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Merrimack Pharmaceuticals Inc

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FY2022 Annual Report · Merrimack Pharmaceuticals Inc
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 10-K

(Mark One)
☒  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2022

or

☐  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission file number 001-35409

Merrimack Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of
incorporation or organization)

th

One Broadway, 14  Floor
Cambridge, MA
(Address of principal executive offices)

04-3210530
(I.R.S. Employer
Identification No.)

02142
(Zip Code)

Registrant’s telephone number, including area code: (617) 720-8606

Securities registered pursuant to Section 12(b) of the Act:

Title of each class
Common Stock, $0.01 par value

Trading Symbol(s)
MACK

Name of each exchange on which registered
Nasdaq Global Market

Securities registered pursuant to Section 12(g) of the Act: Preferred Stock Purchase Rights

Indicate 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 Section 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 preceding 12 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 of this 

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 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
Non-accelerated filer

☐   
☒  

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 financial accounting 

standards provided pursuant to Section 13(a) of the Exchange Act.     ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under 

Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.  ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an 

error to previously issued financial statements.  ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s 

executive officers during the relevant recovery period pursuant to § 240.10D-1(b).   ☐

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 last sale price for such stock on June 30, 2022, was 

$57,237,893.

As of March 7, 2023, there were 14,255,104 shares of Common Stock, $0.01 par value per share, outstanding.

The registrant intends to file a definitive proxy statement pursuant to Regulation 14A in connection with its 2022 Annual Meeting of Stockholders. Portions of such 

proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K.

DOCUMENTS INCORPORATED BY REFERENCE

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TABLE OF CONTENTS

PART I

Item 1.

  Business

Item 1A.

  Risk Factors

Item 1B.

  Unresolved Staff Comments

Item 2.

  Properties

Item 3.

  Legal Proceedings

Item 4.

  Mine Safety Disclosures

PART II

Item 5.

  Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Item 6.

  Selected Financial Data

Item 7.

  Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A.

  Quantitative and Qualitative Disclosures About Market Risk

Item 8.

  Financial Statements and Supplementary Data

Item 9.

  Changes in and Disagreements With Accountants on Accounting and Financial Disclosure

Item 9A.

  Controls and Procedures

Item 9B.

  Other Information

Item 10.

  Directors, Executive Officers and Corporate Governance

Item 11.

  Executive Compensation

PART III

Item 12.

  Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13.

  Certain Relationships and Related Transactions, and Director Independence

Item 14.

  Principal Accountant Fees and Services

Item 15.

  Exhibits and Financial Statement Schedules

Item 16.

  Form 10-K Summary

PART IV

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FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward‑looking statements that involve substantial risks and uncertainties. All statements, other than 

statements of historical facts, contained in this Annual Report on Form 10-K, including statements regarding our strategy, future operations, future financial 
position, future revenues, projected costs, prospects, plans and objectives of management, are forward‑looking statements. The words “anticipate,” 
“believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue” and 
similar expressions are intended to identify forward‑looking statements, although not all forward‑looking statements contain these identifying words.

The forward‑looking statements in this Annual Report on Form 10-K include, among other things, statements about:

•

•

•

•

•

our rights to receive payments related to the accomplishment, if at all, of additional milestone events under the asset purchase and sale 
agreement with Ipsen S.A.;

our rights to receive payments related to the milestone events under the asset purchase agreement with Elevation Oncology, Inc. (formerly 
known as 14ner Oncology, Inc.), when expected or at all;

our cash runway and the sufficiency of our financial resources to fund our operations; 

our estimates regarding expenses; and

our plans to seek to divest our few remaining product candidates.

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue 
reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the 
forward-looking statements we make. We have included important factors in the cautionary statements included in this Annual Report on Form 10-K, 
particularly in Part I, Item 1A. Risk Factors, that could cause actual results or events to differ materially from the forward-looking statements that we make. 
Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures, collaborations or 
investments that we may make.

You should read this Annual Report on Form 10-K and the documents that we have filed as exhibits to this Annual Report on Form 10-K completely 

and with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any 
forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

ONIVYDE® is a registered trademark of Ipsen S.A. Any other trademarks, trade names and service marks referred to in this Annual Report on Form 

10-K are the property of their respective owners.

NOTE REGARDING TRADEMARKS

2

 
 
Item 1. Business

Overview

PART I

We are a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone 

payments related to our sale of ONIVYDE® to Ipsen S.A., or Ipsen, in April 2017 and up to $54.5 million in contingent milestone payments related to our 
sale of MM-121 and MM-111 to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.), or Elevation, in July 2019. We do not have any 
ongoing research or development activities and are seeking potential acquirers for our remaining preclinical and clinical assets. We do not have any 
employees and instead use external consultants for the operation of our company.

On April 3, 2017, we completed the sale of ONIVYDE and MM-436 (the “commercial business”) to Ipsen (the “Ipsen sale”). At the time of the sale 

ONIVYDE was approved in the United States for the second line treatment of metastatic adenocarcinoma of the pancreas. In connection with the Ipsen 
sale, we are eligible to receive up to $450.0 million in additional regulatory approval-based milestone payments.

The remaining up to $450.0 million in potential milestone payments resulting from the Ipsen sale consist of:

•

•

•

$225.0 million upon approval by the U.S. Food and Drug Administration, or FDA, of ONIVYDE for the first-line treatment of metastatic 
adenocarcinoma of the pancreas (“mPDAC”), subject to certain conditions;

$150.0 million upon approval by the FDA of ONIVYDE for the treatment of small-cell lung cancer after failure of first-line chemotherapy; 
and

$75.0 million upon approval by the FDA of ONIVYDE for an additional indication unrelated to those described above.

Ipsen has recently stated that it intends to file a supplemental New Drug Application with the U.S. Food and Drug Administration for Onivyde in 

combination with oxaliplatin plus 5-fluorouracil/leucovorin for the treatment of patients with previously untreated mPDAC following the Fast Track 
Designation granted in 2020.

Our remaining non-commercial assets, including our clinical and preclinical development programs, were not included in the Ipsen sale and all 

material other clinical and pre-clinical development programs have been sold, as described below.

On May 30, 2019, we announced the completion of our review of strategic alternatives, following which our board of directors implemented a series 

of measures designed to extend our cash runway into 2027 and preserve our ability to capture the potential milestone payments resulting from the Ipsen 
sale. We have based this estimate on assumptions that may prove to be wrong, and we could use our financial resources sooner than we currently expect. In 
connection with that announcement, we discontinued the discovery efforts on our remaining preclinical programs: MM-401, an agonistic antibody targeting 
a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein targeting death receptors 4 and 5. 

The termination of our executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by 

July 12, 2019. As of July 12, 2019, we no longer had any employees. We have engaged external consultants to run our day-to-day operations. 

On July 12, 2019, we completed the sale to Elevation, or the Elevation sale, of our anti-HER3 antibody programs, MM-121 (seribantumab) and 

MM-111 for potential use for patients with solid tumors of any origin that have an NRG1 fusion. In connection with the Elevation sale, we are eligible to 
receive up to $54.5 million in additional potential development, regulatory approval and commercial-based milestone payments, consisting of:

•

•

•

$3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United 
States, Europe and Japan; and

up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 
million for MM-121 and MM-111.

3

 
 
 
In January 2023, Elevation announced it is pausing further investment in the clinical development of seribantumab and intends to pursue further 

development only in collaboration with a partner.  Elevation also announced that it intends to present additional interim data from its study of seribantumab 
in the first half of 2023.  

On March 27, 2020, we entered into an Asset Purchase Agreement (the “Celator Asset Purchase Agreement”) with Celator Pharmaceuticals, Inc. 

(the “Buyer”), pursuant to which the Buyer agreed to purchase certain assets (the “Transferred Assets”) relating to certain of our preclinical nanoliposome 
programs (the “Transaction”). We completed the Transaction simultaneously with the execution of the Celator Asset Purchase Agreement for net proceeds 
of $2.1 million, which was recognized in fiscal 2020.

On September 15, 2021, we entered into an Asset Purchase Option Agreement (the “Assets Purchase Option Agreement”) with a third party, 

pursuant to which the third party agreed to obtain an exclusive option, to purchase one of our preclinical programs with a consideration of $0.5 million. 
Under the terms of the Assets Purchase Option Agreement, the third party paid to us the option fee of $0.1 million. The third party had the right to exercise 
the option within 24 months from September 15, 2021. We recognized a gain of $0.1 million related to the option fee payment for the year ended December 
31, 2021. On January 18, 2022, the third party provided written notice to us of its intent to exercise such option and on March 1, 2022, we entered the Asset 
Purchase Option Agreement with the third party. The consideration of $0.5 million was paid to us and a gain of $0.5 million was recognized in March 
2022.

On January 23, 2023, we entered into an Asset Purchase Option Agreement (the “Option Agreement”) with a third party (the “Purchaser”), 

pursuant to which the Purchaser agreed to obtain an exclusive option (the “Option”) to purchase one of the Company’s preclinical programs for total 
potential consideration of $0.7 million. Under the terms of the Option Agreement, the Purchaser paid to us the Option fee of $0.2 million in January 2023. 
The Purchaser may exercise the Option by July 23, 2023.

We previously devoted substantially all of our resources to our drug discovery and development efforts, including conducting clinical trials for our 

product candidates, protecting our intellectual property and providing general and administrative support for these operations. We have financed our 
operations primarily through private placements of convertible preferred stock, collaborations, public offerings of our securities, secured debt financings, 
sales of ONIVYDE® and the Ipsen sale.

As of December 31, 2022, we had unrestricted cash and cash equivalents of $19.4 million. We expect that our cash and cash equivalents as of 
December 31, 2022 will be sufficient to continue our operations beyond 2027, which we estimate is beyond the latest date when the longest term potential 
milestones might be achieved. 

We have a history of losses from our operations. We do not expect to be profitable from our operations in the future unless we receive potential 
future milestone payments, if any. As of December 31, 2022, we had an accumulated deficit of $547.6 million. Our net loss was $1.5 million and $2.5 
million for the years ended December 31, 2022 and 2021, respectively. We do not expect to incur any research and development expenses going forward.

Asset Purchase Agreements

We are party to certain asset purchase agreements which provide for potentially significant milestone payments. We consider the following 

agreements to be material to our business.

Ipsen

On April 3, 2017, we completed the Ipsen sale. Pursuant to the Asset Purchase and Sale Agreement, dated as of January 7, 2017, (the "Ipsen Sale 

Agreement"), between us and Ipsen, Ipsen acquired our right, title and interest in the commercial business. Pursuant to the Ipsen Sale Agreement, we 
received $575.0 million in cash, plus a working capital adjustment of $5.7 million, and are eligible to receive up to $450.0 million in additional regulatory 
approval-based milestone payments. Ipsen has agreed pursuant to the Ipsen Sale Agreement to use commercially reasonable efforts to develop ONIVYDE 
in connection with obtaining the regulatory approval by the FDA of ONIVYDE for certain indications. 

•

In November 2022, Ipsen announced the Phase III NAPOLI 3 trial of Onivyde® (irinotecan liposome injection) plus 5 
fluorouracil/leucovorin and oxaliplatin (the “NALIRIFOX regimen”) met its primary endpoint demonstrating clinically meaningful and 
statistically significant improvement in overall survival compared to nab-paclitaxel plus gemcitabine in 770 previously untreated patients 
with mPDAC and key secondary efficacy outcome of progression-free survival (PFS) also showed significant improvement over the 
comparator arm. Ipsen also announced that the safety profile of Onivyde in the NAPOLI 3 trial was consistent with those observed in the 
previous phase I/II mPDAC study. Ipsen also stated that it intends to file a supplemental New Drug Application with the U.S. Food and Drug 
Administration for Onivyde in combination with oxaliplatin plus 5-fluorouracil/leucovorin for the treatment of patients with previously 
untreated mPDAC following the Fast Track Designation granted in 2020. In January 2023, Ipsen presented clinical trial results at 

4

 
 
the 2023 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium. In February 2023 Ipsen provided guidance 
to investors that it intends to file a supplemental New Drug Application with the U.S. Food and Drug Administration during the first half of 
2023 following the Fast Track Designation granted in 2020 for the use of Onivyde in combination with oxaliplatin plus 5-
fluorouracil/leucovorin for the treatment of patients with previously untreated mPDAC.

•

In August 2022, Ipsen announced that the Phase III RESILIENT trial did not meet its primary endpoint of overall survival compared to 
topotecan. The trial is evaluating Onivyde® (irinotecan liposomal injection) versus topotecan in patients with small cell lung cancer, who 
have progressed on or after platinum-based first-line therapy treatment. RESILIENT is a Phase III trial conducted in two parts; the first part 
read out in 2020 confirming the safety, dosing and efficacy of Onivyde; part two is evaluating the efficacy of Onivyde versus topotecan. In 
the announcement, Ipsen indicated that detailed results from the RESILIENT trial will be presented at an upcoming medical conference.  The 
analysis concluded that the primary endpoint overall survival was not met in patients treated with Onivyde versus topotecan. However, a 
doubling of the secondary endpoint of objective response rate in favor of Onivyde was observed. The safety and tolerability of Onivyde was 
consistent with its already-known safety profile, and no new safety concerns emerged. In the August 2022 announcement, Ipsen reported that 
the clinical study results will be communicated with the regulatory agency. Ipsen indicated that while the results from the analysis of the 
RESILIENT trial have not demonstrated an overall survival benefit with Onivyde in patients in second-line small cell lung cancer, it intends 
to analyze the data further before decisions regarding next steps are made. To date, there have been no further public announcements by Ipsen 
regarding these matters and it remains unclear as to whether Ipsen will continue to seek approval for the use of ONIVYDE in the small cell 
lung cancer application.  If Ipsen elects not to proceed with seeking regulatory approval, or if regulatory approval is not obtained, we would 
not be entitled to the $150 million milestone payment tied to approval of Onivyde for treating small cell lung cancer.

Elevation 

On July 12, 2019, we completed the sale to Elevation, or the Elevation sale, of our anti-HER3 antibody programs, MM-121 (seribantumab) and 
MM-111. In connection with the Elevation sale, we received an upfront cash payment of $3.5 million and are eligible to receive up to $54.5 million in 
additional potential development, regulatory approval and commercial-based milestone payments, consisting of:

•

•

•

$3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United 
States, Europe and Japan; and

up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 
million for MM-121 and MM-111.

In January 2023, Elevation announced it is pausing further investment in the clinical development of seribantumab and intends to pursue further 
development only in collaboration with a partner.  Elevation also announced that it intends to present additional interim data from its study of seribantumab 
in the first half of 2023.

Intellectual Property

We own or control a very limited number of U.S. patents and patent applications and several corresponding foreign patents and patent applications. 

This intellectual property relates to several early stage programs that we are no longer advancing on our own, but that may be of value to one or more 
potential buyer or licensees. During 2023, we will continue to evaluate the usefulness of maintaining the current patent portfolio to our business.

Government Regulation

Government authorities in the United States, at the federal, state and local level, and in other countries extensively regulate, among other things, the 

research, development, testing, manufacture, including any manufacturing changes, packaging, storage, record keeping, labeling, advertising, promotion, 
distribution, marketing, post-approval monitoring and reporting, import and export of pharmaceutical products, biological products and medical devices, 
which does not relate directly to us, however could have an impact on Ipsen and Elevation.

5

 
 
 
 
Data Protection

We are subject to data protection laws and regulations (i.e., laws and regulations that address privacy and data security). The legislative and 
regulatory landscape for data protection continues to evolve, and in recent years there has been an increasing focus on privacy and data security issues. In 
the United States, numerous federal and state laws and regulations, including state data breach notification laws, state health information privacy laws and 
federal and state consumer protection laws govern the collection, use, disclosure and protection of health-related and other personal information. Failure to 
comply with data protection laws and regulations could result in government enforcement actions (which could include civil or criminal penalties), private 
litigation and/or adverse publicity and could negatively affect our operating results and business. In addition, we may obtain health information from third 
parties (e.g., healthcare providers who prescribe our products) that are subject to privacy and security requirements under the federal Health Insurance 
Portability and Accountability Act of 1996, as amended by the Health Information Technology for Economic and Clinical Health Act. We could be subject 
to criminal penalties if we knowingly obtain or disclose individually identifiable health information in a manner that is not authorized or permitted.

Employees

The termination of our executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by 

July 12, 2019. Since July 12, 2019, we no longer have any employees. We have engaged external consultants to run our day-to-day operations.

Financial Information

Financial information is provided in our consolidated financial statements included in this Annual Report on Form 10-K and in Item 7. 

Management’s Discussion and Analysis of Financial Condition and Results of Operations. 

Information about our dependence on limited amounts of customers is provided in Note 1, “Nature of the Business and Summary of Significant 

Accounting Policies – Concentration of Credit Risk” in the accompanying notes to the consolidated financial statements.

Our Corporate Information

We were originally incorporated in the Commonwealth of Massachusetts in 1993 and reincorporated under the laws of the State of Delaware in 
October 2010. Our principal executive offices are located at One Broadway, 14th Floor, Cambridge, MA 02142, and our telephone number is (617) 720-
8606.

Information Available on the Internet

We maintain a website with the address www.merrimack.com. We are not including the information contained on our website as a part of, or 
incorporating it by reference into, this Annual Report on Form 10-K. Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on 
Form 8-K, and all amendments to those reports, are available to you free of charge through the “SEC Filings” link in the “Investors” section of our website 
as soon as reasonably practicable after those materials have been electronically filed with, or furnished to, the Securities and Exchange Commission, or the 
SEC. We also make available on our website our corporate governance guidelines, the charters for our audit committee, corporate governance and 
nominating committee, and organization and compensation committee, and our code of business conduct and ethics, which applies to our directors, officers 
and employees, and such information is available in print and free of charge to any of our stockholders who requests it. In addition, we intend to disclose on 
our website any amendments to, or waivers from, our code of business conduct and ethics that are required to be publicly disclosed pursuant to rules of the 
SEC.

