; and (viii) all other “hard” and “soft” costs incurred in theconstruction of such item or component in accordance with the Approved TI Plans (if applicable) and this Tenant Work Letter; provided that theCost of Improvements shall not include any internal or third-party costs incurred by Landlord. Further, the Cost of Improvements shall notinclude any costs incurred by Landlord to bring the Base Building or Common Areas into compliance with Applicable Laws as of the LeaseCommencement Date (including without limitation, with respect to any alterations or improvements to the same that are triggered by the TenantImprovements) or satisfy Landlord’s warranty and delivery obligations under Section 1.1.1 and Section 5.3.1.4 of the Lease.(c)Construction of Landlord's TI Work. Following completion of the Approved TI Plans, Landlord shall apply for and use reasonableefforts to obtain the necessary permits and approvals to allow construction of all Tenant Improvements. Upon receipt of such permits andapprovals, Landlord shall, at Tenant's expense (subject to Landlord's payment of the Tenant Improvement Allowance), construct and completethe Tenant Improvements substantially in accordance with the Approved TI Plans, subject to Unavoidable Delays and Tenant Delays (if any).Such construction shall be performed in a neat, good and workmanlike manner and shall comply with and conform to all Applicable Laws andUnderlying Documents applicable thereto in force at the time such work is completed. Landlord shall cause Landmark Builders to bid on generalconditions and fee for construction of the Tenant Improvements and provide an estimate for the direct cost of the Tenant Improvements. Tenantshall also have the right to approve all subcontractors engaged by the General Contractor, which subcontractors shall be competitively bid andwhich approval shall not be unreasonably withheld, conditioned or delayed. (d)Changes.(i)If Landlord determines at any time that changes in the Final TI Working Drawings or in any other aspect of the Approved TI Plansrelating to any item of Landlord's TI Work are required as a result of Applicable Laws, or are required at the insistence of the applicablegovernmental authority whose approval is required with respect to Landlord’s TI Work, or are required as a result of unanticipated conditionsencountered in the course of construction, then Landlord shall promptly (A) advise Tenant of such circumstances and (B) at Tenant's sole costand expense, subject to Landlord's payment of the Tenant Improvement Allowance (subject to Landlord’s responsibilities under Section 2(b)above), cause revised Final TI Working Drawings to be prepared by the Architect and submitted to Tenant, for Tenant's information.(ii)If Tenant at any time desires any changes, alterations or additions to the Final TI Working Drawings, Tenant shall submit a detailedwritten request to Landlord specifying such changes, alterations or additions (a "Tenant Change Request"). Upon receipt of any such request,Landlord shall within five (5) business days thereafter notify Tenant of (A) whether the matters proposed in the Tenant Change Request areapproved by Landlord (which approval shall not be unreasonably withheld, conditioned or delayed by Landlord), (B) Landlord's estimate of thenumber of days of delay, if any, which shall be caused in the construction of the Tenant Improvements by such Tenant Change Request ifimplemented (including, without limitation, delays due to the need to obtain any revised plans or drawings and any governmental approvals),and (C) Landlord's estimate of the increase, if any, which shall occur in the cost of construction of the Tenant Improvements affected by suchTenant Change Request if such Tenant Change Request is implemented (including, but not limited to, any costs of compliance with laws orgovernmental regulations that become applicable because of the implementation of the Tenant Change Request). If Landlord approves theTenant Change Request and Tenant notifies Landlord in writing, within three (3) business days after receipt of such notice from Landlord, ofTenant's approval of the Tenant Change Request (including the estimated delays and cost increases, if any, described in Landlord's notice), thenLandlord shall cause such Tenant Change Request to be implemented and Tenant shall be responsible for all actual costs or cost increasesresulting from or attributable to the implementation of the Tenant Change Request, and any delays resulting therefrom which shall causeconstruction of Landlord’s TI Work to be delayed beyond December 4, 2019 shall be deemed to be a Tenant Delay (subject to Landlord'spayment792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT B-3-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  of the Tenant Improvement Allowance). If Tenant fails to notify Landlord in writing of Tenant's approval of such Tenant ChangeRequest within said three (3) business day period, then such Tenant Change Request shall be deemed to be withdrawn and shall be of no furthereffect.(d)Project Management. Unless and until revoked by Landlord by written notice delivered to Tenant, Landlord hereby (i) delegates toProject Manager the authority to exercise all approval rights, supervisory rights and other rights or powers of Landlord under this Tenant WorkLetter with respect to the design and construction of the Tenant Improvements, and (ii) requests that Tenant work with Project Manager withrespect to any logistical or other coordination matters arising in the course of construction of the Tenant Improvements, including monitoringTenant's and Landlord’s compliance with its obligations under this Tenant Work Letter and under the Lease with respect to the design andconstruction of the Tenant Improvements. Tenant acknowledges the foregoing delegation and request, and agrees to cooperate reasonably withProject Manager as Landlord's representative pursuant to such delegation and request. Fees and charges of Project Manager for such servicesshall be at Tenant's sole expense, subject to Landlord's payment of the Tenant Improvement Allowance. Such fees shall equal the sum of (X) theproduct of (A) 2.65% and (B) the amount of the Tenant Improvement Allowance and Additional TI Allowance which Tenant elects to utilize, and(Y) the product of (C) 2.0% and (D) the amount of Tenant Funds Amount which Tenant elects to utilize.3.Completion.