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Puma Biotechnology, Inc.

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FY2020 Annual Report · Puma Biotechnology, Inc.
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SUCCESSFULLY
ADAPTING

TO THE WORLD AROUND US

PUMA BIOTECHNOLOGY, INC.   |   2020 ANNUAL REPORT

Puma is committed to aiding cancer 
patients in need and we quickly 
conformed to the restrictions arising 
from the COVID-19 pandemic.

T
P
A
D
A

PUMA BIOTECHNOLOGY, INC. is a biopharmaceutical com-
pany with a focus on the development and commercial-
ization  of  innovative  products  to  enhance  cancer  care.  
Puma  in-licenses  the  global  development  and  commer-
cialization rights to PB272 (neratinib, oral), PB272 (nerati-
nib, intravenous), and PB357.  
  Neratinib  is  a  potent  irreversible  tyrosine  kinase  in-
hibitor  that  blocks  signal  transduction  through  the  epi-
dermal growth factor receptors, HER1, HER2 and HER4.  
Puma  has  been  focused  on  developing  the  oral  version 
of neratinib, and its most advanced drug candidates are 
directed at the treatment of HER2-positive breast cancer.  
Puma believes that neratinib has clinical applications in 
the treatment of several other cancers as well, including 
non-small  cell  lung  cancer  and  other  solid  tumor  types 
that over-express or have a mutation in HER2.
  Neratinib,  oral  was  approved  by  the  U.S.  Food  and 
Drug  Administration  in  2017  for  the  extended  adjuvant 
treatment of adult patients with early  stage  HER2-over-
expressed/amplified  breast  cancer,  following  adjuvant 
trastuzumab-based therapy. Puma commenced commer-
cial  sales  of  the  drug  in  2017  and  it  is  marketed  in  the 
United  States  as  NERLYNX®  tablets.  In  February  2020, 

NERLYNX was also approved by the FDA in combination 
with capecitabine for the treatment of adult patients with 
advanced or metastatic HER2-positive breast cancer who 
have  received  two  or  more  prior  anti-HER2-based  regi-
mens  in  the  metastatic  setting.  NERLYNX  was  granted 
marketing authorization by the European Commission in 
2018 for the extended adjuvant treatment of adult patients 
with  early  stage  hormone  receptor-positive  HER2-over-
expressed/amplified breast cancer and who are less than 
one  year  from  completion  of  prior  adjuvant  trastuzum-
ab-based therapy. Commercial sales commenced in the 
European Union in 2019. 
  Puma  has  entered  into  additional  exclusive  license 
agreements  with  various  parties  to  commercialize 
NERLYNX in regions outside the United States, including 
the European Union, Canada, Latin America, Greater Chi-
na, Israel, Southeast Asia, Australia, New Zealand, South 
Korea, the Middle East, and parts of Africa. Puma plans 
to continue to pursue the commercialization of NERLYNX 
outside the United States. 
  NERLYNX®  is  a  registered  trademark  of  Puma 
Biotechnology, Inc. 

PRODUCT PIPELINE
Neratinib across the breast cancer therapy spectrum

PHASE I

PHASE II

PHASE III

REGISTRATION

APPROVAL

HER2+ Breast Cancer

  Extended adjuvant 
    Neratinib monotherapy

  Metastatic 
    Monotherapy or  
    combination therapy

  Metastatic with brain mets 
    Monotherapy or  
    combination therapy

HER2-mutant Breast  
Cancer/Solid Tumors

  Metastatic 
    Neratinib (± fulvestrant in MBC**)

CONTROL

ExteNET (Phase III HER2+ EBC*) 

EAP/MAP

FB-10: T-DM1 + neratinib

NALA (Phase III 3rd Line HER2+ MBC**)

TBCRC-022 

SUMMIT: Breast HRC+*** 

SUMMIT: Cervical 

SUMMIT: exon 18 mut NSCLC

SUMMIT (Basket Trial)

* EBC:  Early breast cancer      ** MBC:  Metastatic breast cancer      *** HRc+:  Hormone receptor positive

TO OUR STOCKHOLDERS

The entire world faced challenges in 2020, as the COVID-19 pandemic drastically changed everyone’s way of life. At Puma Bio-
technology, we have remained steadfast in our goal to aid cancer patients in need, overcoming the logistical obstacles imposed 
by COVID-19 to maintain progress in patient enrollment and treatment worldwide. The continued advancement of our ongoing 
NERLYNX® (neratinib) clinical trials is a testament to our Company’s dedication to its mission.

ADAPTING TO OUR NEW OPERATING ENVIRONMENT
2020 was in many ways an unusual year, yet, even in such challenging times, Puma continued to report progress toward its stat-
ed milestones. With all non-essential operations going virtual, Puma acted quickly to equip our sales team to adapt to the current 
environment. Sales representatives, who were limited by travel restrictions and in-person conversations due to the pandemic, 
were retrained to effectively work with physicians via a virtual platform. The goal was to enforce the same degree of impact that 
our sales team was capable of normally, but in a virtual scenario. Within a short time, Puma’s management was able to design 
new procedures for our ‘field’ employees, which allowed them to function effectively in a new setting.

Our ability to function during the COVID-19 pandemic has been limited in many ways, especially in terms of travel. In 2020, we 
were unable to meet with our collaborators in person to talk about new plans on expanding our business. But Puma adapted to the 
new normal, connected with our global partners virtually and was successful in broadening the important collaborations world-
wide to expand the reach of NERLYNX, providing potential treatment to more patients in need. We were able to further the com-
mercialization of NERLYNX in Brunei, Chile, Ecuador, Finland, Hong Kong, Israel, Mainland China, Malaysia, South Korea, Switzer-
land, Taiwan, and New Zealand in the past year, which allowed us to cement our commitment to patients across six continents.

In October, Puma proudly supported an Oncology Research Program (ORP) to investigate NERLYNX, led by the National Com-
prehensive Cancer Network (NCCN), with a $2-million grant. The ORP may include pre-clinical, translational, and clinical trials, 
focusing on the treatment of patients with (i) pediatric tumors; (ii) early stage and metastatic breast cancer; (iii) other HER2-pos-
itive tumors; and (iv) EGFR-mutated glioblastoma multiforme. The first phase of this project began in early 2021.

EXECUTING ON OUR GOAL TO PROVIDE NERLYNX TO PATIENTS IN NEED
COVID-19 posed significant logistical challenges for clinical studies. Cancer patients are particularly vulnerable to the severe 
symptoms of COVID-19, and healthcare staff have been reassigned from clinical work to the front lines in response to rising 
case numbers. Nevertheless, Puma Biotechnology was resilient and steadfast in our mission to provide therapy to patients in 
need. The Company was able to navigate the hurdles and fulfill our goal of reaching patients.

Puma extensively reviewed all available clinical and non-clinical data, finding that NERLYNX does not have a negative effect 
on the immune system, and would therefore not elevate the risk of contracting severe COVID-19 for patients. We have also dili-
gently maintained our supplies of NERLYNX to ensure that treatment courses are not interrupted or upended by the pandemic. 
We have and will continue to put the needs of our patients first, as we strive to improve their lives and alleviate their suffering.

NERLYNX was the first drug to be approved by the U.S. Food and Drug Administration (FDA) for the extended adjuvant treat-
ment of HER2-positive early stage breast cancer. In February 2020, the FDA also approved our supplemental New Drug Ap-
plication (sNDA) for NERLYNX to treat HER2-positive metastatic breast cancer in combination with capecitabine, two months 
ahead of its scheduled review date. NERLYNX is still the only HER2-directed tyrosine kinase inhibitor approved for both early 
stage and metastatic HER2-positive breast cancer.

INNOVATING TO DRIVE VALUE FOR PATIENTS 
Critically, in the face of the COVID-19 pandemic, we have continued to advance our clinical studies of neratinib. Our trials were 
featured in highly regarded industry publications in 2020 and data from our ongoing studies were presented at national and 
international conferences. We have not paused in our efforts to improve the safety and tolerability of neratinib and to test its 
efficacy in newer indications.

 ▶ ExteNET Phase III Trial

The  ExteNET  Phase  III  trial  was  a  multicenter,  randomized,  double-blind,  Phase  III  trial  of  2,840  HER2-positive  early  stage 
breast cancer patients who received NERLYNX after neoadjuvant and/or adjuvant therapy with chemotherapy and trastuzumab. 

Alan H. Auerbach 
Chairman, Chief Executive Officer, President and Founder

Patients were stratified by hormone receptor status and randomly assigned to one year of treatment with either oral NERLYNX 
240 mg/day or placebo.

In October, efficacy results from the ExteNET Phase III trial, published in Clinical Breast Cancer, showed that, for patients who 
had completed adjuvant trastuzumab within one year prior to study, the absolute 5-year invasive disease-free survival benefit 
versus placebo was 5.1%, a significant improvement, and the absolute 8-year overall survival benefit was 2.1%. The study also 
examined patients who did not achieve a pathological complete response, finding the 5-year invasive disease-free survival 
benefit to be 7.4% compared to placebo, and the overall survival benefit was 9.1%. Overall, the study found a long-term benefit 
from NERLYNX in these patients.

 ▶ CONTROL Phase II Trial

The  CONTROL  Phase  II  trial  is  an  open-label  study  investigating  methods  to  improve  the  tolerability  of  NERLYNX  in  pa-
tients with early stage, HER2-positive breast cancer. In August, the interim results from the CONTROL study, published in the 
Annals of Oncology, indicated that several methods of anti-diarrheal strategies showed a significant improvement in neratinib 
tolerability. The most impactful method was using a dose-escalation strategy with loperamide as needed, which showed a 60% 
reduction in grade 3 diarrhea, an 80% reduction in discontinuations, and a 90% reduction in the need to dose reduce. These 
reductions were observed by comparing CONTROL trial patients to similar cohorts in the ExteNET trial.

 ▶ NALA Phase III Trial

Our NALA Phase III trial was aimed at investigating the benefits of neratinib in combination with capecitabine, versus lapatinib 
and capecitabine, in patients with HER2-positive metastatic breast cancer who had previously received two lines of HER2-tar-
geted therapy. In 2019, we shared the results of this trial, which showed a statistically significant increase in progression-free 
survival rates and a numerical increase in overall survival for patients receiving the neratinib combination treatment. These 
findings supported the sNDA that was approved by the FDA in February of 2020.

At  the  San  Antonio  Breast  Cancer  Symposium  (SABCS),  Puma  presented  new  data  expanding  on  our  previous  findings, 
demonstrating that patients in the NERLYNX arm appeared to have better outcomes than the lapatinib arm, specifically refer-
ring to patients who had central nervous system metastases at the baseline of treatment. The proportion of patients requiring 
intervention for CNS disease was 22.8% in the NERLYNX arm versus 29.2% in the lapatinib arm of the study.

 ▶ SUMMIT Phase II Trial

Puma Biotechnology’s SUMMIT Phase II trial is investigating the efficacy and safety of neratinib in patients with (i) HER2 mutant  
metastatic salivary gland cancer; (ii)  EGFR exon 18 mutation-positive lung cancer; (iii) HER2 mutant cervical cancer; (iv) HER2 
mutant solid tumors; (v) HER2 mutant bladder cancer; (vi) HER2 mutant hormone receptor positive breast cancer; (vii) hormone 
receptor negative breast cancer; and (viii) HER4 mutant solid tumors.

In July, results from the treatment of patients in the HER2-positive, metastatic cervical cancer cohort with neratinib were published 
in Gynecologic Oncology. Interim results of this study showed that 3 patients (25%) had confirmed partial responses and 3 pa-
tients had stable disease for more than 16 weeks, resulting in an overall clinical benefit rate of 50%. The safety profile of neratinib 
was similar to other studies. Median progression-free survival was 7.0 months and the median overall survival was 16.8 months.

In November, we announced interim results from the cohort of patients with EGFR Exon 18 Mutated, Metastatic Non-Small Cell 
Lung Cancer (NSCLC) who have been previously treated with an EGFR targeted tyrosine kinase inhibitor. Patients enrolled in the 
study received 240 mg of neratinib daily as a monotherapy. From 10 evaluable patients, 6 (60%) experienced a partial response 
and 4 (40%) experienced a confirmed partial response. A total of 8 patients (80%) experienced a clinical benefit, defined as stable 
disease or partial response for at least 16 weeks.

In December, we presented new findings from the SUMMIT study at the San Antonio Breast Cancer Symposium, detailing the 
treatment of 46 patients with hormone receptor positive metastatic breast cancer with neratinib, trastuzumab and fulvestrant. Of 
30 patients with efficacy data available, 12 (40%) had a confirmed objective response, with a maximum of a 60% overall response. 
Researchers  concluded  that  these  data  demonstrated  encouraging  clinical  activity,  regardless  of  previous  treatment,  and 
encouraged the addition of a trial arm to evaluate neratinib, trastuzumab and fulvestrant, versus trastuzumab and fulvestrant, 
and fulvestrant alone. We are continuing to enroll patients in this arm of the study.

In early January 2021, Puma announced interim results from the biliary tract cancers cohort of patients at the virtual 2021 Gas-
trointestinal Cancers Symposium hosted by the American Society of Clinical Oncology (ASCO GI). Of the 25-patient cohort, 
efficacy data reflected that 4 had confirmed partial responses, and 3 more had stable disease for ≥16 weeks, leading to a 16% 
objective response rate and a 28% clinical benefit rate. The safety profile of patients from this cohort reflected that of those 
treated with neratinib monotherapy and mandatory loperamide prophylaxis in the first 2 months.

In late January 2021, we reported interim results from the cohort of metastatic non-small cell lung cancer (NSCLC) patients 
with epidermal growth factor (EGFR) exon 18 mutations who have been previously treated with an EGFR targeted tyrosine 
kinase inhibitor (TKI). The findings were reported at the virtual 2020 World Conference on Lung Cancer (WCLC 2020) hosted 
by the International Association for the Study of Lung Cancer (IASLC). Of the 10 evaluable patients from this cohort, 6 experi-
enced a partial response (60%) and 8 experienced a clinical benefit (80%). The median duration of response was found to be 
7.5 months and the median progression-free survival was 9.1 months. The safety profile was favorable, with no reports of grade 
3 or higher diarrhea, and no patients requiring a dose hold, dose reduction, hospitalization, or discontinuation of treatment 
due to diarrhea.

FINANCIALS
In  spite  of  the  economic  upheavals  brought  about  by  the  pandemic,  Puma  is  in  a  secure  financial  position  to  advance 
NERLYNX. We ended the year with approximately $93.4 million in cash, cash equivalents and marketable securities, which 
puts the company in a secure financial state in 2021. Net product revenue from NERLYNX in 2020 was $196.7 million and cash 
burn was $19.3 million, which included $20.6 million of payments to the licensor of neratinib.

Additionally, in December, we prevailed over a final appeal brought against our licensed European patent, EP Patent 1848414, 
which covers the use of irreversible EGFR inhibitors in treating gefitinib and/or erlotinib resistant cancer and cancer with a 
T790M EGFR mutation. The European Patent Office Board of Appeals had rejected the claims of Boehringer Ingelheim on 
Puma’s licensed European patent—a decision that prevailed after nearly a decade of legal arguments. This patent was initially 
challenged in November 2011 by Boehringer Ingelheim, and the decision made in February 2014 upheld a subset of the claims 
brought forth in the challenge. Both parties appealed the decision in 2017, and the Board of Appeals ruled in our favor, revers-
ing the 2014 decision, and upholding the initial EP Patent 1848414 as granted. 

FUTURE OUTLOOK
Puma will continue to uphold its mission of keeping cancer patients as our priority and will continue to strive to fulfill the un-
met needs of cancer patients. 2020 was an unprecedented year for all of us and we are thankful for the commitments from all 
frontline healthcare workers. In this virtual new normal, we promise to stay connected, move forward as a team and focus on 
our stated clinical and business milestones.

During the approximately 10-year journey that has led Puma to where it is now, we were fortunate to have many advisors, 
key opinion leaders and scientific minds who helped to guide us in our journey. In March 2021, we were deeply saddened by 
the loss of one of those leaders, Jose Baselga, MD, Ph.D. Dr. Baselga was the Chairman of our Scientific Advisory Board at 
Puma and was one of the breast cancer key opinion leaders who voiced their support of neratinib when the U.S. Food and 
Drug Administration held the meeting of their Oncologic Drugs Advisory Committee in May 2017 to decide whether or not to  
approve neratinib. Dr. Baselga was also one of the first breast cancer researchers to elucidate the role that neratinib might play 
in the treatment of tumors with a HER2 mutation. Dr. Baselga believed in science and he believed in using that science to help 
cancer patients. We are forever grateful to the role that Dr. Baselga played in the Puma story and we will strive to continue 
our mission to help cancer patients, as that is what Dr. Baselga would have wanted us to do. Our condolences go out to Dr. 
Baselga’s family, friends and co-workers who were equally blessed to have had him in their lives. 

In closing, on behalf of our Board of Directors, I would like to commend our dedicated employees, without whom we could not 
pursue our mission and achieve our milestones. I would also like to thank our stockholders and other stakeholders for their 
loyalty and support throughout the year.

Sincerely,

Alan H. Auerbach
Chairman, Chief Executive Officer, President and Founder

Puma maintains a solid 
financial position as we provide 
therapy to breast cancer 
patients around the world.

E
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X
E

Puma continues to grow our scientific impact 
through clinical research milestones, as part 
of our ongoing evaluation of NERLYNX® in 
several cancers, and data announcements at 
industry conferences and in peer-reviewed 
medical journals.

E
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Puma  is  steadfast  in  its  mission  of  improving  the  lives  of  the  cancer  patients 
who  inspire  and  motivate  us.  We  continue  to  present  data  from  our  ongoing 
studies at national and international conferences, most recently the San Antonio 
Breast  Cancer  Symposium  in  December  2020,  the  2020  World  Conference  on 
Lung  Cancer  and  the  2021  Gastrointestinal  Cancers  Symposium  hosted  by 
the  American  Society  of  Clinical  Oncology  (ASCO  GI).  Additionally,  peer-re-
viewed  clinical  data  were  published  in  distinguished  medical  journals,  such  as 
Annals of Oncology, Clinical Breast Cancer and Gynecologic Oncology.

Puma has entered into six exclusive sub-license agreements with partners in 
markets outside of the United States to expand our global reach. Our partner 
companies and their covered regions follow:

BIXINK THERAPEUTICS

South Korea

KNIGHT THERAPEUTICS, INC

Canada

MEDISON PHARMA LTD

Israel

European Union, Greater China, the Middle East, North & West Africa, South Africa & Sudan

PIERRE FABRE

PINT PHARMA INTERNATIONAL S.A.

Latin America 
(including Argentina, Brazil, Chile, Colombia, Mexico & other countries & territories in the region)

SPECIALISED THERAPEUTICS ASIA

Australia, New Zealand & Southeast Asia 
(including Singapore, Malaysia, Brunei, Philippines, Thailand & Vietnam)

FORM 10-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 10-K

(Mark One)
È ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES

EXCHANGE ACT OF 1934

‘ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2020
or

For the transition period from

to

Commission File Number: 001-35703

PUMA BIOTECHNOLOGY, INC.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of
incorporation or organization)

77-0683487
(I.R.S. Employer
Identification No.)

10880 Wilshire Boulevard, Suite 2150
Los Angeles, CA 90024
(424) 248-6500
(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

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

Title of each class
Common Stock, par value $0.0001 per
share

Trading symbol
PBYI

Name of each exchange on which
registered
The NASDAQ Stock Market LLC
(NASDAQ Global Select Market)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities

Act. Yes ‘ No È

Securities registered pursuant to Section 12(g) of the Act: None

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 È

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 È 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 È 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 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 ‘

È
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. È

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ‘ No È
The aggregate market value of voting stock held by non-affiliates of the registrant was approximately $413.3 million as of June 30,

2020, based upon the closing price of $10.43 per share of the registrant’s common stock on the NASDAQ Global Select Market on
Friday, June 30, 2020, the last business day of the registrant’s most recently completed second fiscal quarter. Shares of common stock
held by each executive officer, director and holder of 10% or more of the outstanding common stock have been excluded in that such
persons may be deemed to be affiliates. This determination of affiliate status is not necessarily a conclusive determination for other
purposes. As of February 18, 2021, there were 40,258,460 shares of the registrant’s common stock outstanding.

Documents Incorporated by Reference:
Portions of the Proxy Statement for the registrant’s 2021 Annual Meeting of Stockholders, or the 2021 Proxy Statement, are

incorporated by reference into Part III of the Form 10-K to the extent stated herein.

TABLE OF CONTENTS

Part I
Item 1.
Item 1A.
Item 1B.
Item 2.
Item 3.
Item 4.

Part II
Item 5.

Item 6.
Item 7.

Item 7A.
Item 8.
Item 9.

Item 9A.
Item 9B.

Part III
Item 10.
Item 11.
Item 12.

Item 13.
Item 14.

Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unresolved Staff Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Legal Proceedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mine Safety Disclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer
Purchases of Equity Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selected Financial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Management’s Discussion and Analysis of Financial Condition and Results of

Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quantitative and Qualitative Disclosures About Market Risk . . . . . . . . . . . . . . . . . . . .
Financial Statements and Supplementary Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changes in and Disagreements with Accountants on Accounting and Financial

Disclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Directors, Executive Officers and Corporate Governance . . . . . . . . . . . . . . . . . . . . . . .
Executive Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Ownership of Certain Beneficial Owners and Management and Related

Stockholder Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Certain Relationships and Related Transactions, and Director Independence . . . . . . . .
Principal Accounting Fees and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Part IV
Exhibits, Financial Statement Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 15.
Item 16.
Form 10-K Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhibit Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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F-1

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report contains forward-looking statements within the meaning of Section 21E of the
Securities Exchange Act of 1934, as amended, or the Exchange Act. Any statements about our expectations,
beliefs, plans, objectives, assumptions, future events or performance are not historical facts and may be forward
looking. These forward-looking statements include, but are not limited to, statements about:

•

•

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•

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•

•

•

•

•

•

•

•

•

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•

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the commercialization of NERLYNX® (neratinib);

the development of our drug candidates, including when we expect to undertake, initiate and complete
clinical trials of our product candidates;

the impact of the global COVID-19 pandemic, and measures to control the spread of COVID-19, on
business, financial condition, results of operations and ongoing trials;

the anticipated timing of regulatory filings;

the regulatory approval of our drug candidates;

our use of clinical research organizations and other contractors;

our ability to find collaborative partners for research, development and commercialization of potential
products;

efforts of our sub-licensees to obtain regulatory approval and commercialize NERLYNX in areas
outside the United States;

our ability to market any of our products;

our expectations regarding our costs and expenses;

our anticipated capital requirements and estimates regarding our needs for additional financing;

our ability to compete against other companies and research institutions;

our ability to secure adequate protection for our intellectual property;

our intention and ability to vigorously defend against any litigation to which we are or may become
party;

our estimates for damages that we may be required to pay in connection with the class action lawsuit to
which we are a party;

our ability to attract and retain key personnel; and

our ability to obtain adequate financing.

These statements are often, but not always, made through the use of words or phrases such as “anticipate,”

“estimate,” “plan,” “project,” “continuing,” “ongoing,” “expect,” “believe,” “intend” and similar words or
phrases. Accordingly, these statements involve estimates, assumptions and uncertainties that could cause actual
results to differ materially from those expressed in them. Discussions containing these forward-looking
statements may be found throughout this Annual Report, including the sections entitled “Item 1. Business” in
Part I and “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations” in
Part II of this Annual Report. These forward-looking statements involve risks and uncertainties, including the
risks discussed in the section entitled “Item 1A. Risk Factors” in Part I of this Annual Report that could cause our
actual results to differ materially from those in the forward-looking statements. We undertake no obligation to
update the forward-looking statements or to reflect events or circumstances after the date of this document,
except as required by law. The risks discussed in this Annual Report should be considered in evaluating our
prospects and future financial performance.

1

SUMMARY OF RISK FACTORS

Our business is subject to a number of risks of which you should be aware before making a decision to
invest in our common stock, including those described in the section entitled “Item 1A. Risk Factors” in Part I of
this Annual Report. These risks include, among others, the following:

• We have a history of operating losses and are not profitable and may never become profitable.

• We are currently a single product company with limited commercial sales experience.

• We may not be able to successfully commercialize NERLYNX.

• We may not be able to secure additional financing on favorable terms, or at all, to meet our future

capital needs and our failure to obtain additional financing when needed on acceptable terms, or at all,
could force us to delay, limit, reduce or terminate our product development or commercialization
efforts or other operations.

• The terms of our credit facility place restrictions on our ability to operate our business and on our

financial flexibility, and we may be unable to achieve the revenue necessary for us to incur additional
borrowings under the credit facility or to satisfy the minimum revenue covenants.

• We have limited experience as a company in marketing or distributing pharmaceutical products. If we
are unable to expand our marketing and sales capabilities and successfully commercialize NERLYNX,
our business, results of operations and financial condition may be materially adversely affected.

• We depend on a limited number of customers for a significant amount of our total revenue, and if we

lose any of our significant customers, our business could be harmed.

• Even though the FDA and EC have granted approval of NERLYNX for the extended adjuvant
treatment of early stage, HER2-positive breast cancer and the FDA has granted approval for
NERLYNX for the treatment of metastatic HER2-positive breast cancer, the terms of the approvals
may limit its commercial potential.

•

Interim, “topline” and preliminary data from our clinical trials that we announce or publish from time
to time may change as more patient data become available and are subject to audit and verification
procedures that could result in material changes in the final data.

• NERLYNX or our other drug candidates may cause undesirable side effects or have other properties
when used alone or in combination with other approved products or investigational new drugs that
could delay or prevent their regulatory approval, limit the commercial profile of an approved label, or
result in significant negative consequences following marketing approval, if any, as applicable.