6

 
 
Item 1A. Risk Factors

The following risk factors and other information included in this Annual Report on Form 10-K should be carefully considered. The risks and 

uncertainties described below are not the only ones we face. Additional risks and uncertainties not presently known to us or that we presently deem less 
significant may also impair our business operations. Please see page 2 of this Annual Report on Form 10-K for a discussion of some of the forward-looking 
statements that are qualified by these risk factors. If any of the following risks occur, our business, financial condition, results of operations and future 
growth prospects could be materially and adversely affected.

Risks Related to Our Business Strategy

Our business strategy depends substantially upon our ability to receive future contingent milestone payments. 

Our business strategy depends substantially upon our ability to receive future milestone payments from Ipsen and Elevation. On May 30, 2019, we 
announced the completion of our review of strategic alternatives. Following this review, our board of directors implemented a series of measures designed 
to extend our cash runway into 2027 and preserve our ability to capture the potential milestone payments resulting from the Ipsen sale. We are entitled to 
receive up to $450.0 million in contingent milestone payments related to our sale of ONIVYDE to Ipsen and up to $54.5 million in contingent milestone 
payments related to our sale of MM-121 and MM-111 to Elevation. We do not have any ongoing research or development activities. Any failure to achieve 
such milestones or a perception that the milestones may not be achieved will materially and adversely affect the company and the value of the common 
stock. 

In August 2022, Ipsen announced that the Phase III RESILIENT trial did not meet its primary overall survival endpoint compared to topotecan. The 

trial is evaluating Onivyde® (irinotecan liposomal injection) versus topotecan in patients with small cell lung cancer, who have progressed on or after 
platinum-based first-line therapy treatment.  The analysis concluded that the primary overall survival endpoint was not met in patients treated with Onivyde 
versus topotecan. However, a doubling of the secondary endpoint of objective response rate in favor of Onivyde was observed. The safety and tolerability 
of Onivyde was consistent with its already-known safety profile, and no new safety concerns emerged. In the August 2022 announcement, Ipsen reported 
that the clinical study results will be communicated with the regulatory agency. Ipsen indicated that while the results from the analysis of the RESILIENT 
trial have not demonstrated an overall survival benefit with Onivyde in patients in second-line small cell lung cancer, Ipsen indicated that it intends to 
analyze the data further before decisions regarding next steps are made.  To date, there have been no further public announcement by Ipsen regarding these 
matters and it remains unclear as to whether Ipsen will continue to seek approval for the use of ONIVYDE in the small cell lung cancer application.  If 
Ipsen elects not to proceed with seeking regulatory approval, or regulatory approval is not obtained, we would not be entitled to the $150 million milestone 
payment tied to approval of Onivyde for small cell lung cancer.

In January 2023, Elevation announced it is pausing further investment in the clinical development of seribantumab and intends to pursue further 

development only in collaboration with a partner.  Elevation also announced that it intends to present additional interim data from its study of seribantumab 
in the first half of 2023. If Elevation elects not to proceed with further investment in serbantumab, it is possible that Elevation may not achieve any further 
milestones and we would receive no milestone payments. If Elevation elects not to proceed with seeking regulatory approval, or regulatory approval is not 
obtained, we would not be entitled to the $54.5 million milestone payments tied to approval of seribantumab for patients with solid tumors of any origin 
that have an NRG1 fusion.

Even if some or all of the milestones set forth in the Ipsen sale agreement and Elevation agreement are achieved, it may take significantly longer than 
we anticipate and could require us to raise additional funding in order to maintain our ability to receive payment for such milestones.

Achievement of the milestones set forth in the Ipsen sale agreement and the Elevation agreement are not guaranteed and there is significant risk that 

some or all of such milestones will not be achieved when anticipated, if at all. If achievement of the milestones is delayed beyond what we currently 
anticipate, it could require us to raise additional funds in order to maintain our ability to receive payment for the potential future achievement of such 
milestones. Sources of funds may not be available or, if available, may not be available on terms satisfactory to us. Raising additional funds could be 
dilutive or otherwise disadvantageous to our stockholders. Any delay in receipt of the potential benefit to the company or our stockholders resulting from 
achievement of such milestones, in addition to any additional uncertainty as to whether such milestones will be achieved at all, would materially and 
adversely affect the company and the value of the common stock.

7

 
 
We may be treated as a "public shell" company which could have negative consequences, including potential Nasdaq delisting of our common stock.

Our common stock is currently listed on the Nasdaq Global Market. We have no current plans to delist our common stock from Nasdaq. However, 

following our cessation of normal business operations, we may be treated as a “public shell” company under the Nasdaq rules and the Securities Act of 
1933, as amended, or the Securities Act, or the Exchange Act. Although Nasdaq evaluates whether a listed company is a public shell company based on a 
facts and circumstances determination, a Nasdaq-listed company with no or nominal operations and either no or nominal assets, assets consisting solely of 
cash and cash equivalents, or assets consisting of any amount of cash and cash equivalents and nominal other assets is generally considered to be a public 
shell company. Listed companies determined to be public shell companies by Nasdaq may be subject to delisting proceedings or additional and more 
stringent listing criteria. 

If our common stock is delisted from Nasdaq, or if in the future we determine to delist our common stock, we would expect that such securities 

would qualify for trading over-the-counter, or OTC, in the United States on a market colloquially referred to as the “Pink Sheets.” Securities quoted OTC 
are generally subject to lesser requirements than securities listed for trading on a U.S. national stock exchange, such as Nasdaq, including reduced corporate 
governance and public reporting standards.

If Nasdaq should delist our common stock from trading, or if in the future we determine to delist our common stock, a reduction in some or all of the 

following may occur, each of which could have a material adverse effect on holders of our common stock: the liquidity of our common stock; the market 
price of the common stock; the number of institutional and general investors that will consider investing in the common stock; the number of investors in 
general that will consider investing in the common stock; the number of market makers in our common stock; the availability of information concerning the 
trading prices and volume of the common stock; and the number of broker-dealers willing to execute trades in our common stock. In addition to the 
foregoing, there are certain consequences under the Securities Act of being a public shell company, including the unavailability of Rule 144 thereunder for 
the resale of restricted securities and the inability to utilize Form S-8 for the registration of employee benefit plan securities.

We have been, and in the future may be, subject to securities litigation, which is expensive and could divert our attention. 

We have been, and may in the future be, subject to securities class action litigation. Securities litigation against us could result in substantial costs 

and divert our management’s attention, which could seriously harm our business. 

Actions of activist stockholders against us could be disruptive and potentially costly and the possibility that activist stockholders may seek changes that 
contest, or conflict with, our strategic direction could cause uncertainty about the strategic direction of our business.

Activist stockholders may from time to time attempt to effect changes in our strategic direction and, in furtherance thereof, may seek changes in 

how we are governed. While our board of directors and management strive to maintain constructive, ongoing communications with all of our stockholders, 
including activist stockholders, and welcomes their views and opinions with the goal of working together constructively to enhance value for all 
stockholders, activist campaigns that contest, or conflict with, our strategic direction could have an adverse effect on us because:

•

•

•

•

responding to proxy contests and other actions by activist stockholders can disrupt our operations, be costly and time-consuming, and divert 
the attention of our board of directors and management from the pursuit of business strategies, which could adversely affect our results of 
operations and financial condition;

perceived uncertainties as to our future direction as a result of changes to the composition of our board of directors may lead to the perception 
of a change in the direction of the business, instability or lack of continuity which may be exploited by our competitors, may result in the loss 
of potential business opportunities and make it more difficult to attract and retain qualified personnel and business partners;

these types of actions could cause significant fluctuations in our stock price based on temporary or speculative market perceptions or other 
factors that do not necessarily reflect the underlying fundamentals and prospects of our business; and

if individuals are elected to our board of directors with a specific agenda, it may adversely affect our ability to effectively implement our 
business strategy and create additional value for our stockholders.

In connection with our 2019 Annual Meeting of Stockholders, an activist investor initially proposed its own slate of director candidates. That 
activist investor ultimately withdrew its slate of director candidates prior to the 2019 Annual Meeting of Stockholders and all of our director nominees were 
elected at the 2019 Annual Meeting of Stockholders. In connection with our 2020 Annual Meeting of Stockholders, an activist investor submitted a 
shareholder proposal requiring the board of directors to amend our company charter and/or bylaws, as necessary, to require the chair of our board of 
directors, whenever possible, to be a non-management, 

8

 
  
 
independent member of the board and if the board determined that a chair who was independent when selected is no longer independent, the board would 
be required to select a new chair who satisfies the requirements of the policy within a reasonable amount of time. The shareholder proposal was not 
approved by our shareholders. That activist investor continues to have a Schedule 13D filed with respect to us and it remains a possibility that such activist 
investor may still, from time to time, attempt to effect changes in our strategic direction and, in furtherance thereof, may seek changes in how we are 
governed.

Risks Related to the Sale and Divestiture of Assets

There can be no guarantee that Ipsen will comply with its obligation to use commercially reasonable efforts in connection with the development of 
ONIVYDE or that the milestones set forth in the Ipsen sale agreement will be achieved. 

Ipsen has agreed to use commercially reasonable efforts to develop ONIVYDE in connection with obtaining the regulatory approval by the FDA of 

ONIVYDE for certain indications. There is no guarantee that Ipsen will undertake such development however, or that any of its efforts will lead to the 
successful approval of ONIVYDE for such additional indications or lead to achievement of the milestones set forth in the Ipsen sale agreement. We also do 
not have any right to receive updates on the progress of Ipsen’s development of ONIVYDE beyond what Ipsen chooses to disclose publicly. The milestones 
set forth in the Ipsen sale agreement may not be achieved and we may not receive any future contingent payments. As a result, material information about 
the progress, if any, on the milestones will not be made publicly available unless Ipsen publicly discloses such information.

Our business strategy depends substantially upon our ability to receive future milestone payments from Ipsen. Any failure to achieve such 
milestones or a perception that the milestones may not be achieved will materially and adversely affect the company and the value of the common stock.

There can be no guarantee that Elevation will comply with its obligation to use commercially reasonable efforts in connection with the development of 
MM-121 and MM-111 or that the milestones set forth in the asset purchase agreement with Elevation will be achieved. 

Elevation has agreed to use commercially reasonable efforts to develop MM-121 and MM-111. However, there is no guarantee that Elevation will 

take the steps set forth in the Elevation agreement or that any of its efforts will lead to the successful approval of MM-121 or MM-111 by the FDA or other 
regulatory bodies. The milestones set forth in the Elevation agreement may not be achieved and we may not receive any future contingent payments. 
Because our business strategy depends substantially upon our ability to receive future milestone payments, including from Elevation, any failure to achieve 
such milestones or a perception that the milestones may not be achieved will materially and adversely affect the company and the value of the common 
stock. 

Ipsen did not assume any of the excluded liabilities under the Ipsen sale agreement. 

Pursuant to the Ipsen sale agreement, Ipsen assumed only certain specified liabilities set forth in the Ipsen sale agreement and did not assume all of 
the liabilities associated with the commercial business. Certain liabilities remain with us post-closing. While we believe that we have adequately accrued 
for these liabilities or are adequately insured against certain of the risks associated with such excluded liabilities, we could incur additional expenditures in 
resolving any such liabilities. If we become subject to liability based upon such contractual obligations or otherwise and we are required to indemnify the 
counterparties, it could have a material adverse effect on our financial position.

Elevation did not assume any of the excluded liabilities under the Elevation agreement. 

Pursuant to the Elevation agreement, Elevation assumed only certain specified liabilities set forth in the Elevation agreement and did not assume all 
of the liabilities associated with MM-121 or MM-111. Certain liabilities remain with us post-closing. While we believe that we have adequately accrued for 
these liabilities or are adequately insured against certain of the risks associated with such excluded liabilities, we could incur additional expenditures in 
resolving any such liabilities. If we become subject to liability based upon such contractual obligations or otherwise and we are required to indemnify the 
counterparties, it could have a material adverse effect on our financial position.

The Ipsen sale agreement may expose us to contingent liabilities. 

We have agreed to indemnify Ipsen for certain breaches of representations, warranties or covenants made by us in the Ipsen sale agreement and for 
certain specified existing litigation. We have agreed that if we cannot pay our indemnification obligations, Ipsen will have set-off rights against any future 
contingent payments. Indemnification claims by Ipsen could further materially and adversely affect our financial condition and/or significantly reduce any 
future contingent payments.

9

 
 
The Elevation agreement may expose us to contingent liabilities. 

We have agreed to indemnify Elevation for certain breaches of representations, warranties or covenants made by us in the Elevation agreement. We 

have agreed that Elevation will have set-off rights against any future contingent payments. Indemnification claims by Elevation could materially and 
adversely affect our financial condition and/or significantly reduce any future contingent payments.

Risks Related to Our Financial Position and Need for Additional Capital

We have incurred significant losses since our inception. We expect to incur operating losses for the foreseeable future and may never achieve or 
maintain profitability.

Since inception, we have incurred significant operating losses. Our net loss was $1.5 million and $2.5 million for the years ended December 31, 

2022 and 2021, respectively. As of December 31, 2022, we had an accumulated deficit of $547.6 million. To date, we have financed our operations 
primarily through private placements of convertible preferred stock, collaborations, public offerings of our securities, secured debt financings, sales of 
ONIVYDE and the Ipsen sale. We had devoted substantially all of our efforts to research and development, including clinical trials and to 
commercialization of our first product, ONIVYDE, which was sold to Ipsen. We have not completed development of or commercialized any other product 
candidates or diagnostics other than ONIVYDE. 

Although we are not actively developing product candidates and do not have any current plans to do so, to become and remain profitable, we would 

need to succeed in realizing milestone payments from either or both of the Ipsen and Elevation agreements. We are not developing and commercializing 
products. We expect to dividend out to our stockholders all or substantially all of any milestone payments and we do not anticipate seeking to develop any 
new products with any of our existing cash or any future milestone payments we may receive.  Our failure to achieve these potential milestone payments 
would depress the value of our company. A decline in the value of our company could also cause our stockholders to lose all or part of their investment.

We might not be able to utilize our net operating loss carryforwards and research and development tax credit carryforwards.

As of December 31, 2022, we had net operating loss carryforwards for federal and state income tax purposes of $215.0 million and $300.4 million, 

respectively. Our existing federal and state net operating loss carryforwards begin to expire in 2033. We also had available research and development 
credits for federal and state income tax purposes of approximately $28.7 million and $20.3 million, respectively. The federal and state research and 
development credits will begin to expire in 2022 and 2025, respectively. We also had federal Orphan Drug Credits of approximately $122.7 million that 
begin to expire in 2031. These net operating loss and tax credit carryforwards could expire unused or could be unavailable to offset our future income tax 
liabilities. Under federal income tax law, federal net operating losses incurred in 2018 and in future years may be carried forward indefinitely, but the 
deductibility of such federal net operating losses is limited. It is uncertain how various states will respond to this change in federal tax laws. If our ability to 
use our historical net operating loss and tax credit carryforwards is materially limited, it would harm our future operating results by effectively increasing 
our future tax obligations. In addition, the Ipsen sale was an installment sale given the potential milestone payments that could be received by us in future 
years. If we receive milestone payments in future years pursuant to the Ipsen sale, we will be liable for interest to the federal government pursuant to 
Internal Revenue Code section 453A and state governments pursuant to similar state tax provisions because it was an installment sale. The interest is 
compounding and is calculated based on the number of years between 2017 and the year the milestone payment is received by us. Any interest charges 
cannot be offset by net operating loss carryforwards or tax credits.

Our investments are subject to risks that could result in losses.

We have invested and plan to continue to invest our cash in a variety of financial instruments, principally securities issued by the U.S. government 

and its agencies, investment grade corporate bonds, including commercial paper, and money market instruments. All of these investments are subject to 
credit, liquidity, market and interest rate risk. Such risks, including the failure or severe financial distress of the financial institutions that hold our cash, 
cash equivalents and investments, may result in a loss of liquidity, impairment to our investments, realization of substantial future losses, or a complete loss 
of the investments in the long-term, which may have a material adverse effect on our business, results of operations, liquidity and financial condition. In 
order to manage the risk to our investments, we maintain an investment policy that, among other things, limits the amount that we may invest in any one 
issue or any single issuer and requires us to only invest in high credit quality securities, but there can be no guarantee that our investments will not result in 
losses.

10

 
 
Risks Related to Our Intellectual Property

We may become involved in lawsuits to protect or enforce our patents, which could be expensive, time-consuming and unsuccessful.

Competitors may infringe on our patents. To counter infringement or unauthorized use, we may be required to initiate infringement lawsuits, which 

can be expensive and time-consuming. In addition, in an infringement proceeding, a court may decide that a patent of ours is invalid or unenforceable, or 
may refuse to stop the other party from using the technology at issue on the grounds that our patents do not cover the technology in question. An adverse 
result in any litigation proceeding could put one or more of our patents at risk of being invalidated or interpreted narrowly. Furthermore, because of the 
substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could 
be compromised by disclosure during this type of litigation.

Third parties may initiate legal proceedings alleging that we are infringing their intellectual property rights, the outcome of which would be uncertain 
and could have a material adverse effect on the success of our business.

Our commercial success depends upon our ability and the ability of our collaborators to develop, manufacture, market and sell our products and 

product candidates and use our proprietary technologies without infringing the enforceable proprietary rights of third parties. We may become party to, or 
threatened with, future adversarial proceedings or litigation regarding intellectual property rights with respect to our products and technology, including 
interference or derivation proceedings before the U.S. Patent and Trademark Office. Third parties may assert infringement claims against us based on 
existing patents or patents that may be granted in the future. If we are found to infringe a third party’s intellectual property rights, we could be required to 
obtain a license from such third party to continue developing and marketing our products and technology. However, we may not be able to obtain any 
required license on commercially reasonable terms or at all. Even if we were able to obtain a license, it could be non-exclusive, thereby giving our 
competitors access to the same technologies licensed to us. We could be forced, including by court order, to cease commercializing the infringing 
technology or product. In addition, we could be found liable for monetary damages. A finding of infringement could prevent us from commercializing our 
product candidates, prevent us from divesting certain assets or force us to cease some of our business operations, which could materially harm our business. 
Claims that we have misappropriated the confidential information or trade secrets of third parties can have a similar negative impact on our business.

We may be subject to claims that our employees have wrongfully used or disclosed alleged trade secrets of their former employers.