(a)When Landlord receives written certification from Architect that construction of the Tenant Improvements in the Building has beencompleted in accordance with the Approved TI Plans (except for Punch List Work), Landlord shall prepare and deliver to Tenant a certificatesigned by both Landlord and Architect (the "Substantial Completion Certificate") (i) certifying that the construction of the TenantImprovements has been substantially completed in a good and workmanlike manner in accordance with the Approved TI Plans in all materialrespects, subject only to completion of Punch List Work, and specifying the date of that completion, and (ii) certifying that the TenantImprovements comply in all material respects with all laws, rules, regulations, codes, ordinances, requirements, covenants, conditions andrestrictions applicable thereto at the time of such delivery. Upon receipt by Tenant of the Substantial Completion Certificate and tender ofpossession of the Premises by Landlord to Tenant, and receipt of any certificate of occupancy or its legal equivalent, or other required sign-offsfrom any applicable governmental authority, allowing the legal occupancy of the Premises, the Tenant Improvements will be deemed deliveredto Tenant and "Ready for Occupancy" for all purposes of the Lease (subject to Landlord's continuing obligations with respect to any Punch ListWork, and to any other express obligations of Landlord under the Lease or this Tenant Work Letter with respect to such Tenant Improvements).(b)Promptly following delivery of the Substantial Completion Certificate for the Tenant Improvements in the Building, Project Manageror other representatives of Landlord shall conduct one or more "walkthroughs" of the Building with Tenant and Tenant's representatives, toidentify any items of Punch List Work that may require correction and to prepare a joint punch list reflecting any such items, following whichLandlord shall diligently complete the Punch List Work reflected in such joint punch list. At any time within thirty (30) days after delivery ofsuch Substantial Completion Certificate, Tenant shall be entitled to submit one or more lists to Landlord supplementing such joint punch list byspecifying any additional items of Punch List Work to be performed on the applicable Tenant Improvements, and upon receipt of such list(s),Landlord shall diligently complete such additional Punch List Work. Promptly after Landlord provides Tenant with the Substantial CompletionCertificate and completes all applicable Punch List Work for the Building, Landlord shall cause the recordation of a Notice of Completion (asdefined in the California Civil Code) with respect to the Tenant Improvements.(c)The General Contractor shall furnish at a minimum an industry standard one (1) year warranty covering all Tenant Improvements. Allconstruction, product and equipment warranties and guaranties obtained by Landlord with respect to the Tenant Improvements shall, to theextent reasonably obtainable, include a provision that such warranties and guaranties shall also run to the benefit of Tenant, and Landlord shallcooperate with Tenant in a commercially reasonable manner to assist in enforcing all such warranties and guaranties for the benefit of Tenant.Landlord shall cause Tenant to be named as an additional insured on the general liability insurance and Landlord shall cause the GeneralContractor to maintain worker’s compensation insurance pursuant to applicable state and local statutes and regulations.792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT B-4-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  (d)Notwithstanding any other provisions of this Tenant Work Letter or of the Lease, if Landlord is delayed in substantially completingany of the Tenant Improvements as a result of any Tenant Delay, then the Premises shall be deemed to have been Ready for Occupancy on thedate the Premises would have been Ready for Occupancy absent such Tenant Delay.4.Payment of Costs. (a)Tenant Improvement Allowance. Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letteror in the Lease or as otherwise expressly provided by mutual written agreement of Landlord and Tenant, the cost of construction of the TenantImprovements shall be paid or reimbursed by Landlord up to a maximum amount equal to $125.00 per rentable square foot of the Premises (i.e.,$7,831,875.00 based upon 62,655 rentable square feet in the Premises) (the "Tenant Improvement Allowance"), which amount is being madeavailable by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Premises, less anyreduction in or charge against such amount pursuant to any applicable provisions of this Tenant Work Letter. Tenant shall be responsible, at itssole cost and expense, for payment of the entire Cost of Improvements of the Tenant Improvements in excess of the Tenant ImprovementAllowance (such excess amount is referred to herein as the "Tenant Funds Amount", including (but not limited to) any costs or cost increasesincurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord),and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixturesand personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly setforth below in this paragraph, but Tenant shall be entitled to use or apply the entire Tenant Improvement Allowance toward the Cost ofImprovements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or charges set forth in theLease or in this Tenant Work Letter) prior to being required to expend any of Tenant’s own funds for the Tenant Improvements. The funding ofthe Tenant Improvement Allowance shall be made on a monthly basis or at other convenient intervals mutually approved by Landlord andTenant and in all other respects shall be based on such commercially reasonable disbursement conditions and procedures as Landlord, ProjectManager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no circumstances shall theTenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for anyCost of Improvement (or any other cost or expense) associated with any moveable furniture or trade fixtures, personal property or any other itemor element which, under the applicable provisions of the Lease, will not become Landlord’s property and remain with the Building uponexpiration or termination of the Lease. (b)Additional TI Allowance. In addition to the Tenant Improvement Allowance, Tenant shall have the right, by written notice toLandlord given on or before the Lease Commencement Date, to use up to $45.00 per rentable square foot of the Premises (i.e., up to$2,819,475.00) (the "Additional TI Allowance") towards the payment of the costs of the Tenant Improvement Allowance Items. In the eventTenant exercises its right to use all or any portion of the Additional TI Allowance, Tenant shall be required to pay Landlord, commencing on theLease Commencement Date (the "Additional Payment Commencement Date"), the "Additional TI Allowance Payment," as that term is