• NERLYNX is still under clinical development for various additional indications, and we cannot be
certain that NERLYNX will receive regulatory approval for any other indication for which we may
seek approval.

• We are dependent on international third-party sub-licensees for the development and

commercialization of NERLYNX in several countries outside the United States. The failure of these
sub-licensees to meet their contractual, regulatory or other obligations could adversely affect our
business.

• We have no experience in drug formulation or manufacturing and rely exclusively on third parties to
formulate and manufacture NERLYNX and our drug candidates, and any disruption or loss of these
relationships could delay our development and commercialization efforts.

• Our business, financial condition, results of operations and ongoing clinical trials have been and could

continue to be harmed by the effects of the COVID-19 pandemic.

2

• We depend significantly on intellectual property licensed from Pfizer and the termination of this

license would significantly harm our business and future prospects.

• Our proprietary rights may not adequately protect our intellectual property and potential products, and
if we cannot obtain adequate protection of our intellectual property and potential products, we may not
be able to successfully market our potential products.

3

PART I

ITEM 1.

BUSINESS

Company Overview

Unless otherwise provided in this Annual Report, references to the “Company,” “we,” “us,” and “our”

refer to Puma Biotechnology, Inc., a Delaware corporation formed on April 27, 2007 together with our wholly-
owned subsidiaries, Puma Biotechnology Ltd and Puma Biotechnology B.V.

We are a biopharmaceutical company with a focus on the development and commercialization of innovative

products to enhance cancer care. Our lead product is NERLYNX, an oral version of neratinib, which is a potent
irreversible tyrosine kinase inhibitor, or TKI, that blocks signal transduction through the human epidermal
growth factor receptors, HER1, HER2 and HER4. In 2017, we obtained approval from the United States Food
and Drug Administration, or FDA, to market, and commenced commercialization of NERLYNX in the United
States for the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified
breast cancer following adjuvant trastuzumab-based therapy. More recently, in February 2020, we received FDA
approval to expand the indication for NERLYNX to include its use in combination with capecitabine for the
treatment of adult patients with advanced or metastatic HER2-positive breast cancer who have received two or
more prior anti-HER2-based regimens in the metastatic setting. We believe neratinib has clinical application in
the treatment of several other cancers as well, including other tumor types that over-express or have a mutation in
HER2 or epidermal growth factor receptor, or EGFR, such as cervical cancer, lung cancer or other solid tumors.

Breast cancer is the leading cause of cancer death among women worldwide. Studies show that up to 20% of

breast cancer tumors have an over-expression of the HER2 protein. Women with breast cancer that over-
expresses HER2, referred to as HER2-positive breast cancer, are at greater risk for disease progression and death
than women whose tumors do not over-express HER2. Therapeutic strategies, such as the use of trastuzumab
(marketed as Herceptin ®), pertuzumab (marketed as Perjeta ®) and T-DM1 (marketed as Kadcyla ®), each
produced by Genentech, lapatinib (marketed as Tykerb ®) produced by Novartis, fam-trastuzumab deruxtecan
(marketed as Enhertu ®) by Astra Zeneca and Daiichi Sankyo and tucatinib (Tukysa ®) marketed by Seagen,
given either alone or in combination with chemotherapy, have been developed to improve the treatment of this
type of breast cancer by binding to the HER2 protein. There are a number of trials ongoing that involve various
combinations of these drugs.

Based on pre-clinical studies and clinical trials to date, we believe that neratinib may offer an advantage
over existing treatments that are used in the treatment of patients with HER2-positive breast cancer, including
treatment with trastuzumab, pertuzumab, and T-DM1, fam-trastuzumab deruxtecan and tucatinib. We believe
that by more potently inhibiting HER2 at a different site and/or acting via a mechanism different from other
agents, neratinib may have therapeutic benefits in patients who have been previously treated with these existing
treatments, most notably due to its increased selectivity and irreversible inhibition of the HER2 target enzyme.

We currently market NERLYNX in the United States using our direct specialty sales force consisting of

approximately 68 sales specialists. Our sales specialists are supported by an experienced sales leadership team
consisting of regional managers and directors, as well as a commercial team of experienced professionals in
marketing, access and reimbursement, managed markets, marketing research, commercial operations and sales
force planning and management. In 2018, the European Commission, or EC, granted marketing authorization for
NERLYNX in the European Union for the extended adjuvant treatment of adult patients with early stage
hormone receptor positive HER2-overexpressed/amplified breast cancer and who are less than one year from the
completion of prior adjuvant trastuzumab-based therapy. To facilitate our international activities, we have
entered into exclusive sub-license agreements with various parties to pursue regulatory approval, if necessary,
and commercialize NERLYNX, if approved. We are currently party to several sub-licenses in various regions
outside the United States, including Europe (excluding Russia and Ukraine), Australia, Canada, China, Southeast
Asia, Israel, South Korea, and various countries and territories in Central and South America.

4

We have also implemented a managed access program for neratinib. Managed access programs provide
physicians and patients access to medicines when there are limited or no other therapeutic options available. Our
managed access program for neratinib enables participation from countries outside the United States where
permitted by applicable rules, procedures and regulatory authorities. The program provides access to neratinib for
the treatment of early stage HER2-positive breast cancer (extended adjuvant setting), HER2-positive metastatic
breast cancer and HER2-mutated solid tumors. In order for patients to qualify for our managed access program
they must be unable to participate in any ongoing neratinib clinical trial. Patients in the managed access program
are given neratinib and are instructed to take a prophylaxis which consists of high dose loperamide and
budesonide, during treatment to manage neratinib-related diarrhea. We have partnered with Caligor Opco LLC,
which specializes in early access to medicines, to oversee the managed access program for neratinib.

In addition to commercializing NERLYNX for its approved indications, we are actively conducting the

following trials to evaluate the safety and efficacy of neratinib in various indications:

•

•

•

•

a Phase II clinical trial of neratinib for the extended adjuvant treatment of patients with early stage
HER2-overexpressed/amplified breast cancer who have received prior adjuvant trastuzumab
(Herceptin)-based therapy in which patients are given either: 1) antidiarrheal prophylaxis including
loperamide alone or in combination with budesonide or other agents or 2) escalating doses of neratinib
during the first month (dose escalation) in order to prevent and reduce the neratinib-related diarrhea;

a Phase II clinical trial of neratinib in combination with the drug ado-trastuzumab emtansine (T-DM1,
Kadcyla) in patients with HER2-positive metastatic breast cancer that has metastasized to the brain;

a Phase II clinical trial of neratinib monotherapy or in combination with the drug trastuzumab and/or
other anticancer drugs in the treatment of patients with HER2-negative cancers that have a HER2
mutation; and

a Phase II clinical trial of neratinib monotherapy in patients with non-small cell lung cancer who have
an activating EGFR exon 18 mutation.

The following chart shows each of the approved indications of neratinib and those indications currently

under development, together with their clinical development stage.

5

*
EBC: Early breast cancer
** MBC: Metastatic breast cancer
*** HRC+: Hormone receptor positive

The following table shows the date of approved indications by country.

Strategy

Our goal is to become a leading provider of advanced therapies for the treatment of various forms of cancer.

The following elements comprise our strategy to achieve this objective:

•

Successfully execute our NERLYNX commercial plan. An important near-term objective is to continue
to execute our NERLYNX commercial plan by driving market penetration and duration of therapy
consistent with the current NERLYNX label. We continue to focus our efforts on commercializing
NERLYNX in the United States. In addition, we have entered into exclusive sub-license agreements
with various parties to pursue regulatory approval, if necessary, and commercialize NERLYNX, if
approved, in additional countries worldwide.

• Continue to advance the development of neratinib for the treatment of other HER2-positive, HER2

mutated or EGFR mutated cancer indications. We are primarily focused on developing neratinib for
the treatment of patients with HER2-positive breast cancer, HER2-negative breast cancers with a
HER2 mutation and EGFR mutated lung cancer.

• Expand our product pipeline by pursuing additional applications of neratinib. We believe there are

additional applications for neratinib in the treatment of patients with HER2-negative cancers who have
a HER2 mutation; and in tumor types where HER2 is over-expressed or mutated. We intend to further
evaluate the safety and efficacy of neratinib for treating these cancers.

• Evaluate the commercialization strategies on a product-by-product basis in order to maximize the

value of each. We are currently commercializing NERLYNX using a direct sales force in the United
States and using sub-licensees in certain countries outside of the United States. As we move additional

6

drug candidates through development toward regulatory approval, we plan to evaluate several options
for each drug candidate’s commercialization strategy. These options include building our own internal
sales force; entering into a joint marketing partnership with another pharmaceutical or biotechnology
company, whereby we jointly sell and market the product; and out-licensing our product, whereby
another pharmaceutical or biotechnology company sells and markets our product and pays us a royalty
on sales. Our decision may be different for each product that reaches commercialization and will be
based on a number of factors including capital necessary to execute on each option, size of the market
to be addressed and terms of potential offers from other pharmaceutical and biotechnology companies.

•

In-license or acquire additional drug candidates and technologies in order to build a sustainable
product pipeline by employing multiple therapeutic approaches and disciplined decision criteria based
on clearly defined proof of principal goals. We seek to build a sustainable product pipeline by
employing multiple therapeutic approaches and by acquiring drug candidates belonging to known drug
classes. In addition, we employ disciplined decision criteria to assess drug candidates. A decision by us
to license a drug candidate will depend on a variety of factors, including the scientific merits of the
technology; the costs of the transaction and other economic terms of the proposed license; the amount
of capital required to develop the technology; and the economic potential of the drug candidate, should
it be commercialized. We believe this strategy minimizes our clinical development risk and allows us
to accelerate the development and potential commercialization of current and future drug candidates.

Breast Cancer Overview

Breast cancer is the leading cause of cancer death among women worldwide, with approximately 1 million
new cases reported each year and more than 400,000 deaths per year. Up to 20% of breast cancer tumors show
over-expression of the HER2 protein. Women with breast cancer that over-expresses HER2 are at greater risk for
disease recurrence, progression and death than women whose tumors do not over-express HER2. Therapeutic
strategies have been developed to block HER2 in order to improve the treatment of this type of breast cancer.

Trastuzumab, pertuzumab, lapatinib, T-DM1, fam-trastuzumab deruxtecan and tucatinib are all drugs that

bind to the HER2 protein and thereby cause the cells to cease reproducing. Today, these drugs are used as single
agents, in combination with other drugs and in combination with chemotherapy to treat patients with HER2-
positive breast cancer at various stages.

Currently, the only treatment approved by the FDA for the treatment of neoadjuvant (newly diagnosed)
HER2-positive breast cancer is the combination of pertuzumab plus trastuzumab and taxane chemotherapy. The
FDA-approved treatments for the adjuvant treatment of HER2-positive early stage breast cancer is either the
combination of trastuzumab and chemotherapy, the combination of pertuzumab plus trastuzumab and
chemotherapy, or Kadcyla, which is approved specifically in patients with HER2-positive early stage breast
cancer with residual disease after neoadjuvant treatment. We are aware of a Phase III clinical trial that is
comparing trastuzumab plus pertuzumab plus taxane following anthracyclines versus T-DM1 plus pertuzumab
following anthracyclines as an adjuvant therapy. In addition, we are also aware of a Phase III trial in patients
with high risk HER2-positive early stage breast cancer with residual disease after neoadjuvant treatment that is
testing the combination of Kadcyla plus tucatinib versus Kadcyla alone (the CompassHER2 RD Trial) as well as
a Phase III trial in patients with high risk HER2-positive early stage breast cancer with residual disease after
neoadjuvant treatment that is testing fam-trastuzumab deruxtecan versus Kadcyla alone (the DESTINY-Breast05
Trial).

We believe that there are approximately 30,000 patients in the United States and 37,000 patients in the EU
with early stage HER2-positive breast cancer that get treated with adjuvant treatment. We also believe that there
are approximately 6,400 patients in the United States with third-line and 4,700 patients in the United States with
fourth line HER2-positive metastatic breast cancer. The number of patients with third-line or later HER2-positive
metastatic breast cancer may decrease in future years as the introduction of new neoadjuvant, adjuvant and
extended adjuvant treatments may reduce the number of patients with recurrence of HER2-positive breast cancer
and therefore reduce the number of patients with HER2-positive metastatic breast cancer.

7

We believe that approximately 1% to 12% of all cancer patients have mutation in HER2 kinase in the
United States and that approximately 7% to 9% of all estrogen receptor positive metastatic breast cancer patients
who have received prior endocrine treatment have a mutation in HER2 kinase (approximately 8,000 to 10,000
patients in the United States).

Neratinib

Neratinib is a potent irreversible TKI that blocks signal transduction through the epidermal growth factor

receptors, HER1, HER2 and HER4. Based on pre-clinical studies and clinical trials to date, we believe that
neratinib may offer an advantage over existing treatments that are used in the treatment of patients with HER2-
positive breast cancer. We believe that by more potently inhibiting HER2 at a different site and acting via a
mechanism different from other agents, neratinib may have therapeutic benefits in patients who have been
previously treated with these existing treatments, most notably due to its irreversible inhibition of the HER2
target enzyme.

In addition, we believe neratinib has clinical application in the treatment of several other cancers as well,

including other tumor types that over-express or have a mutation in HER2 or EGFR, such as breast cancer,
cervical cancer, lung cancer or other solid tumors.

Our initial focus is on the commercialization and development of the oral formulation of neratinib.

PB272 (neratinib oral)—Early Stage Breast Cancer

Extended Adjuvant Breast Cancer

In 2017, the FDA approved NERLYNX, formally known as PB272 (neratinib (oral)), for the extended
adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer following
adjuvant trastuzumab-based therapy. In 2018, the EC granted marketing authorization for NERLYNX in the
European Union for the extended adjuvant treatment of adult patients with early stage hormone receptor positive
HER2-overexpressed/amplified breast cancer and who are less than one year from the completion of prior
adjuvant trastuzumab-based therapy. These approvals were obtained based on the two-year data obtained in our
ExteNET trial.

Two-Year ExteNET Data. In July 2014, we announced top line results from our ExteNET trial, a Phase III

clinical trial of neratinib for the extended adjuvant treatment of early stage HER2-positive breast cancer. The
data from this trial were presented in an oral presentation at the American Society of Clinical Oncology, or
ASCO, Annual Meeting in June 2015 and were published online in The Lancet Oncology in February 2016. The
ExteNET trial was a double-blind, placebo-controlled, Phase III trial of neratinib versus placebo after adjuvant
treatment with Herceptin in women with early stage HER2-positive breast cancer. More specifically, the
ExteNET trial enrolled 2,840 patients in 41 countries with early stage HER2-positive breast cancer who had
undergone surgery and adjuvant treatment with trastuzumab. After completion of adjuvant treatment with
trastuzumab, patients were randomized to receive extended adjuvant treatment with either neratinib or placebo
for a period of one year. Patients were then followed for recurrent disease, ductal carcinoma in situ (DCIS), or
death for a period of two years after randomization in the trial.

The safety results of the study showed that the most frequently observed adverse event for the neratinib-
treated patients was diarrhea, with approximately 39.9% of the neratinib-treated patients experiencing grade 3 or
higher diarrhea (one patient, 0.1%, had grade 4 diarrhea). Patients who received neratinib in this trial did not
receive any prophylaxis with antidiarrheal agents to prevent the neratinib-related diarrhea.

The primary endpoint of the ExteNET trial was invasive disease-free survival, or DFS. The results of the
trial demonstrated that treatment with neratinib resulted in a 33% reduction of risk of invasive disease recurrence

8

or death versus placebo (hazard ratio = 0.67, p = 0.009). The two-year DFS rate for the neratinib arm was 93.9%
and the two-year DFS rate for the placebo arm was 91.6%. The secondary endpoint of the trial was disease-free
survival including ductal carcinoma in situ, or DFS-DCIS. The results of the trial demonstrated that treatment
with neratinib resulted in a 37% reduction of risk of disease recurrence including DCIS or death versus placebo
(hazard ratio = 0.63, p = 0.002). The two-year DFS-DCIS rate for the neratinib arm was 93.9% and the two-year
DFS-DCIS rate for the placebo arm was 91.0%.

As an inclusion criteria for the ExteNET trial, patients needed to have tumors that were HER2-positive
using local assessment. In addition, as a pre-defined subgroup in the trial, patients had centralized HER2 testing
performed on their tumor as well. At the time the two-year data was compiled, centralized HER2 testing had
been performed on 1,704 (60%) of the patients in the ExteNET trial and further central testing on available
samples was currently ongoing. For the 1,463 patients whose tumors were HER2-positive by central
confirmation, the results of the trial demonstrated that treatment with neratinib resulted in a 49% reduction of
risk of invasive disease recurrence or death versus placebo (hazard ratio = 0.51, p = 0.002). The two-year DFS
rate for the centrally confirmed patients in the neratinib arm was 94.7% and the 2-year DFS rate for the centrally
confirmed patients in the placebo arm was 90.6%. For the patients in the trial whose tumors were HER2-positive
by central confirmation, the results of the trial demonstrated that treatment with neratinib resulted in a 51%
reduction of risk of disease recurrence including DCIS or death versus placebo (hazard ratio = 0.49, p < 0.001).
The two-year DFS-DCIS rate for the centrally confirmed patients in the neratinib arm was 94.7% and the
two-year DFS rate for centrally confirmed patients in the placebo arm was 90.2%.

For the pre-defined subgroup of patients with hormone receptor positive disease, the results of the trial
demonstrated that treatment with neratinib resulted in a 49% reduction of risk of invasive disease recurrence or
death versus placebo (hazard ratio = 0.51, p = 0.001). The two-year DFS rate for the neratinib arm was 95.4%
and the two-year DFS rate for the placebo arm was 91.2%. For the patients in the trial whose tumors were HER2-
positive by central confirmation, the results of the trial demonstrated that treatment with neratinib resulted in a
75% reduction of risk of invasive disease recurrence or death (hazard ratio = 0.25, p < 0.001). The two-year DFS
rate for the centrally confirmed patients in the neratinib arm was 97.0% and the two-year DFS rate for centrally
confirmed patients in the placebo arm was 88.4%.

Five-Year ExteNET Data. In September 2017, we presented updated data from the ExteNET trial at the
European Society of Medical Oncology, or ESMO, 2017 Congress in Madrid, Spain. The data represented a
predefined five-year invasive disease-free survival, or iDFS, analysis as a follow-up to the primary two-year
iDFS analysis of the Phase III ExteNet trial. The results of the trial demonstrated that after a median follow up of
5.2 years, treatment with neratinib resulted in a 27% reduction of risk of invasive disease recurrence or death
versus placebo (hazard ratio = 0.73, p = 0.008). The five-year iDFS rate for the neratinib arm was 90.2% and the
5-year iDFS rate for the placebo arm was 87.7%. The secondary endpoint of the trial was invasive disease-free
survival including ductal carcinoma in situ, or iDFS-DCIS. The results of the trial demonstrated that treatment
with neratinib resulted in a 29% reduction of risk of disease recurrence, including DCIS or death versus placebo
(hazard ratio = 0.71, p = 0.004). The five-year iDFS-DCIS rate for the neratinib arm was 89.7% and the five-year
iDFS-DCIS rate for the placebo arm was 86.8%.

For the pre-defined subgroup of patients with hormone receptor positive disease, the results of the trial
demonstrated that treatment with neratinib resulted in a 40% reduction of risk of invasive disease recurrence or
death versus placebo (hazard ratio = 0.60, p = 0.002). The five-year iDFS rate for the neratinib arm was 91.2%
and the five-year iDFS rate for the placebo arm was 86.8%. For the pre-defined subgroup of patients with
hormone receptor negative disease, the results of the trial demonstrated that treatment with neratinib resulted in a
hazard ratio of 0.95 (p = 0.762).

The results of the ExteNET trial showed that after two years of follow-up, for patients with hormone
receptor positive, HER2-positive early stage breast cancer patients who were treated within one year after the
completion of trastuzumab based adjuvant therapy, iDFS was 95.3% in the patients treated with neratinib
compared with 90.8% in those receiving placebo (hazard ratio = 0.49; 95% CI: (0.30, 0.78); p=0.002).

9

The safety results were unchanged from the primary two-year iDFS analysis of the study that showed the
most frequently observed adverse event for the neratinib-treated patients was diarrhea, with approximately 39.9%
of the neratinib-treated patients experiencing grade 3 or higher diarrhea (one patient, or 0.1%, had grade 4
diarrhea). Patients who received neratinib in this trial did not receive any prophylaxis with antidiarrheal agents to
prevent the neratinib-related diarrhea.

In October 2020, we announced that efficacy results of neratinib in HER2-positive, hormone receptor-
positive, or HR+, early stage breast cancer, or eBC, from the Phase III ExteNET trial were published in Clinical
Breast Cancer. The manuscript presented data focusing on HR+ patients who initiated treatment within a year of
completing an adjuvant trastuzumab containing treatment (HR+ /< 1 yr) and subgroups of clinical interest
including patients who did not achieve a pathological complete response (no pCR) after neoadjuvant treatment
and therefore were at a high risk of disease recurrence (HR+/ <1 yr, no pCR). In the HR+ /< 1 yr patient
population, the absolute 5-year invasive disease-free survival benefit versus placebo was 5.1% (HR=0.58, 95%
CI 0.41–0.82) and absolute 8-year overall survival benefit was 2.1%. (HR=0.79, 95% CI 0.55–1.13). The 5-year
cumulative incidence of central nervous system (CNS) metastases was 0.7% in the neratinib arm and 2.1% in the
placebo arm.

In the HR+/ <1 yr, no pCR subgroup of patients that were at a high risk of disease recurrence the absolute

5-year iDFS benefit in the neratinib arm versus placebo was 7.4% (HR=0.60; 95% CI 0.33–1.07) and the 8- year
overall survival benefit was 9.1% (HR=0.47; 95% CI 0.23– 0.92).

CONTROL. In February 2015, we initiated the CONTROL trial which is an international, open-label, Phase

II study investigating the use of antidiarrheal prophylaxis or dose escalation in the prevention and reduction of
neratinib-associated diarrhea and, more specifically, grade 3 diarrhea. In the CONTROL trial, patients with
HER2-positive early stage breast cancer who had completed trastuzumab-based adjuvant therapy received
neratinib daily for a period of one year.

In December 2019 and December 2020, interim results from the CONTROL trial were presented at the 2019

CTRC-AACR San Antonio Breast Cancer Symposium and the 2020 CTRC-AACR Sant Antonio Breast Cancer
Symposium, respectively.

The interim results of this trial presented in December 2019 and December 2020 showed that as of the
cutoff date, the incidence of grade 3 diarrhea for the 137 patients who received the loperamide prophylaxis was
31%, the incidence of grade 3 diarrhea for the 64 patients who received the combination of loperamide plus
budesonide was 28%, the incidence of grade 3 diarrhea for the 136 patients who received the combination of
loperamide plus colestipol was 21%, the incidence of grade 3 diarrhea for the 104 patients who received
colestipol alone with loperamide as needed was 32%, and the incidence of grade 3 diarrhea for the 60 patients
who used the dose escalation was 13%. Further information is provided in Table 1 below:

Table 1: Incidence of Treatment-Emergent Diarrhea

Treatment-emergent diarrhea incidence, n (%)
No diarrhea . . . . . . . . . . . . . . . . . . . . . . . .
Grade 1 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grade 2 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grade 3 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grade 4 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diarrhea leading to discontinuation . . . . .
Hospitalization (due to diarrhea) . . . . . . .
Discontinuation of study (any cause) . . . .

Loperamide
(n=137)

Budesonide +
loperamide
(n=64)

Colestipol +
loperamide
(n=136)

Colestipol +
loperamide prn
(n=104)

Neratinib dose
escalation +
loperamide prn
(n=60)

9 (14)
16 (25)
21 (33)
18 (28)
0
5 (8)
0
3 (5)

23 (17)
38 (28)
47 (35)
28 (21)
0
5 (4)
0
10 (7)

5 (5)
34 (33)
32 (31)
33 (32)
0
8 (8)
0
12 (12)

1 (2)
24 (40)
27 (45)
8 (13)
0
2 (3)
0
2 (3)

28 (20)
33 (24)
34 (25)
42 (31)
0
28 (20)
2 (1)
10 (7)

10

Safety Database. Our safety database includes over 3,000 patients who have been treated with neratinib. To

date, the most significant grade 3 or higher adverse event associated with neratinib has been diarrhea, which
occurs in approximately 30% to 40% of patients receiving the drug. Historically, once diarrhea occurred, patients
were treated with loperamide and/or a reduction in the dose of neratinib.

PB272 (neratinib, oral)—Metastatic Breast Cancer

On February 25, 2020, the FDA approved our supplemental New Drug Application, or sNDA, for the use of
neratinib in combination with capecitabine for the treatment of adult patients with advanced or metastatic HER2-
positive breast cancer who have received two or more prior anti-HER2-based regimens in the metastatic setting.
This approval was based on the results from our NALA trial.

Trials of Neratinib as a Single Agent. In 2009, Pfizer Inc., or Pfizer, presented data at the CTRC-AACR San

Antonio Breast Cancer Symposium from a Phase II trial of neratinib administered as a single agent to patients
with HER2-positive metastatic breast cancer. Final results from this trial were published in the Journal of
Clinical Oncology in March 2010.

The trial involved a total of 136 patients, 66 of whom had received prior treatment with trastuzumab and
70 of whom had not received prior treatment with trastuzumab. The results of the study showed that neratinib
was reasonably well-tolerated among both the pretreated patients and the patients who had not received prior
treatment with trastuzumab. Diarrhea was the most common side effect but was manageable with antidiarrheal
agents and dose modification. Efficacy results from the trial showed that the objective response rate was 24% for
patients who had received prior trastuzumab treatment and 56% for patients with no prior trastuzumab treatment.
Furthermore, the median PFS was 22.3 weeks for the patients who had received prior trastuzumab and 39.6
weeks for the patients who had not received prior trastuzumab.