Many of our former employees were previously employed at universities or other biotechnology or pharmaceutical companies, including our 
competitors or potential competitors. Although we try to ensure that our employees do not use the proprietary information or know-how of others in their 
work for us, we may be subject to claims that we or these employees have used or disclosed intellectual property, including trade secrets or other 
proprietary information, of any such employee’s former employer. Litigation may be necessary to defend against these claims. If we fail in defending any 
such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. Even if we are successful in defending 
against such claims, litigation could result in substantial costs and be a distraction to management.

Intellectual property litigation could cause us to spend substantial resources and distract our personnel from their normal responsibilities.

Even if resolved in our favor, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses, 
and could distract our personnel from their normal responsibilities. In addition, there could be public announcements of the results of hearings, motions or 
other interim proceedings or developments and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse 
effect on the price of our common stock. Such litigation or proceedings could substantially increase our operating losses and reduce our resources available 
for development or other activities. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Some of 
our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater 
financial resources. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a material adverse effect 
on our ability to compete in the marketplace and operate our business.

Risks Related to Data Protection and Cybersecurity

Significant disruptions of information technology systems or security breaches could adversely affect our business.

We are increasingly dependent upon information technology systems, infrastructure and data to operate our business. In the ordinary course of 

business, we collect, store and transmit large amounts of confidential information (including, among other things, trade secrets or other intellectual 
property, proprietary business information and personal information). It is critical that we do so in a secure manner to maintain the confidentiality and 
integrity of such confidential information. We also have outsourced significant 

11

 
 
elements of our operations to third parties, and as a result we manage a number of third-party vendors who have or could have access to our confidential 
information. Our information technology systems, and those of third-party vendors with whom we contract, and the large amounts of confidential 
information stored on those systems, make such systems vulnerable to service interruptions or to security breaches from inadvertent or intentional actions 
by our consultants, third-party vendors, and/or business partners, or from cyber-attacks by malicious third parties. Because we outsource our information 
technology systems, we are subject to risks that the activities of our third-party vendors may adversely affect our business even if an attack or breach does 
not directly target our systems. Cyber-attacks are increasing in their frequency, sophistication and intensity, and have become increasingly difficult to 
detect. Cyber-attacks could include the deployment of harmful malware, ransomware, denial-of-service attacks, social engineering and other means to 
affect service reliability and threaten the confidentiality, integrity and availability of information. Cyber-attacks could also include phishing attempts or e-
mail fraud to cause payments or information to be transmitted to an unintended recipient.

Significant disruptions of our information technology systems, or those of our third-party vendors, or security breaches could adversely affect our 

business operations and/or result in the loss, misappropriation and/or unauthorized access, use or disclosure of, or the prevention of access to, confidential 
information, including, among other things, trade secrets or other intellectual property, proprietary business information and personal information, and 
could result in financial, legal, business and reputational harm to us. For example, any such event that leads to unauthorized access, use or disclosure of 
personal information, including personal information regarding our patients or employees, could harm our reputation, require us to comply with federal 
and/or state breach notification laws and foreign law equivalents, and otherwise subject us to liability under laws and regulations that protect the privacy 
and security of personal information. Security breaches and other inappropriate access can be difficult to detect, and any delay in identifying them may lead 
to increased harm of the type described above. While we have implemented security measures to protect our information technology systems and 
infrastructure, there can be no assurance that such measures will prevent service interruptions or security breaches that could adversely affect our business.

Risks Related to Personnel Matters

Our future success depends on our ability to retain qualified personnel.

We do not have any employees and instead use a limited number of external consultants for the operation of our company, any of whom may 

terminate their consultancy with us at any time. We may not be able to attract and retain consultants on acceptable terms given the competition among 
numerous pharmaceutical and biotechnology companies for similar personnel. Our consultants and advisors may be employed by employers other than us 
and may have commitments under consulting or advisory contracts with other entities that may limit their availability to us. We do not maintain “key 
person” insurance.

Our corporate compliance efforts cannot guarantee that we are in compliance with all potentially applicable regulations.

We are subject to extensive regulation by federal, state and other authorities within the United States and numerous entities outside of the United 

States. We cannot provide any assurance that governmental authorities will find that our business practices comply with current or future administrative or 
judicial interpretations of potentially applicable laws and regulations. If we fail to comply with any of these laws and regulations, we could be subject to a 
range of regulatory actions, including suspension or termination of clinical trials, the failure to approve a product candidate, restrictions on our products or 
manufacturing processes, withdrawal of products from the market, significant fines, disqualification or debarment from participation in federally-funded 
healthcare programs or other sanctions or litigation, any of which events may have a significant adverse impact on our business.

Risks Related to Our Common Stock

Our directors and principal stockholders maintain the ability to significantly influence all matters submitted to stockholders for approval.

Our directors and stockholders who own more than 5% of our outstanding common stock, in the aggregate, own 36.8% of our capital stock, which 
includes shares held through funds managed by two of our directors. As a result, if these stockholders were to choose to act together, they would be able to 
significantly influence all matters submitted to our stockholders for approval, as well as our management and affairs. For example, these persons, if they 
choose to act together, would significantly influence the election of directors and approval of any merger, consolidation or sale of all or substantially all of 
our assets. This concentration of voting power could discourage, delay or prevent an acquisition of our company on terms that other stockholders may 
desire.

Provisions in our corporate charter documents and under Delaware law could make an acquisition of us, which may be beneficial to our stockholders, 
more difficult and may prevent attempts by our stockholders to replace or remove our current management.

Provisions in our corporate charter and our bylaws may discourage, delay or prevent a merger, acquisition or other change in control of us that 

stockholders may consider favorable, including transactions in which our stockholders might otherwise receive a 

12

 
 
premium for their shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock, 
thereby depressing the market price of our common stock. In addition, these provisions may frustrate or prevent any attempts by our stockholders to replace 
or remove our current management by making it more difficult for stockholders to replace members of our board of directors. Because our board of 
directors is responsible for appointing the members of our management team, these provisions could in turn affect any attempt by our stockholders to 
replace current members of our management team. Among others, these provisions:

•

•

•

•

•

•

allow the authorized number of our directors to be changed only by resolution of our board of directors;

establish advance notice requirements for stockholder proposals that can be acted on at stockholder meetings and nominations to our board of 
directors;

require that stockholder actions must be effected at a duly called stockholder meeting and prohibit actions by our stockholders by written 
consent;

limit who may call stockholder meetings;

authorize our board of directors to issue preferred stock without stockholder approval, which could be used to institute a “poison pill” that 
would work to dilute the stock ownership of a potential hostile acquirer, effectively preventing acquisitions that have not been approved by 
our board of directors; and

require the approval of the holders of at least 75% of the votes that all our stockholders would be entitled to cast to amend or repeal certain 
provisions of our charter or bylaws.

Moreover, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, 
which prohibits a person who owns in excess of 15% of our outstanding voting stock from merging or combining with us for a period of three years after 
the date of the transaction in which the person acquired in excess of 15% of our outstanding voting stock, unless the merger or combination is approved in a 
prescribed manner.

We have entered into a Section 382 Rights Agreement, and if the share purchase rights issued pursuant to such agreement are exercised, it could 
materially and adversely affect the market price of our common stock.

We entered into a Section 382 Rights Agreement (the "Rights Agreement"), on December 3, 2019, with Computershare Trust Company, N.A., a 

federally chartered trust company, as Rights Agent. The Rights Agreement was amended on December 2, 2022 to extend the term of the Rights Agreement 
through December 2, 2025. The Rights Agreement is intended to discourage acquisitions of our common stock which could result in a cumulative 
“ownership change” as defined under Section 382, thereby preserving our current ability to utilize net operating loss carryforwards to offset future income 
tax obligations, which would become subject to limitations if we were to experience an “ownership change,” as defined under Section 382. While this 
Rights Agreement is intended to preserve our current ability to utilize net operating loss carryforwards, it effectively deters current and future purchasers 
from accumulating 4.9% or more of our common stock, which could delay or discourage takeover attempts that our stockholders may consider favorable. 
In addition, if the share purchase rights issued pursuant to the Rights Agreement are exercised, it could materially and adversely affect the market price of 
our common stock.

Our stock price has been and may in the future be volatile, which could cause holders of our common stock to incur substantial losses.

Our stock price has been and in the future may be subject to substantial price volatility. The stock market in general and the market for 
biotechnology companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular 
companies. As a result of this volatility, our stockholders could incur substantial losses. The market price for our common stock may be influenced by 
many factors, including:

•

•

•

•

•

•

the timing and amount of potential milestone payments that we may receive from Ipsen and/or Elevation;

public disclosures by Ipsen and Elevation of the status and results of their clinical trials and Elevation’s ability to raise capital;

the success of competitive products or technologies;

results of clinical trials of competitors to Ipsen and Elevation;

regulatory or legal developments in the United States and other countries;

developments or disputes concerning patents or other proprietary rights;

13

 
 
 
•

•

•

•

•

•

•

the recruitment or departure of key personnel;

variations in our financial results or those of companies that are perceived to be similar to us;

changes in the structure of healthcare payment systems;

market conditions in the pharmaceutical and biotechnology sectors and issuance of new or changed securities analysts’ reports or 
recommendations;

activism by any single large stockholder or combination of stockholders;

general economic, industry and market conditions; and

the other factors described in this “Risk Factors” section.

Because we do not anticipate paying regular cash dividends on our common stock in the foreseeable future, capital appreciation, if any, will be the sole 
source of gain for holders of our common stock.

We have not historically declared or paid regular cash dividends on our common stock. Although our board of directors declared special cash 

dividends of $6.7 million, $20.0 million and $140.0 million, which were payable on December 23, 2019, September 5, 2019 and May 26, 2017, 
respectively, to stockholders of record as of the close of business on December 16, 2019, August 28, 2019 and May 17, 2017, respectively, we do not 
currently intend to pay any regular cash dividends in the foreseeable future unless we receive milestone payments from Ipsen or Elevation. In addition, the 
terms of any future debt agreements may in the future preclude us from paying dividends. As a result, capital appreciation, if any, of our common stock will 
be the sole source of gain for holders of our common stock for the foreseeable future.

Future sales of shares of our common stock, including by us or our directors, or shares issued upon the exercise of currently outstanding options could 
cause the market price of our common stock to drop significantly, even if our business is doing well.

A substantial portion of our outstanding common stock can be traded without restriction at any time. In addition, a portion of our outstanding 

common stock is currently restricted as a result of federal securities laws, but can be sold at any time subject to applicable volume limitations. As such, 
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 the market that 
the holders of a large number of shares intend to sell shares, by us or others, could reduce the market price of our common stock. In addition, we have a 
significant number of shares that are subject to outstanding options. The exercise of these options and the subsequent sale of the underlying common stock 
could cause a further decline in our stock price. 

The ongoing COVID-19 pandemic may delay or otherwise adversely impact our ability to realize potential milestone payments from the Ipsen sale and 
the Elevation sale and create other additional risks which could have material and adverse impacts on our business, financial condition, liquidity and 
results of operations.

We are unable to accurately predict the full impact that the ongoing coronavirus (“COVID-19”) pandemic will have on our financial condition due 

to numerous factors that are not within our control, including the duration and severity of the outbreak. Specifically, stay-at-home orders, business closures, 
travel restrictions, supply chain disruptions and employee and clinical trial participant illness or quarantines could result in disruptions to Ipsen and 
Elevation’s ability to conduct research, preclinical, clinical and/or regulatory activities that are required to trigger potential milestone payments to us. If 
these activities are significantly delayed, the attainment of any milestone payments we might receive would also likely be delayed. The COVID-19 
pandemic may also significantly affect our ability to sell any remaining preclinical assets due to the inability of potential partners to obtain capital or 
otherwise complete a transaction. In addition, the COVID-19 pandemic has resulted in ongoing volatility in financial markets. If our access to capital is 
restricted or associated borrowing costs increase as a result of developments in financial markets relating to the COVID-19 pandemic, our financial 
condition could be adversely impacted if we seek to raise equity and/or debt financing. At this time, we do not believe that the COVID-19 pandemic will 
have a significant impact on our current day-to-day operations or our near-term financial condition.

To the extent the COVID-19 pandemic adversely affects our business and financial results, it may also have the effect of heightening many of the 

other risks described in the “Risk Factors” sections.

14

 
 
 
 
 
Item 1B. Unresolved Staff Comments

None.

Item 2. Properties

We do not currently own or lease any facilities or property that are material to our business.

Item 3. Legal Proceedings

We are not currently a party to any material legal proceedings.

Item 4. Mine Safety Disclosures

Not applicable.

15

 
 
Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Our common stock is publicly traded on the Nasdaq Global Market under the symbol “MACK”. 

PART II

Holders

As of February 28, 2023, there were approximately 91 holders of record of our common stock. This number does not include beneficial owners 
whose shares are held by nominees in street name. During the fourth quarter of 2022, officers, consultants and former employees and consultants exercised 
outstanding stock options to purchase 804,860 shares of our Class A common stock for net proceeds to us of $6.5 million.

Dividends

We do not currently intend to pay any regular cash dividends in the foreseeable future unless and until we receive any milestone payments from 

Ipsen or Elevation.

Item 6. Selected Financial Data

Not Applicable. 

16

 
 
 
 
 
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion of our financial condition and results of operations should be read in conjunction with our financial statements and the 
notes to those financial statements appearing elsewhere in this Annual Report on Form 10-K. This discussion contains forward-looking statements that 
involve significant risks and uncertainties. As a result of many factors, such as those set forth in Part I, Item 1A. Risk Factors of this Annual Report on 
Form 10-K, which are incorporated herein by reference, our actual results may differ materially from those anticipated in these forward-looking 
statements.

Overview

We are a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone 

payments related to our sale of ONIVYDE® to Ipsen S.A., or Ipsen, in April 2017 and up to $54.5 million in contingent milestone payments related to our 
sale of MM-121 and MM-111 to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.), or Elevation, in July 2019. We do not have any 
ongoing research or development activities and are seeking potential acquirers for our remaining preclinical and clinical assets. We do not have any 
employees and instead use external consultants for the operation of our company.

On April 3, 2017, we completed the sale of ONIVYDE and MM-436 (the “commercial business”) to Ipsen (the “Ipsen sale”). In connection with the 

Ipsen sale, we are eligible to receive up to $450.0 million in additional regulatory approval-based milestone payments. We entered into a license and 
collaboration agreement, or the Servier agreement, between Ipsen and Les Laboratoires Servier SAS, or Servier (as assignee from Shire plc) in 2014, and 
on April 3, 2017, the Servier agreement was assigned to Ipsen in connection with the completion of the Ipsen sale. We have received all $33.0 million in 
milestone payments under the Servier agreement.

The remaining up to $450.0 million in potential milestone payments resulting from the Ipsen sale consist of:

•

•

•

$225.0 million upon approval by the U.S. Food and Drug Administration, or FDA, of ONIVYDE for the first-line treatment of metastatic 
adenocarcinoma of the pancreas, subject to certain conditions;

$150.0 million upon approval by the FDA of ONIVYDE for the treatment of small-cell lung cancer after failure of first-line chemotherapy; 
and

$75.0 million upon approval by the FDA of ONIVYDE for an additional indication unrelated to those described above.

Our non-commercial assets, including our clinical and preclinical development programs, were not included in the Ipsen sale and remain assets of 

ours. 

•

•

In November 2022, Ipsen announced the Phase III NAPOLI 3 trial of Onivyde® (irinotecan liposome injection) plus 5-
fluorouracil/leucovorin and oxaliplatin (the “NALIRIFOX regimen”) met its primary endpoint demonstrating clinically meaningful and 
statistically significant improvement in overall survival compared to nab-paclitaxel plus gemcitabine in 770 previously untreated patients 
with metastatic pancreatic ductal adenocarcinoma (“mPDAC”) and key secondary efficacy outcome of progression-free survival (PFS) also 
showed significant improvement over the comparator arm. Ipsen also announced that the safety profile of Onivyde in the NAPOLI 3 trial was 
consistent with those observed in the previous phase I/II mPDAC study. Ipsen also stated that it intends to file a supplemental New Drug 
Application with the U.S. Food and Drug Administration for Onivyde in combination with oxaliplatin plus 5-fluorouracil/leucovorin for the 
treatment of patients with previously untreated mPDAC following the Fast Track Designation granted in 2020. In January 2023, Ipsen 
presented clinical trial results at the 2023 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium. In February 
2023 Ipsen provided guidance to investors that it intends to file a supplemental New Drug Application with the U.S. Food and Drug 
Administration during the first half of 2023 following the Fast Track Designation granted in 2020 for the use of Onivyde in combination with 
oxaliplatin plus 5-fluorouracil/leucovorin for the treatment of patients with previously untreated mPDAC.

In August 2022, Ipsen announced that the Phase III RESILIENT trial did not meet its primary endpoint of overall survival compared to 
topotecan. The trial is evaluating Onivyde® (irinotecan liposomal injection) versus topotecan in patients with small cell lung cancer, who 
have progressed on or after platinum-based first-line therapy treatment. RESILIENT is a Phase III trial conducted in two parts; the first part 
read out in 2020 confirming the safety, dosing and efficacy of Onivyde; part two is evaluating the efficacy of Onivyde versus topotecan. The 
analysis concluded that the primary endpoint overall survival was not met in patients treated with Onivyde versus topotecan. However, a 
doubling of the secondary endpoint of objective response rate in favor of Onivyde was observed. The safety and tolerability of Onivyde was 
consistent with its already-known safety profile, and no new safety concerns emerged. The clinical study results will be communicated with 
the regulatory agency. Ipsen indicated that while the results from the analysis of the RESILIENT 

17

 
 
trial have not demonstrated an overall survival benefit with Onivyde in patients in second-line small cell lung cancer, Ipsen intends to analyze 
the data further before decisions regarding next steps are made. To date, there have been no further public announcements by Ipsen regarding 
these matters and it remains unclear as to whether Ipsen will continue to seek approval for the use of ONIVYDE in the small cell lung cancer 
application.  If Ipsen elects not to proceed with seeking regulatory approval, or if regulatory approval is not obtained, we would not be 
entitled to the $150 million milestone payment tied to approval of Onivyde for treating small cell lung cancer.