definedbelow, in consideration of Landlord provision of the Additional TI Allowance. The "Additional TI Allowance Payment" shall be determined asthe missing component of an annuity, which annuity shall have (i) the amount of the Additional TI Allowance utilized by Tenant as the presentvalue amount, (ii) a number equal to the number of full calendar months then remaining in the Lease Term as the number of payments, (iii) amonthly interest factor equal to 0.75%, which is equal to nine percent (9%) divided by twelve (12) months per year, and (iv) the Additional TIAllowance Payment as the missing component of the annuity. Following the calculation of the Additional TI Allowance Payment, Landlord andTenant will enter into a lease amendment to confirm the amount thereof. Any portion of the Additional TI Allowance which has not beenclaimed or drawn by Tenant prior to December 31, 2020, shall expire and shall no longer be available to Tenant thereafter. (c)Tenant Funds. For additional funds required to complete the cost of the work, that are in excess of, or elected by Tenant to be used inplace of the Tenant Improvement Allowance, and the Additional TI Allowance, these shall be considered "Tenant Funds." The total cost toconstruct the Tenant Improvements as managed by Landlord and the Project Manager under this Work Letter shall be the "ProjectBudget." Landlord understands that at the time of the agreed upon Guaranteed Maximum Price (GMP), the Tenant Funds amount is an estimateand exact costs will not be known until project closeout. Tenant is required, at the time of agreement of the GMP, to provide a792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT B-5-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  purchase order to Landlord for the full estimated amount of the Tenant Funds, provided that Tenant shall not be required to makepayment, if any, until the close out of the project and a true up of costs are provided to Tenant. In the event the Tenant Funds at project closeoutare less than the amount agreed upon within the Project Budget, Landlord will only bill Tenant for the Tenant Funds that have been utilized. Inthe event the Tenant Funds exceed the amount agreed upon within the Project Budget, through added scope changes requested by Tenant, theTenant shall provide additional purchase orders to Landlord, which will be included in the Tenant Change Request process that the Landlord’srepresentative administers.5.No Agency. Nothing contained in this Tenant Work Letter shall make or constitute Tenant as the agent of Landlord.6.Miscellaneous. All references in this Tenant Work Letter to a number of days shall be construed to refer to calendar days, unlessotherwise specified herein. In all instances where Landlord's or Tenant's approval is required, if no written notice of disapproval is given withinthe applicable time period, at the end of that period Landlord or Tenant shall be deemed to have given approval (unless the provision requiringLandlord's or Tenant's approval expressly states that non-response is deemed to be a disapproval or withdrawal of the pending action or request,in which event such express statement shall be controlling over the general statement set forth in this sentence) and the next succeeding timeperiod shall commence. If any item requiring approval is disapproved by Landlord or Tenant (as applicable) in a timely manner, the procedure forpreparation of that item and approval shall be repeated.7.Removal of Tenant Improvements. Landlord hereby acknowledges that the Tenant Improvements constructed pursuant to the termsof this Tenant Work Letter shall not be subject to removal upon the expiration or earlier termination of this Lease.8.Time Deadlines. Each of Landlord and Tenant shall use commercially reasonable, good faith, efforts and all due diligence tocooperate with the Architect, General Contractor and the other to complete all phases of the construction drawings set forth in this Tenant WorkLetter and the permitting process and to receive the permits as soon as possible after the execution of the Lease. The applicable anticipated datesfor approval of items, plans and drawings, submittal for issuance of permits, and completion of the Tenant Improvements as described in thisTenant Work Letter are set forth and further elaborated upon in Schedule 1 to this Exhibit B attached hereto (the "Time Deadlines"), attachedhereto. Each of Landlord and Tenant agrees to utilize commercially reasonable efforts to comply with the Time Deadlines. 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT B-6-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  SCHEDULE 1TIME DEADLINES 792986.06/WLA186772-00003/2-28-19/gjn/gjnSCHEDULE 1-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  SCHEDULE 2APPROVED SCHEMATIC PLANS 792986.06/WLA186772-00003/2-28-19/gjn/gjnSCHEDULE 2-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  792986.06/WLA186772-00003/2-28-19/gjn/gjnSCHEDULE 2-2-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  EXHIBIT C285 EAST GRAND AVENUENOTICE OF LEASE TERM DATESTo:____________________________________________________________________________________________ Re:Lease dated ____________, 20__ between ____________________, a _____________________ ("Landlord"), and_______________________, a _______________________ ("Tenant") concerning Suite ______ on floor(s) __________ of thebuilding located at ___________________________, California.Gentlemen:In accordance with the Lease (the "Lease"), we wish to advise you and/or confirm as follows: 1.The Lease Term shall commence on or has commenced on _____________ for a term of _______________ ending on_______________. 2.Rent commenced to accrue on ____________. 3.If the Lease Commencement Date is other than the first day of the month, the first billing will contain a pro rata adjustment. Eachbilling thereafter, with the exception of the final billing, shall be for the full amount of the monthly installment as provided for in theLease. 