Data from a second Phase II study, in which patients with confirmed HER2-positive metastatic breast cancer

who had failed treatment with trastuzumab and taxane chemotherapy were given neratinib in combination with
capecitabine, was presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium. The results of the
study showed that the combination of PB272 and capecitabine had acceptable tolerability. The efficacy results
from the trial showed that for the 61 patients in the trial who had not been previously treated with the HER2
targeted anti-cancer drug lapatinib, there was an overall response rate of 64% and a clinical benefit rate of 72%.
In addition, for the seven patients in the trial who had previously been treated with lapatinib, there was an overall
response rate of 57% and a clinical benefit rate of 71%. The median PFS for patients who had not received prior
treatment with lapatinib was 40.3 weeks and the median PFS for the patients who had received prior lapatinib
treatment was 35.9 weeks.

NALA. In February 2013, we reached agreement with the FDA under a Special Protocol Assessment, or

SPA, for our Phase III clinical trial (PUMA-NER-1301 or the NALA trial) of neratinib in patients with HER2-
positive metastatic breast cancer who have failed two or more prior treatments (third-line disease). An SPA is a
written agreement between the trial’s sponsor and the FDA regarding the design, endpoints, and planned
statistical analysis of the Phase III trial with respect to the effectiveness of PB272 for the indication to be studied
to support a New Drug Application, or NDA. The EMA also provided follow-on Scientific Advice, or SA,
consistent with that of the FDA regarding our Phase III trial design and endpoints used for such design to support
the submission of an MAA in the EU.

Pursuant to the SPA and SA, the Phase III NALA trial was designed as a randomized controlled trial of
neratinib plus capecitabine versus Tykerb® (lapatinib) plus capecitabine in patients with third-line HER2-positive
metastatic breast cancer. The trial enrolled 621 patients who were randomized (1:1) to receive either neratinib
plus capecitabine or lapatinib plus capecitabine. The trial was conducted globally at sites in North America,
Europe, Asia-Pacific and South America. The co-primary endpoints of the trial were centrally confirmed PFS and
overall survival, or OS. An alpha level of 1% was allocated to the PFS and 4% allocated to OS.

11

In June 2019, we announced that results from the Phase III NALA trial were presented at the ASCO 2019
Annual Meeting in Chicago. For the primary analysis of centrally confirmed PFS, treatment with neratinib plus
capecitabine resulted in a statistically significant improvement in centrally confirmed PFS (hazard ratio=0.76,
p=0.0059) compared to treatment with lapatinib plus capecitabine. Because the hazard ratio was found to not be
constant over time (i.e., the proportional hazard assumption did not hold), the statistical analysis plan for the
NALA trial prespecified that a restricted means survival analysis at 24 months would be performed. In this
prespecified analysis the mean PFS for the patients treated with neratinib plus capecitabine was 8.8 months and
the mean PFS for the patients treated with lapatinib plus capecitabine was 6.6 months.

For the primary analyses of OS, neratinib plus capecitabine resulted in an improvement in OS that, although

not statistically significant, trended numerically in favor of the neratinib plus capecitabine arm of the study
(hazard ratio = 0.88, p=0.21). The median OS for the patients treated with neratinib plus capecitabine was 21.0
months and the median OS for the patients treated with lapatinib plus capecitabine was 18.7 months. In the
prespecified restricted means analysis the mean OS at 48 months for the patients treated with neratinib plus
capecitabine was 24.0 months and the mean OS for the patients treated with lapatinib plus capecitabine was 22.2
months.

For the secondary endpoint of time to intervention for symptomatic central nervous system disease (also
referred to as brain metastases), the results of the trial showed that treatment with neratinib plus capecitabine led
to an improvement over the combination of lapatinib plus capecitabine. The overall cumulative incidence of CNS
metastases was 22.8% for the neratinib plus capecitabine arm and 29.2% for the lapatinib plus capecitabine arm
(p=0.043). For the secondary endpoint of duration of response, neratinib plus capecitabine treatment resulted in a
longer duration of response compared to lapatinib and capecitabine treatment, with a median response of 8.54
months compared to a median response of 5.55 months (HR = 0.495, p = 0.0004).

Treatment-emergent adverse events (TEAEs) were similar between arms: TEAEs leading to neratinib/
lapatinib discontinuation were lower with neratinib (10.9%) than with lapatinib (14.5%). There was a higher rate
of grade 3 diarrhea with neratinib plus capecitabine compared to lapatinib plus capecitabine (24.4% vs 12.5%);
however, the discontinuations due to diarrhea (neratinib plus capecitabine: 2.6%, lapatinib plus capecitabine:
2.3%) were similar in both arms.

Metastatic Breast Cancer with Brain Metastases

Approximately one-half of the patients with HER2-positive metastatic breast cancer develop metastases that
spread to their brain. The current antibody-based treatments, including trastuzumab and pertuzumab, do not enter
the brain and therefore are not believed to be effective in treating these patients.

Neratinib is currently being tested in a clinical trial in collaboration with Translational Breast Cancer
Research Consortium (TBCRC) referred to as TBCRC 022. The purpose of this study is to determine how well
neratinib works in treating breast cancer that has spread to the brain. In this research study, the investigators are
looking to see how well neratinib works to decrease the size of or stabilize breast cancer that has metastasized to
the brain

In June 2017, we presented interim data from the TBCRC 022 at the ASCO 2017 Annual Meeting. The
multicenter Phase II clinical trial enrolled patients with HER2-positive metastatic breast cancer who have brain
metasteses. The trial enrolled three cohorts of patients. Patients in the second cohort (n=5) represent patients who
had brain metastases which were amenable to surgery and who were administered neratinib monotherapy prior to
and after surgical resection. The third cohort (target enrollment=60) enrolled two sub-groups of patients (prior
lapatinib-treated and no prior lapatinib) with progressive brain metastases who were administered neratinib in
combination with the chemotherapy drug capecitabine. The oral presentation reflected only the patients in the
third cohort of patients without prior lapatinib exposure (cohort 3A, n=37), who all had progressive brain
metastases at the time of enrollment and who received the combination of capecitabine plus neratinib.

12

In cohort 3A, 30% of the patients had received prior craniotomy, 65% of the patients had received prior
whole brain radiotherapy, and 35% had received prior stereotactic radiosurgery to the brain. No patients had
received prior treatment with lapatinib.

The primary endpoint of the trial was CNS Objective Response Rate according to a composite criteria that

included volumetric brain MRI measurements, steroid use, neurological signs and symptoms, and Response
Evaluation Criteria in Solid Tumors (RECIST) evaluation for non-CNS sites. The secondary endpoint of the trial
was CNS response by Response Assessment in Neuro-Oncology-Brain Metastases, or RANO-BM, criteria. The
efficacy results from the trial showed that 49% of patients experienced a CNS Objective Response by the
composite criteria. The results also showed that the CNS response rate using the RANO-BM criteria was 24%.
The median time to CNS progression was 5.5 months and the median overall survival was 13.5 months, though
49% of patients remain alive and survival data are immature.

The results for cohort 3A showed that the most frequently observed severe adverse event for the 37 patients
evaluable for safety was diarrhea. Patients received antidiarrheal prophylaxis consisting of high dose loperamide,
given together with the combination of capecitabine plus neratinib for the first cycle of treatment in order to try
to reduce the neratinib-related diarrhea. Among the 37 patients evaluable for safety, 32% of the patients had
grade 3 diarrhea and 41% had grade 2 diarrhea.

The TBCRC 022 trial is currently enrolling patients in an arm of the study that is administering neratinib in

combination with the drug ado-trastuzumab emtansine (T-DM1, Kadcyla) in patients with HER2-positive
metastatic breast cancer that has metastasized to the brain. Data from this trial are expected in the second half of
2021.

In April 2018, we announced that NERLYNX has been included as a recommended treatment option in the

latest National Comprehensive Cancer Network, or NCCN, Clinical Practice Guidelines in Oncology Central
Nervous System Cancers for Breast Cancer patients with brain metastases. The NCCN designated NERLYNX in
combination with capecitabine as a category 2B treatment option and NERLYNX in combination with paclitaxel
as a category 2B treatment option. Use, as designated for breast cancer patients with brain metastases, is outside
the FDA-approved indication for NERLYNX and considered investigational, and we do not market or promote
NERLYNX for these uses.

PB272 (neratinib, oral)—Other Potential Applications

HER2 Mutation-Positive Solid Tumors

Based on the results from the Cancer Genome Atlas Study, we estimate that between 1% and 12% of each

solid tumor has a mutation in HER2.

SUMMIT -- Basket Trial for HER2 Mutation-Positive Solid Tumors. In October 2013, we announced that we

had initiated a Phase II clinical trial of neratinib as a single agent in patients with solid tumors that have an
activating HER2 mutation, which we refer to as the SUMMIT basket trial. The Phase II SUMMIT basket trial is
an open-label, multicenter, multinational study to evaluate the safety and efficacy of PB272 administered daily to
patients who have solid tumors with activating HER2 or HER3 mutations.

In May 2014, we expanded the first cohort from the SUMMIT basket trial. Interim results from this ongoing

Phase II trial were presented at the 2017 American Association for Cancer Research Annual Meeting and were
published in January 2018 in Nature. All patients received loperamide (16 mg per day initially) prophylactically
for the first cycle of treatment in order to reduce the neratinib-related diarrhea. Included in the presentation were
data on 141 patients enrolled in the neratinib monotherapy arm of the trial, including 124 patients with HER2
mutations and 17 patients with HER3 mutations. This included patients with 21 unique tumor types, with the
most common being breast, lung, bladder and colorectal cancer. There were also 30 distinct HER2 and 12

13

distinct HER3 mutations observed among these patients, with the most frequent HER2 variants involving S310,
L755, A755_G776insYVMA and V777.

The interim safety results observed in the SUMMIT study were consistent with that observed previously in
metastatic patients with HER2 amplified tumors. With anti-diarrheal prophylaxis and management, diarrhea has
not been a treatment-limiting side effect in SUMMIT. The interim safety results of the study showed that the
most frequently observed adverse event was diarrhea. For the 141 patients enrolled in the neratinib monotherapy
arm with safety data available as of March 10, 2017, 31 patients (22%) reported grade 3 diarrhea. The median
duration of grade 3 diarrhea for those patients was two days. Four patients (2.8%) permanently discontinued
neratinib due to diarrhea and 21 patients (14.9%) temporarily discontinued neratinib due to diarrhea and then
restarted after the diarrhea subsided.

HER2-Mutated, Non-Amplified Breast Cancer

A HER2 mutation in patients with HER2-negative breast cancer was identified as part of a study performed

by the Cancer Genome Atlas Network and published in Cancer Discovery in December 2012. We believe this
mutation may occur in an estimated 2% of patients with breast cancer. Pre-clinical data from this publication
demonstrated that neratinib was active in pre-clinical models of HER2-negative breast cancer that have this
HER2 mutation and that neratinib has more anti-cancer activity than either trastuzumab or lapatinib in cells with
this mutation. A Phase II trial of neratinib in HER2-negative breast cancer patients who have a HER2 mutation
opened for enrollment in December 2012.

In December 2020, we announced that updated interim results from the SUMMIT basket trial in the HER2-

mutant, hormone receptor positive breast cancer cohort were presented at the San Antonio Breast Cancer
Symposium. In the HER2-mutant, hormone receptor (HR)-positive breast cancer cohort, 51 patients received 240
mg of neratinib daily in combination with trastuzumab and fulvestrant. In this cohort, patients had received a
median of four prior lines of therapy in the metastatic setting (range 1-10 prior regimens) before entering the
trial. 36 patients (70.6%) had received prior fulvestrant, 35 patients (68.6%) had received prior aromatase
inhibitor and 4 patients (7.8%) had received prior tamoxifen. Further, 30 patients (58.8%) received prior cyclin-
dependent kinase 4/6-inhibitor (CDK4/6i) therapy. Thirty-five patients (68.6%) had received prior chemotherapy.

The interim efficacy summary of the breast cohort that received neratinib in combination with trastuzumab

and fulvestrant showed that for the 37 RECIST efficacy evaluable patients, 17 patients (45.9%) experienced a
confirmed objective response, including one complete response (2.7%) and 16 (43.2%) partial responses, and 20
patients (54.1%) experienced clinical benefit (clinical benefit is defined as confirmed complete response or
partial response or stable disease for at least 24 weeks). The median duration of response was 10.9 months and
the median progression-free survival was 8.3 months.

The safety profile observed in patients treated with the combination of neratinib plus trastuzumab plus
fulvestrant in the SUMMIT study was consistent with that observed previously in metastatic patients with HER2
amplified tumors. All patients received anti-diarrheal prophylaxis with loperamide alone. The interim safety
results of the study showed that the most frequently observed adverse event was diarrhea. For the 51 safety
evaluable patients enrolled in this cohort, 20 patients (39.2%) reported grade 3 diarrhea. The median duration of
grade 3 diarrhea for those patients was 6 days. No patient permanently discontinued neratinib due to diarrhea.

14

Table 1: HER2-Mutant, HR-Positive Metastatic Breast Cancer
Phase II SUMMIT Trial Interim Efficacy Results Summary as of October 16, 2020

Patients with RECIST v1.1 Measurable Disease

Subgroups

Prior CDK4/6i

Prior Fulvestrant

RECIST Evaluable
Patients
(n=37)
17 (45.9)
1 (2.7)
16 (43.2)

Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Objective response (confirmed)a n (%) . . . . . . . . . . . . . . . . .
CR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Objective response rate, % (95% CI) . . . . . . . . . . . . . . 45.9 (29.5–63.1) 39.1 (19.7-61.5) 44.0 (24.4–65.1)

(n=25)
11 (44.0)
0
11 (44.0)

(n=23)
9 (39.1)
0
9 (39.1)

Best overall response, n (%) . . . . . . . . . . . . . . . . . . . . . . . . .
CR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Best overall response rate, % (95% CI)

21 (56.8)
1 (2.7)
20 (54.1)

11 (47.8)
0
11 (47.8)

13 (52.0)
0
13 (52.0)

Medianb DOR, months (95% CI) . . . . . . . . . . . . . . . . . . . . . 10.9 (6.4–NE)
Clinical benefitc – n (%) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CR or PR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SD >24 weeks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clinical benefit rate, % (95% CI) . . . . . . . . . . . . . . . . . 54.1 (36.9–70.5) 52.2 (30.6–73.2) 56.0 (34.9–75.6)
8.3 (3.1–12.5)

. . . . . . . . . . . . 56.8 (39.5–72.9) 47.8 (26.8-69.4) 52.0 (31.3–72.2)
8.4 (5.8–12.5)
14 (56.0)
11 (44.0)
3 (12.0)

8.7 (6.4–10.9)
12 (52.2)
9 (39.1)
3 (13.0)

Medianb PFS time to event, months (95% CI) . . . . . . . . . . .

20 (54.1)
17 (45.9)
3 (8.1)

8.2 (4.0–15.1)

8.3 (4.2–14.5)

a

b

c

Objective response rate (ORR) is defined as either a complete or partial response that is confirmed no less
than 4-weeks after the criteria for response are initially met

Kaplan-Meier analysis
Clinical benefit rate (CBR) is defined as confirmed CR or PR or stable disease (SD) for ≥24 weeks (within
+/– 7-day visit window).

EGFR Exon 18 Mutated Non Small Cell Lung Cancer

Exon 18 mutations comprise approximately 5% of the EGFR mutations detected in lung cancer. Pre-clinical

data have demonstrated that neratinib was active in pre-clinical models of EGFR exon 18 mutated lung cancer
and neratinib was previously shown to be active in treating patients with exon 18 mutated lung cancer in a Phase
II trial that was published in the Journal of Clinical Oncology in 2010.

In November 2020, we announced interim results from the ongoing SUMMIT trial of neratinib in the cohort

of metastatic non-small cell lung cancer, or NSCLC, patients with EGFR exon 18 mutations who have been
previously treated with an EGFR targeted TKI. In the EGFR exon 18 mutation cohort, patients with lung cancer
with single or complex EGFR exon 18 mutations, who were EGFR TKI naïve or were previously exposed to
EGFR TKI, were enrolled into this study and received 240 mg of neratinib daily as a single agent.

In this cohort of 11, patients had received a median of two prior lines of therapy in the metastatic setting

(range 1-3 prior regimens) before entering the trial. Ten patients had been previously treated with an EGFR
targeted TKI (gefitinib, erlotinib, osimertinib and/or afatinib).

The interim efficacy results from the trial showed that for the 10 evaluable patients who had been treated
with a prior EGFR TKI, six patients (60%) experienced a partial response, which included four patients (40%)
with a confirmed partial response. Eight patients (80%) experienced clinical benefit (clinical benefit is defined as
confirmed complete response or partial response or stable disease for at least 16 weeks). The median duration of
response was 7.5 months and the median progression free survival was 9.1 months. The success criteria for both
the first stage and the second stage of the Simon’s 2-stage design were met and enrollment in the second stage of
this cohort continues.

15

The safety profile observed in the subgroup of patients with EGFR exon 18 mutated NSCLC showed that
for the 11 patients who received neratinib in the trial, there were no reports of grade 3 or higher diarrhea. Four
patients (36%) reported grade 1 and one patient (9%) reported grade 2 diarrhea. No patients required a dose hold,
dose reduction, hospitalization or permanently discontinued neratinib due to diarrhea.

Clinical Testing of Our Products in Development

Each of our products in development, and likely all future drug candidates we in-license, will require
extensive pre-clinical and clinical testing to determine the safety and efficacy of the product applications prior to
seeking and obtaining regulatory approval. This process is expensive and time consuming. In completing these
trials, we are dependent upon third-party consultants, consisting mainly of investigators and collaborators, who
will conduct such trials.

We and our third-party consultants conduct pre-clinical testing in accordance with Good Laboratory
Practices, or GLP, and clinical testing in accordance with Good Clinical Practice standards, or GCP, which are
international ethical and scientific quality standards utilized for pre-clinical and clinical testing, respectively.
GCP is the standard for the design, conduct, performance, monitoring, auditing, recording, analysis and reporting
of clinical trials and the FDA requires compliance with GCP regulations in the conduct of clinical trials.
Additionally, our pre-clinical and clinical testing completed in the EU is conducted in accordance with applicable
EU standards, such as the EU Clinical Trials Directive (Directive 2001/20/EC of April 4, 2001), or the EU
Clinical Trials Directive, and the national laws of the 28 member states of the EU, or Member States,
implementing its provisions.

We have entered into, and may enter into in the future, master service agreements with clinical research

organizations, or CROs, with respect to initiating, managing and conducting the clinical trials of our products.
These contracts contain standard terms for the type of services provided that contain cancellation clauses
requiring between 30 and 45 days written notice and that obligate us to pay for any services previously rendered
with prepaid, unused funds being returned to us.

Competition

The development and commercialization of new products to treat cancer is highly competitive, and we face
considerable competition from major pharmaceutical, biotechnology and specialty cancer companies. As a result,
there are and will likely continue to be extensive research and substantial financial resources invested in the
discovery and development of new cancer products. Our competitors include, but are not limited to, Genentech,
Novartis, Roche, Boehringer Ingelheim, Takeda, Daiichi Sankyo and Seagen. None of these companies are
developing their drugs for the extended adjuvant treatment of early stage HER2-positive breast cancer that has
been previously treated with a trastuzumab-containing regimen. All of these competitors are developing their
drugs for the treatment of early stage and/or metastatic HER2-positive breast cancer and/or for cancers that have
a HER2 mutation. We are an early commercial stage company with a limited history of operations, sales,
marketing and commercial manufacturing. Many of our competitors have substantially more financial and
technical resources than we do. In addition, many of our competitors have more experience than we have in
pre-clinical and clinical development, manufacturing, regulatory and global commercialization. We are also
competing with academic institutions, governmental agencies and private organizations that are conducting
research in the field of cancer.

We anticipate that we will face intense competition if we are able to commercialize additional product
candidates. We expect that our products under development and in clinical trials will address major markets
within the cancer sector. Our competition will be determined in part by the potential indications for which drugs
are developed and ultimately approved by regulatory authorities. Additionally, the timing of market introduction
of some of our potential products or of competitors’ products may be an important competitive factor.
Accordingly, the speed with which we can develop products, complete pre-clinical testing, clinical trials and

16

approval processes, and supply commercial quantities to market are expected to be important competitive factors.
We expect that competition among products approved for sale will be based on various factors, including product
efficacy, safety, reliability, availability, price, reimbursement and patent position.

Sales and Marketing

We currently have a U.S. direct specialty sales force of approximately 68 sales specialists who are focused

on promoting NERLYNX to oncologists. This sales force is supported by an experienced leadership team
consisting of regional managers and directors, as well as a commercial team of experienced professionals in
marketing, access and reimbursement, managed markets, marketing research, commercial operations, and sales
force planning and management. In addition, our commercial infrastructure includes capabilities in
manufacturing, medical affairs, quality control, and compliance.

We launched NERLYNX in the United States in July 2017, and our focus is to establish NERLYNX as the

first choice for extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified
breast cancer following adjuvant trastuzumab-based therapy.

In 2018, the EC granted marketing authorization for NERLYNX in the European Union for the extended

adjuvant treatment of adult patients with early stage hormone receptor positive HER2-overexpressed/amplified
breast cancer and who are less than one year from the completion of prior adjuvant trastuzumab-based therapy.
We plan to continue to pursue commercialization of NERLYNX in Europe and other countries outside the United
States, where approved. To facilitate our international activities, we have entered into exclusive sub-license
agreements with various parties to pursue regulatory approval, if necessary, and commercialize NERLYNX, if
approved. We are currently party to several sub-licenses in various regions outside the United States, including
Europe (excluding Russia and Ukraine), Australia, Canada, China, Southeast Asia, Israel, South Korea, and
various countries and territories in Central and South America. As we expand into additional territories we will
continue to evaluate whether we seek to commercialize NERLYNX in those territories directly or through
additional sub-licenses.

Intellectual Property and License Agreements

We hold a worldwide exclusive license under our license agreement with Pfizer to 21 granted U.S. patents
and four pending U.S. patent applications, as well as foreign counterparts thereof, and other patent applications
and patents claiming priority therefrom to develop and commercialize certain compounds, including neratinib.

In the United States, we have a license to an issued patent, which currently will expire in 2025, for the
composition of matter of neratinib, our lead compound. We also have a license to an issued U.S. patent for the
use of neratinib in the treatment of breast cancer, which currently expires in 2025, an issued patent for the use of
neratinib in the extended adjuvant treatment of early stage HER2-positive breast cancer that has previously been
treated with a trastuzumab containing regimen that expires in 2030, two issued patents for the use of neratinib in
combination with capecitabine the later of which expires in 2031 and two issued patents for the formulation of
NERLYNX that expire in 2030, one issued patent for the preparation of the polymorphic forms of neratinib, and
three issued patents for the use of the polymorphic forms of neratinib in the treatment of breast cancer. In
jurisdictions which permit such, we will seek patent term extensions where possible for certain of our patents
(discussed further below, including in “Government Regulation”). We plan to pursue additional patents in and
outside the United States from the four pending U.S. patent applications noted above and the 77 pending foreign
patent applications, respectively, covering neratinib composition, formulations, and combinations and uses
thereof, and additional therapeutic uses of neratinib. In addition, we will pursue patent protection for any new
discoveries or inventions made in the course of our development of neratinib.

In the United States, marketing approval for neratinib was obtained on July 17, 2017, which provided five

years of regulatory exclusivity. Marketing approval in the United States for neratinib in combination with

17

capecitabine was obtained on February 25, 2020, which provided three years of regulatory exclusivity. Requests
for patent term extension under the Hatch-Waxman Act have been filed for two patents in the United States: U.S.
Patent No. 7,399,865 and U.S. Patent No. 9,211,291. We elected to apply patent term extension to U.S. Patent
No. 7,399,865. The U.S. Patent and Trademark Office, or USPTO, has determined that U.S. Patent No. 7,399,865
is eligible for five years of patent term extension. Once extended, U.S. Patent No. 7,399,865 will expire
December 29, 2030. See “Government Regulation” below. If we obtain marketing approval in the United States
for new uses or combinations therapies for neratinib, we may be eligible for additional periods of regulatory
exclusivity, such as three-year market exclusivity covering the new use. If we obtain marketing approval for
neratinib or other drug candidates or in certain jurisdictions outside the United States, we may be eligible for
regulatory protection, such as, eight to eleven years of data and marketing exclusivity potentially are available for
new drugs in the European Union; up to five years of patent extension are potentially available in Europe
(Supplemental Protection Certificate), and eight years of data exclusivity are potentially available in Japan. In
Europe, marketing approval for neratinib was obtained on August 31, 2018, which provided 10 years of
regulatory exclusivity. Between 2019 and 2020, marketing approval for neratinib was obtained in Argentina,
Brunei, Canada, Chile, China, Ecuador, Hong Kong, Israel, Malaysia, Singapore and Taiwan. Where available
and eligible, regulatory or data exclusivity has been obtained, or is currently being pursued in these jurisdictions
outside the United States and Europe. Patent term extension or supplemental protection certificate are being, or
will be, pursued in jurisdictions where available and eligible, including Chile, Europe and Taiwan. Current
market approved jurisdictions where patent term extensions or supplemental protection certificates are not
available, not eligible, or not pursued, include Argentina, Brunei, Canada, China, Ecuador, Hong Kong, Israel,
Malaysia and Singapore. There can be no assurance that we will qualify for any such regulatory exclusivity, or
that any such exclusivity will prevent competitors from seeking approval solely on the basis of their own studies.
See “Government Regulation” below.