On May 30, 2019, we announced the completion of our review of strategic alternatives, following which our board of directors implemented a series 

of measures designed to extend our cash runway into 2027 and preserve our ability to capture the potential milestone payments resulting from the Ipsen 
sale. We have based this estimate on assumptions that may prove to be wrong, and we could use our financial resources sooner than we currently expect. In 
connection with that announcement, we discontinued the discovery efforts on our remaining preclinical programs: MM-401, an agonistic antibody targeting 
a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein targeting death receptors 4 and 5. We are seeking 
potential acquirers for our remaining preclinical and clinical assets.

The termination of our executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by 
July 12, 2019. As of July 12, 2019, we did not have any employees. We have engaged external consultants to run our day-to-day operations. We have also 
entered into consulting agreements with certain former members of our executive management team who are supporting our relationship with current 
partners, assisting with the potential sale of remaining preclinical and clinical assets, and assisting with certain legal and regulatory matters and the 
continued wind-down of operations.

On July 12, 2019, we completed the sale to Elevation, or the Elevation sale, of our anti-HER3 antibody programs, MM-121 (seribantumab) and 
MM-111. In connection with the Elevation sale, we received an upfront cash payment of $3.5 million and are eligible to receive up to $54.5 million in 
additional potential development, regulatory approval and commercial-based milestone payments, consisting of:

•

•

•

$3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

Up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United 
States, Europe and Japan; and

Up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 
million for MM-121 and MM-111.

In January 2023, Elevation announced it is pausing further investment in the clinical development of seribantumab and intends to pursue further 

development only in collaboration with a partner. Elevation also announced that it intends to present additional interim data from its study of seribantumab 
in the first half of 2023.

On March 27, 2020, we entered into an Asset Purchase Agreement (the “Celator Asset Purchase Agreement”) with Celator Pharmaceuticals, Inc. 

(the “Buyer”), pursuant to which the Buyer agreed to purchase certain assets (the “Transferred Assets”) relating to certain of our preclinical nanoliposome 
programs (the “Transaction”). We completed the Transaction simultaneously with the execution of the Celator Asset Purchase Agreement. Under the terms 
of the Celator Asset Purchase Agreement, the Buyer paid to us a cash payment of $2.3 million and reimbursed us for $0.2 million related to certain 
specified expenses and to assume certain liabilities with respect to the Transferred Assets. We incurred $0.4 million expenses related to the Transaction.

On September 15, 2021, we entered into an Asset Purchase Option Agreement (the “Asset Purchase Option Agreement”) with a third party, pursuant 

to which the third party agreed to obtain an exclusive option, to purchase one of our preclinical programs with a consideration of $0.5 million. Under the 
terms of the Asset Purchase Option Agreement, the third party paid to us the option fee of $0.1 million. The third party had the right to exercise the option 
within 24 months from September 15, 2021. We recognized a gain of $0.1 million related to the option fee payment for the year ended December 31, 2021. 
On January 18, 2022, the third party provided written notice to us of its intent to exercise such option. On March 1, 2022, we entered the Asset Purchase 
Option Agreement with the third party. The consideration of $0.5 million was paid to us and a gain of $0.5 million was recognized in March 2022.

On January 23, 2023, we entered into an Asset Purchase Option Agreement (the “Option Agreement”) with a third party (the “Purchaser”), 
pursuant to which the Purchaser agreed to obtain an exclusive option (the “Option”) to purchase one of the Company’s preclinical programs with a 
consideration of $0.7 million. Under the terms of the Option Agreement, the Purchaser paid to us the Option fee of $0.2 million in January 2023. The 
Purchaser may exercise the Option prior to July 23, 2023.

18

 
 
We previously devoted substantially all of our resources to our drug discovery and development efforts, including conducting clinical trials for our 

product candidates, protecting our intellectual property and providing general and administrative support for these operations. We have financed our 
operations primarily through private placements of convertible preferred stock, collaborations, public offerings of our securities, secured debt financings, 
sales of ONIVYDE and the Ipsen sale.

As of December 31, 2022, we had unrestricted cash and cash equivalents of $19.4 million. We expect that our cash and cash equivalents as of 
December 31, 2022 will be sufficient to continue our operations beyond 2027, which we estimate is beyond the latest date when the longest-term potential 
Ipsen milestone may be achieved.

We have a history of losses from our operations. We do not expect to be profitable from our operations in the future unless we receive potential 
future milestone payments, if any. As of December 31, 2022, we had an accumulated deficit of $547.6 million. Our net loss was $1.5 million and $2.5 
million for years ended December 31, 2022 and 2021, respectively. We do not expect to incur any research and development expenses going forward.

Financial Operations Overview

General and administrative expenses

General and administrative expenses consist primarily of stock-based compensation expenses, legal, intellectual property, business development, 
finance, information technology, corporate communications and investor relations. Other general and administrative expenses include costs for board of 
director’s costs, insurance expenses, legal and professional fees, and accounting and information technology services fees.

Interest income

Interest income consists primarily of interest income associated with our money market fund.

Critical Accounting Policies and Significant Judgments and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, 
which we have prepared in accordance with the rules and regulations of the Securities and Exchange Commission, or the SEC, and generally accepted 
accounting principles in the United States, or GAAP. The preparation of these consolidated financial statements requires us to make estimates and 
assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial 
statements, as well as the reported expenses during the reporting periods. We evaluate our estimates and judgments on an ongoing basis. We base our 
estimates on historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis 
for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Our actual results may differ from 
these estimates under different assumptions or conditions.

While our significant accounting policies are more fully described in Note 1, “Nature of the Business and Summary of Significant Accounting 
Policies,” in the accompanying notes to the consolidated financial statements appearing at the end of this Annual Report on Form 10-K, we believe that the 
following accounting policies are the most critical to aid in fully understanding and evaluating our financial condition and results of operations.

Accrued expenses

As part of the process of preparing financial statements, we are required to estimate accrued expenses. This process involves identifying services 
that have been performed on our behalf and estimating the level of services performed and the associated costs incurred for such services where we have 
not yet been invoiced or otherwise notified of actual cost. We record these estimates in our consolidated financial statements as of each balance sheet date. 

In accruing service fees, we estimate the time period over which services will be provided and the level of effort in each period. If the actual timing 
of the provision of services or the level of effort varies from the estimate, we will adjust the accrual accordingly. In the event that we do not identify costs 
that have been incurred or we under or overestimate the level of services performed or the costs of such services, our actual expenses could differ from 
such estimates. The date on which some services commence, the level of services performed on or before a given date and the cost of such services are 
often subjective determinations. We make estimates based on the facts and circumstances known to us at the time and in accordance with GAAP. There 
have been no material changes in estimates for the periods presented.

19

 
 
 
Stock-based compensation expense

We account for our stock-based compensation awards in accordance with Accounting Standards Codification, or ASC, 718, Compensation – Stock 
Compensation. ASC 718 requires all share-based payments to employees, including grants of employee stock options, to be recognized in the consolidated 
statements of operations and comprehensive loss based on their grant date fair values. For stock options granted to employees and to members of our board 
of directors for their service on the board of directors, we estimate the grant date fair value of each option award using the Black-Scholes option pricing 
model. The use of the Black-Scholes option pricing model requires us to make assumptions with respect to the expected term of the option, the expected 
volatility of our common stock consistent with the expected term of the option, the risk-free interest rate consistent with the expected term of the option and 
the expected dividend yield of our common stock. Stock-based compensation expense related to employee stock options is measured using the fair value of 
the award at the grant date and is adjusted quarterly to reflect actual forfeitures. Stock-based compensation expense is then recognized on a straight-line 
basis over the vesting period, which is also the requisite service period.

Results of Operations

Comparison of the years ended December 31, 2022 and 2021

(in thousands)
Operating expenses:
General and administrative expenses
Gain on sales of assets
Total operating expenses
Loss from operations
Interest income
Loss before income tax expense
Income tax expense
Net loss

Years Ended December 31,
2022

2021

  $

  $

2,174     $
(445 )  
1,729    
(1,729 )  
188    
(1,541 )  
(3 )  
(1,544 )   $

2,616  
(144 )
2,472  
(2,472 )
20  
(2,452 )
(3 )
(2,455 )

General and administrative expenses

General and administrative expenses were $2.2 million for the year ended December 31, 2022 compared to $2.6 million for the year ended 

December 31, 2021, a decrease of $0.4 million, or 15%. This decrease was primarily attributable to the decrease in both share-based compensation expense 
and patent costs.

Gain on sales of assets

Gain on sale of assets was $0.5 million for the year ended December 31, 2022, primarily attributable to the fee to purchase one of our preclinical 

programs paid by a third party pursuant to the Asset Purchase Option Agreement. Gain on sale of assets was $0.1 million for the year ended December 31, 
2021, attributable to the sale of certain of our preclinical programs to a third party. 

Interest income

Interest income was $0.2 million for the year ended December 31, 2022 and less than $0.1 million for the year ended December 31, 2021, primarily 

attributable to the increase in our interest rate associated with our money market fund.

Liquidity and Capital Resources

Sources of liquidity

We have financed our operations from inception through December 31, 2022 primarily through private placements of convertible preferred stock, 
collaborations, public offerings of our securities, secured debt financings, sales of ONIVYDE and the Ipsen sale. Through December 31, 2022, we have 
received $580.7 million from the Ipsen sale, $268.2 million from the sale of convertible preferred stock and warrants, $126.7 million of net proceeds from 
the sale of common stock in our initial public offering and a July 2013 follow-on underwritten public offering, $38.6 million of net proceeds from our 2015 
“at the market offering” program, or the ATM offering, $39.6 million of net proceeds from a secured debt financing, $120.6 million of net proceeds from 
the issuance of the convertible notes in our July 2013 underwritten public offering, $168.5 million of net proceeds from the issuance of the 2022 notes, 
$492.5 million of upfront license fees, milestone payments, reimbursement of research and development costs and manufacturing services and other 
payments from our collaborations, $68.9 million of cash receipts related to ONIVYDE sales, $33.0 million in milestone payments related to the 
development and commercialization of ONIVYDE and $14.7 million in net borrowings 

20

 
 
 
 
 
 
 
   
 
 
     
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
pursuant to the loan agreement with Hercules. In 2022, we also received cash proceeds of $6.5 million from the exercise of stock options. As of December 
31, 2022, we had unrestricted cash and cash equivalents of $19.4 million.

Cash flows

The following table provides information regarding our cash flows for the years ended December 31, 2022 and 2021:

(in thousands)
Net cash used in operating activities
Net cash provided by investing activities
Net cash provided by financing activities
Net increase in cash and cash equivalents

Years Ended December 31,
2021
2022

  $

  $

(1,742 )   $
445      
6,533      
5,236     $

(218 )
144  
239  
165  

Operating activities

Cash used in operating activities was $1.7 million during the year ended December 31, 2022. The cash used in operating activities was primarily a 

result of our $1.5 million net loss and net decrease in assets and liabilities of $0.2 million. The net loss was adjusted by a net decrease in assets and 
liabilities of $0.2 million, which was primarily driven by decreases in prepaid expenses and other assets of $0.2 million. This decrease included non-cash 
adjustments of $0.4 million gain on the sale of in-process research and development assets, offset by $0.1 million of stock-based compensation expense. 

Cash used in operating activities was $0.2 million during the year ended December 31, 2021. The cash used in operating activities was primarily a 

result of our $2.5 million net loss and net decrease in assets and liabilities of $0.2 million. The net loss was adjusted by a net decrease in assets and 
liabilities of $2.0 million, which was primarily driven by decreases in prepaid expenses and other assets of $2.2 million, partially offset by a decrease in 
accounts payable, accrued expenses and other of $0.2 million. This decrease included non-cash adjustments of $0.1 million gain on the sale of in-process 
research and development assets, offset by $0.4 million of stock-based compensation expense.

Investing activities

Cash provided by investing activities of $0.4 million and $0.1 million during the years ended December 31, 2022 and 2021, respectively, was due to 

proceeds from the sale of in-process research and development. 

Financing activities

Cash provided by financing activities of $6.5 million and $0.2 million during the years ended December 31, 2022 and 2021, respectively, was due to 

proceeds from the exercise of stock options. 

Funding requirements

We have incurred significant expenses and operating losses to date. On May 30, 2019, we announced the completion of our review of strategic 
alternatives, following which our board of directors implemented a series of measures designed to extend our cash runway into 2027 and preserve our 
ability to capture the potential milestone payments resulting from the Ipsen sale. In connection with that announcement, we discontinued the discovery 
efforts on our remaining preclinical programs and implemented a reduction in headcount resulting in the termination of all remaining employees as of July 
12, 2019. Our future capital requirements will depend on many factors, including:

•

•

•

•

•

•

the timing and amount of potential milestone payments related to ONIVYDE that we may receive from Ipsen;

the timing and amount of potential milestone payments that we may receive from Elevation;

the timing and amount of any special dividend to our stockholders that our board of directors may declare;

the timing and amount of general and administrative expenses required to continue to operate our company;

the extent to which we owe any taxes for current, future or prior periods, including as a result of any audits by taxing authorities;

the extent to which we invest in any future research or development activities of our product candidates;

21

 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
•

•

•

the costs of preparing, filing and prosecuting patent applications and maintaining, enforcing and defending intellectual property-related 
claims; 

the extent to which we acquire or invest in businesses, products and technologies; and

the costs associated with operating as a public company and maintaining compliance with exchange listing and SEC requirements.

We do not believe that we will be able to raise a material amount of capital through the sale of our equity securities or debt financing. Rather, our 

goal is to judiciously expend our remaining cash until such time, if ever, as we receive additional milestone payments from Ipsen and Elevation.  There can 
be no assurance as to the timing, terms or consummation of any financing or divestiture of our few remaining intellectual property assets. We do not have 
any committed external sources of funds. In the unlikely event that we raise additional capital through the sale of equity or convertible debt securities, the 
ownership interest of our stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect 
the rights of our stockholders. Debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific 
actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through arrangements with third 
parties, we may have to relinquish valuable rights to our future revenue streams or product candidates.

Off-Balance Sheet Arrangements

We did not have during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined under SEC rules.

Tax Loss Carryforwards

At December 31, 2022, we had net operating loss carryforwards for federal and state income tax purposes of $215.0 million and $300.4 million, 

respectively. Our existing federal and state net operating loss carryforwards begin to expire in 2033. We also had available research and development 
credits for federal and state income tax purposes of approximately $28.7 million and $20.3 million, respectively. The federal and state research and 
development credits will begin to expire in 2022 and 2025, respectively. As of December 31, 2022, we also had available investment tax credits for state 
income tax purposes of less than $0.1 million which do not expire. We have orphan drug credits of $122.7 million, which begin to expire in 2031. 

We have evaluated the positive and negative evidence bearing upon the realizability of our deferred tax assets, which are comprised principally of 

net operating loss carryforwards and research and development credits. Under the applicable accounting standards, we have considered our history of losses 
and concluded that it is more likely than not that we will not recognize the benefits of federal and state deferred tax assets. Accordingly, a full valuation 
allowance has been established against the deferred tax assets. 

Utilization of the net operating loss and tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal 
Revenue Code due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the 
amount of net operating loss and tax credit carryforwards that can be utilized annually to offset future taxable income and tax. We completed an evaluation 
of ownership changes through November 16, 2022 to assess whether utilization of our net operating loss or tax credit carryforwards would be subject to an 
annual limitation under Section 382 of the Internal Revenue Code. We believe we can utilize our tax attributes generated through November 16, 2022 as a 
result of the analysis. To the extent an ownership change has occurred after November 16, 2022 or occurs in the future, the net operating loss and tax credit 
carryforwards may be subject to limitation. 

We have not, as of yet, conducted a study of our domestic research and development credit carryforwards and Orphan Drug Credits. This study may 

result in an increase or decrease to our credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being 
presented as an uncertain tax position. A full valuation allowance has been provided against our credits, and if an adjustment is required, this adjustment 
would be offset by an adjustment to the valuation allowance. As a result, there would be no impact to the statement of operations and comprehensive loss, 
balance sheet or cash flows if an adjustment were required.

382 Rights Agreement

On December 3, 2019, we entered into a Section 382 Rights Agreement, or the Rights Agreement, with Computershare Trust Company, N.A., a 

federally chartered trust company, as Rights Agent. Pursuant to the Rights Agreement, on December 13, 2019, we issued a dividend of one preferred share 
purchase right, or a Right, for each share of our common stock to the stockholders of record 

22

 
 
on that date. Each Right entitles the registered holder to purchase from us one one-thousandth of a share of Series Z Junior Preferred Stock, par value $0.01 
per share, or the Preferred Shares, at a price of $18.00 per one one-thousandth of a Preferred Share represented by a Right, subject to adjustment. The 
description and terms of the Rights are set forth in the Rights Agreement. In December 2022, we extended the term of the Rights Plan through December 2, 
2025.

Recent Accounting Pronouncements

See Note 1, “Nature of the Business and Summary of Significant Accounting Policies,” in the accompanying notes to the consolidated financial 

statements for a description of recent accounting pronouncements applicable to our business.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

We invest in money market funds. The goals of our investment policy are preservation of capital, fulfillment of liquidity needs and fiduciary control 

of cash and investments. We also seek to maximize income from our investments without assuming significant risk.

Our primary exposure to market risk is interest income sensitivity, which is affected by changes in the general level of interest rates, particularly 

because our investments are in short-term marketable securities. Due to the short-term duration of our investment portfolio and the low risk profile of our 
investments, an immediate 10% change in interest rates would not have a material effect on the fair market value of our portfolio. We have the ability and 
intention to hold our investments until maturity, and therefore, we would not expect our operating results or cash flows to be affected to any significant 
degree by the effect of a sudden change in market interest rates on our investment portfolio.

We do not currently have any auction rate or mortgage-backed securities. We do not believe our cash and cash equivalents have significant risk of 

default or illiquidity, however we cannot provide absolute assurance that in the future our investments will not be subject to adverse changes in market 
value.