4.Your rent checks should be made payable to __________ at ______________. "Landlord": , a By: Its: Agreed to and Accepted asof , 200 . "Tenant": a By: Its: 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT C-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  EXHIBIT D285 EAST GRAND AVENUEFORM OF TENANT'S ESTOPPEL CERTIFICATEThe undersigned as Tenant under that certain Lease (the "Lease") made and entered into as of ___________, 20___ by and between_______________ as Landlord, and the undersigned as Tenant, for Premises consisting of the entire office building located at______________________________, California, certifies as follows as of the date hereof:1.Attached hereto as Exhibit A is a true and correct copy of the Lease and all amendments and modifications thereto. The documentscontained in Exhibit A represent the entire agreement between the parties as to the Premises.2.The undersigned currently occupies the Premises described in the Lease, the Lease Term commenced on __________, and the LeaseTerm expires on ___________, and the undersigned has no option to terminate or cancel the Lease or to purchase all or any part of the Premises,the Building and/or the Project.3.Base Rent became payable on ____________.4.The Lease is in full force and effect and has not been modified, supplemented or amended in any way except as provided in Exhibit A.5.Tenant has not transferred, assigned, or sublet any portion of the Premises nor entered into any license or concession agreements withrespect thereto which are in effect as of the date hereof except as follows:6.All monthly installments of Base Rent, all Additional Rent and all monthly installments of estimated Additional Rent have been paidwhen due through ___________. The current monthly installment of Base Rent is $_____________________.7.To the undersigned's knowledge, Landlord is not in default thereunder. In addition, the undersigned has not delivered any notice toLandlord regarding a default by Landlord thereunder. The Lease does not require Landlord to provide any rental concessions or to pay anyleasing brokerage commissions except as expressly set forth therein. 8.No rental has been paid more than thirty (30) days in advance and no security has been deposited with Landlord except as provided inthe Lease. 9.As of the date hereof, to the undersigned’s knowledge there are no existing defenses or offsets, or, to the undersigned's knowledge,claims or any basis for a claim, that Tenant has against Landlord.10.If Tenant is a corporation or partnership, each individual executing this Estoppel Certificate on behalf of Tenant hereby represents andwarrants that Tenant is a duly formed and existing entity qualified to do business in California and that Tenant has full right and authority toexecute and deliver this Estoppel Certificate and that each person signing on behalf of Tenant is authorized to do so.11.To the undersigned’s knowledge, there are no actions pending against the undersigned under the bankruptcy or similar laws of theUnited States or any state.12.Tenant has not received written notice of its non-compliance or violation of Applicable Laws with respect to its use of the Premises,including, but not limited to, Applicable Laws relating to Hazardous Materials, which remains uncured. 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT D-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  13.To the undersigned's knowledge, all tenant improvement work to be performed by Landlord under the Lease as of the date hereof hasbeen completed in accordance with the Lease and has been accepted by the undersigned and all reimbursements and allowances due to theundersigned under the Lease as of the date hereof in connection with any tenant improvement work have been paid in full. The undersigned acknowledges that this Estoppel Certificate may be delivered to Landlord or to a prospective mortgagee or prospectivepurchaser, and acknowledges that said prospective mortgagee or prospective purchaser will be relying upon the statements contained herein in making theloan or acquiring the property of which the Premises are a part and that receipt by it of this certificate is a condition of making such loan or acquiring suchproperty.Executed at on the day of , 200_. "Tenant": , a By: Its: By: Its: 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT D-2-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  EXHIBIT E285 EAST GRAND AVENUEENVIRONMENTAL QUESTIONNAIREENVIRONMENTAL QUESTIONNAIREFOR COMMERCIAL AND INDUSTRIAL PROPERTIES Tenant Name: Lease Address: Lease Type (check correct box – right click to properties): ☐ Primary Lease/Lessee ☐ Sublease from: Instructions: The following questionnaire is to be completed by the Lessee representative with knowledge of the planned operations for the specifiedbuilding/location. Please print clearly and attach additional sheets as necessary. 1.0PROCESS INFORMATIONDescribe planned site use, including a brief description of manufacturing processes and/or pilot plants planned for this site, if any. 2.0HAZARDOUS MATERIALS – OTHER THAN WASTE Will (or are) non-waste hazardous materials be/being used or stored at this site? If so, continue with the next question. If not, go to Section 3.0. 2.1Are any of the following materials handled on the Property? ☐ Yes ☐ No[A material is handled if it is used, generated, processed, produced, packaged, treated, stored, emitted, discharged, or disposed.] If YES,check (right click to properties) the applicable correct Fire Code hazard categories below.☐Combustible dusts/fibers☐Explosives☐Flammable liquids☐Combustible liquids (e.g., oils)☐Compressed gas - inert☐Flammable solids/pyrophorics☐Cryogenic liquids - inert☐Compressed gas -flammable/pyrophoric☐Organic peroxides☐Cryogenic liquids - flammable☐Compressed gas - oxidizing☐Oxidizers - solid or liquid☐Cryogenic liquids - oxidizing☐Compressed gas - toxic☐Reactives - unstable or waterreactive☐Corrosives - solid or liquid☐Compressed gas - corrosive☐Toxics - solid or liquid 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT E-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  2-2.For all materials checked in Section 2.1 above, please list the specific material(s), use(s), and quantities of each used or stored on the site inthe table below; or attach a separate inventory. NOTE: If proprietary, the constituents need not be named but the hazard information andvolumes are required.Material/ChemicalPhysical State (Solid,Liquid, or Gas)Container SizeNumber of ContainersUsed & StoredTotal QuantityUnits (pounds forsolids, gallons orliters for liquids,& cubic feet forgases) 2-3.Describe the planned storage area location(s) for the materials in Section 2-2 above. Include site maps and drawings as appropriate. 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT E-2-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  2-4.Other hazardous materials. Check below (right click to properties) if applicable. NOTE: If either of the latter two are checked (BSL-3and/or radioisotope/radiation), be advised that not all lease locations/cities or lease agreements allow these hazards; and if either ofthese hazards are planned, additional information will be required with copies of oversight agency authorizations/licenses as theybecome available.