The intellectual property portfolio that was licensed from Pfizer in 2011 when we licensed neratinib
included issued patents in a number of countries, including in Europe (EP1848414) relating to methods of
treating gefitinib-and/or erlotinib-resistant cancer by administering an irreversible epidermal growth factor
receptor inhibitor. In addition, in March 2020, we obtained issuance of U.S. Patent No. 10,603,314 containing
claims for methods of treating gefitinib-and/or erlotinib-resistant non-small cell lung cancer (NSCLC) cancer and
U.S. Patent No. 10,596,162 containing claims for methods of treating gefitinib-and/or erlotinib-resistant NSCLC
having a T790M mutation in EGFR. Regarding Europe, the EP1848414 patent that was issued in Europe in April
2011 included specific claims that included a pharmaceutical composition for use in treating cancer in a subject
with a cancer having a mutation in epidermal growth factor receptor with a T790M mutation. On November 28,
2011, Boehringer Ingelheim International GmbH filed an opposition to this patent asking for this patent to be
revoked. Oral proceedings were held before the Opposition Division of the European Patent Office in Munich,
Germany on February 4, 2014. The decision of the Opposition Division was to uphold the granted claims of the
European patent that relate to the T790M mutation without any modification. This included specific claims that
include claims for the pharmaceutical composition comprising an irreversible epidermal growth factor receptor
inhibitor for use in treating cancer in a subject having a T790M mutation, and claims for the pharmaceutical
composition for use in the treatment of numerous cancers, including lung cancer and non-small cell lung cancer.
Both parties appealed that decision in 2017. At a final hearing, on December 20, 2020, the Board of Appeals
announced its decision, concluding that the opposition was inadmissible and reversing the European Opposition
Division decision issued in 2014, thereby upholding the EP Patent 1848414 as originally granted.

An Opposition was filed by Hexal AG, or Hexal, on August 3, 2016 against European Patent No.

EP2416774 which was licensed from Pfizer in 2011, and which claims neratinib for use in a method for treating
HER-2/neu overexpressed/amplified cancer and improving IDFS, wherein the method comprises delivering
neratinib therapy to HER-2/neu overexpressed/amplified cancer patients following the completion of at least one
year of trastuzumab adjuvant therapy, and wherein the neratinib therapy comprises treating the cancer patients
with neratinib for at least twelve months. An oral hearing was held December 8, 2017, wherein the patent was
maintained as granted. Hexal then appealed, which appeal is pending.

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On October 4, 2017, Hexal also filed an Opposition to European Patent No. EP2326329 which was licensed

from Pfizer in 2011, and which claims a combination of neratinib and pharmaceutically acceptable salts thereof
with capecitabine for use in a method of treating an Erb-2 positive metastatic breast cancer. An oral hearing was
held on February 13, 2019, wherein the patent was maintained as granted. Hexal then appealed, which appeal is
pending.

On May 21, 2020, Hexal also filed an Opposition to European Patent No. EP2498756, which was licensed

from Pfizer in 2011, and which claims, inter alia, tablet formulations of neratinib maleate comprising
intragranular and extragranular components. Oral hearings have not yet been scheduled, and briefings exchange
between the parties are still in progress.

An Opposition was filed by Generics (UK) Ltd., or Generics, on September 3, 2015 against European Patent

No. EP2656844, which was licensed from Pfizer in 2011, and which claims, inter alia, a pharmaceutical pack
containing 50 to 300 mg of neratinib and pharmaceutically acceptable salts thereof and vinorelbine for use in a
method of treating a neoplasm. An oral hearing was held July 3, 2017, wherein the patent was maintained as
granted. Generics then appealed. The appeal was dismissed by the Board of Appeal of the European Patent
Office on August 11, 2020, and the EP2656844 patent was upheld as originally granted.

Unipharm filed a pre-grant opposition to Israeli Patent Application No. IL210616 on January 31, 2016. This

application was licensed from Pfizer in 2011. An oral hearing was held in Jerusalem before the Israeli Patent
Office on January 22, 2018. The patent was granted by the Israeli Patent Office upon filing of amendments to the
claims. No opposition to the patent has been filed within the allowed opposition period. The granted claims are
directed to use of a combination of neratinib and capecitabine in the manufacture of a medicament for treating a
neoplasm.

Our goal is to obtain, maintain and enforce patent protection for our products, formulations, processes,
methods and other proprietary technologies, preserve our trade secrets, and operate without infringing on the
proprietary rights of other parties, both in the United States and in other countries. Our policy is to actively seek
to obtain, where appropriate, the broadest intellectual property protection possible for our current product
candidates and any future product candidates, proprietary information and proprietary technology through a
combination of contractual arrangements and patents, both in the United States and abroad. However, even patent
protection may not always provide us with complete protection against competitors who seek to circumvent our
patents. See “Risk Factors—Risks Related to Our Intellectual Property—Our proprietary rights may not
adequately protect our intellectual property and potential products, and if we cannot obtain adequate protection of
our intellectual property and potential products, we may not be able to successfully market our potential
products.”

We depend upon the skills, knowledge and experience of our scientific and technical personnel, as well as

that of our advisors, consultants and other contractors, none of which is patentable. To help protect our
proprietary know-how, which is not patentable, and inventions for which patents may be difficult to obtain or
enforce, we rely on trade secret protection and confidentiality agreements to protect our interests. To this end, we
require all of our employees, consultants, advisors and other contractors to enter into confidentiality agreements
that prohibit the disclosure of confidential information and, where applicable, require disclosure and assignment
to us of the ideas, developments, discoveries and inventions important to our business.

In-License Agreement

We license the worldwide exclusive rights for the development, manufacture and commercialization of

neratinib (oral), neratinib (intravenous), PB357, and certain related compounds from Pfizer. Under the license
agreement, Pfizer is obligated to transfer to us certain information, records, regulatory filings, materials and
inventory controlled by Pfizer and relating to or useful for developing these compounds and to continue to
conduct certain ongoing clinical studies until a certain time. After that time, we are obligated to continue such

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studies pursuant to an approved development plan, including after the license agreement terminates for reasons
unrelated to Pfizer’s breach of the license agreement, subject to certain specified exceptions. We are also
obligated to commence a new clinical trial for a product containing one of these compounds within a specified
period of time and use commercially reasonable efforts to complete such trial and achieve certain milestones as
provided in a development plan. If certain of our out-of-pocket costs in completing such studies exceed a
mutually agreed amount, Pfizer will pay for certain additional out-of-pocket costs to complete such studies. We
must use commercially reasonable efforts to develop and commercialize products containing these compounds in
specified major-market countries and other countries in which we believe it is commercially reasonable to
develop and commercialize such products.

As consideration for the license, we are required to make payments totaling $187.5 million upon the
achievements of certain milestones if all such milestones are achieved. FDA approval of NERLYNX in July
2017 triggered a one-time milestone payment. In June 2020, we entered into a letter agreement, or the Letter
Agreement, with Pfizer relating to the method of payment associated with a one-time milestone payment under
the license agreement with Pfizer. The Letter Agreement permits us to make the milestone payment in
installments with portions of the amount payable to Pfizer (including interest) made in June and November 2020
for approximately $20.6 million in the aggregate and the remaining portion to be made in September 2021 for
approximately $21.9 million. Unpaid portions of the milestone payment will accrue interest at 6.25% per annum
until paid. The installment payments and accrued interest are included in accrued in-licensed rights on the
accompanying consolidated balance sheets.

The license agreement originally stipulated that should we commercialize any of the compounds licensed
from Pfizer or any products containing any of these compounds, we will be obligated to pay to Pfizer incremental
annual royalties between approximately 10% and 20% of net sales of all such products, subject, in some
circumstances, to certain reductions.

In July 2014, we signed an amendment to the license agreement with Pfizer that, among other things
reduced the annual royalties to be paid on net sales of licensed products from a tiered royalty rate structure
ranging between 10% to 20% to a fixed rate in the low to mid-teens.

Our royalty obligation continues, on a product-by-product and country-by-country basis, until the later of

(i) the last to expire valid claim of a licensed patent covering the applicable licensed product in such country, or
(ii) the earlier of generic competition for such licensed product reaching a certain level of sales in such country or
expiration of a certain time period after first commercial sale of such licensed product in such country. We can
terminate the license agreement at will at any time or for safety concerns, in each case upon specified advance
notice. Each party may terminate the license agreement if the other party fails to cure any breach of a material
obligation by such other party within a specified time period. Pfizer may terminate the license agreement in the
event of our bankruptcy, receivership, insolvency or similar proceeding. The license agreement contains other
customary clauses and terms as are common in similar agreements in the industry.

Sub-License Agreements

Specialised Therapeutics Agreement

On November 20, 2017, we entered into a sub-license agreement, or the Specialised Therapeutics
Agreement, with Specialised Therapeutics Asia Pte Ltd., or STA. Pursuant to the Specialised Therapeutics
Agreement, we granted to STA, under certain of our intellectual property rights relating to neratinib, an
exclusive, sublicensable (under certain circumstances) license to commercialize any pharmaceutical product
containing neratinib in finished form for the extended adjuvant treatment of patients with early stage HER2-
positive breast cancer and HER2-positive metastatic breast cancer in Australia, Brunei, Cambodia, Indonesia,
Laos, Malaysia, Myanmar, New Zealand, Papua New Guinea, Philippines, Singapore, Thailand, Timor-Leste and
Vietnam, or the STA Territory.

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The Specialised Therapeutics Agreement sets forth the parties’ respective obligations with respect to the
development, commercialization, and supply of the licensed product. Within the STA Territory, STA will be
generally responsible for regulatory and commercialization activities, and we will be solely responsible for the
manufacturing and supply of the licensed product under a supply agreement entered into between the parties.

Pursuant to the Specialised Therapeutics Agreement, we received an upfront payment and will potentially
receive additional regulatory milestone payments. In addition, we will receive double-digit royalties on sales of
licensed products, calculated as a percentage of net sales of licensed products throughout the STA Territory.

The term of the Specialised Therapeutics Agreement continues, on a country-by-country basis, until the later

of (i) the expiration or abandonment of the last patent covering the licensed product or (ii) the earlier of (a) the
date upon which sales of generic versions of licensed product reach a specified level in such country, or (b) the
tenth anniversary of the first commercial sale of the licensed product in such country. The Specialised
Therapeutics Agreement may be terminated by either party if the other party commits a material breach, subject
to a customary cure period, or if the other party is insolvent. The Specialised Therapeutics Agreement will also
terminate upon the termination of the supply agreement for licensed products between the parties.

CANbridge Agreement

On January 30, 2018, we entered into a sub-license agreement, or the CANbridge Agreement, with

CANbridge BIOMED Limited, or CANbridge. Pursuant to the CANbridge Agreement, we granted to
CANbridge, under certain of our intellectual property rights relating to neratinib, an exclusive, sublicensable
(under certain circumstances) license to develop and commercialize any pharmaceutical product containing
neratinib for the treatment of human disease, or for purposes of this description, the Field, in the People’s
Republic of China, or the CANbridge Territory, including mainland China, Hong Kong, Macao, and Taiwan.

In July 2020, we filed a request for arbitration against CANbridge, in connection with the CANbridge

Agreement, and CANbridge subsequently filed its response to our request for arbitration and brought
counterclaims. On February 24, 2021, we and CANbridge resolved our dispute, which is described further in the
section entitled “Item 3. Legal Proceedings” below. As part of the settlement, we and CANbridge agreed to enter
into a termination agreement, or the CANbridge Termination Agreement, to terminate the CANbridge Agreement
and all agreements related to the CANbridge Agreement, effective as of the same date as the settlement. Subject
to the terms of the CANbridge Termination Agreement, we agreed to pay CANbridge a one-time termination fee
of $20.0 million to return all rights to neratinib in Greater China back to us and assist with the transfer of such
rights to us.

Medison Agreement:

During the first quarter of 2018, we entered into a sub-license agreement, or the Medison Agreement, with

Medison Pharma Ltd., or Medison. Pursuant to the Medison Agreement, we granted to Medison, under certain of
our intellectual property rights relating to neratinib, an exclusive license to commercialize neratinib and certain
related compounds and participate in the named patient supply in Israel, or the Medison Territory, subject to the
terms of the Medison Agreement and the related supply agreement. Pursuant to the Medison Agreement, we will
potentially receive milestone payments due to us upon successful completion of certain separate, distinct
performance obligations. In addition, we are entitled to receive double-digit royalties on sales of licensed
products, calculated as a percentage of net sales of licensed products in the Medison Territory.

Pint Agreement

On March 30, 2018, we entered into a sub-license agreement, or the Pint Agreement, with Pint Pharma

International SA, or Pint. Pursuant to the Pint Agreement, we granted to Pint, under certain of our intellectual
property rights relating to neratinib, an exclusive, sublicensable (under certain circumstances) license to develop

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and commercialize any product containing neratinib and certain related compounds in Belize, Costa Rica, El
Salvador, Guatemala, Honduras, Nicaragua, and Panama, Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador,
Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela, French Guiana, the Falkland Islands, and Mexico,
or the Pint Territory.

The Pint Agreement sets forth the parties’ respective obligations with respect to the development,

commercialization, and supply of the licensed product. Pint will, at its expense, develop the licensed product for
the purpose of obtaining regulatory approval in the Pint Territory, subject to our consent to conduct such
development activities and approval of certain aspects of clinical studies conducted by Pint. Within the Pint
Territory, Pint will also be responsible for regulatory and commercialization activities. We will be solely
responsible for the manufacturing and supply of the licensed product under a supply agreement that will be
entered into between the parties, subject to certain exceptions therein.

Pursuant to the Pint Agreement, we received an upfront payment and will potentially receive additional
regulatory and sales-based milestone payments. In addition, we are entitled to receive double-digit royalties on
sales of licensed products, calculated as a percentage of net sales of licensed products throughout the Pint
Territory.

The term of the Pint Agreement continues, on a country-by-country basis, until the later of (i) the expiration

or abandonment of the last licensed patent covering the licensed product in such country, or (ii) the earlier of
(a) the date upon which sales of generic versions of licensed product reach a specified level in such country, or
(b) the tenth anniversary of the first commercial sale of the licensed product in such country. The Pint Agreement
may be terminated by either party if the other party commits a material breach, subject to a customary cure
period, or if the other party is insolvent. Pint may also terminate the Pint Agreement at will, for certain safety
concerns.

Knight Agreement

On January 9, 2019, we entered into a sub-license agreement, or the Knight Agreement, with Knight
Therapeutics, Inc., or Knight. Pursuant to the Knight Agreement, we granted to Knight, under certain of the our
intellectual property rights relating to neratinib, an exclusive, sublicensable (under certain circumstances) license
(i) to commercialize any product containing neratinib and certain related compounds in Canada, or the Knight
Territory, (ii) to seek and maintain regulatory approvals for the licensed products in the Knight Territory and
(iii) to manufacture the licensed products anywhere in the world solely for the development and
commercialization of the licensed products in the Knight Territory for human use, subject to the terms of the
Knight Agreement and a supply agreement to be negotiated and executed by the parties.

Under the terms of the Knight Agreement, we will be solely responsible for the manufacturing and supply of

the licensed products to Knight, but under limited circumstances Knight may obtain the right to manufacture the
licensed products under the supply agreement.

The Knight Agreement sets forth the parties’ respective obligations with respect to the commercialization of

the licensed products. Within the Knight Territory, we will be solely responsible for obtaining the regulatory
approval for the indication of extended adjuvant treatment of HER2-positive early stage breast cancer, or the
Initial Indication, and Knight will use commercially reasonable efforts to prepare, file and manage regulatory
filings for any other indications in the field of human use. Promptly after obtaining the regulatory approval for
the Initial Indication in the Knight Territory, we will transfer such regulatory approval to Knight, and Knight will
own and hold any regulatory approvals for the licensed products in the Knight Territory in its name.

Pursuant to the Knight Agreement, we received an upfront payment and will potentially receive additional
regulatory and commercial milestone payments. In addition, we are entitled to receive double-digit royalties on
sales of licensed products, calculated as a percentage of net sales of licensed products in the Knight Territory.

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The term of the Knight Agreement continues, on a licensed product-by-licensed product basis, until the later

of (i) the expiration or abandonment of the last valid claim of the licensed patents that covers such licensed
product in the Territory, or (ii) the earlier of (a) the time when generic competitors to such licensed product have
achieved a specified level in such country, or (b) ten (10) years following the date of first commercial sale of
such licensed product in the Territory. The Knight Agreement may be terminated by either party if the other
party commits a material breach, subject to a customary cure period, or if the other party is insolvent.

Pierre Fabre Agreement

On March 29, 2019, we entered into a sub-license agreement, or the Pierre Fabre Agreement, with Pierre
Fabre Medicament SAS, or Pierre Fabre. Pursuant to the Pierre Fabre Agreement, we granted to Pierre Fabre
under certain of our intellectual property rights relating to neratinib an exclusive, sub-licensable (under certain
circumstances) license to develop, manufacture and commercialize any pharmaceutical product containing
neratinib for therapeutic and prophylactic indications for human or veterinary use in European countries
excluding Russia and Ukraine, along with countries in North Africa and francophone countries of West Africa, or
the Pierre Fabre Territory. On November 25, 2019, we entered into a license amendment, or the First Pierre
Fabre Amendment, with Pierre Fabre to extend Pierre Fabre’s licensed territory to the Middle East, South Africa,
Sudan and Turkey, or together with the Pierre Fabre Territory, the First Pierre Fabre Territory.

On February 24, 2021, we entered into a second license amendment, or the Second Pierre Fabre

Amendment, with Pierre Fabre to further extend Pierre Fabre’s licensed territory to Greater China, or the Second
Pierre Fabre Territory, which includes mainland China, Taiwan, Hong Kong and Macao, or each a China Region.

Pursuant to the Pierre Fabre Agreement, we received an upfront payment and will potentially receive
additional regulatory and sales-based milestone payments based on regulatory and sales activities in the First
Pierre Fabre Territory. Pursuant to the Second Pierre Fabre Amendment, we will receive an upfront payment of
$50 million, as well as additional regulatory and sales-based milestone payments up to $240 million based solely
on regulatory and sales activities in the Second Pierre Fabre Territory. In addition, we will receive double-digit
royalties based on sales of the licensed products in the First Pierre Fabre Territory, on the one hand, and double-
digit royalties based on sales of the licensed products in the Second Pierre Fabre Territory, on the other hand. For
the purposes of calculating royalties, sales of the licensed products in the Second Pierre Fabre Territory will be
excluded from the sales of licensed products made in the First Pierre Fabre Territory.

Under the terms of the Pierre Fabre Agreement, as amended, we are obligated to supply Pierre Fabre with

the licensed products in accordance with the related supply agreement. Pierre Fabre will be responsible for
conducting additional clinical studies and leading regulatory activities in connection with the European
Medicines Agency, or EMA, and Greater China.

The term of the Pierre Fabre Agreement, as amended, continues until, on a country-by-country basis, the
later of (i) the expiration or abandonment of the last licensed patent covering the licensed product in such country
and (ii) the earlier of (a) the date upon which sales of generic versions of the licensed product reach a specified
level in such country, or (b) the tenth anniversary of the first commercial sale of a licensed product in such
country.

The Pierre Fabre Agreement, as amended, may be terminated by either party, in its entirety, if the other
party commits a material breach, subject to a cure period, or if the other party is insolvent, and Pierre Fabre may
terminate the Pierre Fabre Agreement, as amended, at its convenience or if there is evidence of safety issues with
the licensed product. Pierre Fabre may terminate the Pierre Fabre Agreement, as amended, on a
territory-by-territory basis, by terminating only the First Pierre Fabre Territory or the Second Pierre Fabre
Territory, for any of the foregoing reasons. We may terminate the Pierre Fabre Agreement, as amended, on a
China Region-by-China Region bases or, under certain circumstances, in the entire Second Pierre Fabre Territory
if Pierre Fabre is in material violation of certain anti-corruption laws.

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Bixink Agreement

During the second quarter of 2020, we entered into a sub-license agreement, or the Bixink Agreement, with
Bixink Therapeutics Co., Ltd., or Bixink. The Bixink Agreement granted intellectual property rights and set forth
the respective obligations with respect to development, commercialization and supply of NERLYNX in South
Korea, or the Bixink Territory. The Bixink Agreement includes potential milestone payments due to us upon
successful completion of certain performance obligations, such as achieving regulatory approvals. In addition, we
are entitled to receive double-digit royalties on sales of licensed products, calculated as a percentage of net sales
of licensed products throughout the Bixink Territory.

Manufacturing

We do not currently have our own manufacturing facilities. We intend to continue to use our financial

resources to accelerate commercialization of NERLYNX and development of our drug candidates rather than
diverting resources to establish our own manufacturing facilities. We intend to meet our pre-clinical and clinical
trial manufacturing requirements by establishing relationships with third-party manufacturers and other service
providers to perform these services for us. While our drug candidates were being developed by Pfizer, both the
drug substance and drug product were manufactured by third-party contractors. We are currently using the same
third-party contractors to manufacture, supply, store and distribute our products in clinical trials and commercial
quantities.

Should any of our other drug candidates obtain marketing approval, we anticipate establishing relationships

with third-party manufacturers and other service providers in connection with commercial production of our
products. We have some flexibility in securing other manufacturers to produce our drug candidates; however, our
alternatives may be limited due to proprietary technologies or methods used in the manufacture of some of our
drug candidates.

Government Regulation

United States—FDA Process

The research, development, testing, manufacture, labeling, promotion, advertising, distribution and
marketing, among other things, of drug products are extensively regulated by governmental authorities in the
United States and other countries. In the United States, the FDA regulates drugs under the Federal Food, Drug,
and Cosmetic Act, or the FDCA, and its implementing regulations. Failure to comply with the applicable U.S.
requirements may subject us to administrative or judicial sanctions, such as FDA refusal to approve pending
NDAs, warning letters, fines, civil penalties, product recalls, product seizures, total or partial suspension of
production or distribution, injunctions and/or criminal prosecution.

Drug Approval Process. None of our drug product candidates may be marketed in the United States until the

drug has received FDA approval. The steps required before a drug may be marketed in the United States
generally include the following:

•

•

•

•

•

completion of extensive pre-clinical laboratory tests, animal studies, and formulation studies in
accordance with the FDA’s GLP requirements and other applicable regulations;

submission to the FDA of an Investigational New Drug application, or IND, for human clinical testing,
which must become effective before human clinical trials may begin;

approval by an independent institutional review board, or IRB, or ethics committee at each clinical site
before each trial may be initiated;

performance of adequate and well-controlled human clinical trials in accordance with GCP
requirements to establish the safety and efficacy of the drug for each proposed indication;

submission to the FDA of an NDA after completion of all pivotal clinical trials;

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•

•

•

satisfactory completion of an FDA advisory committee review, if applicable;

satisfactory completion of an FDA pre-approval inspection of the manufacturing facility or facilities at
which the active pharmaceutical ingredient, or API, and finished drug product are produced and tested
to assess compliance with current Good Manufacturing Practices, or cGMPs; and

FDA review and approval of the NDA prior to any commercial marketing or sale of the drug in the
United States.

Pre-clinical tests include laboratory evaluation of product chemistry, toxicity and formulation, as well as

animal studies. The conduct of the pre-clinical tests and formulation of the compounds for testing must comply
with federal regulations and requirements. The results of the pre-clinical tests, together with manufacturing
information and analytical data, are submitted to the FDA as part of an IND, which must become effective before
human clinical trials may begin. An IND will automatically become effective 30 days after receipt by the FDA,
unless before that time the FDA raises concerns or questions about the conduct of the trial, such as whether
human research subjects will be exposed to an unreasonable health risk. In such a case, the IND sponsor and the
FDA must resolve any outstanding FDA concerns or questions before clinical trials can proceed. We cannot be
sure that submission of an IND will result in the FDA allowing clinical trials to begin.

Clinical trials involve administration of the investigational drug to human subjects under the supervision of

qualified investigators. Clinical trials are conducted under protocols detailing the objectives of the study, the
parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. Each protocol must be
provided to the FDA as part of a separate submission to the IND. Further, an IRB for each medical center
proposing to conduct the clinical trial must review and approve the study protocol and informed consent
information for study subjects for any clinical trial before it commences at that center, and the IRB must monitor
the study until it is completed. There are also requirements governing reporting of ongoing clinical trials and
clinical trial results to public registries. Study subjects must sign an informed consent form before participating
in a clinical trial.

Clinical trials necessary for product approval typically are conducted in three sequential phases, but the
phases may overlap. Phase I usually involves the initial introduction of the investigational drug into a limited
population, typically healthy humans, to evaluate its short-term safety, dosage tolerance, metabolism,
pharmacokinetics and pharmacologic actions, and, if possible, to gain an early indication of its effectiveness.
Phase II usually involves trials in a limited patient population to (i) evaluate dosage tolerance and appropriate
dosage; (ii) identify possible adverse effects and safety risks; and (iii) evaluate preliminarily the efficacy of the
drug for specific targeted indications. Multiple Phase II clinical trials may be conducted by the sponsor to obtain
information prior to beginning larger and more expensive Phase III clinical trials. Phase III trials, commonly
referred to as pivotal studies, are undertaken in an expanded patient population at multiple, geographically
dispersed clinical trial centers to further evaluate clinical efficacy and test further for safety by using the drug in
its final form. Post-approval trials, sometimes referred to as Phase IV studies, may be conducted after initial
marketing approval. These trials are used to gain additional experience from the treatment of patients in the
intended therapeutic indication. In certain instances, the FDA may mandate the performance of Phase IV clinical
trials as a condition of approval of an NDA.