Item 8. Financial Statements and Supplementary Data

Our consolidated financial statements, together with the report of our independent registered public accounting firm, appear on pages F-1 through F-

16 of this Annual Report on Form 10-K.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our principal executive and financial officer, evaluated the effectiveness of our disclosure controls and 

procedures as of December 31, 2022. The term “disclosure controls and procedures,” as defined in Rules 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 information required to be disclosed by a company in the reports that it 
files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. 
Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a 
company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its 
principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure. Management recognizes that any 
controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management 
necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure 
controls and procedures as of December 31, 2022, our principal executive and financial officer concluded that, as of such date, our disclosure controls and 
procedures were effective at the reasonable assurance level.

23

 
 
 
Internal Control Over Financial Reporting

Management’s Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting for the company. Internal control 

over financial reporting is defined in Rule 13a-15(f) or 15d-15(f) promulgated under the Exchange Act as a process designed by, or under the supervision 
of, the company’s principal executive and principal financial officers and effected by the company’s board of directors, management and other personnel, to 
provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance 
with GAAP and includes those policies and procedures that:

•

•

•

pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of the assets of 
the company;

provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with 
GAAP, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and 
directors of the company; and

provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of the company’s assets 
that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Therefore, even those systems 

determined to be effective can provide only reasonable assurance with respect to financial statement preparation and presentation. Projections of any 
evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree 
of compliance with the policies or procedures may deteriorate.

Our management assessed the effectiveness of our internal control over financial reporting as of December 31, 2022. In making this assessment, 

management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in Internal Control-Integrated 
Framework (2013). Based on its assessment, management concluded that, as of December 31, 2022, our internal control over financial reporting is effective 
based on those criteria.

This annual report does not include an attestation report of our registered public accounting firm regarding internal control over financial reporting. 
Management’s report was not subject to attestation by our registered public accounting firm pursuant to rules of the Securities and Exchange Commission 
that permit us to provide only management’s report in this annual report.

Changes in Internal Control Over Financial Reporting

No change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) occurred during the 

year ended December 31, 2022 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information

None.

Item 9C. Disclosure Regarding Foreign Jurisdictions That Prevent Inspections

Not applicable.

24

 
 
 
 
Item 10. Directors, Executive Officers and Corporate Governance

PART III

The information required by this Item 10 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2023 Annual 

Meeting of Stockholders and is incorporated herein by reference.

Item 11. Executive Compensation

The information required by this Item 11 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2023 Annual 

Meeting of Stockholders and is incorporated herein by reference.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

The information required by this Item 12 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2023 Annual 

Meeting of Stockholders and is incorporated herein by reference.

Item 13. Certain Relationships and Related Transactions, and Director Independence

The information required by this Item 13 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2023 Annual 

Meeting of Stockholders and is incorporated herein by reference.

Item 14. Principal Accountant Fees and Services

The information required by this Item 14 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2023 Annual 

Meeting of Stockholders and is incorporated herein by reference.

25

 
 
Item 15. Exhibits and Financial Statement Schedules

(1)

Financial Statements

PART IV

Our consolidated financial statements are set forth on pages F-1 through F-16 of this Annual Report on Form 10-K and are incorporated herein by 

reference.

(2)

Financial Statement Schedules

Schedules have been omitted since they are either not required or not applicable or the information is otherwise included herein.

(3)

Exhibits

Exhibit 
Number

Description of Exhibit

  2.1

  Asset Purchase and Sale Agreement, dated as of January 7, 2017, by and between the Registrant and Ipsen S.A. (incorporated by reference to 

Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on January 9, 2017)

  3.1

  Restated Certificate of Incorporation of the Registrant, as amended (incorporated by reference to Exhibit 3.1 to the Registrant’s Quarterly 

Report on Form 10-Q filed on August 7, 2018)

  3.2

  Amended and Restated Bylaws of the Registrant (incorporated by reference to Exhibit 3.5 to the Registrant’s Registration Statement on Form 

S-1, as amended, filed on January 13, 2012)

  3.3

  Certificate of Designation of Series Z Junior Preferred Stock of the Registrant, as filed with the Secretary of State of the State of Delaware 
on December 3, 2019 (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K filed on December 3, 2019)

  4.1

  Specimen certificate evidencing shares of common stock (incorporated by reference to Exhibit 4.1 to the Registrant’s Annual Report on 

Form 10-K filed on March 12, 2018)

  4.4

  Section 382 Rights Agreement, dated as of December 3, 2019, between the Registrant and Computershare Trust Company, N.A., as Rights 

Agent (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K filed on December 3, 2019)

  4.5*

  Description of the Registrant’s Securities Registered under Section 12 of the Exchange Act

 4.5.1*

  First Amendment to Section 382 Rights Agreement

10.1#

  2008 Stock Incentive Plan (incorporated by reference to Exhibit 10.2 to the Registrant’s Registration Statement on Form S-1, as amended, 

filed on July 8, 2011)

10.2#

  2011 Stock Incentive Plan (incorporated by reference to Exhibit 10.3 to the Registrant’s Registration Statement on Form S-1, as amended, 

filed on January 13, 2012)

10.3#

  2021 Incentive Award Plan (as set forth on Annex A in the Company’s Definitive Proxy Statement for the 2021 Annual Meeting of 

Stockholders, filed on April 22, 2021)

10.4#

  Form of Incentive Stock Option Agreement under 2011 Stock Incentive Plan (incorporated by reference to Exhibit 10.4 to the Registrant’s 

Registration Statement on Form S-1, as amended, filed on January 13, 2012)

10.5#

  Form of Non-Qualified Stock Option Agreement under 2011 Stock Incentive Plan (incorporated by reference to Exhibit 10.5 to the 

Registrant’s Registration Statement on Form S-1, as amended, filed on January 13, 2012)

10.12#

  Form of Indemnification Agreement between the Registrant and each director and executive officer (incorporated by reference to Exhibit 

10.12 to the Registrant’s Registration Statement on Form S-1, as amended, filed on August 19, 2011)

10.31†

  Asset Purchase Agreement, dated as of May 28, 2019, by and between the Registrant and 14ner Oncology, Inc. (incorporated by reference to 

Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on May 30, 2019)

10.32

  Amendment No. 1 to Asset Purchase Agreement, dated as of June 24, 2019, by and between the Registrant and 14ner Oncology, Inc. 

(incorporated by reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on June 24, 2019)

26

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Exhibit 
Number

Description of Exhibit

10.33

  Amendment No. 2 to Asset Purchase Agreement, dated as of June 28, 2019, by and between the Registrant and 14ner Oncology, Inc. 

(incorporated by reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on July 1, 2019)

10.39

  Cooperation Agreement, dated as of September 18, 2019, by and among the Registrant, Newtyn Management, LLC, Newtyn Partners, LP, 

Newtyn TE Partners, LP, Noah G. Levy, Newtyn Capital Partners, LP, Ledo Capital, LLC, Western Standard, LLC, Western Standard 
Partners, LP, Western Standard Partners QP, LP and Eric D. Andersen (incorporated by reference to Exhibit 10.1 to the Registrant’s Current 
Report on Form 8-K filed on September 20, 2019)

10.40

  Asset Purchase Agreement, dated as of March 27, 2020, by and between the Registrant and Celator Pharmaceuticals, Inc. (incorporated by 

reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on March 30, 2020)

21.1*

23.1*

31.1*

  Subsidiaries of the Registrant

  Consent of Marcum LLP, an independent registered public accounting firm

  Certification of Principal Executive Officer pursuant to Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted 

pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

31.2*

  Certification of Principal Financial Officer pursuant to Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted 

pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

32.1+

  Certification of Principal Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley 

Act of 2002

32.2+

  Certification of Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley 

Act of 2002

101.INS*

  Inline XBRL Instance Document - The instance document does not appear in the interactive data file because its XBRL tags are embedded 

within the inline XBRL document.

101.SCH*   Inline XBRL Taxonomy Extension Schema Document

101.CAL*   Inline XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF*   Inline XBRL Taxonomy Extension Definition Linkbase Document

101.LAB*   Inline XBRL Taxonomy Extension Label Linkbase Database

101.PRE*   Inline XBRL Taxonomy Extension Presentation Linkbase Document

104

  Cover Page Interactive Data File (embedded within the Inline XBRL document)

* Filed herewith.

+ Furnished herewith.

# Management contract or compensatory plan, contract or agreement.

† Confidential treatment granted as to portions of the exhibit. Confidential materials omitted and filed separately with the Securities and Exchange 

Commission.

Item 16. Form 10-K Summary

Not applicable.

27

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on 

its behalf by the undersigned, thereunto duly authorized.

SIGNATURES

Date: March 9, 2023

  MERRIMACK PHARMACEUTICALS, INC.

  By:

/s/ Gary L. Crocker 
Gary L. Crocker
President

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the 

registrant and in the capacities and on the dates indicated.

Signature 

/s/ Gary L. Crocker
Gary L. Crocker

/s/ Eric D. Andersen
Eric D. Andersen

/s/ Noah G. Levy
Noah G. Levy

/s/ Ulrik B. Nielsen, Ph.D.
Ulrik B. Nielsen, Ph.D.

/s/ Ana Radeljevic
Ana Radeljevic

Title 

  President and Chairman of the Board (Principal 
Executive, Financial and Accounting Officer)

  Director

  Director

  Director

  Director

Date 

March 9, 2023

March 9, 2023

March 9, 2023

March 9, 2023

March 9, 2023

 
 
 
 
   
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
MERRIMACK PHARMACEUTICALS, INC.
INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting Firm (PCAOB ID 688) 
Consolidated Balance Sheets
Consolidated Statements of Operations and Comprehensive Loss
Consolidated Statements of Stockholders’ Equity
Consolidated Statements of Cash Flows
Notes to Consolidated Financial Statements

F-1

F-2
F-3
F-4
F-5
F-6
F-7

 
 
 
 
Report of Independent Registered Public Accounting Firm

To the Shareholders and Board of Directors of
Merrimack Pharmaceuticals, Inc.

Opinion on the Financial Statements
We have audited the accompanying consolidated balance sheets of Merrimack Pharmaceuticals, Inc. (the “Company”) as of December 31, 2022 and 2021, 
the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for each of the two years in the period ended 
December 31, 2022, and the related notes (collectively referred to as the “financial statements”).  In our opinion, the financial statements present fairly, in 
all material respects, the financial position of the Company as of December 31, 2022 and 2021, and the results of its operations and its cash flows for each 
of the two years in the period ended December 31, 2022, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial 
statements  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 of the 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 audits to obtain reasonable 
assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor 
were 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 of 
internal  control  over  financial  reporting  but  not  for  the  purpose  of  expressing  an  opinion  on  the  effectiveness  of  the  Company's  internal  control  over 
financial 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,  and 
performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in 
the  financial  statements.  Our  audits  also  included  evaluating  the  accounting  principles  used  and  significant  estimates  made  by  management,  as  well  as 
evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matters
Critical audit matters are matters arising from the current period audit of the financial statements that were communicated or required to be communicated 
to  the  audit  committee  and  that:  (1)  relate  to  accounts  or  disclosures  that  are  material  to  the  financial  statements  and  (2)  involved  our  especially 
challenging, subjective, or complex judgments. We determined that there are no critical audit matters.

/s/ Marcum LLP

Marcum LLP

We have served as the Company’s auditor since 2019.

Boston, MA
March 9, 2023

F-2

 
 
  
  
 
 
  
 
 
  
  
  
  
  
  
  
  
 
 
 
Merrimack Pharmaceuticals, Inc.

Consolidated Balance Sheets

(in thousands, except per share amounts)
Assets
Current assets:
   Cash and cash equivalents
   Prepaid expenses and other current assets
      Total current assets
Other assets
      Total assets

Liabilities and stockholders’ equity
Current liabilities:
   Accounts payable, accrued expenses and other
      Total current liabilities
      Total liabilities
Commitments and contingencies
Stockholders’ equity:
   Preferred stock, $0.01 par value: 10,000 shares authorized at December 31, 2022
      and 2021 no shares issued or outstanding at December 31, 2022 or 2021
   Common stock, $0.01 par value: 30,000 shares authorized at December 31, 2022
      and 2021; 14,215 and 13,410 shares issued and outstanding at December 31, 
      2022 and 2021
   Additional paid-in capital
   Accumulated deficit
      Total stockholders’ equity
      Total liabilities and stockholders’ equity

December 31,

2022

2021

19,439     $
389  
19,828  
8  
19,836  

  $

  $

589  
589  
589  

14,203  
480  
14,683  
66  
14,749  

562  
562  
562  

—  

—  

1,342  
565,541  
(547,636 )
19,247  
19,836  

  $

1,334  
558,945  
(546,092 )
14,187  
14,749  

  $

  $

  $

  $

The accompanying notes are an integral part of these consolidated financial statements.

F-3

 
 
 
 
 
 
   
 
 
   
 
   
 
   
 
   
 
 
   
 
 
   
 
 
   
 
   
 
   
 
   
 
   
 
 
   
 
 
   
 
   
 
   
 
   
 
   
 
 
   
 
 
   
 
 
   
 
 
   
 
 
   
 
 
 
Merrimack Pharmaceuticals, Inc. 

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except per share amounts)
Operating expenses:
   General and administrative expenses
   Gain on sales of assets
      Total operating expenses
Loss from operations
Other income and expenses:
   Interest income
Loss before income tax expense
Income tax expense
Net loss and comprehensive loss

Net loss per common share - basic and diluted

Weighted-average common shares used to compute basic and diluted net loss per common share

Years Ended December 31,

2022

2021

2,174     $
(445 )  
1,729    
(1,729 )  

188    
(1,541 )  
(3 )  

(1,544 )
(0.11 )   $

13,524    

2,616  
(144 )
2,472  
(2,472 )

20  
(2,452 )
(3 )
(2,455 )

(0.18 )

13,407  

  $

  $

The accompanying notes are an integral part of these consolidated financial statements.

F-4

 
 
 
 
 
 
   
 
 
     
   
 
 
 
 
 
 
 
 
 
 
     
   
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
(in thousands)
Balance at January 1, 2021
Exercise of stock options
Stock-based compensation
Net loss
Balance at December 31, 2021
Exercise of stock options
Stock-based compensation
Net loss
Balance at December 31, 2022

Merrimack Pharmaceuticals, Inc.

Consolidated Statements of Stockholders’ Equity

Common Stock

Shares

Amount

Additional
Paid-In
Capital

13,380     $
30      
—      
—      
13,410     $
805      
—      
—      
14,215     $

1,334     $
—      
—      
—      
1,334     $
8      
—      
—      
1,342     $

558,309     $
239      
397      
—      
558,945     $
6,525      
71      
—      
565,541     $

The accompanying notes are an integral part of these consolidated financial statements.

F-5

Accumulated
Deficit
(543,637 )   $
—      
—      
(2,455 )    
(546,092 )   $
—      
—      
(1,544 )    
(547,636 )   $

Total
Stockholders’
Equity

16,006  
239  
397  
(2,455 )
14,187  
6,533  
71  
(1,544 )
19,247  

 
 
 
 
   
 
   
 
   
 
 
 
   
   
   
   
 
   
   
   
   
   
   
   
   
   
 
 
 
Merrimack Pharmaceuticals, Inc.

Consolidated Statements of Cash Flows

(in thousands)
Cash flows from operating activities
Net loss
Adjustments to reconcile net loss to net cash used in operating activities
   Gain on sales of in-process research and development
   Stock-based compensation expense
   Changes in operating assets and liabilities:
   Prepaid expenses and other assets
   Accounts payable, accrued expenses and other
      Net cash used in operating activities
Cash flows from investing activities
Proceeds from sale of in-process research and development assets
      Net cash provided by investing activities
Cash flows from financing activities
Proceeds from exercise of options
      Net cash provided by financing activities
Net increase in cash and cash equivalents
Cash and cash equivalents, beginning of period
Cash and cash equivalents, end of period

Years Ended December 31,
2021
2022

  $

(1,544 )   $

(2,455 )

(445 )  
71    

149    
27    
(1,742 )  

445    
445    

6,533    
6,533    
5,236    
14,203    
19,439     $

(144 )
397  

2,192  
(208 )
(218 )

144  
144  

239  
239  
165  
14,038  
14,203  

  $

The accompanying notes are an integral part of these consolidated financial statements.

F-6

 
 
 
 
 
 
   
 
 
     
   
 
     
   
 
 
 
 
 
 
 
     
   
 
 
 
 
 
 
 
 
 
 
     
   
 
 
 
 
 
 
 
     
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Merrimack Pharmaceuticals, Inc.

Notes to Consolidated Financial Statements

1. Nature of the Business and Summary of Significant Accounting Policies

Nature of the Business

Merrimack Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up 
to $450.0 million in contingent milestone payments related to its sale of ONIVYDE® and MM-436 (the “Commercial Business”) to Ipsen S.A. (“Ipsen”) in 
April 2017 (the “Ipsen Sale”). The Company does not have any ongoing research or development activities and is seeking potential acquirers for its few 
remaining preclinical and clinical assets. The Company does not have any employees and instead uses external consultants for the operation of the 
Company.

The $450.0 million in potential milestone payments resulting from the Ipsen Sale consist of:

•

•

•

$225.0 million upon approval by the U.S. Food and Drug Administration (“FDA”) of ONIVYDE for the first-line treatment of metastatic 
adenocarcinoma of the pancreas, subject to certain conditions;

$150.0 million upon approval by the FDA of ONIVYDE for the treatment of small-cell lung cancer after failure of first-line chemotherapy; 
and

$75.0 million upon approval by the FDA of ONIVYDE for an additional indication unrelated to those described above.

On May 30, 2019, the Company announced the completion of its review of strategic alternatives, following which the Company’s board of directors 

(the “Board”) implemented a series of measures designed to extend the Company’s cash runway and preserve its ability to capture the potential milestone 
payments resulting from the Ipsen Sale. In connection with that announcement, the Company discontinued the discovery efforts on its remaining preclinical 
programs: MM-401, an agonistic antibody targeting a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein 
targeting death receptors 4 and 5. The Company is seeking potential acquirers for its remaining preclinical and clinical assets.

The Company’s termination of its executive management team and all other employees was substantially completed by June 28, 2019 and fully 

completed by July 12, 2019. As of July 12, 2019, the Company no longer had any employees. The Company has engaged external consultants to run the 
day-to-day operations of the Company. The Company has also entered into consulting agreements with certain former members of its executive 
management team who are supporting the Company’s relationship with current partners, assisting with the potential sale of remaining preclinical and 
clinical assets, and assisting with certain legal and regulatory matters and the continued wind-down of operations.