☐Risk Group 2/Biosafety Level-2Biohazards☐Risk Group 3/Biosafety Level-3Biohazards☐Radioisotopes/Radiation3.0HAZARDOUS WASTE (i.e., REGULATED CHEMICAL WASTE)Are (or will) hazardous wastes (be) generated? ☐ Yes ☐ NoIf YES, continue with the next question. If not, skip this section and go to section 4.0. 3.1Are or will any of the following hazardous (CHEMICAL) wastes generated, handled, or disposed of (where applicable and allowed) on theproperty? ☐Liquids☐Process sludges☐PCBs☐Solids☐Metals☐wastewater 3-2.List and estimate the quantities of hazardous waste identified in Question 3-1 above.HAZRDOUS (CHEMICAL)WASTE GENERATEDSOURCEWASTE TYPEAPPROX.MONTHLYQUANTITYwith unitsDISPOSITION [e.g., off-sitelandfill, incineration, fuelblending scrap metal;wastewater neutralization(onsite or off-site)]RCRA listed(federal)Non-RCRA(Calif-orniaONLY orrecycle) ☐☐ ☐☐ ☐☐ ☐☐ ☐☐ 3-3.Waste characterization by: Process knowledge ☐ EPA lab analysis ☐ Both ☐ 3-4.Please include name, location, and permit number (e.g. EPA ID No.) for transporter and disposal facility if applicable. Attach separatepages as necessary. If not yet known, write “TBD.” Hazardous Waste Transporter/DisposalFacility NameFacility LocationTransporter (T) orDisposal (D) FacilityPermit Number 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT E-3-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  3-5.Are pollution controls or monitoring employed in the process to prevent or minimize the release of wastes into the environment? NOTE:This does NOT mean fume hoods; examples include air scrubbers, cyclones, carbon or HEPA filters at building exhaust fans,sedimentation tanks, pH neutralization systems for wastewater, etc.☐ Yes ☐ NoIf YES, please list/describe: 4.0OTHER REGULATED WASTE (i.e., REGULATED BIOLOGICAL WASTE, referred to as “Medical Waste” in California) 4-1.Will (or do) you generate medical waste? ☐ Yes ☐ No If NO, skip to Section 5.0. 4-2.Check the types of waste that will be generated, all of which fall under the California Medical Waste Act:☐Contaminated sharps (i.e., ifcontaminated with ≥ Risk Group2 materials)☐Animal carcasses☐Pathology waste known or suspectedto be contaminated with ≥ RiskGroup 2 pathogens)☐Red bag biohazardous waste (i.e.,with ≥ Risk Group 2 materials)for autoclaving☐Human or non-human primateblood, tissues, etc.(e.g., clinical specimens)☐Trace Chemotherapeutic Wasteand/or Pharmaceutical waste NOTotherwise regulated as RCRAchemical waste 4-3.What vendor will be used for off-site autoclaving and/or incineration? 4-5.Do you have a Medical Waste Permit for this site? ☐ Yes ☐ No, not required. ☐ No, but an application will be submitted.5.0UNDERGROUND STORAGE TANKS (USTS) & ABOVEGROUND STORAGE TANKS (ASTS) 5-1.Are underground storage tanks (USTs), aboveground storage tanks (ASTs), or associated pipelines used for the storage of petroleumproducts, chemicals, or liquid wastes present on site (lease renewals) or required for planned operations (new tenants)? ☐ Yes ☐ No NOTE: If you will have your own diesel emergency power generator, then you will have at least one AST! [NOTE: If a backup generatorservices multiple tenants, then the landlord usually handles the permits.]If NO, skip to section 6.0. If YES, please describe capacity, contents, age, type of the USTs or ASTs, as well any associated leakdetection/spill prevention measures. Please attach additional pages if necessary. UST orASTCapacity(gallons)ContentsYearInstalledType (Steel, Fiberglass, etc.)Associated Leak Detection /Spill Prevention Measures* *NOTE: The following are examples of leak detection / spill prevention measures: integrity testing, inventory reconciliation, leakdetection system, overfill spill protection, secondary containment, cathodic protection.792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT E-4-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  5-2.Please provide copies of written tank integrity test results and/or monitoring documentation, if available. 5-3.Is the UST/AST registered and permitted with the appropriate regulatory agencies? ☐ Yes ☐ No, not yet If YES, please attach a copy of the required permit(s). See Section 7-1 for the oversight agencies that issue permits, with the exception ofthose for diesel emergency power generators which are permitted by the local Air Quality District (Bay Area Air Quality ManagementDistrict = BAAQMD; or San Diego Air Pollution Control District = San Diego APCD). 5-4.If this Questionnaire is being completed for a lease renewal, and if any of the USTs/ASTs have leaked, please state the substance released,the media(s) impacted (e.g., soil, water, asphalt, etc.), the actions taken, and all remedial responses to the incident. 5-5.If this Questionnaire is being completed for a lease renewal, have USTs/ASTs been removed from the Property?☐ Yes ☐ NoIf YES, please provide any official closure letters or reports and supporting documentation (e.g., analytical test results, remediation reportresults, etc.). 5-6.For Lease renewals, are there any above or below ground pipelines on site used to transfer chemicals or wastes?☐ Yes ☐ NoFor new tenants, are installations of this type required for the planned operations? ☐ Yes ☐ NoIf YES to either question in this section 5-6, please describe. 6.0ASBESTOS CONTAINING BUILDING MATERIALSPlease be advised that an asbestos survey may have been performed at the Property. If provided, please review the information that identifies thelocations of known asbestos containing material or presumed asbestos containing material. All personnel and appropriate subcontractors should benotified of the presence of these materials, and informed not to disturb these materials. Any activity that involves the disturbance or removal of thesematerials must be done by an appropriately trained individual/contractor. 7.0OTHER REGULATORY PERMITS/REQUIREMENTS 7-1.Does the operation have or require an industrial wastewater permit to discharge into the local National Pollutant Discharge EliminationSystem (NPDES)? [Example: This applies when wastewater from equipment cleaning is routed through a pH neutralization system prior todischarge into the sanitary or lab sewer for certain pharmaceutical manufacturing wastewater; etc.] Permits are obtained from theregional sanitation district that is treating wastewater.☐ Yes ☐ No ☐ No, but one will be prepared and submitted to the Landlord property management company.If so, please attach a copy of this permit or provide it later when it has been prepared. 