Furthermore, the sponsor, the FDA or an IRB may suspend clinical trials at any time on various grounds,
including a finding that the subjects or patients are being exposed to an unacceptable health risk. Similarly, an
IRB can suspend or terminate approval of a clinical trial at its institution, such as in the circumstances where the
clinical trial is not being conducted in accordance with the IRB’s requirements or if the drug has been associated
with unexpected serious harm to patients. In addition, some clinical trials are overseen by an independent group
of qualified experts organized by the sponsor, known as a data safety monitoring board or committee. Depending
on its charter, this group may determine whether a trial may move forward at designated check points based on
access to certain data from the trial.

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During the development of a new drug, sponsors are given an opportunity to meet with the FDA at certain
points. These points may be prior to submission of an IND, at the end of Phase II clinical testing, and before an
NDA is submitted. Meetings at other times may be requested. These meetings can provide an opportunity for the
sponsor to share information about the data gathered to date, for the FDA to provide advice, and for the sponsor
and the FDA to reach consensus on the next phase of development. Sponsors typically use the end of a Phase II
meeting to discuss their Phase II clinical results and present their plans for the pivotal Phase III clinical trial that
they believe will support submission of an NDA.

A sponsor may request an SPA to reach an agreement with the FDA that the protocol design, clinical
endpoints, and statistical analyses are acceptable to support regulatory approval of the product candidate with
respect to effectiveness in the indication studied. If such an agreement is reached, it will be documented and
made part of the administrative record, and it will be binding on the FDA except in limited circumstances, such
as if the FDA identifies a substantial scientific issue essential to determining the safety or effectiveness of the
product after clinical studies begin, if the relevant data, assumptions, or information provided by the sponsor in a
request for SPA change are found to be false statements or misstatements or omit relevant facts, or if the sponsor
fails to follow the protocol that was agreed upon with the FDA. A documented SPA may be modified, and such
modification will be deemed binding on the FDA review division, except under the circumstances described
above, if FDA and the sponsor agree in writing to modify the protocol and such modification is intended to
improve the study. There is no guarantee that a study will ultimately be adequate to support an approval, even if
the study is subject to an SPA.

Concurrent with clinical trials, companies usually complete additional animal safety studies and must also

develop additional information about the chemistry and physical characteristics of the drug and finalize a process
for manufacturing the product in accordance with cGMP requirements. The manufacturing process must be
capable of consistently producing quality batches of the drug candidate and the manufacturer must develop
methods for testing the quality, purity and potency of the final drugs. Additionally, appropriate packaging must
be selected and tested, and stability studies must be conducted to demonstrate that the drug candidate does not
undergo unacceptable deterioration over its shelf life.

Assuming successful completion of the required clinical testing, the results of pre-clinical studies and of

clinical trials, together with other detailed information, including information on the manufacture and
composition of the drug, are submitted to the FDA in the form of an NDA requesting approval to market the
product for one or more indications. An NDA must be accompanied by a significant user fee, which is waived for
the first NDA submitted by a qualifying small business.

The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its

intended use and whether its manufacturing is cGMP-compliant to assure and preserve the product’s identity,
strength, quality and purity. Under the Prescription Drug User Fee Act, or PDUFA, guidelines that are currently
in effect, the FDA has a goal of ten months from the date of “filing” of a standard NDA for a new molecular
entity to review and act on the submission. This review typically takes twelve months from the date the NDA is
submitted to FDA because the FDA has approximately two months to make a “filing” decision after the
application is submitted. The FDA conducts a preliminary review of all NDAs within the first 60 days after
submission, before accepting them for filing, to determine whether they are sufficiently complete to permit
substantive review. The FDA may request additional information rather than accept an NDA for filing. In this
event, the NDA must be resubmitted with the additional information. The resubmitted application also is subject
to a filing review before the FDA accepts it for filing and substantive review.

The FDA also may refer an application for a novel drug to an advisory committee. An advisory committee is

a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and
provides a recommendation as to whether the application should be approved and under what conditions. The
FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations
carefully when making decisions.

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Before approving an NDA, the FDA inspects the facility or the facilities at which the drug and/or its active

pharmaceutical ingredient is manufactured and will not approve the product unless the manufacturing is in
compliance with cGMPs and adequate to assure consistent production of the product within required
specifications. Additionally, before approving an NDA, the FDA will typically inspect one or more clinical sites
to assure compliance with GCPs. If the FDA determines that the application, manufacturing process or
manufacturing facilities are not acceptable, it will outline the deficiencies in the submission and often will
request additional testing or information. Notwithstanding the submission of any requested additional
information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for
approval.

After the FDA evaluates an NDA, it will issue an approval letter or a Complete Response Letter. An

approval letter authorizes commercial marketing of the drug for specific indications. A Complete Response
Letter indicates that the review cycle of the application is complete and the application will not be approved in its
present form. A Complete Response Letter usually describes the specific deficiencies in the NDA identified by
the FDA and may require additional clinical data and/or additional pivotal Phase III clinical trial(s), and/or other
significant, expensive and time-consuming requirements related to clinical trials, pre-clinical studies or
manufacturing. Even if such additional information is submitted, the FDA may ultimately decide that the NDA
does not satisfy the criteria for approval.

If regulatory approval of a product is granted, such approval will be granted for particular indications and

may entail limitations on the indicated uses for which such product may be marketed. For example, the FDA
could approve the NDA with a Risk Evaluation and Mitigation Strategy to mitigate risks of the drug, which could
include medication guides, physician communication plans, or elements to assure safe use, such as restricted
distribution methods, patient registries or other risk minimization tools. Once the FDA approves a drug, the FDA
may withdraw product approval if ongoing regulatory requirements are not met or if safety problems occur after
the product reaches the market. In addition, the FDA may require testing, including Phase IV clinical trials, and
surveillance programs to monitor the safety effects of approved products that have been commercialized. The
FDA has the power to prevent or limit further marketing of a product based on the results of these post-marketing
programs or other information. In addition, new government requirements, including those resulting from new
legislation, may be established, or the FDA’s policies may change, which could impact the timeline for
regulatory approval or otherwise impact ongoing development programs.

Expedited Review and Approval Programs. The FDA has various programs, including fast track designation,

priority review, accelerated approval, and breakthrough therapy designation, which are intended to expedite or
simplify the process for reviewing certain drugs and in the case of accelerated approval, provide for approval on
the basis of surrogate or intermediate endpoints. Even if a drug qualifies for one or more of these programs, the
FDA may later decide that the drug no longer meets the conditions for qualification or that the time period for
FDA review or approval will not be shortened. Generally, drugs that may be eligible for these programs are those
for serious or life-threatening diseases or conditions, those with the potential to address unmet medical needs,
and those that offer meaningful benefits over existing treatments. Fast track designation, breakthrough therapy
designation, priority review and accelerated approval do not change the standards for approval but may expedite
the development or approval process.

For example, fast track designation is designed to facilitate the development and expedite the review of
drugs designed to treat serious or life-threatening diseases or conditions and which demonstrate the potential to
address an unmet medical need for such diseases or conditions. Fast track designation applies to the combination
of the product and the specific indication for which it is being studies. The sponsor of a fast track product
candidate has opportunities for more frequent interactions with the FDA review team during development. With
regard to a fast track-designated product, the FDA may also consider for review sections of the NDA on a rolling
basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the
sections of the NDA, the FDA agrees to accept sections of the NDA and determines that the schedule is
acceptable, and the sponsor pays any required user fees upon submission of the first section of the NDA. Any

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product submitted to the FDA for approval, including a product with a fast track designation, may also be eligible
for other types of FDA programs intended to expedite development and review, such as priority review and
accelerated approval. A product is eligible for priority review if it is designed to treat a serious condition, and if
approved, would provide a significant improvement in safety or effectiveness compared to available products.
The FDA will attempt to direct additional resources to the evaluation of an application for a new drug designated
for priority review in an effort to facilitate the review. The FDA endeavors to review applications with priority
review designations within six months of the filing date as compared to ten months for review of new molecular
entity NDAs under its current PDUFA review goals.

Drug products intended for serious or life threatening conditions may be eligible for accelerated approval
upon a determination that the product has an effect on a surrogate endpoint, which is a laboratory measurement
or physical sign used as an indirect or substitute measurement representing a clinically meaningful outcome, or
an effect on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality and that is
reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into
account the severity, rarity or prevalence of the condition and the availability or lack of alternative treatments. As
a condition of approval, the FDA may require that a sponsor of a drug receiving accelerated approval perform
post-marketing clinical trials to verify or characterize the anticipated effect on irreversible morbidity or mortality
or other clinical benefit. Products receiving accelerated approval may be subject to expedited withdrawal
procedures if the sponsor fails to conduct the required clinical trials in a timely manner, or if such trials fail to
verify the predicted clinical benefit. In addition, the FDA currently requires pre-approval of promotional
materials as a condition for accelerated approval.

The Food and Drug Administration Safety and Innovation Act established a category of drugs referred to as
“breakthrough therapies” that may be eligible to receive breakthrough therapy designation. A sponsor may seek
FDA designation of a product candidate as a “breakthrough therapy” if the product is intended, alone or in
combination with one or more other drugs, to treat a serious or life-threatening disease or condition and
preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing
therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in
clinical development. Drugs designated as breakthrough therapies receive all the benefits of a fast track
designation, as well as intensive guidance on efficient drug development and organizational commitment
involving senior managers in the FDA.

Post-Approval Requirements. After a drug has been approved by the FDA for sale, the FDA may require

that certain post-approval requirements be satisfied, including the conduct of additional clinical studies. In
addition, certain changes to an approved product, such as adding new indications, making certain manufacturing
changes, or making certain additional labeling claims, are subject to further FDA review and approval. Before a
company can market products for additional indications, it must obtain additional approvals from the FDA.
Obtaining approval for a new indication generally requires that additional clinical studies be conducted. A
company cannot be sure that any additional approval for new indications for any product candidate will be
approved on a timely basis, or at all.

If post-approval conditions are not satisfied, the FDA may withdraw its approval of the drug. In addition,

holders of an approved NDA are required to (i) report certain adverse reactions to the FDA and maintain
pharmacovigilance programs to proactively look for these adverse events; (ii) comply with certain requirements
concerning advertising and promotional labeling for their products; and (iii) continue to have quality control and
manufacturing procedures conform to cGMPs after approval. The FDA periodically inspects the sponsor’s
records related to safety reporting and/or manufacturing facilities; this latter effort includes assessment of
ongoing compliance with cGMPs. Accordingly, manufacturers must continue to expend time, money and effort
in the area of production and quality control to maintain cGMP compliance. We use third-party manufacturers to
produce our products in clinical and commercial quantities, and future FDA inspections may identify compliance
issues at the facilities of our contract manufacturers that may disrupt production or distribution, or require

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substantial resources to correct. In addition, discovery of problems with a product after approval may result in
restrictions on a product, manufacturer or holder of an approved NDA, including, among other things:

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•

•

•

•

restrictions on the marketing or manufacturing of the product, complete withdrawal of the product from
the market or product recalls;

fines, warning letters or holds on post-approval clinical trials;

refusal of the FDA to approve pending applications or supplements to approved applications, or
suspension or revocation of existing product approvals;

product seizure or detention, or refusal to permit the import or export of products; or

injunctions or the imposition of civil or criminal penalties.

The FDA closely regulates the marketing, labeling, advertising and promotion of drugs. A company can
make only those claims relating to safety and efficacy that are approved by the FDA and in accordance with the
provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations
prohibiting the promotion of off-label uses. Failure to comply with these requirements can result in, among other
things, adverse publicity, warning letters, corrective advertising and potential civil and criminal penalties.
Physicians may prescribe legally available products for uses that are not described in the product’s labeling and
that differ from those tested and approved by the FDA. Such off-label uses are common across medical
specialties. Physicians may believe that such off-label uses are the best treatment for many patients in varied
circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA
does, however, restrict manufacturer’s communications on the subject of off-label use of their products.

Patent Term Restoration and Marketing Exclusivity. Depending upon the timing, duration and specifics of

FDA approval of the use of our drugs, some of our U.S. patents may be eligible for limited patent term extension
under the Drug Price Competition and Patent Term Restoration Act of 1984, referred to as the Hatch-Waxman
Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as
compensation for patent term lost during product development and the FDA regulatory review process. However,
patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the
product’s approval date. The patent term restoration period is generally one-half the time between the effective
date of an IND and the submission date of an NDA, plus the time between the submission date of an NDA and
the approval of that application. Only one patent applicable to an approved drug is eligible for the extension and
the extension must be requested prior to expiration of the patent. The USPTO, in consultation with the FDA,
reviews and approves the application for any patent term extension or restoration. We have filed for patent term
extension for two U.S. patents, U.S. Patent No. 7,399,865 and U.S. Patent No. 9,211,291. We elected to apply
patent term extension to U.S. Patent No. 7,399,865. The USPTO has determined that U.S. Patent No. 7,399,865
is eligible for five years of patent term extension. Once extended, U.S. Patent No. 7,399,865 will expire
December 29, 2030.

Data and market exclusivity provisions under the FDCA also can delay the submission or the approval of

certain applications. The FDCA provides a five-year period of non-patent data exclusivity within the
United States to the first applicant to gain approval of an NDA for a new chemical entity. A drug is a new
chemical entity if the FDA has not previously approved any other new drug containing the same active moiety,
which is the molecule or ion responsible for the action of the drug substance. During the exclusivity period, the
FDA may not accept for review an abbreviated new drug application, or ANDA, or an NDA submitted under
section 505(b)(2) of the FDCA by another company for another version of such drug where the applicant does
not own or have a legal right of reference to all the data required for approval. However, an application may be
submitted after four years if it contains a certification of patent invalidity or non-infringement. Currently, ten
U.S. Patents are listed in the patent data under the FDA’s Approved Drug Products with Therapeutic Equivalence
Evaluations, or the Orange Book, in connection with neratinib: U.S. Patent Nos. 7,399,865, 7,982,043, 8,518,446,
8,669,273, 8,790,708, 9,139,558, 9,211,291, 9,265,784, 9,630,946, and 10,035,788, with expected patent

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expiration dates ranging from October 2025 to July 2031. The FDCA also provides three years of marketing
exclusivity for an NDA, 505(b)(2) NDA or supplement to an existing NDA if new clinical investigations, other
than bioavailability studies, conducted or sponsored by the applicant are deemed by the FDA to be essential to
the approval of the application, for example, for new indications, dosages or strengths of an existing drug. This
three-year exclusivity covers only the conditions associated with the new clinical investigations and does not
prohibit the FDA from approving ANDAs or 505(b)(2) NDAs for drugs containing the original active agent or
from accepting and reviewing an application referencing the approved drug’s application. Five-year and three-
year exclusivity will not delay the submission or approval of a full NDA; however, an applicant submitting a full
NDA would be required to conduct, or obtain a right of reference to all of the pre-clinical studies and clinical
trials necessary to demonstrate safety and effectiveness. Marketing approval for neratinib was obtained in the
United States on July 17, 2017, which provided five years of regulatory exclusivity. Marketing approval for
neratinib in combination with capecitabine was obtained in the United States on February 25, 2020, which
provided three years of regulatory exclusivity. The earliest a generic may challenge any of the U.S. Patents listed
in the Orange Book in connection with neratinib by filing an ANDA is in July 2021.

Foreign Regulation

In addition to regulations in the United States, we will be subject to a variety of foreign regulations
governing clinical trials and commercial sales and distribution of our products. Whether or not we obtain FDA
approval for a product, we must obtain approval by the comparable regulatory authorities of foreign countries
before we can commence clinical trials and approval of foreign countries or economic areas, such as the EU,
before we may market products in those countries or areas. The approval process and requirements governing the
conduct of clinical trials, product licensing, pricing and reimbursement vary greatly from place to place, and the
time may be longer or shorter than that required for FDA approval.

In the European Economic Area, or EEA, which is comprised of the Member States of the EU plus Norway,

Iceland and Liechtenstein, medicinal products can only be commercialized after obtaining a Marketing
Authorization, or MA. There are two types of MAs:

• Community MAs – These are issued by the EC through the Centralized Procedure, based on the

opinion of the Committee for Medicinal Products for Human Use, or CHMP, of the EMA, and are
valid throughout the entire territory of the EEA. The Centralized Procedure is mandatory for certain
types of products, such as biotechnology medicinal products, orphan medicinal products, and medicinal
products indicated for the treatment of AIDS, cancer, neurodegenerative disorders, diabetes, auto-
immune and viral diseases. The Centralized Procedure is optional for products containing a new active
substance not yet authorized in the EEA; for products that constitute a significant therapeutic, scientific
or technical innovation; or for products that are in the interest of public health in the EU.

• National MAs – These are issued by the competent authorities of the Member States of the EEA and
only cover their respective territory and are available for products not falling within the mandatory
scope of the Centralized Procedure. Where a product has already been authorized for marketing in a
Member State of the EEA, this National MA can be recognized in another Member State through the
Mutual Recognition Procedure. If the product has not received a National MA in any Member State at
the time of application, it can be approved simultaneously in various Member States through the
Decentralized Procedure. Under the Decentralized Procedure, an identical dossier is submitted to the
competent authorities of each of the Member States in which the MA is sought, one of which is
selected by the applicant as the Reference Member State. The competent authority of the Reference
Member State prepares a draft assessment report, a draft summary of the product characteristics, or
SmPC, and a draft of the labeling and package leaflet, which are sent to the other Member States
(referred to as the Member States Concerned) for their approval. If the Member States Concerned raise
no objections, based on a potential serious risk to public health, to the assessment, SmPC, labeling or
packaging proposed by the Reference Member State, the product is subsequently granted a National
MA in all the Member States, i.e., in the Reference Member State and the Member States Concerned.

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Under the above described procedures, before granting the MA, the EMA or the competent authorities of the

Member States of the EEA assess the risk-benefit balance of the product on the basis of scientific criteria
concerning its quality, safety and efficacy.

As in the United States, it may be possible in foreign countries to obtain a period of market and/or data
exclusivity that would have the effect of postponing the entry into the marketplace of a competitor’s generic
product. For example, if any of our products receive marketing approval in the EEA, we expect they will benefit
from eight years of data exclusivity and 10 years of marketing exclusivity. An additional non-cumulative
one-year period of marketing exclusivity is possible if during the data exclusivity period (the first eight years of
the 10-year marketing exclusivity period), we obtain an authorization for one or more new therapeutic indications
that are deemed to bring a significant clinical benefit compared to existing therapies. The data exclusivity period
begins on the date of the product’s first marketing authorization in the EEA and prevents generics from relying
on the marketing authorization holder’s pharmacological, toxicological and clinical data for a period of eight
years. After eight years, a generic product application may be submitted, and generic companies may rely on the
marketing authorization holder’s data. However, a generic cannot launch until two years later (or a total of 10
years after the first marketing authorization in the EU of the innovator product), or three years later (or a total of
11 years after the first marketing authorization in the EU of the innovator product) if the marketing authorization
holder obtains marketing authorization for a new indication with significant clinical benefit within the eight-year
data exclusivity period. In Japan, our products may be eligible for eight years of data exclusivity. There can be no
assurance that we will qualify for such regulatory exclusivity, or that such exclusivity will prevent competitors
from seeking approval solely on the basis of their own studies.

When conducting clinical trials in the EU, we must adhere to the provisions of the European Union Clinical

Trials Directive (Directive 2001/20/EC) and the laws and regulations of the EU Member States implementing
them. These provisions require, among other things, that the prior authorization of an Ethics Committee and the
competent Member State authority is obtained before commencing the clinical trial. In April 2014, the EU passed
the Clinical Trials Regulation (Regulation 536/2014), which will replace the current Clinical Trials Directive. To
ensure that the rules for clinical trials are identical throughout the European Union, the EU Clinical Trials
Regulation was passed as a regulation that is directly applicable in all EU member states. All clinical trials
performed in the European Union are required to be conducted in accordance with the Clinical Trials Directive
until the Clinical Trials Regulation becomes applicable. According to the current plans of the EMA, the Clinical
Trials Regulation is expected to become applicable in late 2021 but could be delayed.

Coverage and Reimbursement

In the United States and internationally, sales of NERLYNX and any other products that we market in the

future, and our ability to generate revenues on such sales, are dependent, in significant part, on the availability of
adequate coverage and reimbursement from third-party payors, such as state and federal governments, managed
care providers and private insurance plans. Private insurers, such as health maintenance organizations and
managed care providers, have implemented cost-cutting and reimbursement initiatives and likely will continue to
do so in the future. These include establishing formularies that govern the drugs and biologics that will be offered
and the out-of-pocket obligations of member patients for such products. We may need to conduct
pharmacoeconomic studies to demonstrate the cost-effectiveness of our products for formulary coverage and
reimbursement. Even with such studies, our products may be considered less safe, less effective or less cost-
effective than existing products, and third-party payors may not provide coverage and reimbursement for our
product candidates, in whole or in part.

In addition, particularly in the United States and increasingly in other countries, we are required to provide

discounts and pay rebates to state and federal governments and agencies in connection with purchases of our
products that are reimbursed by such entities. It is possible that future legislation in the United States and other
jurisdictions could be enacted to potentially impact reimbursement rates for the products we are developing and
may develop in the future and could further impact the levels of discounts and rebates paid to federal and state

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government entities. Any legislation that impacts these areas could impact, in a significant way, our ability to
generate revenues from sales of products that, if successfully developed, we bring to market.

Political, economic and regulatory influences are subjecting the healthcare industry in the United States to

fundamental changes. There have been, and we expect there will continue to be, legislative and regulatory
proposals to change the healthcare system in ways that could significantly affect our future business. For
example, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education
Reconciliation Act, or collectively, the ACA, enacted in March 2010, substantially changed the way healthcare is
financed by both governmental and private insurers. Among other cost containment measures, ACA established:

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an annual, nondeductible fee on any entity that manufactures or imports certain branded prescription
drugs and biologic agents;

a new Medicare Part D coverage gap discount program, in which pharmaceutical manufacturers who
wish to have their drugs covered under Part D must offer discounts to eligible beneficiaries during their
coverage gap period, or the donut hole; and

a new formula that increases the rebates a manufacturer must pay under the Medicaid Drug Rebate
Program.

Since its enactment, there have been judicial and Congressional challenges to certain aspects of the ACA, as

well as recent efforts by the Trump administration to repeal or replace certain aspects of the ACA. By way of
example, the Tax Cuts and Jobs Act was enacted, which, among other things, removes penalties for not
complying with the ACA’s individual mandate to carry health insurance. On December 14, 2018, a U.S. District
Court Judge in the Northern District of Texas, ruled that the individual mandate is a critical and inseverable
feature of the ACA, and therefore, because it was repealed as part of the Tax Act, the remaining provisions of the
ACA are invalid as well. On December 18, 2019, the U.S. Court of Appeals for the Fifth Circuit ruled that the
individual mandate was unconstitutional and remanded the case back to the District Court to determine whether
the remaining provisions of the ACA are invalid as well. The U.S. Supreme Court is currently reviewing the
case, although it remains unclear when or how the Supreme Court will rule. It is also unclear how other efforts to
challenge, repeal or replace the ACA will impact the ACA.

In addition, other legislative changes have been proposed and adopted in the United States since the ACA
was enacted. For example, the Budget Control Act of 2011, among other things, included aggregate reductions to
Medicare payments to providers of 2% per fiscal year, which went into effect on April 1, 2013 and, due to
subsequent legislative amendments to the statute, will remain in effect through 2030, with the exception of a
temporary suspension from May 1, 2020 through March 31, 2021, unless additional Congressional action is
taken. The American Taxpayer Relief Act of 2012, among other things, reduced Medicare payments to several
types of providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of
limitations period for the government to recover overpayments to providers from three to five years. Individual
states in the United States have also become increasingly active in passing legislation and implementing
regulations designed to control pharmaceutical product pricing, including price or patient reimbursement
constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency
measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.
Recently, there has also been heightened governmental scrutiny over the manner in which drug manufacturers set
prices for their marketed products, which has resulted in several Congressional inquiries and proposed bills
designed to, among other things, bring more transparency to product pricing, review the relationship between
pricing and manufacturer patient programs, and reform government program reimbursement methodologies for
drug products. For example, the 21st Century Cures Act changes the reimbursement methodology for infusion
drugs and biologics furnished through durable medical equipment in an attempt to remedy over- and
underpayment of certain drugs.

Similar political, economic and regulatory developments are occurring in the EU and may affect the ability

of pharmaceutical companies to profitably commercialize their products. In addition to continuing pressure on

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prices and cost containment measures, legislative developments at the EU or member state level may result in
significant additional requirements or obstacles. The delivery of healthcare in the EU, including the
establishment and operation of health services and the pricing and reimbursement of medicines, is almost
exclusively a matter for national, rather than EU, law and policy. National governments and health service
providers have different priorities and approaches to the delivery of health care and the pricing and
reimbursement of products in that context. In general, however, the healthcare budgetary constraints in most EU
member states have resulted in restrictions on the pricing and reimbursement of medicines by relevant health
service providers. Coupled with ever-increasing EU and national regulatory burdens on those wishing to develop
and market products, this could restrict or regulate post-approval activities and affect the ability of
pharmaceutical companies to commercialize their products. In international markets, reimbursement and
healthcare payment systems vary significantly by country, and many countries have instituted price ceilings on
specific products and therapies.