On July 12, 2019, the Company completed the sale to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.) (“Elevation”) of its anti-
HER3 antibody programs, MM-121 (seribantumab) and MM-111 (the “Elevation Sale”). In connection with the Elevation Sale, the Company received an 
upfront cash payment of $3.5 million. The Company is also eligible to receive up to $54.5 million in additional potential development, regulatory approval 
and commercial-based milestone payments, consisting of:

•

•

•

$3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

Up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United 
States, Europe and Japan; and

Up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 
million for MM-121 and MM-111.

On September 15, 2021, the Company entered into an Asset Purchase Option Agreement (the "Asset Purchase Option Agreement") with a third 

party, pursuant to which the third party agreed to obtain an exclusive option, to purchase one of the Company’s preclinical programs with a consideration of 
$0.5 million. Under the terms of the Asset Purchase Option Agreement, the third party paid to the Company the option fee of $0.1 million. The third party 
may exercise the option within 24 months from September 15, 2021. The Company recognized a gain of $0.1 million related to the option fee payment for 
the year ended December 31, 2021. On January 18, 2022, the third party provided written notice to the Company of its intent to exercise such option. On 
March 1, 2022 the Company and the third party entered into the Asset Purchase Option Agreement. The consideration of $0.5 million was paid to the 
Company and a gain of $0.5 million was recognized in March 2022.

F-7

 
 
 
On January 23, 2023, the Company entered into an Asset Purchase Option Agreement (the “Option Agreement”) with a third party (the 

“Purchaser”), pursuant to which the Purchaser agreed to obtain an exclusive option (the “Option”) to purchase one of the Company’s preclinical programs 
with a consideration of $0.7 million. Under the terms of the Option Agreement, the Purchaser paid to the Company the Option fee of $0.2 million in 
January 2023. The Purchaser may exercise the Option prior to July 23, 2023.

The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, among other things, its ability 

to secure additional capital to fund operations, development by competitors of new technological innovations, protection of proprietary technology and 
compliance with government regulations. None of the Company’s product candidates sold to others or retained by the Company are approved for any 
indication by the FDA or any other regulatory agency. The Company operates in an environment of rapid change in technology and substantial competition 
from pharmaceutical and biotechnology companies, among others. In addition, the Company is dependent upon the services of its external consultants for 
the operation of the Company. The Company’s business strategy depends substantially upon its ability to receive future milestone payments from Ipsen. 
Any failure to achieve such milestones or a perception that the milestones may not be achieved will materially and adversely affect the Company and the 
value of its common stock.

In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are conditions 

and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the 
date that the consolidated financial statements are issued. As of December 31, 2022, the Company had an accumulated deficit of $547.6 million. During the 
year ended December 31, 2022, the Company incurred a net loss of $1.5 million and used $1.7 million of cash in operating activities. The Company 
expects to continue to generate operating losses in the foreseeable future. Based on current projections, the Company expects that its cash and cash 
equivalents of $19.4 million at December 31, 2022 will allow the Company to continue its operations beyond 2027, which the Company estimates is 
beyond the latest date that the longest-term potential Ipsen milestone may be achieved. The continued viability of the Company beyond that point is 
dependent on its ability to raise additional capital to finance its operations or to reduce operating expenses. There can be no assurance that the Company 
will be able to obtain sufficient capital to cover its costs on acceptable terms, if at all.

The Company expects that it would finance any future cash needs through a combination of divestitures of its product candidates or other assets, 

equity offerings and debt financings. There can be no assurance as to the timing, terms or consummation of any divestiture or financing, and the terms of 
any such financing may adversely affect the holdings or the rights of the Company’s stockholders or require the Company to relinquish rights to certain of 
its revenue streams or product candidates.

Summary of Significant Accounting Policies

Segment Information

Operating segments are defined as components of an enterprise engaging in business activities for which discrete financial information is available 
and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company views its 
operations and manages its business as one operating segment and the Company operates in only one geographic region (the United States).

Basis of Presentation and Consolidation

The accompanying consolidated financial statements have been prepared under U.S. generally accepted accounting principles (“GAAP”) and 

include the accounts of the Company and its wholly owned subsidiaries, all intercompany accounts and transactions have been eliminated.

Use of Estimates

GAAP requires the Company’s management to make estimates and judgments that may affect the reported amounts of assets, liabilities, revenues, 
expenses and related disclosures. The Company bases estimates and judgments on historical experience and on various other factors that it believes to be 
reasonable under the circumstances. The most significant estimates in these consolidated financial statements include, but may not be limited to, accounting 
for stock-based compensation and the accrual of remaining clinical trial expenses and professional service expenses. The Company’s actual results may 
differ from these estimates under different assumptions or conditions. The Company evaluates its estimates on an ongoing basis. Changes in estimates are 
reflected in reported results in the period in which they become known by the Company’s management. 

Cash and Cash Equivalents

Cash and cash equivalents are short-term, highly liquid investments with original maturities of three months or less at the date of purchase. 

Investments qualifying as cash equivalents primarily consist of money market funds.

Fair Value of Financial Instruments

F-8

 
 
Fair value is an exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly 
transaction between market participants. Fair value is determined based on observable and unobservable inputs. Observable inputs reflect readily obtainable 
data from independent sources, while unobservable inputs reflect certain market assumptions. As a basis for considering such assumptions, GAAP 
establishes a three-tier value hierarchy, which prioritizes the inputs used to develop the assumptions and for measuring fair value as follows: (Level 1) 
observable inputs such as quoted prices in active markets for identical assets; (Level 2) inputs other than the quoted prices in active markets that are 
observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data, which requires the Company to develop 
its own assumptions. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs 
when determining fair value.

Accrued Expenses

As part of the process of preparing financial statements, the Company is required to estimate accrued expenses. This process involves identifying 

services that have been performed on the Company’s behalf and estimating the level of services performed and the associated costs incurred for such 
services where the Company has not yet been invoiced or otherwise notified of actual cost. The Company records these estimates in its consolidated 
financial statements as of each balance sheet date. Examples of estimated accrued expenses include:

•

•

•

fees due to contract research organizations in connection with preclinical and toxicology studies and clinical trials;

fees paid to investigative sites in connection with clinical trials; and

professional service fees.

In accruing service fees, the Company estimates the time period over which services will be provided and the level of effort in each period. If the 

actual timing of the provision of services or the level of effort varies from the estimate, the Company adjusts the accrual accordingly. In the event that the 
Company does not identify costs that have been incurred or it under or overestimates the level of services performed or the costs of such services, its actual 
expenses could differ from such estimates. The date on which some services commence, the level of services performed on or before a given date and the 
cost of such services are often subjective determinations. The Company prepares its estimates based on the facts and circumstances known to it at the time 
and in accordance with GAAP. There have been no material changes in estimates for the periods presented.

General and Administrative Expenses

General and administrative expenses are comprised of consulting fees and other related costs for personnel, including stock-based compensation 

expenses and benefits, in the Company’s commercial, legal, intellectual property, business development, finance, information technology, corporate 
communications, investor relations and human resources departments. Other general and administrative expenses include costs for employee training and 
development, board of directors costs, depreciation, insurance expenses, facility-related costs, professional fees for legal services, including patent-related 
expenses, and accounting and information technology services.

Stock-Based Compensation Expense

The Company accounts for all stock-based payments to non-employees, including grants of stock options, to be recognized in the consolidated 

statements of operations and comprehensive loss based on their grant date fair values. For stock options granted to members of the Board for their service 
on the Board, the Company estimates the grant date fair value of each option award using the Black-Scholes option pricing model. The use of the Black-
Scholes option pricing model requires the Company to make assumptions with respect to the expected term of the option, the expected volatility of the 
Company’s common stock consistent with the expected term of the option, the risk-free interest rate consistent with the expected term of the option and the 
expected dividend yield of the Company’s common stock. Stock-based compensation expense related to employee stock options is measured using the fair 
value of the award at the grant date and is adjusted quarterly to reflect actual forfeitures. Stock-based compensation expense is then recognized on a 
straight-line basis over the vesting period, which is also the requisite service period.

Net Loss Per Common Share

Basic net loss per share is calculated by dividing the net loss attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of 

common shares outstanding during the period. 

Diluted net loss per share is computed by dividing the net loss attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of 

dilutive common shares outstanding during the period. Dilutive shares outstanding is calculated by adding to the weighted shares outstanding any potential 
(unissued) shares of common stock from outstanding stock options based on the treasury 

F-9

 
 
stock method. In a period when a net loss is reported, all common stock equivalents are excluded from the calculation because they would have an anti-
dilutive effect, meaning the loss per share would be reduced. Therefore, in periods where a loss is reported, there is no difference in basic and dilutive loss 
per share.

The Company follows the two-class method when computing net loss per share, when it has issued shares that meet the definition of participating 

securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or 
accumulated and participating rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to 
be allocated between common and participating securities based on their respective rights to receive dividends, as if all income for the period has been 
distributed, or losses to be allocated if they are contractually required to fund losses. There were no amounts allocated to participating securities for the 
years ended December 31, 2022 and 2021, as the Company was in a loss position and had no shares that met the definition of participating securities 
outstanding as of December 31, 2022 and 2021.

Income Taxes

The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized 

for the estimated future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and their 
respective tax bases. Deferred tax assets and liabilities are measured using enacted rates in effect for the year in which these temporary differences are 
expected to be recovered or settled. Valuation allowances are provided if based on the weight of available evidence, it is more likely than not that some or 
all of the deferred tax assets will not be realized.

The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions and other issues. Reserves 

are based on a determination of whether and how much of a tax benefit taken by the Company in its tax filing is more likely than not to be realized 
following resolution of any potential contingencies present related to the tax benefit. Potential interest and penalties associated with such uncertain tax 
positions are recorded as components of income tax expense. To date, the Company has not taken any uncertain tax positions or recorded any reserves, 
interest or penalties.

Concentration of Credit Risk

Financial instruments that subject the Company to credit risk consist primarily of cash and cash equivalents. The Company places its cash deposits 

in accredited financial institutions and, therefore, the Company’s management believes these funds are subject to minimal credit risk. The Company invests 
cash equivalents in money market funds. The Company has no significant off-balance sheet concentrations of credit risk such as foreign currency exchange 
contracts, option contracts or other hedging arrangements. 

Recently Adopted Accounting Pronouncements

In December 2019, the FASB issued ASU 2019-12, “Income Taxes—Simplifying the Accounting for Income Taxes (Topic 740) (“ASU 2019-12”),” 

which simplifies the accounting for income taxes. The new guidance removes certain exceptions to the general principles in ASC 740 such as recognizing 
deferred taxes for equity investments, the incremental approach to performing intra-period tax allocation and calculating income taxes in interim periods. 
The standard also simplifies accounting for income taxes under U.S. GAAP by clarifying and amending existing guidance, including the recognition of 
deferred taxes for goodwill, the allocation of taxes to members of a consolidated group and requiring that an entity reflect the effect of enacted changes in 
tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. This guidance is effective for annual 
periods beginning after December 15, 2020, and interim periods thereafter; however, early adoption is permitted. The new guidance was adopted on 
January 1, 2021 and it did not have a material impact on the Company’s consolidated financial statements and related disclosures.

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that 

the Company adopts as of the specified effective date. Unless otherwise discussed above, the Company does not believe that the adoption of recently issued 
standards has or may have a material impact on the Company’s consolidated financial statements or disclosures.

F-10

 
  
 
 
2. Net Loss Per Common Share

The stock options are excluded from the calculation of diluted loss per share because the net loss for the years ended December 31, 2022 and 2021 

causes such securities to be anti-dilutive. Securities excluded from the calculation of diluted loss per share are shown in the chart below:

(in thousands)
Outstanding options to purchase common stock

3. Fair Value of Financial Instruments

Years Ended December 31,

2022

2021

824    

1,778  

The Company’s cash and cash equivalents, accounts receivable, prepaid expenses, and other current assets, accounts payable, accrued expenses and 

variable interest rate note payable are recorded at cost, which approximates fair value due to their short-term nature. 

The following tables summarize assets measured at fair value on a recurring basis as of December 31, 2022 and 2021 and the input categories 

associated with those assets:

(in thousands)
Cash equivalents:
Money market funds
  Totals

(in thousands)
Cash equivalents:
Money market funds
  Totals

Level 1

December 31, 2022
Level 2

Level 3

18,148  
18,148  

  $
  $

—     $
—     $

Level 1

December 31, 2021
Level 2

Level 3

12,934  
12,934  

  $
  $

—     $
—     $

—  
—  

—  
—  

  $
  $

  $
  $

There were no liabilities measured at fair value on a recurring basis as of December 31, 2022 and 2021.

4. Accounts Payable, Accrued Expenses and Other

Accounts payable, accrued expenses and other as of December 31, 2022 and 2021 consisted of the following:

(in thousands)
Accounts payable
Accrued goods and services
Accrued clinical trial costs
Others
  Total accounts payable, accrued expenses and other

December 31,

2022

2021

  $

  $

188     $
139      
71      
191      
589     $

120  
167  
84  
191  
562  

5. Common Stock

As of December 31, 2022 and 2021, the Company had 30.0 million shares of $0.01 par value common stock authorized.   There were approximately 

14.2 million and 13.4 million shares of common stock issued and outstanding as of December 31, 2022 and 2021, respectively.

Stockholder Rights Agreement

On November 22, 2019, the Board created, as of and contingent with the Section 382 Rights Agreement with Computershare Trust Company, N.A., 

as Rights Agent (the “Rights Agreement”) being signed, a series of junior participating preferred stock of the Company to be designated “Series Z Junior 
Participating Preferred Stock” with a par value of $0.01 per share, and stated the designation and number of shares:

F-11

 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
     
   
 
 
 
 
 
 
 
 
 
 
 
 
   
 
     
   
 
 
 
 
 
 
 
   
 
   
   
   
 
 
 
 
 
 
Designation and Amount. The shares of this series are designated as Series Z Junior Participating Preferred Stock (the “Series Z Junior Preferred 

Stock”), and the number of shares constituting the Series Z Junior Preferred Stock shall be 30,000. Such number of shares may be increased or decreased 
by resolution of the Board; provided, that no decrease shall reduce the number of shares of Series Z Junior Preferred Stock to a number less than the 
number of shares then outstanding plus the number of shares reserved for issuance upon the exercise of outstanding options, rights or warrants or upon the 
conversion of any outstanding securities issued by the Company convertible into Series Z Junior Preferred Stock.

On December 3, 2019, the Company entered into the Rights Agreement in an effort to protect stockholder value by attempting to diminish the risk 

that the Company’s ability to use its net operating losses (“NOLs”) to reduce potential future federal income tax obligations may become substantially 
limited. The Company’s ability to utilize its NOLs may be substantially limited if the Company experiences an "ownership change" within the meaning of 
Section 382 of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"). The Rights Agreement is intended to act as a deterrent to 
any person acquiring beneficial ownership of 4.9% or more of the Company’s outstanding common stock without the approval of the Board.

The Board authorized the issuance of one Right for each outstanding share of common stock, par value $0.01 per share, of the Company, payable to 

stockholders of record date of the close of business on December 13, 2019 (the “Record Date”). Subject to the terms, provisions and conditions of the 
Rights Agreement, if the Rights become exercisable, each Right would initially represent the right to purchase from the Company one one-thousandth of a 
share of Series Z Junior Preferred Stock, par value $0.01 per share, of the Company (the “Preferred Shares”) for a purchase price of $18.00 (the “Purchase 
Price”). Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder of the Company, including, without limitation, the right 
to vote or to receive dividends.

The Rights will not be exercisable until the earlier of (i) ten business days after a public announcement that a person has become an “Acquiring 
Person” by acquiring beneficial ownership of 4.9% or more of outstanding common stock has become such (or, in the event an exchange is effected in 
accordance with Section 24 of the Rights Agreement and the Board determines that a later date is advisable, then such later date), and (ii) ten business days 
(or such later date as may be specified by the Board prior to such time as any person becomes an Acquiring Person) after the commencement of a tender or 
exchange offer by or on behalf of a person that, if completed, would result in such person becoming an Acquiring Person (the “Distribution Date”).

Until the Distribution Date, the Rights will be transferred with and only with the common stock, and (unless the Rights are redeemed or expire) the 
surrender or transfer of any common stock outstanding on or after the Record Date will constitute the transfer of the Rights associated with such common 
stock. Upon the Distribution Date, the Rights may be transferred separately from the common stock, and each Right, other than Rights held by an 
Acquiring Person, will entitle its holder to purchase from the Company one one-thousandth of a Preferred Share in exchange for the Purchase Price. The 
Rights will be evidenced, with respect to any of the common stock certificates outstanding as of the Record Date, by such common stock certificate with a 
copy of the Summary of Rights to Purchase Preferred Shares.

If any person becomes an Acquiring Person, proper provision shall be made so that each holder of a Rights, other than rights beneficially owned by 

an Acquiring Person, an associate or affiliate of the Acquiring Person or any person with whom such person is acting in concert (all of which will thereafter 
be void), will thereafter have the right to receive, upon exercise thereof, that number of common stock having a market value equal to two times the 
Purchase Price of the Right. If the Board so elects, the Company shall deliver, upon payment of the Purchase Price, an amount of cash or securities 
equivalent in value to the number of common stock issuable upon exercise of a Right.

If, at any time after a person becomes an Acquiring Person, the Company is acquired in a merger or other business combination transaction or 50% 

or more of its consolidated assets or earning power are sold, proper provision will be made so that each holder of a Right will thereafter have the right to 
receive, upon the exercise thereof at the then current Purchase Price, that number of shares of common stock of the acquiring company which at the time of 
such transaction will have a market value of two times the Purchase Price.

At any time prior to the time any person becomes an Acquiring Person, the Board may redeem the Rights in whole, but not in part, at a price of 

$0.0001 per Right (the “Redemption Price”). The redemption of the Rights may be made effective at such time, on such basis and with such conditions as 
the Board in its sole discretion may establish. Immediately upon any redemption of the Rights, the right to exercise the Rights will terminate and the only 
right of the holders of Rights will be to receive the Redemption Price.