7-2.Has a Hazardous Materials Business Plan (HMBP) been developed for the site and submitted via the State of California ElectronicReporting System (CERS)? [NOTE: The trigger limits for having to do this are ≥ 200 cubic feet if any one type of compressed gas(exceptfor carbon dioxide and inert simple asphyxiant gases, which have a higher trigger limit of ≥ 1,000 cubic feet); ≥ 55 gallons if any onetype792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT E-5-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  of hazardous chemical liquid; and ≥500 pounds of any one type of hazardous chemical solid. So a full-sixe gas cylinder and a 260-liter ofliquid nitrogen are triggers! Don’t forget the diesel fuel in a backup emergency generator if the diesel tank size is ≥ 55 gallons and it ispermitted under the tenant (rather than under the landlord).] NOTE: Each local Certified Unified Program Agency (CUPA) in Californiagoverns the HMBP process so start there. Examples: the CUPA for cities in San Mateo County is the County Environmental HealthDepartment; the CUPA for the City of Hayward, CA is the Hayward Fire Department; the CUPA for Mountain View is the Mountain ViewFire Department; and, the CUPA for San Diego is the County of San Diego Hazardous Materials Division (HMD),☐ Yes ☐ No, not required. ☐ No, but one will be prepared and submitted, and a copy will be provided to the landlord propertymanagement company.If one has been completed, please attach a copy. Continue to provide updated versions as they are completed. This is a legal requirementin that State law requires that the owner/operator of a business located on leased or rented real property shall notify, in writing, the owner ofthe property that the business is subject to and is in compliance with the Hazardous Materials Business Plan requirements (Health andSafety Code Chapter 6.95 Section 25505.1). 7-3.NOTE: Please be advised that if you are involved in any tenant improvements that require a construction permit, you will be asked toprovide the local city with a Hazardous Materials Inventory Statement (HMIS) to ensure that your hazardous chemicals fall within theapplicable Fire Code fire control area limits for the applicable construction occupancy of the particular building. The HMIS will includemuch of the information listed in Section 2-2. Neither the landlord nor the landlord’s property management company expressly warrantsthat the inventory provided in Section 2-2 will necessarily meet the applicable California Fire Code fire control area limits for buildingoccupancy, especially in shared tenant occupancy situations. It is the responsibility of the tenant to ensure that a facility and site canlegally handle the intended operations and hazardous materials desired/ needed for its operations, but the landlord is happy to assist in thisdetermination when possible.CERTIFICATION I am familiar with the real property described in this questionnaire. By signing below, I represent and warrant that the answers to the above questions arecomplete and accurate to the best of my knowledge. I also understand that Lessor will rely on the completeness and accuracy of my answers in assessing anyenvironmental liability risks associated with the property. Signature: Name: Title: Date: Telephone: 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT E-6-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  EXHIBIT F285 EAST GRAND AVENUE(Letterhead of a money center bankacceptable to the Landlord) FAX NO. [(___) ___-____]SWIFT: [Insert No., if any][Insert Bank Name And Address] DATE OF ISSUE: BENEFICIARY:[Insert Beneficiary Name And Address]APPLICANT:[Insert Applicant Name And Address] LETTER OF CREDIT NO. EXPIRATION DATE: AT OUR COUNTERSAMOUNT AVAILABLE:USD[Insert Dollar Amount](U.S. DOLLARS [Insert Dollar Amount])LADIES AND GENTLEMEN:WE HEREBY ESTABLISH OUR IRREVOCABLE STANDBY LETTER OF CREDIT NO. ___________ IN YOUR FAVOR FOR THE ACCOUNT OF [InsertTenant's Name], A [Insert Entity Type], UP TO THE AGGREGATE AMOUNT OF USD[Insert Dollar Amount] ([Insert Dollar Amount] U.S. DOLLARS)EFFECTIVE IMMEDIATELY AND EXPIRING ON ___(Expiration Date)___ AVAILABLE BY PAYMENT UPON PRESENTATION OF YOUR DRAFT ATSIGHT DRAWN ON [Insert Bank Name] WHEN ACCOMPANIED BY THE FOLLOWING DOCUMENT(S):1.THE ORIGINAL OF THIS IRREVOCABLE STANDBY LETTER OF CREDIT AND AMENDMENT(S), IF ANY.2.BENEFICIARY'S SIGNED STATEMENT PURPORTEDLY SIGNED BY AN AUTHORIZED REPRESENTATIVE OF [InsertLandlord's Name], A [Insert Entity Type] ("LANDLORD") STATING THE FOLLOWING:"THE UNDERSIGNED HEREBY CERTIFIES THAT THE LANDLORD, EITHER (A) UNDER THE LEASE (DEFINED BELOW), OR(B) AS A RESULT OF THE TERMINATION OF SUCH LEASE, HAS THE RIGHT TO DRAW DOWN THE AMOUNT OF USD IN ACCORDANCE WITH THE TERMS OF THAT CERTAIN OFFICE LEASE DATED [Insert Lease Date], ASAMENDED (COLLECTIVELY, THE "LEASE"), OR SUCH AMOUNT CONSTITUTES DAMAGES OWING BY THE TENANT TOBENEFICIARY RESULTING FROM THE BREACH OF SUCH LEASE BY THE TENANT THEREUNDER, OR THE TERMINATIONOF SUCH LEASE, AND SUCH AMOUNT REMAINS UNPAID AT THE TIME OF THIS DRAWING."OR"THE UNDERSIGNED HEREBY CERTIFIES THAT WE HAVE RECEIVED A WRITTEN NOTICE OF [Insert Bank Name]'SELECTION NOT TO EXTEND ITS STANDBY LETTER OF CREDIT NO. ___________ AND HAVE NOT RECEIVED AREPLACEMENT LETTER OF CREDIT WITHIN AT LEAST SIXTY (60) DAYS PRIOR TO THE PRESENT EXPIRATION DATE."792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT F-1-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  OR"THE UNDERSIGNED HEREBY CERTIFIES THAT BENEFICIARY IS ENTITLED TO DRAW DOWN THE FULL AMOUNT OFLETTER OF CREDIT NO. ___________ AS THE RESULT OF THE FILING OF A VOLUNTARY PETITION UNDER THE U.S.BANKRUPTCY CODE OR A STATE BANKRUPTCY CODE BY THE TENANT UNDER THAT CERTAIN OFFICE LEASE DATED[Insert Lease Date], AS AMENDED (COLLECTIVELY, THE "LEASE"), WHICH FILING HAS NOT BEEN DISMISSED AT THETIME OF THIS DRAWING."OR"THE UNDERSIGNED HEREBY CERTIFIES THAT BENEFICIARY IS ENTITLED TO DRAW DOWN THE FULL AMOUNT OFLETTER OF CREDIT NO. ___________ AS THE RESULT OF AN INVOLUNTARY PETITION HAVING BEEN FILED UNDER THEU.S. BANKRUPTCY CODE OR A STATE BANKRUPTCY CODE AGAINST THE TENANT UNDER THAT CERTAIN OFFICELEASE DATED [Insert Lease Date], AS AMENDED (COLLECTIVELY, THE "LEASE"), WHICH FILING HAS NOT BEENDISMISSED AT THE TIME OF THIS DRAWING."OR"THE UNDERSIGNED HEREBY CERTIFIES THAT BENEFICIARY IS ENTITLED TO DRAW DOWN THE FULL AMOUNT OFLETTER OF CREDIT NO. ________________ AS THE RESULT OF THE REJECTION, OR DEEMED REJECTION, OF THATCERTAIN OFFICE LEASE DATED [Insert Lease Date], AS AMENDED, UNDER SECTION 365 OF THE U.S. BANKRUPTCYCODE."SPECIAL CONDITIONS:PARTIAL DRAWINGS AND MULTIPLE PRESENTATIONS MAY BE MADE UNDER THIS STANDBY LETTER OF CREDIT, PROVIDED, HOWEVER,THAT EACH SUCH DEMAND THAT IS PAID BY US SHALL REDUCE THE AMOUNT AVAILABLE UNDER THIS STANDBY LETTER OF CREDIT.ALL INFORMATION REQUIRED WHETHER INDICATED BY BLANKS, BRACKETS OR OTHERWISE, MUST