In the future, there may continue to be additional proposals relating to the reform of the U.S. healthcare
system and international healthcare systems. Future legislation, or regulatory actions implementing recent or
future legislation may have a significant effect on our business. Our ability to successfully commercialize
products depends in part on the extent to which reimbursement for the costs of our products and related
treatments will be available in the United States and worldwide from government health administration
authorities, private health insurers and other organizations. The adoption of certain proposals could limit the
prices we are able to charge for our products, the amounts of reimbursement available for our products, and limit
the acceptance and availability of our products. Therefore, substantial uncertainty exists as to the reimbursement
status of newly approved health care products by third-party payors.

Sales and Marketing

The FDA regulates all advertising and promotion activities for products under its jurisdiction prior to and

after approval, including standards and regulations for direct-to-consumer advertising, dissemination of off-label
information, industry-sponsored scientific and educational activities and promotional activities involving the
Internet. Drugs may be marketed only for the approved indications and in accordance with the provisions of the
approved label. Further, if there are any modifications to the drug, including changes in indications, labeling, or
manufacturing processes or facilities, we may be required to submit and obtain FDA approval of a new or
supplemental NDA, which may require us to collect additional data or conduct additional pre-clinical studies and
clinical trials. Failure to comply with applicable FDA requirements may subject a company to adverse publicity,
enforcement action by the FDA, corrective advertising, consent decrees and the full range of civil and criminal
penalties available to the FDA.

Physicians may prescribe legally available drugs for uses that are not described in the drug’s labeling and
that differ from those tested by us and approved by the FDA. Such off-label uses are common across medical
specialties, and often reflect a physician’s belief that the off-label use is the best treatment for the patient. The
FDA does not regulate the behavior of physicians in their choice of treatments, but FDA regulations do impose
stringent restrictions on manufacturers’ communications regarding off-label uses. Failure to comply with
applicable FDA requirements may subject a company to adverse publicity, enforcement action by the FDA,
corrective advertising, consent decrees and the full range of civil and criminal penalties available to the FDA.

Outside the United States, our ability to market a product is contingent upon obtaining marketing

authorization from the appropriate regulatory authorities. The requirements governing marketing authorization,
pricing and reimbursement vary widely from country to country.

Other Healthcare Laws

We may also be subject to various federal and state laws pertaining to health care “fraud and abuse,”
including anti-kickback laws and false claims laws, data privacy and security laws and transparency laws.

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The federal Anti-Kickback Statute, or AKS, prohibits, among other things, any person or entity from
knowingly and willfully soliciting, receiving, offering or paying any remuneration, directly or indirectly, overtly
or covertly, in cash or in kind, to induce or reward either the referral of an individual for, or the purchase, order
or recommendation of an item or service reimbursable, in whole or in part, under a federal healthcare program,
such as the Medicare and Medicaid programs. The term “remuneration” has been broadly interpreted to include
anything of value. There are a number of statutory exceptions and regulatory safe harbors protecting some
common activities from prosecution; however, these are drawn narrowly and require strict compliance in order to
offer protection. Additionally, a person or entity does not need to have actual knowledge of the statute or specific
intent to violate it in order to have committed a violation.

Federal civil and criminal false claims laws, such as the federal False Claims Act, or FCA, prohibit

individuals or entities from, among other things, knowingly presenting, or causing to be presented false, fictitious
or fraudulent claims for payment or approval by the federal government, including federal health care programs,
such as Medicare and Medicaid, and knowingly making, using or causing to be made or used a false record or
statement material to a false or fraudulent claim, or knowingly making a false statement to improperly avoid,
decrease or conceal an obligation to pay money to the federal government. Private individuals can bring “qui
tam” actions under the FCA, on behalf of the government and such individuals, commonly known as
“whistleblowers,” may share in amounts paid by the entity to the government in fines or settlement. Moreover, a
claim including items or services resulting from a violation of the AKS constitutes a false or fraudulent claim for
purposes of the FCA.

The federal Civil Monetary Penalties law prohibits, among other things, offering or transferring

remuneration to a federal healthcare beneficiary that a person knows or should know is likely to influence the
beneficiary’s decision to order or receive items or services reimbursable by the government from a particular
provider or supplier.

The federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, created federal
criminal statutes that prohibit knowingly and willfully executing, or attempting to execute, a scheme to defraud
or to obtain, by means of false or fraudulent pretenses, representations or promises, any money or property
owned by, or under the control or custody of, any healthcare benefit program, including private third-party
payors and knowingly and willfully falsifying, concealing or covering up by trick, scheme or device, a material
fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or
payment for healthcare benefits, items or services. Like the AKS, a person or entity does not need to have actual
knowledge of the statute or specific intent to violate it in order to have committed a violation.

The federal transparency requirements under the Physician Payments Sunshine Act, created under the ACA,
requires, among other things, certain manufacturers of drugs, devices, biologics and medical supplies reimbursed
under Medicare, Medicaid, or the Children’s Health Insurance Program to annually report to CMS information
related to payments and other transfers of value provided to physicians (defined to include doctors, dentists,
optometrists, podiatrists and chiropractors), certain other healthcare professionals beginning in 2022, and
teaching hospitals and physician ownership and investment interests, including such ownership and investment
interests held by a physician’s immediate family members.

There are also state and foreign law equivalents of each of the above federal laws, such as state anti-
kickback and false claims laws, that may impose similar or more prohibitive restrictions, and may apply to items
or services reimbursed by any non-governmental third-party payors, including private insurers. Similar
restrictions are also imposed on the promotion and marketing of medicinal products in the EU and other
countries. Laws (including those governing promotion, marketing and anti-kickback provisions), industry
regulations and professional codes of conduct often are strictly enforced.

Violations of fraud and abuse laws may be punishable by criminal and/or civil sanctions, including fines and

civil monetary penalties, the possibility of exclusion from federal health care programs (including Medicare and

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Medicaid) and corporate integrity agreements, which impose, among other things, rigorous operational and
monitoring requirements on companies. Similar sanctions and penalties also may be imposed upon executive
officers and employees, including criminal sanctions against executive officers under the so-called “responsible
corporate officer” doctrine, even in situations where the executive officer did not intend to violate the law and
was unaware of any wrongdoing. Given the penalties that may be imposed on companies and individuals if
convicted, allegations of such violations often result in settlements even if the company or individual being
investigated admits no wrongdoing. Settlements often include significant civil sanctions, including fines and civil
monetary penalties, and corporate integrity agreements.

Data Privacy and Security

Pharmaceutical companies may be subject to U.S. federal and state and foreign health information privacy,

security and data breach notification laws, which may govern the collection, use, disclosure and protection of
health-related and other personal information. In the U.S., HIPAA imposes privacy, security and breach reporting
obligations with respect to individually identifiable health information upon “covered entities” (health plans,
health care clearinghouses and certain health care providers), and their respective business associates, individuals
or entities that create, received, maintain or transmit protected health information in connection with providing a
service for or on behalf of a covered entity. HIPAA mandates the reporting of certain breaches of health
information to HHS, affected individuals and if the breach is large enough, the media. Entities that are found to
be in violation of HIPAA as the result of a breach of unsecured protected health information, a complaint about
privacy practices or an audit by HHS, may be subject to significant civil, criminal and administrative fines and
penalties and/or additional reporting and oversight obligations if required to enter into a resolution agreement and
corrective action plan with HHS to settle allegations of HIPAA non-compliance. Even when HIPAA does not
apply, according to the Federal Trade Commission or the FTC, failing to take appropriate steps to keep
consumers’ personal information secure constitutes unfair acts or practices in or affecting commerce in violation
of Section 5(a) of the Federal Trade Commission Act. The FTC expects a company’s data security measures to
be reasonable and appropriate in light of the sensitivity and volume of consumer information it holds, the size
and complexity of its business, and the cost of available tools to improve security and reduce vulnerabilities.
Individually identifiable health information is considered sensitive data that merits stronger safeguards.

In addition, certain state and non-U.S. laws, such as the European Union General Data Protection
Regulation, or the GDPR, govern the privacy and security of personal information, including health-related
information in certain circumstances, some of which are more stringent than HIPAA and many of which differ
from each other in significant ways and may not have the same effect, thus complicating compliance efforts.
Failure to comply with these laws, where applicable, can result in the imposition of significant civil and/or
criminal penalties and private litigation. For example, the California Consumer Privacy Act, or CCPA, went into
effect January 1, 2020, which, among other things, creates new data privacy obligations for covered companies
and provides new privacy rights to California residents, including the right to opt out of certain disclosures of
their information. The CCPA also creates a private right of action with statutory damages for certain data
breaches, thereby potentially increasing risks associated with a data breach. Although the law includes limited
exceptions for health-related information, including for “protected health information” maintained by a covered
entity or business associate and clinical trial data, it may regulate or impact our processing of personal
information depending on the context. Further, the California Privacy Rights Act, or the CPRA, recently passed
in California. The CPRA will impose additional data protection obligations on covered companies doing business
in California, including additional consumer rights processes, limitations on data uses, new audit requirements
for higher risk data, and opt outs for certain uses of sensitive data. It will also create a new California data
protection agency authorized to issue substantive regulations and could result in increased privacy and
information security enforcement. The majority of the provisions will go into effect on January 1, 2023, and
additional compliance investment and potential business process changes may be required. In Europe, the GDPR
went into effect in May 2018 and introduces strict requirements for processing the personal data of European
Union data subjects. Companies that must comply with the GDPR face increased compliance obligations and
risk, including more robust regulatory enforcement of data protection requirements and potential fines for

35

noncompliance of up to €20 million or 4% of the annual global revenues of the noncompliant company,
whichever is greater. Relatedly, following the United Kingdom’s withdrawal from the EEA and the European
Union, and the expiry of the transition period, companies have to comply with the GDPR and the GDPR as
incorporated into United Kingdom national law, the latter regime having the ability to separately fine up to the
greater of £17.5 million or 4% of global turnover.

Other Laws and Regulatory Processes

We are subject to a variety of financial disclosure and securities trading regulations as a public company in

the United States with securities traded on the NASDAQ Global Select Market, including laws relating to the
oversight activities of the Securities and Exchange Commission, or the SEC, and the rules and regulations of The
NASDAQ Stock Market LLC. In addition, the Financial Accounting Standards Board, or FASB, the SEC, and
other bodies that have jurisdiction over the form and content of our accounts, our financial statements and other
public disclosure are constantly discussing and interpreting proposals and existing pronouncements designed to
ensure that companies best display relevant and transparent information relating to their respective businesses.

Our present and future business has been and will continue to be subject to various other laws and
regulations. Various laws, regulations and recommendations relating to safe working conditions, laboratory
practices, experimental use of animals, and the purchase, storage, movement, import and export, and use and
disposal of hazardous or potentially hazardous substances used in connection with our research work are or may
be applicable to our activities. Certain agreements entered into by us involving exclusive license rights or
acquisitions may be subject to national or supranational antitrust regulatory control, the effect of which cannot be
predicted. The extent of government regulation that might result from future legislation or administrative action
cannot accurately be predicted.

Research and Development Expenses

Research and development activities, which include personnel costs, research supplies, clinical and

pre-clinical study costs, are the primary source of our overall expenses. Such expenses related to the research and
development of our product candidates totaled $97.7 million for the year ended December 31, 2020,
$132.9 million for the year ended December 31, 2019 and $164.9 million for the year ended December 31, 2018.

Human Capital

Health, Wellness, and Safety

As of December 31, 2020, our workforce consisted of 267 full-time employees reporting out of our two
offices in the United States—Los Angeles, CA and San Francisco, CA—along with a field-based commercial
team. We are an equal opportunity employer and believe strongly in hiring a diverse, equitable, and inclusive
workforce. This is reflected in our numbers with our total workforce being approximately 58% women, 40%
ethnically diverse and 75% over the age of 40. The following table summarizes our workforce by location for the
years ended December 31, 2020 and December 31, 2019:

Los Angeles . . . . . . . . . . . . . . . . . . . . . . . . .
South San Francisco . . . . . . . . . . . . . . . . . .
Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31, 2020

December 31, 2019

86
67
114

267

83
70
116

269

We believe that the safety and health of our employees and their families is essential to our business. Our

culture is driven by a desire to do what is right, and we strive to support the well-being of our employees.
Beginning in March 2020, we have supported our employees and government efforts to curb the COVID-19

36

pandemic through a multi-faceted, communication, infrastructure, and behavior modification and enforcement
effort that includes:

•

•

•

•

establishing clear and regular COVID-19 policies, safety protocols, and updates to all employees;

strongly encouraging all office-based employees to work from home;

implementing protocols to address actual and suspected COVID-19 cases and potential exposure; and

prohibiting all domestic and international non-essential travel for all employees.

Our financial, medical, and mental health benefits that were already in place prior to the COVID-19

pandemic were designed to help employees through crisis, and we further expanded our offerings to create
appropriate “work from home” conditions for success and wellness, to include:

•

•

•

•

•

•

•

ergonomic webinars, 1x1 evaluations, and reimbursement for ergonomic equipment;

phone and internet subsidies;

purchasing additional IT equipment and office supplies;

increasing communications related to our free EAPs, work/life assistance programs, and mental health
benefits;

professional resiliency coaching;

subsidized subscriptions to ClassPass – access to fitness, wellness, and mindfulness classes; and

purchasing Fitbits for all full-time employees.

Compensation & Benefits

We know that developing and keeping great people is a vital part of our competitive edge and essential to

providing the best patient care. For this reason, we offer a robust total compensation package in an effort to
attract and engage high caliber employees.

Since 2019, we have offered personalized total compensation statements to all full-time employees. These

statements provide a transparent view of each employee’s monetary and non-monetary benefits. Employee’s total
compensation represents a broad spectrum of plans and programs designed to reward and motivate employees
throughout their careers.

Our total rewards package consists of competitive market-based salary and cash target bonus based on

geography for every employee. Bonus opportunity and equity compensation increase as a percentage of total
compensation based on level of responsibility with actual bonus payout based on performance.

In addition to competitive salaries and performance incentives, we offer employees 100% employer-paid
benefits that include medical, dental, vision, life insurance, paid time off and family leave, 401(k) match, fertility
benefits, volunteer days and more. Our benefit programs are constantly evolving to meet our employees’ needs
and renew our commitment to them as a vital resource to our continued success.

Culture and Communication

How we conduct our business is just as important as what we do. Our core values are the principles that

guide our company strategy and our individual actions. At all times we strive to distinguish ourselves as a
respected biopharmaceutical company that is differentiated by top talent and innovative products to enhance
cancer care.

All employees are responsible for upholding our core values, including to be patient-centric, to

communicate, collaborate, innovate and be respectful, as well as for adhering to our Code of Ethics. These values

37

nurture an inclusive workforce striving for excellence that puts the well-being of our patients first. We continue
to utilize our Human Resources Information System, or HRIS, platform to track human capital metrics, employee
demographics and turnover. The majority of our employees have obtained advanced degrees in their professions,
and we support their continued development with individualized development plans and objectives, mentoring,
coaching, training and conference attendance.

Communication is critical in our ability to continuously enhance our company culture and create a more
inclusive environment. The implementation and distribution of quarterly company newsletters have allowed us to
share what is important and impactful to us as a business. It also allows for us to share stories and events that
have affected our employees and co-workers across the country on both a personal and professional level. We
hold town halls with our leaders to speak with employees about our vision and to receive feedback on matters
important to them. Additionally, we have dynamic information technology systems, which allow for a more
synergistic atmosphere.

Corporate Information and History

Our principal executive offices are located at 10880 Wilshire Boulevard, Suite 2150, Los Angeles,

California 90024 and our telephone number is (424) 248-6500. Our internet address is
www.pumabiotechnology.com. Our annual, quarterly and current reports, and any amendments to those reports,
filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 may be accessed free
of charge through our website after we have electronically filed or furnished such material with the SEC. We also
make available free of charge on or through our website our Code of Business Conduct and Ethics, Corporate
Governance Guidelines, Audit Committee Charter, Compensation Committee Charter, Nominating and
Corporate Governance Committee Charter and Research and Development Committee Charter. We will disclose
on a current report on Form 8-K or on our website any amendment or waiver of the Code of Business Conduct
and Ethics for our executive officers and directors. Any amendment or waiver disclosed on our website will
remain available on our website for at least 12 months after the initial disclosure.

The reference to www.pumabiotechnology.com (including any other reference to such address in this Annual

Report) is an inactive textual reference only, meaning that the information contained on or accessible from the
website is not part of this Annual Report on Form 10-K and is not incorporated in this report by reference.

We were originally incorporated in the State of Delaware in April 2007 under the name Innovative

Acquisitions Corp. We were a “shell” company registered under the Exchange Act with no specific business plan
or purpose until we acquired Puma Biotechnology, Inc., a privately-held Delaware corporation formed on
September 15, 2010, or Former Puma, in October 2011. As a result of this transaction, Former Puma become our
wholly-owned subsidiary and subsequently merged with and into us, at which time we adopted Former Puma’s
business plan and changed our name to “Puma Biotechnology, Inc.”

38

ITEM 1A. RISK FACTORS

In addition to the other information contained in this Annual Report, the following risk factors should be

considered carefully in evaluating our company. Our business, financial condition, liquidity and results of
operations could be materially adversely affected by any of these risks. The risks and uncertainties described
below are not the only ones we face. Additional risks and uncertainties that we are unaware of, or that we
currently believe are not material, may also become important factors that affect us.

Risks Related to our Financial Condition and Capital Requirements

We have a history of operating losses and are not profitable and may never become profitable.

We have a history of operating losses, with net losses of $60.0 million, $75.6 million, and $113.6 million for

the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, we had an
accumulated deficit of approximately $1.3 billion, outstanding indebtedness of approximately $98.3 million and
cash and cash equivalents of $85.3 million. We have devoted substantially all of our resources to identifying,
acquiring and developing NERLYNX and to its commercialization in the indications for which it has received
regulatory approval. Biopharmaceutical development is a highly speculative undertaking and involves a
substantial degree of risk. We anticipate that we will continue to incur operating losses for the foreseeable future
as our efforts to commercialize NERLYNX in existing indications, and develop NERLYNX for additional
indications continue.

In 2017, the FDA approved NERLYNX for the extended adjuvant treatment of adult patients with early
stage HER2-overexpressed/amplified breast cancer following adjuvant trastuzumab-based therapy. In February
2020, NERLYNX was also approved by the FDA in combination with capecitabine for the treatment of adult
patients with advanced or metastatic HER2-positive breast cancer who have received two or more prior anti-
HER2-based regimens in the metastatic setting. In 2018, the EC granted marketing authorization for NERLYNX
in the European Union for the extended adjuvant treatment of adult patients with early stage hormone receptor
positive HER2-overexpressed/amplified breast cancer and who are less than one year from the completion of
prior adjuvant trastuzumab-based therapy. Although we have begun to commercialize NERLYNX in the U.S.
and Europe in these indications, we continue to experience net losses and may never become profitable.
Moreover, we are continuing to develop NERLYNX for additional indications. The successful development and
commercialization of any drug candidate will require us to perform a variety of functions, including:

•

•

•

•

•

•

undertaking pre-clinical development and clinical trials;

hiring additional personnel;

participating in regulatory approval processes;

formulating and manufacturing products;

initiating and conducting sales and marketing activities; and

implementing additional internal systems and infrastructure.

We will need to generate significant revenue in order to achieve and maintain profitability. We may not be
able to generate this revenue or achieve profitability in the future. As a result, we expect our losses to continue
for the foreseeable future. Accordingly, we cannot assure you that we will achieve profitability in the future or
that, if we do become profitable, we will sustain profitability. Our failure to achieve or maintain profitability
could negatively impact the value of our common stock.

We are currently a single product company with limited commercial sales experience.

We have invested a significant portion of our efforts and financial resources in the development and

commercialization of our lead product, NERLYNX. NERLYNX is the only product for which we currently

39

receive product revenue, and we expect NERLYNX to constitute the vast majority of our product revenue for the
foreseeable future. By virtue of being dependent on a single product, we do not have the ability to spread out risk
or commercial fluctuations across a portfolio of products. As a result, our success depends almost entirely on the
commercial success of NERLYNX. NERLYNX is the first product that we, as an organization, have launched
and commercialized, and there is no guarantee that we will be able to do so successfully. There are numerous
examples of unsuccessful product launches and failures to meet high expectations of market potential, including
by pharmaceutical companies with more experience and resources than we have.

We may not be able to successfully commercialize NERLYNX.

The commercial success of NERLYNX depends on the extent to which patients and physicians accept and
adopt NERLYNX. For example, if the expected patient population is smaller than we estimate or if physicians
are unwilling to prescribe or patients are unwilling to take or continue to take NERLYNX, due to the related side
effects, including diarrhea, or otherwise, the commercial success of NERLYNX will be limited. Thus, significant
uncertainty remains regarding the commercial potential of NERLYNX. We believe our ability to effectively
increase product revenue from NERLYNX will depend on our ability to, among other things:

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

achieve and maintain compliance with regulatory requirements;

create and sustain market demand for and achieve market acceptance of NERLYNX through our
marketing and sales activities and other arrangements established for the promotion of NERLYNX;

compete with other breast cancer drugs (either in the present or in the future);

educate physicians and patients about the benefits, administration and use of NERLYNX;

train, deploy and support a qualified sales force;

secure formulary approvals for NERLYNX at a substantial number of targeted hospitals;

ensure that our third-party manufacturers manufacture NERLYNX in sufficient quantities, in
compliance with requirements of the FDA and similar foreign regulatory agencies where NERLYNX is
approved, and at acceptable quality and pricing levels in order to meet commercial demand;

ensure that our third-party manufacturers develop, validate and maintain commercially viable
manufacturing processes that are compliant with current Good Manufacturing Practice, or cGMP,
regulations;

implement and maintain agreements with wholesalers, distributors and group purchasing organizations
on commercially reasonable terms;

ensure that our entire supply chain efficiently and consistently delivers NERLYNX to our customers;

receive adequate levels of coverage and reimbursement for NERLYNX from commercial health plans
and governmental health programs;

provide co-pay assistance to help qualified patients with out-of-pocket costs associated with their
NERLYNX prescription and/or other programs to ensure patient access to our products;

obtain acceptance of NERLYNX as safe and effective by patients and the medical community;

influence the nature of publicity related to our product relative to the publicity related to our
competitors’ products;

obtain regulatory approvals for additional indications for the use of NERLYNX; and

• maintain and defend our patent protection and regulatory exclusivity for NERLYNX and to comply
with our obligations under, and otherwise maintain, our intellectual property license with Pfizer and
our license agreements with third parties.

40

We cannot assure you that we will successfully address each of these uncertainties or any others we may

face in the commercialization of NERLYNX. In addition, we are dependent on international third-party
sub-licensees for the development and commercialization of NERLYNX in several countries outside the United
States. The failure of these sub-licensees to meet their contractual, regulatory or other obligations could
adversely affect international sales of NERLYNX and hinder our ability to generate revenue. These uncertainties,
combined with our limited experience in selling and marketing NERLYNX, make it difficult to evaluate our
current business, predict our future prospects and forecast our financial performance.

We may not be able to secure additional financing on favorable terms, or at all, to meet our future capital
needs and our failure to obtain additional financing when needed on acceptable terms, or at all, could force us
to delay, limit, reduce or terminate our product development or commercialization efforts or other operations.

Our operations have consumed substantial amounts of cash since inception. As we continue to

commercialize NERLYNX, our costs and expenses may increase in the future due to, among other things, the
cost of a direct sales force and the cost of manufacturing. We will also continue to expend substantial amounts on
research and development of our other product candidates, including conducting clinical trials. Our future capital
requirements will depend on many factors, including:

•

•

•

•

•

•

•

•

•

•

the costs and expenses of our U.S. sales and marketing infrastructure, and of manufacturing;

the degree of success we experience in commercializing NERLYNX;

the revenue generated by the sale of NERLYNX and any other products that may be approved;

the costs, timing and outcomes of clinical trials and regulatory reviews associated with our other
product candidates;

the emergence of competing products;

the extent to which NERLYNX is adopted by the physician community and patients;

the number and types of future products we develop and commercialize;

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

the costs of operating as a public company and compliance with existing and future regulations; and

the extent and scope of our general and administrative expenses.

While our consolidated financial statements have been prepared on a going concern basis, we expect to
continue incurring significant losses for the foreseeable future and will continue to remain dependent on our
ability to obtain sufficient funding to sustain operations and successfully commercialize NERLYNX. We are
party to a credit facility with Oxford Finance LLC, or Oxford, providing for term loans equaling a total of
$100 million, which mature on June 1, 2024. As of December 31, 2020, we had $100 million in principal
amounts outstanding. While we have been successful in raising financing in the past, there can be no assurance
that we will be able to do so in the future. Additional financing may not be available on a timely basis on terms
acceptable to us, or at all. We may raise funds in equity or debt financings to access funds for our capital needs.
If we raise additional funds through further issuances of equity or convertible debt securities, our existing
stockholders could suffer significant dilution in their percentage ownership of our company, and any new equity
securities we issue could have rights, preferences and privileges senior to those of holders of our common stock.
Any debt financing obtained by us in the future would cause us to incur debt service expenses and could include
restrictive covenants relating to our capital raising activities and other financial and operational matters, which
may make it more difficult for us to obtain additional capital and pursue business opportunities. If we are unable
to obtain adequate financing or financing on terms satisfactory to us when we require it, we may terminate or
delay the development of one or more of our product candidates, delay clinical trials necessary to market our
products, or delay establishment of sales and marketing capabilities or other activities necessary to

41

commercialize our products. If this were to occur, our ability to continue to grow and support our business and to
respond to business challenges could be significantly limited. Furthermore, our ability to obtain funding may be
adversely impacted by uncertain market conditions, our success in commercializing neratinib, unfavorable
decisions of regulatory authorities or adverse clinical trial results. The outcome of these matters cannot be
predicted at this time.