F-12

 
  
  
  
  
  
 
  
 
At any time after any person becomes an Acquiring Person and prior to the acquisition by any person or group of a majority of the outstanding 
common stock, the Board may exchange the Rights (other than Rights owned by an Acquiring Person, which shall have become void), in whole or in part, 
at an exchange ratio of one common stock per Right (subject to adjustment). The exchange of the Rights by the Board may be made effective at such time, 
on such basis and with such conditions as the Board in its sole discretion may establish.

The Rights were due to expire on the earlier of (i) the close of business on December 2, 2022, (ii) the close of business on the date that the Board 
determines that (A) the Rights Agreement is no longer necessary or desirable for the preservation of the Tax Benefits or (B) the Tax Benefits have been 
fully utilized and may no longer be carried forward, (iii) the time at which the Rights are redeemed, (iv) the time at which the Rights are exchanged, and (v) 
if the Rights Agreement has not been approved by the stockholders prior to the conclusion of the Company’s 2020 annual meeting, the close of business on 
such date. On December 2, 2022, the Rights Agreement was extended and will expire on December 2, 2025, but would terminate at the time of the 
Company’s 2023 annual meeting if the extension is not approved by the Company’s shareholders at that annual meeting.

The Purchase Price payable, and the number of Preferred Shares or other securities or property issuable, upon exercise of the Rights is subject to 

adjustment from time to time to prevent dilution (i) in the event of a stock dividend on the Preferred Shares payable in Preferred Shares or a subdivision or 
combination of the Preferred Shares, (ii) upon the grant to holders of the Preferred Shares of certain rights or warrants to subscribe for or purchase 
Preferred Shares at a price, or securities convertible into Preferred Shares with a conversion price, less than the then current market price of the Preferred 
Shares, or (iii) upon the distribution to holders of the Preferred Shares of evidences of indebtedness or assets (excluding regular periodic cash dividends 
paid out of earnings or retained earnings or dividends payable in Preferred Shares) or of subscription rights or warrants (other than those referred to above). 
The number of outstanding Rights and the number of Preferred Shares issuable upon exercise of each Right are also subject to adjustment in the event of a 
stock split of the Common Shares or a stock dividend on the Common Shares payable in Common Shares or subdivisions, consolidations or combinations 
of the Common Shares occurring, in any such case, prior to the Distribution Date.

With certain exceptions, no adjustment in the Purchase Price will be required until cumulative adjustments require an adjustment of at least 1% in 
such Purchase Price. No fractional Preferred Shares will be issued (other than fractions which are integral multiples of one one-thousandth of a Preferred 
Share, which may, at the election of the Company, be evidenced by depositary receipts), and in lieu thereof, an adjustment in cash will be made based on 
the market price of the Preferred Shares on the last trading day prior to the date of exercise.

6. Stock-Based Compensation

On April 15, 2021, the Company’s Board of Directors adopted the 2021 Incentive Award Plan (the “2021 Plan”) to replace the 2011 Stock 
Incentive Plan (the “2011 Plan”). The 2021 Plan was approved by the Company’s stockholders at the Company’s Annual Meeting of Stockholders held on 
June 10, 2021. The 2021 Plan is administered by the Company’s Board of Directors and permits the Company to grant incentive and non-qualified stock 
options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards.

The Company initially reserved 275,000 of its common stock for the issuance of awards under the 2021 Plan. There were 22,000 options granted 
during each of  the years ended December 31, 2022 and 2021 under the 2021 Plan. The weighted-average grant date fair value per share of stock options 
granted during the year ended December 31, 2022 and 2021 was $3.11 and $3.68, respectively. At December 31, 2022, there were 231,000 shares 
remaining available for grant under the 2021 Plan.

Stock options granted to non-employee directors in 2022 and 2021 vest over a one-year period, ending on the earlier of the one-year anniversary of 

the grant date or the day prior to the Company’s next annual meeting of stockholders after the grant date. 

The fair value of stock options granted to employees during the years ended December 31, 2022 and 2021 was estimated at the date of grant using 

the following assumptions:

Risk-free interest rate
Expected dividend yield
Expected term
Expected volatility

F-13

Years Ended December 31,
2021
2022
0.73%
3.03%
0%
0%
5.2 years
5.2 years
68.48%
68.02%

 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The Company uses the simplified method to calculate the expected term, as it does not have sufficient historical exercise data to provide a 

reasonable basis upon which to estimate the expected term of its stock options. Under this approach, the expected term is calculated to be the average of the 
ten-year contractual term of the option and the weighted-average vesting term of the option, taking into consideration multiple vesting tranches. The 
computation of expected volatility is based on the historical volatility of the Company. The risk-free interest rate is based on a treasury instrument whose 
term is consistent with the expected life of the stock options. Stock-based compensation expense related to employee stock options is measured using the 
fair value of the award at the grant date and is adjusted quarterly to reflect actual forfeitures. Stock-based compensation expense is then recognized on a 
straight-line basis over the vesting period, which is also the requisite service period. The Company recognized stock-based compensation expense of $0.1 
million and $0.4 million during the years ended December 31, 2022 and 2021, respectively.

The following table summarizes stock option activity during the year ended December 31, 2022:

(in thousands, except per share amounts)
Outstanding at December 31, 2021
Granted
Exercised
Forfeited
Outstanding at December 31, 2022

Vested and expected to vest at December 31, 2022
Exercisable at December 31, 2022

Options

Weighted-
Average
Exercise Price

1,778     $
22     $
(805 )   $
(171 )   $
824     $
824     $
813     $

11.46      
5.20    
8.12    
23.18    

12.38      
12.38      
12.48      

Weighted-
Average
Remaining
Contractual Term
(in years)

Aggregate
Intrinsic
Value

5.32     $

148  

4.28     $
4.28     $
4.21     $

2,498  
2,498  
2,429  

The aggregate intrinsic value was calculated as the difference between the exercise price of the stock options and the fair value of the underlying 

common stock. The aggregate intrinsic value of options exercised during the year ended December 31, 2022 and 2021 was $3.0 million and less than $0.1 
million, respectively.

As of December 31, 2022, there was less than $0.1 million of total unrecognized stock-based compensation expense related to unvested employee 

stock options. The Company expects to recognize this expense over a weighted-average period of approximately 0.3 years.

7. Income Taxes

Intraperiod tax allocation rules require the Company to allocate the provision for income taxes between operations and other categories of earnings, 

such as discontinued operations. In periods in which there is pre-tax loss from operations and pre-tax income in other categories of earnings, such as 
discontinued operations, the Company must allocate to operations an income tax benefit for the loss in operations with an offsetting income tax expense to 
discontinued operations. 

For the years ended December 31, 2022 and 2021, the Company recognized an income tax expense less than $0.1 million.

A reconciliation of the Company’s effective tax rate to the statutory federal income tax rate is as follows:

Federal income tax at statutory federal rate
State taxes
Permanent differences
Stock-based compensation
Tax credits
Recapture of tax credits
Other
Change in valuation allowance
  Total

F-14

Years Ended December 31,
2021
2022

21.0 %   
6.1      
—      
(2.8 )    
(6.5 )    
0.0      
(0.1 )    
(17.9 )    
(0.2 )%   

21.0 %
4.9  
0.3  
0.1  
0.1  
0.0  
1.3  
(27.8 )
(0.1 )%

 
 
 
 
   
 
 
   
 
 
 
 
   
 
 
 
   
   
     
   
   
     
   
   
     
   
   
   
   
 
 
 
 
 
 
 
 
 
 
   
 
   
   
   
   
   
   
   
   
   
 
 
The reconciliation of the Company’s effective tax rate to the statutory tax rate includes a reduction to the deferred tax asset for stock options that 

have been forfeited. The Company will no longer receive a tax deduction for these options in the future and as such the deferred tax asset has been reversed 
into income tax expense. An offsetting reduction to the valuation allowance has also been recorded.

Temporary differences that give rise to significant net deferred tax assets as of December 31, 2022 and 2021 are as follows:

(in thousands)
Deferred tax assets:
   Net operating losses
   Capitalized research and development expenses
   Credit carryforwards
   Deferred compensation
   Election out of installment method
   Accrued expenses
   Other temporary differences
   Installment sale tax basis
      Total gross deferred tax assets
Valuation allowance
Net deferred tax assets

December 31,

2022

2021

64,135     $
141      
167,397      
1,181      
820      
44      
621      
15,869      
250,208      
(250,208 )    
—     $

62,619  
282  
167,498  
1,993  
956  
44  
672  
15,869  
249,933  
(249,933 )
—  

  $

  $

At December 31, 2022, the Company had net operating loss carryforwards for federal and state income tax purposes of $215.0 million and $300.4 

million, respectively. The Company's existing federal and state net operating loss carryforwards begin to expire in 2034 and 2033, respectively. The 
Company also had available research and development credits for federal and state income tax purposes of approximately $28.7 million and $20.3 million, 
respectively. The federal and state research and development credits will begin to expire in 2022 and 2025, respectively. As of December 31, 2022, the 
Company also had available investment tax credits for state income tax purposes of less than $0.1 million which do not expire. The Company has orphan 
drug credits of $122.7 million, which begin to expire in 2031.

Utilization of the net operating loss and tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal 
Revenue Code due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the 
amount of net operating loss and tax credit carryforwards that can be utilized annually to offset future taxable income and tax. The Company completed an 
evaluation of ownership changes through November 16, 2022 to assess whether utilization of the Company’s net operating loss or tax credit carryforwards 
would be subject to an annual limitation under Section 382 of the Internal Revenue Code. The Company believes it can utilize its tax attributes generated 
through November 16, 2022 as a result of the analysis. To the extent an ownership change has occurred after November 16, 2022 or occurs in the future, 
the net operating loss and tax credit carryforwards may be subject to limitation. 

The Company has not, as of yet, conducted a study of its domestic research and development credit carryforwards and orphan drug credits. This 
study may result in an increase or decrease to the Company's credit carryforwards; however, until a study is completed and any adjustment is known, no 
amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company's credits, and if an adjustment 
is required, this adjustment would be offset by an adjustment to the valuation allowance. As a result, there would be no impact to the statement of 
operations and comprehensive loss, balance sheet or cash flows if an adjustment were required.

As of December 31, 2022, the Company has evaluated the positive and negative evidence bearing upon the realizability of its remaining deferred tax 

assets, which are comprised principally of net operating loss carryforwards and research and development credits. Under the applicable accounting 
standards, management has considered the Company's history of losses and concluded that it is more likely than not that the Company will not recognize 
the benefits of its deferred tax assets. Accordingly, a full valuation allowance has been established against the deferred tax assets. The change in the 
valuation allowance against the deferred tax assets in the years ended December 31, 2022 and 2021 was as follows:

(in thousands)
December 31, 2021
December 31, 2022

Balance at
Beginning
of Period

Additions

Deductions

Balance at
End of
Period

  $

249,252     $
249,933      

681     $
275      

—     $
—      

249,933  
250,208  

F-15

 
 
 
 
 
 
 
   
 
 
     
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
   
   
 
 
 
   
 
 
 
The change in the valuation allowance in the year ended December 31, 2022 primarily relates to the net operating loss deferred tax assets generated 

for the current year.

8. Subsequent Events

The Company and Purchaser entered into the Option Agreement dated January 23, 2023 (see Note 1 for further details), pursuant to which the 

Company granted to Purchaser an exclusive option during a fixed period of time to negotiate a definitive asset purchase agreement to acquire one of the 
Company's preclinical programs. In January 2023, the Company received payment of the Option fee from the Purchaser.

F-16

 
 
Exhibit 4.5

DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS 

AMENDED

The following description of the securities of Merrimack Pharmaceuticals, Inc. (“us,” “our,” “we” or the “Company”) registered under Section 12 of the 
Securities  Exchange  Act  of  1934,  as  amended  (the  “Exchange  Act”),  is  intended  as  a  summary  only  and  therefore  is  not  a  complete  description.  This 
description is based upon, and is qualified by reference to, our certificate of incorporation, our bylaws and applicable provisions of the Delaware General 
Corporation  Law  (the  “DGCL”).  You  should  read  our  certificate  of  incorporation  and  bylaws,  which  are  incorporated  by  reference  as  Exhibit  3.1  and 
Exhibit 3.2, respectively, to the Annual Report on Form 10-K of which this Exhibit is a part, for the provisions that are important to you.

Authorized Capital Stock

Our  authorized  capital  stock  consists  of  30,000,000  shares  of  common  stock  and  10,000,000  shares  of  preferred  stock,  of  which  30,000  shares  are 
designated as series Z junior participating preferred stock. Our common stock is registered under Section 12(b) of the Exchange Act, and we have preferred 
stock purchase rights registered under Section 12(g) of the Exchange Act. 

Common Stock 

Voting Rights. Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders and do not have 
cumulative voting rights. Each election of directors by our stockholders will be determined by a plurality of the votes cast by the stockholders entitled to 
vote on the election. In general, except (1) for the election of directors, (2) as described below under “—Provisions of Our Certificate of Incorporation and 
Bylaws and Delaware Law That May Have Anti-Takeover Effects—Super-Majority Voting,” (3) in the future to the extent that we have two or more classes 
or series of stock outstanding with separate voting rights and (4) as otherwise required by law, any matter to be voted on by our stockholders at any meeting 
is decided by the vote of the holders of a majority in voting power of the votes cast by the holders of shares of our stock present or represented at the 
meeting and voting affirmatively or negatively on such matter. 

Dividends. Holders of common stock are entitled to receive proportionately any dividends as may be declared by our board of directors, subject to any 
preferential dividend rights of outstanding preferred stock. 

Liquidation and Dissolution. In the event of our liquidation or dissolution, the holders of our common stock are entitled to receive proportionately all assets 
available for distribution to stockholders after the payment of all debts and other liabilities and subject to the prior rights of any of our outstanding preferred 
stock. 

Other Rights. Holders of our common stock have no preemptive, subscription, redemption or conversion rights. The rights, preferences and privileges of 
holders of our common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of our preferred stock that we 
may designate and issue in the future. 

Preferred Stock 

Under the terms of our certificate of incorporation, our board of directors is authorized to issue shares of preferred stock in one or more series without 
stockholder  approval.  Our  board  of  directors  has  the  discretion  to  determine  the  rights,  preferences,  privileges  and  restrictions,  including  voting  rights, 
dividend  rights,  conversion  rights,  redemption  privileges  and  liquidation  preferences,  of  each  series  of  preferred  stock.  The  purpose  of  authorizing  our 
board of directors to issue preferred stock and determine its rights and preferences is to eliminate delays associated with a stockholder vote on specific
issuances.  The  issuance  of  preferred  stock,  while  providing  flexibility  in  connection  with  possible  acquisitions,  future  financings  and  other  corporate 
purposes, could have the effect of making it more difficult for a third party to acquire, or could discourage a third party from seeking to acquire, a majority 
of our outstanding voting stock.

 
  
 
Effects of Authorized but Unissued Stock 

We have shares of common stock and preferred stock available for future issuance without stockholder approval, subject to any limitations imposed by the 
listing  standards  of  The  Nasdaq  Global  Market.  We  may  utilize  these  additional  shares  for  a  variety  of  corporate  purposes,  including  for  future  public 
offerings to raise additional capital or facilitate corporate acquisitions or for payment as a dividend on our capital stock. The existence of unissued and 
unreserved  common  stock  and  preferred  stock  may  enable  our  board  of  directors  to  issue  shares  to  persons  friendly  to  current  management  or  to  issue 
preferred stock with terms that could have the effect of making it more difficult for a third party to acquire, or could discourage a third party from seeking 
to acquire, a controlling interest in our company by means of a merger, tender offer, proxy contest or otherwise. In addition, if we issue preferred stock, the 
issuance  could  adversely  affect  the  voting  power  of  holders  of  common  stock  and  the  likelihood  that  such  holders  will  receive  dividend  payments  and 
payments upon liquidation. 

Provisions of Our Certificate of Incorporation and Bylaws and Delaware Law That May Have Anti-Takeover Effects 

Delaware Law. We are subject to Section 203 of the DGCL. Subject to certain exceptions, Section 203 prevents a publicly held Delaware corporation from 
engaging in a “business combination” with any “interested stockholder” for three years following the date that the person became an interested stockholder, 
unless the interested stockholder attained such status with the approval of our board of directors, the business combination is approved by our board of 
directors and stockholders in a prescribed manner, or the interested stockholder acquired at least 85% of our outstanding voting stock in the transaction in 
which  it  became  an  interested  stockholder.  A  “business  combination”  includes,  among  other  things,  a  merger  or  consolidation  involving  us  and  the 
“interested stockholder” and the sale of more than 10% of our assets. In general, an “interested stockholder” is any entity or person beneficially owning 
15% or more of our outstanding voting stock and any entity or person affiliated with or controlling or controlled by such entity or person. 

Stockholder Action; Special Meeting of Stockholders; Advance Notice Requirements for Stockholder Proposals and Director Nominations. Our certificate 
of incorporation and our bylaws provide that any action required or permitted to be taken by our stockholders at an annual meeting or special meeting of 
stockholders may only be taken if it is properly brought before such meeting and may not be taken by written action in lieu of a meeting. Our certificate of 
incorporation  and  our  bylaws  also  provide  that,  except  as  otherwise  required  by  law,  special  meetings  of  the  stockholders  can  only  be  called  by  our 
chairman of the board, our chief executive officer or our board of directors. In addition, our bylaws establish an advance notice procedure for stockholder 
proposals  to  be  brought  before  an  annual  meeting  of  stockholders,  including  proposed  nominations  of  candidates  for  election  to  our  board  of  directors. 
Stockholders at an annual meeting may only consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the 
direction of our board of directors, or by a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has 
delivered timely written notice in proper form to our secretary of the stockholder’s intention to bring such business before the meeting. These provisions 
could have the effect of delaying until the next stockholder meeting stockholder actions that are favored by the holders of a majority of our outstanding 
voting securities. These provisions also could discourage a third party from making a tender offer for our common stock, because even if it acquired a 
majority of our outstanding voting stock, it would be able to take action as a stockholder, such as electing new directors or approving a merger, only at a 
duly called stockholders meeting and not by written consent. 