BE COMPLETED AT THE TIME OFDRAWING. [Please Provide The Required Forms For Review, And Attach As Schedules To The Letter Of Credit.]ALL SIGNATURES MUST BE MANUALLY EXECUTED IN ORIGINALS.ALL BANKING CHARGES ARE FOR THE APPLICANT'S ACCOUNT.IT IS A CONDITION OF THIS STANDBY LETTER OF CREDIT THAT IT SHALL BE DEEMED AUTOMATICALLY EXTENDED WITHOUTAMENDMENT FOR A PERIOD OF ONE YEAR FROM THE PRESENT OR ANY FUTURE EXPIRATION DATE, UNLESS AT LEAST SIXTY (60) DAYSPRIOR TO THE EXPIRATION DATE WE SEND YOU NOTICE BY NATIONALLY RECOGNIZED OVERNIGHT COURIER SERVICE THAT WE ELECTNOT TO EXTEND THIS LETTER OF CREDIT FOR ANY SUCH ADDITIONAL PERIOD. SAID NOTICE WILL BE SENT TO THE ADDRESS INDICATEDABOVE, UNLESS A CHANGE OF ADDRESS IS OTHERWISE NOTIFIED BY YOU TO US IN WRITING BY RECEIPTED MAIL OR COURIER. ANYNOTICE TO US WILL BE DEEMED EFFECTIVE ONLY UPON ACTUAL RECEIPT BY US AT OUR DESIGNATED OFFICE. IN NO EVENT, ANDWITHOUT FURTHER NOTICE FROM OURSELVES, SHALL THE EXPIRATION DATE BE EXTENDED BEYOND A FINAL EXPIRATION DATE OF ___(120 days from the Lease Expiration Date).THIS LETTER OF CREDIT MAY BE TRANSFERRED SUCCESSIVELY IN WHOLE OR IN PART ONLY UP TO THE THEN AVAILABLE AMOUNT INFAVOR OF A NOMINATED TRANSFEREE ("TRANSFEREE"),792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT F-2-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  ASSUMING SUCH TRANSFER TO SUCH TRANSFEREE IS IN COMPLIANCE WITH ALL APPLICABLE U.S. LAWS AND REGULATIONS. AT THETIME OF TRANSFER, THE ORIGINAL LETTER OF CREDIT AND ORIGINAL AMENDMENT(S) IF ANY, MUST BE SURRENDERED TO US TOGETHERWITH OUR TRANSFER FORM (AVAILABLE UPON REQUEST) AND PAYMENT OF OUR CUSTOMARY TRANSFER FEES, WHICH FEES SHALL BEPAYABLE BY APPLICANT (PROVIDED THAT BENEFICIARY MAY, BUT SHALL NOT BE OBLIGATED TO, PAY SUCH FEES TO US ON BEHALF OFAPPLICANT, AND SEEK REIMBURSEMENT THEREOF FROM APPLICANT). IN CASE OF ANY TRANSFER UNDER THIS LETTER OF CREDIT, THEDRAFT AND ANY REQUIRED STATEMENT MUST BE EXECUTED BY THE TRANSFEREE AND WHERE THE BENEFICIARY'S NAME APPEARSWITHIN THIS STANDBY LETTER OF CREDIT, THE TRANSFEREE'S NAME IS AUTOMATICALLY SUBSTITUTED THEREFOR.ALL DRAFTS REQUIRED UNDER THIS STANDBY LETTER OF CREDIT MUST BE MARKED: ''DRAWN UNDER [Insert Bank Name] STANDBYLETTER OF CREDIT NO. ___________."WE HEREBY AGREE WITH YOU THAT IF DRAFTS ARE PRESENTED TO [Insert Bank Name] UNDER THIS LETTER OF CREDIT AT OR PRIOR TO[Insert Time – (e.g., 11:00 AM)], ON A BUSINESS DAY, AND PROVIDED THAT SUCH DRAFTS PRESENTED CONFORM TO THE TERMS ANDCONDITIONS OF THIS LETTER OF CREDIT, PAYMENT SHALL BE INITIATED BY US IN IMMEDIATELY AVAILABLE FUNDS BY OUR CLOSE OFBUSINESS ON THE SUCCEEDING BUSINESS DAY. IF DRAFTS ARE PRESENTED TO [Insert Bank Name] UNDER THIS LETTER OF CREDIT AFTER[Insert Time – (e.g., 11:00 AM)], ON A BUSINESS DAY, AND PROVIDED THAT SUCH DRAFTS CONFORM WITH THE TERMS AND CONDITIONS OFTHIS LETTER OF CREDIT, PAYMENT SHALL BE INITIATED BY US IN IMMEDIATELY AVAILABLE FUNDS BY OUR CLOSE OF BUSINESS ON THESECOND SUCCEEDING BUSINESS DAY. AS USED IN THIS LETTER OF CREDIT, "BUSINESS DAY" SHALL MEAN ANY DAY OTHER THAN ASATURDAY, SUNDAY OR A DAY ON WHICH BANKING INSTITUTIONS IN THE STATE OF CALIFORNIA ARE AUTHORIZED OR REQUIRED BY LAWTO CLOSE. IF THE EXPIRATION DATE FOR THIS LETTER OF CREDIT SHALL EVER FALL ON A DAY WHICH IS NOT A BUSINESS DAY THENSUCH EXPIRATION DATE SHALL AUTOMATICALLY BE EXTENDED TO THE DATE WHICH IS THE NEXT BUSINESS DAY.PRESENTATION OF A DRAWING UNDER THIS LETTER OF CREDIT MAY BE MADE ON OR PRIOR TO THE THEN CURRENT EXPIRATION DATEHEREOF BY HAND DELIVERY, COURIER SERVICE, OVERNIGHT MAIL, OR FACSIMILE. PRESENTATION BY FACSIMILE TRANSMISSION SHALLBE BY TRANSMISSION OF THE ABOVE REQUIRED SIGHT DRAFT DRAWN ON US TOGETHER WITH THIS LETTER OF CREDIT TO OURFACSIMILE NUMBER, [Insert Fax Number – (___) ___-____], ATTENTION: [Insert Appropriate Recipient], WITH TELEPHONIC CONFIRMATION OFOUR RECEIPT OF SUCH FACSIMILE TRANSMISSION AT OUR TELEPHONE NUMBER [Insert Telephone Number – (___) ___-____] OR TO SUCHOTHER FACSIMILE OR TELEPHONE NUMBERS, AS TO WHICH YOU HAVE RECEIVED WRITTEN NOTICE FROM US AS BEING THE APPLICABLESUCH NUMBER. WE AGREE TO NOTIFY YOU IN WRITING, BY NATIONALLY RECOGNIZED OVERNIGHT COURIER SERVICE, OF ANY CHANGEIN SUCH DIRECTION. ANY FACSIMILE PRESENTATION PURSUANT TO THIS PARAGRAPH SHALL ALSO STATE THEREON THAT THE ORIGINALOF SUCH SIGHT DRAFT AND LETTER OF CREDIT ARE BEING REMITTED, FOR DELIVERY ON THE NEXT BUSINESS DAY, TO [Insert Bank Name]AT THE APPLICABLE ADDRESS FOR PRESENTMENT PURSUANT TO THE PARAGRAPH FOLLOWING THIS ONE.WE HEREBY ENGAGE WITH YOU THAT ALL DOCUMENT(S) DRAWN UNDER AND IN COMPLIANCE WITH THE TERMS OF THIS STANDBYLETTER OF CREDIT WILL BE DULY HONORED IF DRAWN AND PRESENTED FOR PAYMENT AT OUR OFFICE LOCATED AT [Insert Bank Name],[Insert Bank Address], ATTN: [Insert Appropriate Recipient], ON OR BEFORE THE EXPIRATION DATE OF THIS CREDIT, ___(Expiration Date)___.IN THE EVENT THAT THE ORIGINAL OF THIS STANDBY LETTER OF CREDIT IS LOST, STOLEN, MUTILATED, OR OTHERWISE DESTROYED, WEHEREBY AGREE TO ISSUE A DUPLICATE ORIGINAL HEREOF UPON RECEIPT OF A WRITTEN REQUEST FROM YOU AND A CERTIFICATION BYYOU (PURPORTEDLY SIGNED BY YOUR AUTHORIZED REPRESENTATIVE) OF THE LOSS, THEFT, MUTILATION, OR OTHER DESTRUCTION OFTHE ORIGINAL HEREOF.792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT F-3-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  EXCEPT SO FAR AS OTHERWISE EXPRESSLY STATED HEREIN, THIS STANDBY LETTER OF CREDIT IS SUBJECT TO THE "INTERNATIONALSTANDBY PRACTICES" (ISP 98) INTERNATIONAL CHAMBER OF COMMERCE (PUBLICATION NO. 590). Very truly yours,(Name of Issuing Bank)By: 792986.06/WLA186772-00003/2-28-19/gjn/gjnEXHIBIT F-4-Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  LEASE 285 EAST GRAND AVENUE BAYSIDE AREA DEVELOPMENT, LLC,a Delaware limited liability company,as Landlord,andUNITY BIOTECHNOLOGY, INC.,a Delaware corporation,as Tenant. 