The terms of our credit facility place restrictions on our ability to operate our business and on our financial
flexibility, and we may be unable to achieve the revenue necessary for us to incur additional borrowings under
the credit facility or to satisfy the minimum revenue covenants.

The terms of our credit facility place restrictions on our ability to operate our business and our financial
flexibility. As of December 31, 2020, we had $100 million in principal amounts outstanding under the credit
facility. The credit facility is secured by substantially all of our personal property, other than our intellectual
property.

The credit facility includes affirmative and negative covenants applicable to us, our current subsidiaries and
any subsidiaries we create in the future. The affirmative covenants include, among others, covenants requiring us
to maintain our legal existence and governmental approvals, deliver certain financial reports, maintain insurance
coverage and satisfy certain requirements regarding deposit accounts. We must also achieve product revenue,
measured as of the last day of each fiscal quarter on a trailing year to date basis. New minimum revenue levels
will be established for each subsequent fiscal year by mutual agreement of us, Oxford, as collateral agent, and the
lender. The negative covenants include, among others, restrictions on us transferring collateral, incurring
additional indebtedness, engaging in mergers or acquisitions, paying dividends or making other distributions,
making investments, creating liens, selling assets and suffering a change in control, in each case subject to certain
exceptions. These covenants may make it difficult for us to operate our business. In addition, we are in the early
stages of commercializing NERLYNX and we cannot assure you that we will be able to achieve the minimum
revenue requirements provided for in the credit facility. Our failure to satisfy the revenue, or any other, covenant
could result in an event of default under the loan.

The credit facility also includes events of default, the occurrence and continuation of which could cause
interest to be charged at the rate that is otherwise applicable plus 5% and would provide Oxford, as collateral
agent, with the right to exercise remedies against us and the collateral securing the credit facility, including
foreclosure against the property securing the credit facility, including our cash. These events of default include,
among other things, our failure to pay principal or interest due under the credit facility, a breach of certain
covenants under the credit facility, our insolvency, a material adverse change, the occurrence of any default
under certain other indebtedness in an amount greater than $500,000 and one or more judgments against us in an
amount greater than $500,000 individually or in the aggregate that remains unsatisfied, unvacated, or unstayed
for a period of 10 days after its entry.

Risks Related to Commercialization of our Product Candidates

We have limited experience as a company in marketing or distributing pharmaceutical products. If we are
unable to expand our marketing and sales capabilities and successfully commercialize NERLYNX, our
business, results of operations and financial condition may be materially adversely affected.

A key part of our strategy is to continue to build our sales, marketing and distribution capabilities to
commercialize NERLYNX successfully in the United States. In order to market NERLYNX successfully, we
must continue to build our sales, marketing, managerial, compliance, and related capabilities or make
arrangements with third parties to perform these services. If we are unable to establish and maintain adequate
sales, marketing, and distribution capabilities, whether independently or with third parties, we may not be able to
commercialize NERLYNX appropriately and may not become profitable.

42

In the United States, we rely on a direct sales force. NERLYNX is a marketed drug and none of the
members of our sales force had ever promoted NERLYNX prior to its commercial launch. There are risks with
establishing, growing and maintaining our own sales and marketing capabilities, including:

•

•

•

•

•

•

•

•

the expense and time required to recruit and train a sales force;

our inability to recruit, retain or motivate adequate numbers of effective and qualified sales and
marketing personnel;

the inability to provide adequate training to sales and marketing personnel;

the need to train our sales force to ensure that a consistent and appropriate message about NERLYNX
is being delivered to our potential customers;

the inability of sales personnel to obtain access to physicians or convince adequate numbers of
physicians to prescribe any product;

our inability to equip the sales force with effective materials, including medical and sales literature, to
help them inform and educate physicians and patients about the benefits of NERLYNX and its proper
administration;

unforeseen costs and expenses associated with creating an independent sales and marketing
organization; and

the premature or unnecessary incurrence of significant commercialization expenses if the commercial
launch of a product is delayed or does not occur for any reason.

If we are unable to effectively address these risks, our efforts to commercialize NERLYNX successfully

could be harmed, which would negatively impact our ability to generate product revenue.

Additionally, we will need to maintain and further develop our sales force to achieve commercial success,

and we will be competing with other pharmaceutical and biotechnology companies to recruit, hire, train and
retain marketing and sales personnel. In the event we are unable to continue to develop and effectively maintain
our commercial team, including our U.S. sales force, our ability to successfully commercialize NERLYNX
would be limited, and we would not be able to generate product revenue successfully.

Similarly, if we enter into arrangements with third parties to perform sales, marketing and distribution
services, our product revenue or the profitability associated with any product revenue may be lower than if we
were to market and sell any products that we develop ourselves. In addition, we may not be successful in entering
into arrangements with third parties to sell and market our products or may be unable to do so on terms that are
favorable to us. We may have little control over such third parties, and any of them may fail to devote the
necessary resources and attention to sell and market our products effectively. Moreover, we may be negatively
impacted by other factors outside of our control relating to such third parties, including, but not limited to, their
inability to comply with regulatory requirements. If we do not establish sales, marketing and distribution
capabilities successfully, either on our own or in collaboration with third parties, we will not be successful in
commercializing our products.

We depend on a limited number of customers for a significant amount of our total revenue, and if we lose any
of our significant customers, our business could be harmed.

The majority of our revenue comes from a limited number of customers. In 2020, two customers

individually comprised approximately 33% and 21%, respectively, of our total product revenue. We expect that
revenue from a limited number of customers will continue to account for a large portion of our revenue in the
future. The loss by us of any of these customers, or a material reduction in their purchases or their market
pricing, could harm our business, results of operations, financial condition and prospects. In addition, if any of
these customers were to fail to pay us in a timely manner, it could harm our cash flow.

43

Even though the FDA and EC have granted approval of NERLYNX for the extended adjuvant treatment of
early stage, HER2-positive breast cancer and the FDA has granted approval for NERLYNX for the treatment
of metastatic HER2-positive breast cancer, the terms of the approvals may limit its commercial potential.

Even though the FDA and EC have granted approval of NERLYNX, the scope and terms of the approvals

may limit our ability to commercialize NERLYNX and, therefore, our ability to generate substantial sales
revenue. The FDA and EC have both approved NERLYNX for the extended adjuvant treatment of early stage,
HER2-positive breast cancer in patients who are less than one year from the completion of prior adjuvant
trastuzumab-based therapy. In connection with the FDA and EC approvals, we have committed to conduct
certain post-marketing studies. We have completed the post-marketing commitments related to the FDA
approval, and the post-marketing studies related to the EC approval are ongoing. If we fail to comply with all of
our post-marketing commitments, or if the results of the post-marketing studies, or any other ongoing clinical
studies of NERLYNX, are negative, the FDA or the EC could decide to withdraw its respective approval, add
warnings or narrow the approved indication in the product label.

Regulatory approval for any approved product is limited by the FDA to those specific indications and
conditions for which clinical safety and efficacy have been demonstrated as set forth on the product label. If
we market NERLYNX for uses beyond such approved indications, we could be subject to enforcement action,
which could have a material adverse effect on our business.

The FDA strictly regulates marketing, labeling, advertising and promotion of prescription drugs. These

regulations include standards and restrictions for direct-to-consumer advertising, industry-sponsored scientific
and educational activities, promotional activities involving the internet and off-label promotion. Any regulatory
approval that the FDA grants is limited to those specific diseases and indications for which a product is deemed
to be safe and effective by the FDA. For example, the FDA-approved label for NERLYNX is limited to the
extended adjuvant treatment of adult patients with early stage, HER2-positive breast cancer following adjuvant
trastuzumab-based therapy, and in combination with capecitabine, to the treatment of adult patients with
advanced or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2 based
regimens in the metastatic setting. In addition to the FDA approval required for new formulations, any new
indication for an approved product also requires FDA approval. If we are not able to obtain FDA approval for
any desired future indications for our drugs and drug candidates, our ability to effectively market and sell our
products may be reduced and our business may be adversely affected.

While physicians in the United States may choose, and are generally permitted, to prescribe drugs for uses

that are not described in the product’s labeling and for uses that differ from those tested in clinical trials and
approved by the regulatory authorities, our ability to promote the products is narrowly limited to those
indications that are specifically approved by the FDA. These “off-label” uses are common across medical
specialties and may constitute an appropriate treatment for some patients in varied circumstances. For example,
in April 2018, we announced that NERLYNX (neratinib) has been included as a recommended treatment option
in the latest NCCN Clinical Practice Guidelines in Oncology Central Nervous System Cancers for Breast Cancer
patients with brain metastases. The NCCN designated NERLYNX in combination with capecitabine as a
category 2A treatment option and NERLYNX in combination with paclitaxel as a category 2B treatment option.
Use, as designated for breast cancer patients with brain metastases, is outside the FDA approved indication for
NERLYNX and considered investigational, and we do not market or promote NERLYNX for these uses.
Regulatory authorities in the United States generally do not regulate the behavior of physicians in their choice of
treatments. Regulatory authorities do, however, restrict communications by pharmaceutical companies on the
subject of off-label use. Although recent court decisions suggest that certain off-label promotional activities may
be protected under the First Amendment, the scope of any such protection is unclear. If our promotional activities
fail to comply with the FDA’s regulations or guidelines, we may be subject to warnings from, or enforcement
action by, these authorities. In addition, our failure to follow FDA rules and guidelines relating to promotion and
advertising may cause the FDA to issue warning letters or untitled letters, bring an enforcement action against us,
suspend or withdraw an approved product from the market, require a recall or institute fines or civil fines, or

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could result in disgorgement of money, operating restrictions, injunctions or criminal prosecution, any of which
could harm our reputation and our business.

Health care reform measures may hinder or prevent our products’ and product candidates’ commercial
success.

The United States and some foreign jurisdictions have enacted or are considering enacting a number of
legislative and regulatory proposals to change the healthcare system in ways that could affect our ability to
profitably sell our product and product candidates, if and when they are approved. Among policy makers and
payors in the United States and elsewhere, there is significant interest in promoting changes in healthcare
systems with the stated goals of containing healthcare costs, improving quality and/or expanding access. In the
United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly
affected by major legislative initiatives.

In March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and

Education Reconciliation Act, or collectively, the ACA, became law in the United States. The ACA substantially
changed and will continue to change the way healthcare is financed by both governmental and private insurers
and significantly affects the pharmaceutical industry. Among the provisions of the ACA, of greatest importance
to the pharmaceutical industry are the following:

•

•

•

•

•

•

•

•

•

•

an annual, nondeductible fee on any entity that manufactures or imports certain branded prescription
drugs and biologic agents, apportioned among these entities according to their market share in certain
government healthcare programs;

an increase in the rebates a manufacturer must pay under the Medicaid Drug Rebate Program to 23.1%
and 13% of the average manufacturer price for branded and generic drugs, respectively;

a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate
Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected;

a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer
point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during
their coverage gap period, as a condition for the manufacturers’ outpatient drugs to be covered under
Medicare Part D;

extension of manufacturers’ Medicaid rebate liability to covered drugs dispensed to individuals who
are enrolled in Medicaid managed care organizations;

expansion of eligibility criteria for Medicaid programs by, among other things, allowing states to offer
Medicaid coverage to additional individuals, which began in April 2010, and by adding new eligibility
categories for certain individuals with income at or below 133% of the Federal Poverty Level
beginning in 2014, thereby potentially increasing manufacturers’ Medicaid rebate liability;

increase in the number of entities eligible for discounts under the Public Health Service pharmaceutical
pricing program;

a new requirement to annually report drug samples that manufacturers and distributors provide to
physicians;

a licensure framework for follow-on biologic products; and

a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct
comparative clinical effectiveness research, along with funding for such research.

Since its enactment, there have been judicial and Congressional challenges to certain aspects of the ACA.
As a result, there have been delays in the implementation of, and action taken to repeal or replace, certain aspects
of the ACA. By way of example, the Tax Cuts and Job Act was enacted, which, among other things, removes the

45

penalties for not complying with the ACA’s individual mandate to carry health insurance. On December 14,
2018, a U.S. District Court Judge in the Northern District of Texas, ruled that the individual mandate is a critical
and inseverable feature of the ACA, and therefore, because it was repealed as part of the Tax Act, the remaining
provisions of the ACA are invalid as well. On December 18, 2019, the U.S. Court of Appeals for the Fifth Circuit
ruled that the individual mandate was unconstitutional and remanded the case back to the District Court to
determine whether the remaining provisions of the ACA are invalid as well. The U.S. Supreme Court is currently
reviewing the case, although it remains unclear when or how the Supreme Court will rule. It is also unclear how
other efforts to challenge, repeal or replace the ACA will impact the ACA or our business. We cannot predict the
ultimate content, timing or effect of any healthcare reform legislation or the impact of potential legislation on us.

In addition, other legislative changes have been proposed and adopted in the United States since the ACA

was enacted. For example, the Budget Control Act of 2011 resulted in aggregate reductions to Medicare
payments to providers of 2% per fiscal year, which went into effect on April 1, 2013 and, due to subsequent
legislative amendments, will remain in effect through 2030, with the exception of a temporary suspension from
May 1, 2020 through March 31, 2021, unless additional Congressional action is taken. On January 2, 2013, the
American Taxpayer Relief Act of 2012, among other things, also reduced Medicare payments to several
providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of
limitations period for the government to recover overpayments to providers from three to five years. Recently,
there has been heightened governmental scrutiny over the manner in which drug manufacturers set prices for
their marketed products, which has resulted in several Congressional inquiries and proposed bills designed to,
among other things, bring more transparency to product pricing, review the relationship between pricing and
manufacturer patient programs, and reform government program reimbursement methodologies for drug
products. For example, the 21st Century Cures Act changes the reimbursement methodology for infusion drugs
and biologics furnished through durable medical equipment in an attempt to remedy over- and underpayment of
certain drugs. We cannot predict all of the ways in which future federal or state legislative or administrative
changes relating to healthcare reform will affect our business.

Individual states in the United States have also become increasingly active in passing legislation and
implementing regulations designed to control pharmaceutical and biological product pricing, including price or
patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure
and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk
purchasing. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding
procedures to determine what pharmaceutical products and which suppliers will be included in their prescription
drug and other healthcare programs.

We anticipate that other healthcare reform measures that may be adopted in the future may result in
additional reductions in Medicare and other healthcare funding, more rigorous coverage criteria, new payment
methodologies and additional downward pressure on the price that we receive for any approved product, and
could seriously harm our business. Any reduction in reimbursement from Medicare or other government
programs may result in a similar reduction in payments from private payors. The implementation of cost
containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain
profitability or commercialize our product and product candidates, if approved.

In the EU, similar political, economic and regulatory developments may affect our ability to profitably
commercialize NERLYNX and our other product candidates, if approved. In addition to continuing pressure on
prices and cost containment measures, legislative developments at the EU or member state level may result in
significant additional requirements or obstacles that may increase our operating costs. The delivery of healthcare
in the EU, including the establishment and operation of health services and the pricing and reimbursement of
medicines, is almost exclusively a matter for national, rather than EU, law and policy. National governments and
health service providers have different priorities and approaches to the delivery of health care and the pricing and
reimbursement of products in that context. In general, however, the healthcare budgetary constraints in most EU
member states have resulted in restrictions on the pricing and reimbursement of medicines by relevant health

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service providers. Coupled with ever-increasing EU and national regulatory burdens on those wishing to develop
and market products, this could restrict or regulate post-approval activities and affect our ability to
commercialize NERLYNX and our other product candidates, if approved. In international markets,
reimbursement and healthcare payment systems vary significantly by country, and many countries have instituted
price ceilings on specific products and therapies.

We cannot predict the likelihood, nature or extent of government regulation that may arise from future
legislation or administrative action, either in the United States or abroad. If we or our collaborators are slow or
unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we or
our collaborators are not able to maintain regulatory compliance, NERLYNX may lose any regulatory approval
that may have been obtained and we may not achieve or sustain profitability.

Failure to obtain or maintain adequate coverage and reimbursement for our products or product candidates,
if approved, could limit our ability to market those products and decrease our ability to generate revenue.

Successful commercial sales of any approved products will depend on the availability of adequate coverage

and reimbursement from government health administration authorities, private health insurers and other third-
party payors. Each third-party payor separately decides which products it will cover and establishes the
reimbursement level, and there is no guarantee that any of our approved products or product candidates that may
be approved for marketing by regulatory authorities will receive adequate coverage or reimbursement levels.
Obtaining and maintaining coverage approval for a product is time-consuming, costly and may be difficult. We
may be required to conduct expensive pharmacoeconomic studies to justify coverage and reimbursement or the
level of coverage and reimbursement relative to other therapies. If coverage and adequate reimbursement are not
available or limited, we may not be able to successfully commercialize any product or product candidate for
which we obtain marketing approval. Government authorities and third-party payors have attempted to control
costs by limiting coverage and the amount of reimbursement for particular medications. Increasingly, third-party
payors are requiring that drug companies provide them with predetermined discounts from list prices and are
challenging the prices charged for drugs and biologics. Even if we obtain coverage for a given product, the
resulting reimbursement rates may be inadequate and may affect the demand for, or the price of, any product
candidate for which we obtain marketing approval.

We expect to experience pricing pressures in connection with the sale of our current or future commercial

products, due to the trend toward managed healthcare, the increasing influence of health maintenance
organizations and additional legislative proposals. There may be additional pressure by payors and healthcare
providers to use generic drugs that contain the active ingredients found in neratinib or any other drug candidates
that we may develop. If we fail to successfully secure and maintain adequate coverage and reimbursement for our
products or are significantly delayed in doing so, we will have difficulty achieving market acceptance of our
products and expected revenue and profitability which would have a material adverse effect on our business,
results of operations and financial condition.

We are subject to federal and state healthcare fraud and abuse laws, false claims laws and physician payment
transparency laws. Failure to comply with these laws may subject us to substantial penalties.

We do not and will not control referrals of healthcare services or bill directly to Medicare, Medicaid or other

third-party payors. However, federal and state healthcare laws and regulations pertaining to fraud and abuse and
physician payment transparency laws and regulations apply to us depending on programs we operate and have
been asserted by the government and others to apply to companies like us, and our arrangements with healthcare
providers, customers and other entities, including our marketing practices, educational programs and pricing
policies. These laws include:

•

the federal Anti-Kickback Statute, which prohibits, among other things, persons or entities from
knowingly and willfully soliciting, receiving, offering or paying remuneration, directly or indirectly, in

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•

•

•

•

•

exchange for or to induce either the referral of an individual for, or the purchase, order or
recommendation of, any good or service for which payment may be made under federal healthcare
programs, such as the Medicare and Medicaid programs. A person or entity does not need to have
actual knowledge of the federal Anti-Kickback Statute or specific intent to violate it to have committed
a violation.;

federal false claims laws, including, without limitation, the False Claims Act, which prohibit, among
other things, individuals or entities from knowingly presenting, or causing to be presented, claims for
payment from Medicare, Medicaid or other federal third-party payors that are false or fraudulent, such
as engaging in improper promotion of products or submitting inaccurate price reports to the Medicaid
Drug Rebate program. In addition, the government may assert that a claim including items or services
resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim
for purposes of the False Claims Act;

the federal Civil Monetary Penalties law, which prohibits, among other things, offering or transferring
remuneration to a federal healthcare beneficiary that a person knows or should know is likely to
influence the beneficiary’s decision to order or receive items or services reimbursable by the
government from a particular provider or supplier;

federal criminal laws that prohibit executing a scheme to defraud any federal healthcare benefit
program or making false statements relating to healthcare matters; similar to the federal Anti-Kickback
Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to
violate it to have committed a violation;

the federal Physician Payment Sunshine Act, which requires manufacturers of drugs, devices, biologics
and medical supplies for which payment is available under Medicare, Medicaid or the Children’s
Health Insurance Program (with certain exceptions) to report annually to Centers for Medicare &
Medicaid Services, or CMS, information related to payments or other “transfers of value” made to
physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), certain
other healthcare professionals starting in 2022, and teaching hospitals, and requires applicable
manufacturers and group purchasing organizations to report annually to CMS ownership and
investment interests held by the physicians described above and their immediate family members and
payments or other “transfers of value” to such physician owners (manufacturers are required to submit
reports to CMS by the 90th day of each calendar year);

analogous state equivalents of each of the above federal laws, such as anti-kickback and false claims
laws which may apply to sales or marketing arrangements and claims involving healthcare items or
services reimbursed by any third-party payor, including commercial insurers; state laws that require
pharmaceutical companies to comply with the industry’s voluntary compliance guidelines and the
applicable compliance guidance promulgated by the federal government or otherwise restrict payments
that may be made to healthcare providers and other potential referral sources; and state laws that
require drug manufacturers to report information related to payments and other transfers of value to
physicians and other healthcare providers or marketing expenditures and pricing information;; and

• European and other foreign law equivalents of each of these laws, including reporting requirements

detailing interactions with and payments to healthcare providers.

Because of the breadth of these laws and the narrowness of the statutory exceptions and safe harbors
available under such laws, it is possible that some of our business activities, including our relationships with
physicians and other healthcare providers, some of whom recommend, purchase and/or prescribe our products,
and the manner in which we promote our products, could be subject to challenge under one or more of such laws.

We are also exposed to the risk that our employees, independent contractors, principal investigators,
consultants, vendors, distributors and agents may engage in fraudulent or other illegal activity. While we have
policies and procedures in place prohibiting such activity, misconduct by these parties could include, among

48

other infractions or violations, intentional, reckless and/or negligent conduct or unauthorized activity that violates
FDA requirements, including those laws that require the reporting of true, complete and accurate information to
the FDA, manufacturing standards, federal and state healthcare fraud and abuse laws and regulations, laws that
require the true, complete and accurate reporting of financial information or data or other commercial or
regulatory laws or requirements. It is not always possible to identify and deter misconduct by our employees and
other third parties, and the precautions we take to detect and prevent this activity may not be effective in
controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other
actions or lawsuits stemming from a failure to be in compliance with such laws or regulations.

If our operations are found to violate any of the laws described above or any other laws and regulations that
apply to us, we may be subject to penalties, including civil and criminal penalties, damages, fines, disgorgement,
the curtailment or restructuring of our operations, the exclusion from participation in federal and state healthcare
programs and imprisonment of officers involved, any of which could adversely affect our ability to market our
current and any future products, once approved, and materially adversely affect our business, results of
operations and financial condition. Any action against us for violation of these laws, even if we successfully
defend against it, could cause us to incur significant legal expenses and divert our management’s attention from
the operation of our business.

If we fail to comply with our reporting and payment obligations under the Medicaid Drug Rebate Program or
other governmental pricing programs in the United States, we could be subject to additional reimbursement
requirements, penalties, sanctions and fines, which could have a material adverse effect on our business,
results of operations and financial condition.

We participate in the Medicaid Drug Rebate Program, as administered by CMS, and other federal and state

government pricing programs in the United States, and we may participate in additional government pricing
programs in the future. These programs generally require us to pay rebates or otherwise provide discounts to
government payors in connection with drugs, including NERLYNX, that are dispensed to beneficiaries of these
programs. In some cases, such as with the Medicaid Drug Rebate Program, the rebates are based on pricing and
rebate calculations that we report on a monthly and quarterly basis to the government agencies that administer
the programs. Pricing and rebate calculations are complex, vary among products and programs, and are often
subject to interpretation by governmental or regulatory agencies and the courts. The terms, scope and complexity
of these government pricing programs change frequently. Responding to current and future changes may increase
our costs and the complexity of compliance will be time consuming.

In addition, there is increased focus by the Office of Inspector General on the methodologies used by
manufacturers to calculate average manufacturer price, or AMP, and best price, or BP, to assess manufacturer
compliance with reporting requirements under the Medicaid Drug Rebate Program. We are liable for errors
associated with our submission of pricing data and for any overcharging of government payors. For example,
failure to submit monthly/quarterly AMP and BP data on a timely basis could result in a civil monetary penalty
per day for each day the submission is late beyond the due date. Failure to make necessary disclosures and/or to
identify overpayments could result in allegations against us under the Federal False Claims Act and other laws
and regulations.

Any required refunds to the U.S. government or responding to a government investigation or enforcement

action would be expensive and time consuming and could have a material adverse effect on our business, results
of operations and financial condition. In the event that CMS were to terminate our rebate agreement, no federal
payments would be available under Medicaid or Medicare for our covered outpatient drugs.

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Risks Related to the Discovery and Development of our Products

Interim, “topline” and preliminary data from our clinical trials that we announce or publish from time to time
may change as more patient data become available and are subject to audit and verification procedures that
could result in material changes in the final data.

From time to time, we may publicly disclose preliminary or topline data from our preclinical studies and
clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings
and conclusions are subject to change following a more comprehensive review of the data related to the
particular study or trial. We also make assumptions, estimations, calculations and conclusions as part of our
analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As
a result, the topline or preliminary results that we report may differ from future results of the same studies, or
different conclusions or considerations may qualify such results, once additional data have been received and
fully evaluated. Preliminary and topline data also remain subject to audit and verification procedures that may
result in the final data being materially different from the preliminary data we previously published.
Consequently, preliminary and topline data should be viewed with caution until the final data are available.

Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical

outcomes may materially change as patient enrollment continues and more patient data become available.
Adverse differences between preliminary or interim data and final data could significantly harm our business
prospects. Further, disclosure of interim data by us or by our competitors could result in volatility in the price of
our common stock after this offering.

In addition, others, including regulatory agencies, may not accept or agree with our assumptions, estimates,

calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could
impact the value of the particular program, the approvability or commercialization of the particular product
candidate or product and our company in general. In addition, the information we choose to publicly disclose
regarding a particular study or clinical trial is based on what is typically extensive information, and you or others
may not agree with what we determine is material or otherwise appropriate information to include in our
disclosure.