Super-Majority Voting. The  DGCL  provides  generally  that  the  affirmative  vote  of  a  majority  of  the  shares  entitled  to  vote  on  any  matter  is  required  to 
amend a corporation’s certificate of incorporation or bylaws, unless a corporation’s certificate of incorporation or bylaws, as the case may be, requires a 
greater percentage. Our bylaws may be amended or repealed by a majority vote of our board of directors or the affirmative vote of the holders of at least 
75% of the votes that all our stockholders would be entitled to cast in any annual election of directors. In addition, the affirmative vote of the holders of at 
least  75%  of  the  votes  that  all  our  stockholders  would  be  entitled  to  cast  in  any  election  of  directors  is  required  to  amend  or  repeal  or  to  adopt  any 
provisions inconsistent with any of the provisions of our certificate of incorporation described above.

 
 
 
Removal of Directors by Stockholders. Our bylaws provide that members of our board of directors may be removed, with or without cause, by a majority in 
voting power of the shares of capital stock of our company issued and outstanding and entitled to vote in any annual election of directors, subject to any 
rights of any series of preferred stock.

Preferred Stock Purchase Rights

Pursuant to a Section 382 Rights Agreement (the “Rights Agreement”), dated December 3, 2019, between us and Computershare Trust Company, N.A., as 
Rights Agent, the Company issued a dividend of one preferred share purchase right (a “Right”) for each share of common stock, payable on December 13, 
2019 (the “Record Date”) to the stockholders of record on that date.  Each Right entitles the registered holder to purchase from the Company one one-
thousandth  of  a  share  of  Series  Z  Junior  Preferred  Stock  (the  “Preferred  Shares”)  of  the  Company,  at  a  price  of  $18.00  per  one  one-thousandth  of  a 
Preferred Share represented by a Right (the “Purchase Price”), subject to adjustment. 

This  description  of  the  Rights  is  based  upon,  and  qualified  by  reference  to,  the  Rights  Agreement.  You  should  read  the  Rights  Agreement  which  is 
incorporated by reference as an exhibit to the Annual Report on Form 10-K of which this Exhibit is a part, for the provisions that are important to you. The 
Certificate of Designation of Series Z Junior Preferred Participating Stock is also incorporated by reference as an exhibit to the Annual Report on Form 10-
K of which this Exhibit is a part.  Capitalized terms used but not defined in this section are defined in the Rights Agreement.

The Rights

The Rights are not exercisable until the Distribution Date. The Distribution Date will be the earlier of (i) the Close of Business on the tenth day following a 
public announcement that an Acquiring Person (as defined below) has become such (or, in the event an exchange is effected in accordance with Section 24 
of the Rights Agreement and the board determines that a later date is advisable, then such later date) or (ii) the Close of Business on the tenth Business Day 
(or  such  later  date  as  may  be  determined  by  action  of  the  board  prior  to  such  time  as  any  Person  becomes  an  Acquiring  Person)  following  the 
commencement of a tender offer or exchange offer, the consummation of which would result in the Beneficial Ownership by a Person or group of 4.9% or 
more of the then outstanding common stock.

Until  the  Distribution  Date,  the  Rights  will  be  transferred  with  and  only  with  the  common  stock,  and  (unless  the  Rights  are  redeemed  or  expire)  the 
surrender or transfer of any common stock outstanding on or after the Record Date will constitute the transfer of the Rights associated with such common 
stock.  Upon  the  Distribution  Date,  the  Rights  may  be  transferred  separately  from  the  common  stock,  and  each  Right,  other  than  Rights  held  by  an 
Acquiring Person, will entitle its holder to purchase from the Company one one-thousandth of a Preferred Share in exchange for the Purchase Price.

The Rights will be evidenced, with respect to any of the common stock certificates outstanding as of the Record Date, by such common stock certificate 
with a copy of the Summary of Rights to Purchase Preferred Shares substantially in the form attached as Exhibit C to the Rights Agreement (unless such 
Rights are recorded in book entry).

Acquiring Person

An “Acquiring Person” is any Person or group of Affiliated or Associated Persons that has acquired Beneficial Ownership (as defined below) of 4.9% or 
more of the common stock then outstanding. However, a Person shall not be deemed to be an Acquiring Person if such Person, at the time of the first public 
announcement of the Rights Agreement, is a Beneficial Owner of 4.9% or more of the common stock then outstanding (a “Grandfathered Stockholder”); 
provided, however, that if a Grandfathered Stockholder increases its Beneficial Ownership of the common stock of the Company as of any date on or after 
the date of the public announcement of this Agreement, then such Grandfathered Stockholder shall no longer be deemed to be a Grandfathered Stockholder 
unless, upon such acquisition of Beneficial Ownership of additional common stock of the Company, such Person is not then the Beneficial Owner of 4.9% 
or more of the common stock of the Company then outstanding; provided, further, that upon the first decrease of a Grandfathered Stockholder’s Beneficial 
Ownership  below  4.9%  of  the  common  stock  of  the  Company  then  outstanding,  such  Grandfathered  Stockholder  shall  no  longer  be  deemed  to  be  a 
Grandfathered Stockholder and this proviso shall have no further force or effect with respect to such Person.

 
 
 
In  general,  “Beneficial  Ownership”  shall  include  any  securities  such  Person,  or  any  of  such  Person’s  Affiliates  or  Associates  (i)  would  be  deemed  to 
actually  or  constructively  own  for  purposes  of  Section  382  of  the  Code  and  the  regulations  promulgated  thereunder,  (to  the  extent  ownership  of  such 
securities  would  be  attributed  to  such  Persons  under  Section  382  of  the  Code  and  the  regulations  promulgated  thereunder),  or  (ii)  which  are  directly  or 
indirectly beneficially owned by any other Person with whom such Person has any agreement, arrangement or understanding, whether or not in writing, for 
the purpose of acquiring, holding, voting or disposing of any securities of the Company or cooperating in obtaining, changing or influencing the control of 
the Company; provided, that the effect of such agreement, arrangement or understanding is to treat such Person as an “entity” under Section 1.382-3(a)(1) 
of the Department of Treasury regulations.

From  and  after  the  time  any  Person  becomes  an  Acquiring  Person,  if  the  Rights  evidenced  by  a  Right  Certificate  are  or  were  acquired  or  Beneficially 
Owned by an Acquiring Person, an Associate or Affiliate of an Acquiring Person or any Person with whom such Person is Acting in Concert, such Rights 
shall become void, and any holder of such Rights shall thereafter have no right to exercise such Rights.

Flip-in Event

If any Person becomes an Acquiring Person, proper provision shall be made so that each holder of a Rights, other than Rights Beneficially Owned by an 
Acquiring Person, an Associate or Affiliate of the Acquiring Person or any Person with whom such Person is Acting in Concert (all of which will thereafter 
be void), will thereafter have the right to receive, upon exercise thereof, that number of shares of common stock having a market value equal to two times 
the Purchase Price of the Right. If the board so elects, the Company shall deliver, upon payment of the Purchase Price, an amount of cash or securities 
equivalent in value to the number of shares of common stock issuable upon exercise of a Right.

Flip-over Event

If, at any time after a Person becomes an Acquiring Person, the Company is acquired in a merger or other business combination transaction or 50% or more 
of its consolidated assets or earning power are sold, proper provision will be made so that each holder of a Right will thereafter have the right to receive, 
upon the exercise thereof at the then current Purchase Price, that number of shares of common stock of the acquiring company which at the time of such 
transaction will have a market value of two times the Purchase Price.

Exchange

At any time after any Person becomes an Acquiring Person and prior to the acquisition by any Person or group of a majority of the outstanding common 
stock, the board may exchange the Rights (other than Rights owned by an Acquiring Person, which shall have become void), in whole or in part, at an 
exchange ratio of one share of common stock per Right (subject to adjustment). The exchange of the Rights by the Board may be made effective at such 
time, on such basis and with such conditions as the board in its sole discretion may establish.

Preferred Shares

Preferred Shares purchasable upon exercise of the Rights will not be redeemable. Each Preferred Share will be entitled to a quarterly dividend payment of 
1,000 multiplied by the dividend declared per share of common stock. In the event of liquidation, the holders of the Preferred Shares will be entitled to a 
payment  per  share  equal  to  1,000  multiplied  by  the  aggregate  payment  made  per  share  of  common  stock.  Each  Preferred  Share  will  have  1,000  votes, 
voting together with the common stock. In the event of any merger, consolidation or other transaction in which common stock is exchanged, each Preferred 
Share will be entitled to receive 1,000 multiplied by the amount received per share of common stock. Because of the nature of the dividend, liquidation and 
voting rights of the Preferred Shares, the value of the one one-thousandth of a Preferred Share purchasable upon exercise of each Right should approximate 
the value of one share of common stock.

 
 
 
Purchase Price Adjustments

The  Purchase  Price  payable,  and  the  number  of  Preferred  Shares  or  other  securities  or  property  issuable,  upon  exercise  of  the  Rights  is  subject  to 
adjustment from time to time to prevent dilution (i) in the event of a stock dividend on the Preferred Shares payable in Preferred Shares or a subdivision or 
combination  of  the  Preferred  Shares,  (ii)  upon  the  grant  to  holders  of  the  Preferred  Shares  of  certain  rights  or  warrants  to  subscribe  for  or  purchase 
Preferred Shares at a price, or securities convertible into Preferred Shares with a conversion price, less than the then current market price of the Preferred 
Shares, or (iii) upon the distribution to holders of the Preferred Shares of evidences of indebtedness or assets (excluding regular periodic cash dividends 
paid out of earnings or retained earnings or dividends payable in Preferred Shares) or of subscription rights or warrants (other than those referred to above). 
The number of outstanding Rights and the number of Preferred Shares issuable upon exercise of each Right are also subject to adjustment in the event of a 
stock  split  of  the  common  stock  or  a  stock  dividend  on  the  common  stock  payable  in  shares  of  common  stock  or  subdivisions,  consolidations  or 
combinations of the common stock occurring, in any such case, prior to the Distribution Date.

With certain exceptions, no adjustment in the Purchase Price will be required until cumulative adjustments require an adjustment of at least 1% in such 
Purchase Price. No fractional Preferred Shares will be issued (other than fractions which are integral multiples of one one-thousandth of a Preferred Share, 
which  may,  at  the  election  of  the  Company,  be  evidenced  by  depositary  receipts),  and  in  lieu  thereof,  an  adjustment  in  cash  will  be  made  based  on  the 
market price of the Preferred Shares on the last trading day prior to the date of exercise.

Expiration

The Rights will expire on the earlier of (i) the Close of Business on December 2, 2022, (ii) the close of business on the date that the board determines that 
(A) the Rights Agreement is no longer necessary or desirable for the preservation of the Tax Benefits or (B) the Tax Benefits have been fully utilized and 
may no longer be carried forward, (iii) the time at which the Rights are redeemed, (iv) the time at which the Rights are exchanged, and (v) if the Rights 
Agreement has not been approved by the stockholders prior to the conclusion of the Company’s 2020 annual meeting, the Close of Business on such date.

Redemption

At any time prior to the time any Person becomes an Acquiring Person, the board may redeem the Rights in whole, but not in part, at a price of $0.0001 per 
Right (the “Redemption Price”). The redemption of the Rights may be made effective at such time, on such basis and with such conditions as the board in 
its sole discretion may establish. Immediately upon any redemption of the Rights, the right to exercise the Rights will terminate and the only right of the 
holders of Rights will be to receive the Redemption Price.

Amendment

The terms of the Rights may be amended by the board without the consent of the holders of the Rights. However, from and after such time as any Person 
becomes an Acquiring Person, the Rights Agreement shall not be amended or supplemented in any manner which would adversely affect the interests of 
the holders of Rights (other than Rights owned by an Acquiring Person, which shall have become void).

Rights of Holders

Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder of the Company, including, without limitation, the right to vote or 
to receive dividends.

 
 
 
Process to Seek Exemption

Any person who desires to effect any acquisition of securities that would, if consummated, result in such person becoming an Acquiring Person may, prior 
to such time and in accordance with Section 36 of the Rights Agreement, request that the board grant an exemption with respect to such acquisition under 
the Rights Agreement so that such Person would be deemed to be an “Exempt Person” under the Rights Agreement.

 
 
 
FIRST AMENDMENT TO SECTION 382 RIGHTS AGREEMENT

Exhibit 4.5.1

This First Amendment to Section 382 Rights Agreement (the “First Amendment”) is made as of December 2, 2022 by and between MERRIMACK 
PHARMACEUTICALS, INC. (the “Company” and COMPUTERSHARE TRUST COMPANY, N.A. as Rights Agent (the “Rights Agent”), amending the 
Section 382 Rights Agreement by and between the Company and the Rights Agent dated December 3, 2022 (the “Original Rights Agreement”). Except as 
set forth herein, any defined terms contained herein have the meaning set forth in the Original Rights Agreement.

WHEREAS (a) the Company and certain of its Subsidiaries have generated certain Tax Benefits for United States federal and state income tax 

purposes, (b) the Company desires to avoid an “ownership change” within the meaning of Section 382 of the Code and the Treasury Regulations 
promulgated thereunder and similar state tax laws, and thereby preserve its ability to utilize such Tax Benefits, and (c) in furtherance of such objective, the 
Company and the Rights Agent entered into the Original Rights Agreement; and

WHEREAS the Company and the Rights Agent wish to amend the Original Rights Agreement to extend the term of the Original Rights Agreement 

through December 2, 2025;

NOW, THEREFORE, the Company and the Rights Agent agree as follows:

1.

The definition of “Final Expiration Date” is hereby amended to read as follows:

“(u) Final Expiration Date” means the earlier of (i) the Close of Business on December 2, 2025 or (ii) the Close of Business on the date that the Board 
determines that (A) this Agreement is no longer necessary or desirable for the preservation of the Tax Benefits or (B) the Tax Benefits have been fully 
utilized and may no longer be carried forward.

2.

The definition of “Early Termination Date” is hereby amended to read as follows:

(o) “Early Expiration Date” means, if Stockholder Approval has not been obtained by the Close of Business on the date on which the Company’s 2023 
annual meeting of stockholders is concluded (or, if later, the date on which the votes of the stockholders of the Company with respect to such meeting are 
certified), the Close of Business on such date. For the avoidance of doubt, if Stockholder Approval is obtained then there shall be no Early Expiration Date.

3.

Except as modified herein, all other terms and conditions set forth in the Original Rights Agreement are hereby ratified and confirmed in all 
respects.

 
 
 
 
  
 
  
 
  
 
 
SUBSIDIARIES OF THE REGISTRANT

Name
Merrimack Pharmaceuticals UK Limited*
Merrimack Securities Corporation*

Jurisdiction of Incorporation
UK
Massachusetts

* wholly owned

Exhibit 21.1

 
 
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement of Merrimack Pharmaceuticals, Inc. on Form S-3 (No. 333-222093) and Form 
S-8 (Nos. 333-180996, 333-186370, 333-194313, 333-202346, 333-209745, 333-223577, 333-230084, 333-237155 and 333- 268609) of our report dated 
March 9, 2023 with respect to our audits of the consolidated financial statements of Merrimack Pharmaceuticals, Inc. as of December 31, 2022 and 2021 
and  for  the  years  then  ended,  which  report  is  included  in  this  Annual  Report  on  Form  10-K  of  Merrimack  Pharmaceuticals,  Inc.  for  the  year  ended 
December 31, 2022.

Exhibit 23.1

/s/ Marcum LLP

Marcum LLP
Boston, Massachusetts

March 9, 2023

 
 
 
 
Exhibit 31.1

I, Gary L. Crocker, certify that:

CERTIFICATIONS

1.

2.

3.

4.

I have reviewed this Annual Report on Form 10-K of Merrimack Pharmaceuticals, Inc.;

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 the 
statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this 
report;

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the 
financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in 
Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-
15(f)) for the registrant and have:

a)

b)

c)

d)

Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to 
ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those 
entities, particularly during the period in which this report is being prepared;

Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our 
supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for 
external purposes in accordance with generally accepted accounting principles;

Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the 
effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent 
fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to 
materially affect, the registrant’s internal control over financial reporting; and

5.

The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the 
registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a)

b)

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are 
reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal 
control over financial reporting.

Date: March 9, 2023

/s/ Gary L. Crocker
Gary L. Crocker
President
(Principal Executive Officer)

 
 
 
 
 
Exhibit 31.2

I, Gary L. Crocker, certify that:

CERTIFICATIONS

1.

2.

3.

4.

I have reviewed this Annual Report on Form 10-K of Merrimack Pharmaceuticals, Inc.;

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 the 
statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this 
report;

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the 
financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in 
Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-
15(f)) for the registrant and have:

a)

b)

c)

d)

Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to 
ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those 
entities, particularly during the period in which this report is being prepared;

Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our 
supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for 
external purposes in accordance with generally accepted accounting principles;

Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the 
effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent 
fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to 
materially affect, the registrant’s internal control over financial reporting; and

5.

The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the 
registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a)

b)

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are 
reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal 
control over financial reporting.

Date: March 9, 2023

/s/ Gary L. Crocker
Gary L. Crocker
President
(Principal Financial Officer)

 
 
 
 
 
CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 32.1

In connection with the Annual Report on Form 10-K of Merrimack Pharmaceuticals, Inc. (the “Company”) for the period ended December 31, 2022 

as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, Gary L. Crocker, President of the Company, 
hereby certifies, pursuant to 18 U.S.C. Section 1350, that to his knowledge:

(1)

(2)

the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the 
Company.

Date: March 9, 2023

/s/ Gary L. Crocker
Gary L. Crocker
President
(Principal Executive Officer)

 
 
 
 
 
CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 32.2

In connection with the Annual Report on Form 10-K of Merrimack Pharmaceuticals, Inc. (the “Company”) for the period ended December 31, 2022 

as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, Gary L. Crocker, President of the Company, 
hereby certifies, pursuant to 18 U.S.C. Section 1350, that to his knowledge:

(1)

(2)

the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the 
Company.

Date: March 9, 2023

/s/ Gary L. Crocker
Gary L. Crocker
President
(Principal Financial Officer)