792986.06/WLA186772-00003/2-28-19/gjn/gjn Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]. TABLE OF CONTENTS Page1.PREMISES, BUILDING, PROJECT, AND COMMON AREAS42.LEASE TERM; OPTION TERM53.BASE RENT74.ADDITIONAL RENT85.USE OF PREMISES146.SERVICES AND UTILITIES197.REPAIRS218.ADDITIONS AND ALTERATIONS239.COVENANT AGAINST LIENS2510.INSURANCE2511.DAMAGE AND DESTRUCTION2712.NONWAIVER2813.CONDEMNATION2814.ASSIGNMENT AND SUBLETTING2915.SURRENDER OF PREMISES; OWNERSHIP AND REMOVAL OF TRADE FIXTURES3216.HOLDING OVER3317.ESTOPPEL CERTIFICATES3318.SUBORDINATION3319.DEFAULTS; REMEDIES3420.COVENANT OF QUIET ENJOYMENT3621.SECURITY DEPOSIT3722.COMMUNICATIONS AND COMPUTER LINE4023.SIGNS4024.COMPLIANCE WITH LAW4025.LATE CHARGES4126.LANDLORD'S RIGHT TO CURE DEFAULT; PAYMENTS BY TENANT4127.ENTRY BY LANDLORD4228.TENANT PARKING4229.MISCELLANEOUS PROVISIONS42 EXHIBITS AOUTLINE OF PREMISES BTENANT WORK LETTER CFORM OF NOTICE OF LEASE TERM DATES DFORM OF TENANT'S ESTOPPEL CERTIFICATE EENVIRONMENTAL QUESTIONNAIRE FFORM OF LETTER OF CREDIT 792986.06/WLA186772-00003/2-28-19/gjn/gjn(i) Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]. INDEX Page(s)Abatement Event36Accountant13Advocate Arbitrators6Alterations23Base Building22Base Rent7Brokers46Building4Common Areas4Comparable Transactions6Concessions6Contemplated Effective Date30Contemplated Transfer Space30Direct Expenses8Eligibility Period36Emergency23Estimate13Estimate Statement13Estimated Direct Expenses12Expense Year8Fair Rental Value,6Force Majeure44Generator20Intention to Transfer Notice30Landlord1Landlord Parties25L‑C36L‑C Amount36Lease1Lease Commencement Date5Lease Expiration Date5Lease Term5Lease Year5Lines39Mail44Net Worth32Neutral Arbitrator6Nine Month Period30Notices44Objectionable Name40Operating Expenses8Outside Agreement Date6Premises4Project,4Sign Specifications39Specialty Improvements23Statement12Subject Space29Summary1Tax Expenses11792986.06/WLA186772-00003/2-28-19/gjn/gjn(ii) Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.].  Page(s)Tenant1Tenant Work Letter4Tenant's Accountant13Tenant's Share12Transfer Notice29Transferee29 792986.06/WLA186772-00003/2-28-19/gjn/gjn(iii)Bayside Area Development, LLC[285 East Grand Avenue][Unity Biotechnology, Inc.]. Exhibit 23.1CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRMWe consent to the incorporation by reference in the Registration Statement (Form S-8 No. 333-224726) pertaining to the 2013 Equity IncentivePlan, the 2018 Incentive Award Plan and 2018 Employee Stock Purchase Plan of Unity Biotechnology, Inc. of our report dated March 6, 2019, withrespect to the financial statements of Unity Biotechnology, Inc. included in this Annual Report (Form 10-K) for the year ended December 31, 2018./s/ Ernst & Young LLPRedwood City, CaliforniaMarch 6, 2019  Exhibit 31.1CERTIFICATION PURSUANT TORULES 13a-14(a) AND 15d-14(a) UNDER THE SECURITIES EXCHANGE ACT OF 1934,AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002I, Keith R. Leonard Jr., certify that:1.I have reviewed this Annual Report on Form 10-K of Unity Biotechnology, Inc. for the year ended December 31, 2018;2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make thestatements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by thisreport;3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects thefinancial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;4.The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined inExchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have: (a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, toensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within thoseentities, particularly during the period in which this report is being prepared; (b)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about theeffectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and (c)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recentfiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely tomaterially affect, the registrant's internal control over financial reporting; and5.The registrant's other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to theregistrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions): (a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonablylikely to adversely affect the registrant's ability to record, process, summarize and report financial information; and (b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal controlover financial reporting. Date: March 6, 2019 By:/s/ Keith R. Leonard Jr. Keith R. Leonard Jr. Chairman and Chief Executive Officer(Principal Executive Officer)  Exhibit 31.2CERTIFICATION PURSUANT TORULES 13a-14(a) AND 15d-14(a) UNDER THE SECURITIES EXCHANGE ACT OF 1934,AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002I, Robert C. Goeltz II, certify that:1.I have reviewed this Annual Report on Form 10-K of Unity Biotechnology, Inc. for the year ended December 31, 2018;2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make thestatements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by thisreport;3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects thefinancial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;4.The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined inExchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have: (a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, toensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within thoseentities, particularly during the period in which this report is being prepared; (b)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about theeffectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and (c)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recentfiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely tomaterially affect, the registrant's internal control over financial reporting; and5.The registrant's other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to theregistrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions): (a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonablylikely to adversely affect the registrant's ability to record, process, summarize and report financial information; and (b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal controlover financial reporting. Date: March 6, 2019 By:/s/ Robert C. Goeltz II Robert C. Goeltz II Chief Financial Officer(Principal Financial Officer)  Exhibit 32.1CERTIFICATION PURSUANT TO18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TOSECTION 906 OF THE SARBANES-OXLEY ACT OF 2002In connection with the Annual Report of Unity Biotechnology, Inc. (the “Company”) on Form 10-K for the year ending December 31, 2018 as filedwith the Securities and Exchange Commission on the date hereof (the “Report”), I, Keith R. Leonard Jr., Chairman and Chief Executive Officer of theCompany, and Robert C. Goeltz II, Chief Financial Officer of the Company, do each hereby certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that: (1)The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2)The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of theCompany for the period covered by the Report. Date: March 6, 2019 By:/s/ Keith R. Leonard Jr. Keith R. Leonard Jr. Chairman and Chief Executive Officer(Principal Executive Officer) Date: March 6, 2019 By:/s/ Robert C. Goeltz II Robert C. Goeltz II Chief Financial Officer(Principal Financial Officer) 

Continue reading text version or see original annual report in PDF format above