If the interim, topline, or preliminary data that we report differ from actual results, or if others, including

regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and
commercialize, our product candidates may be harmed, which could harm our business, operating results,
prospects or financial condition.

NERLYNX or our other drug candidates may cause undesirable side effects or have other properties when
used alone or in combination with other approved products or investigational new drugs that could delay or
prevent their regulatory approval, limit the commercial profile of an approved label, or result in significant
negative consequences following marketing approval, if any, as applicable.

Undesirable side effects caused by NERLYNX or our other drug candidates could cause us or regulatory

authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or
denial of regulatory approval by the FDA or other comparable foreign authorities. To date, subjects treated with
NERLYNX have experienced drug-related side effects including diarrhea. Results of our trials could reveal a
high and unacceptable severity and prevalence of these or other side effects. In such an event, our trials could be
suspended or terminated and the FDA or comparable foreign regulatory authorities could order us to cease
further development of or deny approval of our product candidates for any or all targeted indications. The drug-
related side effects could affect patient recruitment or the ability of enrolled patients to complete clinical trials or
result in potential product liability claims. Any of these occurrences may harm our business, financial condition
and prospects significantly.

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Additionally, if we or others later identify undesirable side effects caused by any approved product,
including in combination with other approved products or investigational new drugs, a number of potentially
significant negative consequences could result, including:

•

•

regulatory authorities may withdraw approvals of such product;

regulatory authorities may require additional warnings on the label;

• we may be required to create a medication guide outlining the risks of such side effects for distribution

to patients;

• we could be sued and held liable for harm caused to patients; and

•

our reputation may suffer.

Any of these events could prevent us from achieving or maintaining market acceptance of NERLYNX or
the particular product candidate, if approved, and could significantly harm our business, results of operations and
prospects.

NERLYNX is still under clinical development for various additional indications, and we cannot be certain that
NERLYNX will receive regulatory approval for any other indication for which we may seek approval.

The FDA and the EC have both approved NERLYNX for the extended adjuvant treatment of adult patients
with early stage hormone receptor positive HER2-overexpressed/amplified breast cancer and who are less than
one year from the completion of prior adjuvant trastuzumab-based therapy. In February 2020, the FDA also
approved NERLYNX in combination with capecitabine, for the treatment of adult patients with advanced or
metastatic HER2-positive breast cancer who have received two or more prior anti-HER2 based regimens in the
metastatic setting. We expect that a substantial portion of our efforts and expenditures over the next few years
will be devoted to the development of NERLYNX in various additional indications. Accordingly, our business
currently depends heavily on the successful development and regulatory approval of NERLYNX for additional
indications. The research, testing, manufacturing, labeling, approval, sale, marketing and distribution of drug
products are and will remain subject to extensive regulation by the FDA and other regulatory authorities in the
United States and other countries that each have differing regulations. We are not permitted to market
NERLYNX for other indications or any of our other drug candidates in the United States until we receive
approval of an NDA from the FDA or in the EU until we receive approval from the EC, as applicable, for such
indications, or, in any foreign countries, until requisite approval from such countries.

Approval of NERLYNX by the FDA or the EC for any particular indication does not ensure that a foreign

jurisdiction will also approve NERLYNX for such indication, nor does it ensure that NERLYNX will be
approved by the FDA for any other indications. Obtaining approval of an NDA or foreign marketing application
is an extensive, lengthy, expensive and inherently uncertain process, and the FDA or a foreign regulator may
delay, limit or deny approval of a drug candidate for many reasons, including:

• we may not be able to demonstrate that NERLYNX or any other drug candidate is safe and effective as

a treatment for our targeted indications to the satisfaction of the FDA or other regulator;

•

•

•

the results of our clinical trials may not meet the level of statistical or clinical significance required by
the FDA or other regulator for marketing approval;

the FDA or other regulator may disagree with the number, design, size, conduct or implementation of
our clinical trials;

the clinical research organization, or CRO, that we retain to conduct clinical trials or any other third
parties involved in the conduct of trials may take actions outside of our control that materially
adversely impact our clinical trials;

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•

•

•

•

•

•

•

•

the FDA or other regulator may not find the data from pre-clinical studies and clinical trials sufficient
to demonstrate that the clinical and other benefits of NERLYNX or any other drug candidate outweigh
the safety risks;

the FDA or other regulator may disagree with our interpretation of data from our pre-clinical studies
and clinical trials or may require that we conduct additional studies or trials;

the FDA or other regulator may not accept data generated at our clinical trial sites;

if our NDA is reviewed by an advisory committee, the FDA may have difficulties scheduling an
advisory committee meeting in a timely manner or the advisory committee may recommend against
approval of our application or may recommend that the FDA require, as a condition of approval,
additional pre-clinical studies or clinical trials, limitations on approved labeling or distribution and use
restrictions;

the advisory committee may recommend that the FDA require, as a condition of approval, additional
pre-clinical studies or clinical trials, limitations on approved labeling or distribution and use
restrictions;

the FDA may require development of a Risk Evaluation and Mitigation Strategy as a condition of
approval;

the FDA or other regulator may identify deficiencies in the manufacturing processes or facilities of our
third-party manufacturers; or

the FDA or other regulator may change its approval policies or adopt new regulations.

If we do not obtain regulatory approval of NERLYNX for other indications, whether in the United States or
in other jurisdictions, we will not be able to market NERLYNX for such indications in those jurisdictions, which
will limit our commercial revenue.

Even though the FDA has approved NERLYNX for the extended adjuvant treatment of early stage, HER2-
positive breast cancer in adult patients following adjuvant trastuzumab-based therapy, and in combination
with capecitabine, for the treatment of adult patients with advanced or metastatic HER2-positive breast cancer
who have received two or more prior anti-HER2 based regimens in the metastatic setting, we will be subject to
ongoing obligations and continued regulatory review with regard to NERLYNX and any other drug candidates
that receive FDA approval, which may result in significant additional expense. Additionally, NERLYNX and
our drug candidates, if approved, could be subject to labeling and other restrictions and market withdrawal
and we may be subject to penalties if we fail to comply with regulatory requirements or experience
unanticipated problems with our products.

The FDA’s approval of the NDA for NERLYNX and any regulatory approvals that we receive for our other

drug candidates may also be subject to limitations on the approved indicated uses for which the product may be
marketed or to the conditions of approval, or contain requirements for potentially costly post-marketing testing,
including Phase IV clinical trials, and surveillance to monitor the safety and efficacy of the drug candidate. In
addition, the manufacturing processes, labeling, packaging, distribution, adverse event reporting, storage,
advertising, promotion and recordkeeping for the product will be subject to extensive and ongoing regulatory
requirements. These requirements include submissions of safety and other post-marketing information and
reports, registration, as well as continued compliance with cGMPs and GCPs for any clinical trials that we
conduct post-approval. Later discovery of previously unknown problems with a product, including adverse
events of unanticipated severity or frequency, or with our third-party manufacturers or manufacturing processes,
or failure to comply with regulatory requirements, may result in, among other things:

•

•

restrictions on the marketing or manufacturing of the product, withdrawal of the product from the
market, or voluntary or mandatory product recalls;

fines, warning letters or holds on clinical trials;

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•

•

•

refusal by the FDA to approve pending applications or supplements to approved applications filed by
us, or suspension or revocation of product license approvals;

product seizure or detention, or refusal to permit the import or export of products; and

injunctions or the imposition of civil or criminal penalties.

The FDA’s policies may change and additional government regulations may be enacted that could prevent,

limit or delay regulatory approval of our drug candidates. If we are slow or unable to adapt to changes in existing
requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory
compliance, we may lose any marketing approval that we may have obtained, which would adversely affect our
business, prospects and ability to achieve or sustain profitability.

We also cannot predict the likelihood, nature or extent of government regulation that may arise from future
legislation or administrative or executive action, either in the United States or abroad. For example, the results of
the 2020 Presidential Election may impact our business and industry. Namely, the Trump administration has
taken several executive actions, including the issuance of a number of Executive Orders, that could impose
significant burdens on, or otherwise materially delay, FDA’s ability to engage in routine regulatory and oversight
activities such as implementing statutes through rulemaking, issuance of guidance, and review and approval of
marketing applications. It is difficult to predict whether or how these Executive Orders will be implemented, or
whether they will be rescinded or replaced under a Biden Administration. The policies and priorities of an
incoming administration are unknown and could materially impact the regulations governing our products.

Disruptions at the FDA and other government agencies caused by funding shortages or global health
concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise
prevent new or modified products from being developed, approved or commercialized in a timely manner or at
all, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors,

including government budget and funding levels, statutory, regulatory, and policy changes, the FDA’s ability to
hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the
FDA’s ability to perform routine functions. Average review times at the FDA have fluctuated in recent years as a
result. In addition, government funding of other government agencies that fund research and development
activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA
and other agencies may also slow the time necessary for new drugs or modifications to approved drugs to be
reviewed and/or approved by necessary government agencies, which would adversely affect our business. For
example, over the last several years, including for 35 days beginning on December 22, 2018, the U.S.
government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough
critical FDA employees and stop critical activities.

Separately, in response to the COVID-19 pandemic, on March 10, 2020 the FDA announced its intention to

postpone most inspections of foreign manufacturing facilities, and on March 18, 2020, the FDA temporarily
postponed routine surveillance inspections of domestic manufacturing facilities. Subsequently, on July 10, 2020
the FDA announced its intention to resume certain pre-announced, on-site inspections of domestic manufacturing
facilities subject to a risk-based prioritization system. The FDA intends to use this risk-based assessment system
to identify the categories of regulatory activity that can occur within a given geographic area, ranging from
mission critical inspections to resumption of all regulatory activities. Regulatory authorities outside the United
States may adopt similar restrictions or other policy measures in response to the COVID-19 pandemic. If a
prolonged government shutdown occurs, or if global health concerns continue to prevent the FDA or other
regulatory authorities from conducting their regular inspections, reviews, or other regulatory activities, it could
significantly impact the ability of the FDA or other regulatory authorities to timely review and process our
regulatory submissions, which could have a material adverse effect on our business.

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Clinical trials are very expensive, time-consuming and difficult to design and implement.

Although NERLYNX has been approved by the FDA for the extended adjuvant treatment of early stage,

HER2-positive breast cancer, and in combination with capecitabine for the treatment of adult patients with
advanced or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2 based
regimens in the metastatic setting, NERLYNX is still under development for various indications in the United
States, and our other drug candidates are in development, as well, all of which will require extensive clinical
testing before we can submit any NDA for regulatory approval. We cannot predict with any certainty that any
NDA or supplemental NDA seeking to expand the indication for NERLYNX will be approved by the FDA.
Human clinical trials are very expensive and difficult to design and implement, in part because they are subject to
rigorous regulatory requirements. The clinical trial process is also time consuming. We estimate that clinical
trials of our other drug candidates will take at least several years to complete. Furthermore, failure can occur at
any stage of the trials, and we could encounter problems that cause us to abandon or repeat clinical trials. The
results of pre-clinical studies and early clinical trials of our drug candidates may not be predictive of the results
of later-stage clinical trials. Drug candidates in later stages of clinical trials may fail to show the desired safety
and efficacy traits despite having progressed through pre-clinical studies and initial clinical trials. A number of
companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to
lack of efficacy or adverse safety profiles, notwithstanding promising results in earlier trials. Our future clinical
trial results may not be successful.

We do not know whether our future clinical trials will begin on time or enroll patients on time, or whether

our ongoing and/or future clinical trials will be completed on schedule or at all. Clinical trials can be delayed for
a variety of reasons, including delays related to:

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the FDA or comparable foreign regulatory authorities disagreeing as to the design or implementation of
our clinical studies;

obtaining regulatory authorizations to commence a trial or reaching a consensus with regulatory
authorities on trial design;

any failure or delay in reaching an agreement with CROs and clinical trial sites, the terms of which can
be subject to extensive negotiation and may vary significantly among different CROs and trial sites;

obtaining approval from one or more institutional review boards, or IRBs;

IRBs refusing to approve, suspending or terminating the trial at an investigational site, precluding
enrollment of additional subjects, or withdrawing their approval of the trial;

changes to clinical trial protocol;

clinical sites deviating from trial protocol or dropping out of a trial;

• manufacturing sufficient quantities of product candidate or obtaining sufficient quantities of

combination therapies for use in clinical trials;

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subjects failing to enroll or remain in our trial at the rate we expect, or failing to return for post-
treatment follow-up;

subjects choosing an alternative treatment for the indication for which we are developing our product
candidates, or participating in competing clinical trials;

lack of adequate funding to continue the clinical trial;

subjects experiencing severe or unexpected drug-related adverse effects;

occurrence of serious adverse events in trials of the same class of agents conducted by other
companies;

selection of clinical end points that require prolonged periods of clinical observation or analysis of the
resulting data;

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a facility manufacturing our product candidates or any of their components being ordered by the FDA
or comparable foreign regulatory authorities to temporarily or permanently shut down due to violations
of current good manufacturing practice, or cGMP, regulations or other applicable requirements, or
infections or cross-contaminations of product candidates in the manufacturing process;

any changes to our manufacturing process that may be necessary or desired;

third-party clinical investigators losing the licenses or permits necessary to perform our clinical trials,
not performing our clinical trials on our anticipated schedule or consistent with the clinical trial
protocol, good clinical practices, or GCP, or other regulatory requirements;

third-party contractors not performing data collection or analysis in a timely or accurate manner; or

third-party contractors becoming debarred or suspended or otherwise penalized by the FDA or other
government or regulatory authorities for violations of regulatory requirements, in which case we may
need to find a substitute contractor, and we may not be able to use some or all of the data produced by
such contractors in support of our marketing applications.

In addition, disruptions caused by the COVID-19 pandemic may increase the likelihood that we encounter

such difficulties or delays in initiating, enrolling, conducting or completing our planned and ongoing clinical
trials. Further, we, the FDA, foreign regulatory authorities, or an IRB may suspend our clinical trials at any time
if it appears that we or our collaborators are failing to conduct a trial in accordance with regulatory requirements,
that we are exposing participants to unacceptable health risks, or if the FDA or such other regulator finds
deficiencies in our IND or comparable submissions or the conduct of these trials. Therefore, we cannot predict
with any certainty the schedule for commencement and completion of future clinical trials. If we experience
delays in the commencement or completion of our clinical trials, or if we terminate a clinical trial prior to
completion, the commercial prospects of our drug candidates could be harmed, and our ability to generate
revenue from the drug candidates may be delayed. In addition, any delays in our clinical trials could increase our
costs, slow down the approval process and jeopardize our ability to commence product sales and generate
revenue. Any of these occurrences may harm our business, financial condition and results of operations. In
addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials
may also ultimately lead to the denial of regulatory approval of our drug candidates.

Enrollment and retention of patients in clinical trials is an expensive and time-consuming process and could
be made more difficult or rendered impossible by multiple factors outside our control.

We may encounter delays in enrolling, or be unable to enroll, a sufficient number of patients to complete
any of our clinical trials, and even once enrolled we may be unable to retain a sufficient number of patients to
complete any of our trials. Patient enrollment and retention in clinical trials depends on many factors, including
the size of the patient population, the nature of the trial protocol, the existing body of safety and efficacy data
with respect to the study drug, the number and nature of competing treatments and ongoing clinical trials of
competing drugs for the same indication, the proximity of patients to clinical sites and the eligibility criteria for
the study. Furthermore, any negative results we may report in clinical trials of any of our drug candidates may
make it difficult or impossible to recruit and retain patients in other clinical studies of that same drug candidate.
Delays or failures in planned patient enrollment and/or retention may result in increased costs, program delays or
both, which could have a harmful effect on our ability to develop our drug candidates or could render further
development impossible. In addition, we expect to rely on CROs and clinical trial sites to ensure proper and
timely conduct of our future clinical trials and, while we intend to enter into agreements governing their services,
we will be limited in our ability to compel their actual performance.

The results of our clinical trials may not support our drug candidate claims.

Even if our clinical trials are completed as planned, we cannot be certain that their results will support the
safety and effectiveness of our drug candidates for our targeted indications. Success in pre-clinical testing and

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early clinical trials does not ensure that later clinical trials will be successful, and we cannot be sure that the
results of later clinical trials will replicate the results of prior clinical trials and pre-clinical testing. A failure of a
clinical trial to meet its predetermined endpoints would likely cause us to abandon a drug candidate and may
delay development of other drug candidates.

Moreover, pre-clinical and clinical data are often susceptible to varying interpretations and analyses and
many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical
trials nonetheless failed to obtain FDA, EMA or comparable foreign regulatory authority approval. We cannot
guarantee that the FDA or foreign regulatory authorities will interpret trial results as we do, and more trials could
be required before we are able to submit applications seeking approval of our product candidates. To the extent
that the results of the trials are not satisfactory to the FDA or foreign regulatory authorities for support of a
marketing application, we may be required to expend significant resources, which may not be available to us, to
conduct additional trials in support of potential approval of our product candidates. Even if regulatory approval is
secured for any of our product candidates, the terms of such approval may limit the scope and use of our product
candidate, which may also limit its commercial potential. Furthermore, the approval policies or regulations of the
FDA, EMA or comparable foreign regulatory authorities may significantly change in a manner rendering our
clinical data insufficient for approval, which may lead to the FDA, EMA or comparable foreign regulatory
authorities delaying, limiting or denying approval of our product candidates.

Risks Related to Third Parties

We are dependent on international third-party sub-licensees for the development and commercialization of
NERLYNX in several countries outside the United States. The failure of these sub-licensees to meet their
contractual, regulatory or other obligations could adversely affect our business.

We have entered into exclusive sub-license agreements with several third parties that provide these
sub-licensees exclusive rights to the development and commercialization of NERLYNX in Europe (excluding
Russia and Ukraine), Australia, Canada, China, Southeast Asia, Israel, South Korea, and various countries and
territories in Central and South America. As a result, we are entirely dependent on these parties to achieve
regulatory approval of NERLYNX for marketing in these countries and for the commercialization of
NERLYNX, if approved. The timing and amount of any milestone and royalty payments we may receive under
these agreements, as well as the commercial success of NERLYNX in those regions outside of the United States,
will depend on, among other things, the efforts, allocation of resources and successful commercialization of
NERLYNX by the licensees. We also depend on these third parties to comply with all applicable laws relative to
the development and commercialization of our products in those countries. We do not control the individual
efforts of these licensees and have limited ability to terminate these agreements if the licensees do not perform as
anticipated. The failure of these licensees to devote sufficient time and effort to the development and
commercialization of NERLYNX; to meet their obligations to us, including for future royalty and milestone
payments; to adequately deploy business continuity plans in the event of a crisis; and/or to satisfactorily resolve
significant disagreements with us or address other factors could have an adverse impact on our financial results
and operations. In addition, if these third parties violate, or are alleged to have violated, any laws or regulations
during the performance of their obligations for us, it is possible that we could suffer financial and reputational
harm or other negative outcomes, including possible legal consequences.

Any termination, breach or expiration of any of these sub-license agreements could have a material adverse
effect on our financial position by reducing or eliminating the potential for us to receive license fees, milestones
and royalties. In such an event, we may be required to devote additional efforts and to incur additional costs
associated with pursuing regulatory approval and commercialization of the applicable products and product
candidates. Alternatively, we may attempt to identify and transact with a new sub-licensee, but there can be no
assurance that we would be able to identify a suitable sub-licensee or transact on terms that are favorable to us.

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We have no experience in drug formulation or manufacturing and rely exclusively on third parties to
formulate and manufacture NERLYNX and our drug candidates, and any disruption or loss of these
relationships could delay our development and commercialization efforts.

We have no experience in drug formulation or manufacturing and do not intend to establish our own
manufacturing facilities. We lack the resources and expertise to formulate or manufacture NERLYNX and our
drug candidates. While our drug candidates were being developed by Pfizer, both the drug substance and drug
product were manufactured by third-party contractors. We are using the same third-party contractors to
manufacture, supply, store and distribute drug supplies for our clinical trials and the commercialization of
NERLYNX. If we are unable to continue our relationships with one or more of these third-party contractors, we
could experience delays in our development or commercialization efforts as we locate and qualify new
manufacturers. We intend to rely on one or more third-party contractors to manufacture the commercial supply of
our drugs. Our anticipated future reliance on a limited number of third-party manufacturers exposes us to the
following risks:

• We may be unable to identify manufacturers on acceptable terms or at all because the number of

potential manufacturers is limited, and the FDA must approve any replacement manufacturer. This
approval would require new testing and compliance inspections. In addition, a new manufacturer would
have to be educated in, or develop substantially equivalent processes for, production of our products
after receipt of FDA approval.

• Our third-party manufacturers might be unable to formulate and manufacture our drugs in the volume

and of the quality required to meet our clinical and/or commercial needs.

• Our future contract manufacturers may not perform as agreed or may not remain in the contract

manufacturing business for the time required to supply our clinical trials or to successfully produce,
store and distribute our products for commercialization, as applicable.

• The facilities used by our contract manufacturers to manufacture NERLYNX and our other drug
candidates must be approved by the FDA pursuant to inspections that are conducted following
submission of an NDA to the FDA. We do not control the manufacturing process of, and are
completely dependent on, our contract manufacturing partners for compliance with cGMP regulations
for manufacture of both active drug substances and finished drug products. If our contract
manufacturers cannot successfully manufacture material that conforms to our specifications and the
strict regulatory requirements of the FDA or others, they will not be able to secure and/or maintain
regulatory approval for their manufacturing facilities. In addition, drug manufacturers are subject to
ongoing periodic unannounced inspection by the FDA and similar non-U.S. regulatory agencies and
corresponding state agencies to ensure strict compliance with cGMP regulations and other government
regulations and corresponding foreign standards. If the FDA or a comparable foreign regulatory
authority does not approve these facilities for the manufacture of our drug candidates or if it withdraws
any such approval in the future, we may need to find alternative manufacturing facilities, which would
significantly impact our ability to develop, obtain regulatory approval for our other drug candidates, if
approved, or market NERLYNX.

•

If any third-party manufacturer makes improvements in the manufacturing process for our products, we
may not own, or may have to share, the intellectual property rights to the innovation.

Each of these risks could delay our clinical trials, the approval, if any, of our drug candidates by the FDA or

the commercialization of NERLYNX or our other drug candidates, or result in higher costs or deprive us of
potential product revenue.

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If our third-party manufacturers fail to manufacture NERLYNX in sufficient quantities and at acceptable
quality and pricing levels, or fail to fully comply with cGMP regulations, we may face delays in
commercialization or be unable to meet market demand, and may lose potential revenues.

The manufacture of NERLYNX requires significant expertise and capital investment, including the
development of advanced manufacturing techniques, process controls and the use of specialized processing
equipment. Our third-party manufacturers must comply with federal, state and foreign regulations, including the
FDA’s regulations governing cGMP, enforced by the FDA through its facilities inspection program and by
similar regulatory authorities in other jurisdictions where we do business. These requirements include, among
other things, quality control, quality assurance and the maintenance of records and documentation. The FDA or
similar foreign regulatory authorities at any time may implement new standards or change their interpretation and
enforcement of existing standards for manufacture, packaging or testing of our products. Any failure by us or our
third-party manufacturers to comply with applicable regulations may result in fines and civil penalties,
suspension of production, product seizure or recall, operating restrictions, imposition of a consent decree,
modification or withdrawal of product approval or criminal prosecution and would limit the availability of our
product. Any manufacturing defect or error discovered after products have been produced and distributed also
could result in significant consequences, including costly recall procedures, re-stocking costs, damage to our
reputation and potential for product liability claims.

If our third-party manufacturers are unable to produce the required commercial quantities of NERLYNX to
meet market demand for NERLYNX on a timely basis or at all, or if they fail to comply with applicable laws for
the manufacturing of NERLYNX, we will suffer damage to our reputation and commercial prospects and we will
lose potential revenue.

We rely on third parties to conduct our pre-clinical studies and clinical trials. If these third parties do not
successfully carry out their contractual duties or meet expected deadlines, we may not be able to obtain
regulatory approval for our drug candidates.

We depend upon independent investigators and collaborators, such as CROs, universities and medical
institutions, to conduct our pre-clinical studies and clinical trials under agreements with us. These collaborators
are not our employees and we cannot control the amount or timing of resources that they devote to our programs.
Nevertheless, we are responsible for ensuring that each of our clinical trials is conducted in accordance with
regulatory requirements, including GCP requirements, and the applicable protocol. If we, or any of our CROs or
third party contractors, fail to comply with applicable GCPs, the clinical data generated in our clinical trials may
be deemed unreliable and the FDA or comparable foreign regulatory authorities may require us to perform
additional clinical trials before approving our marketing applications. We cannot assure you that upon inspection
by a given regulatory authority, such regulatory authority will determine that any of our clinical trials comply
with GCP regulations. In addition, our clinical trials must be conducted with product produced under current
cGMP regulations. Our failure to comply with these regulations may require us to repeat clinical trials, which
would delay the regulatory approval process. Moreover, third party contractors and investigators may not assign
as great a priority to our programs or pursue them as diligently as we would if we were undertaking such
programs ourselves. If outside collaborators fail to devote sufficient time and resources to our drug-development
programs, or if their performance is substandard or otherwise fails to satisfy applicable regulatory requirements,
the approval of our FDA applications, if any, and our introduction of new drugs, if any, will be delayed. These
collaborators may also have relationships with other commercial entities, some of whom may compete with us. If
our collaborators assist our competitors to our detriment, our competitive position would be harmed. If any of our
relationships with these third-party collaborators terminate, we may not be able to enter into arrangements with
alternative third parties on commercially reasonable terms, or at all. Switching or adding additional third parties
to our clinical trial programs can involve substantial costs and require extensive management time and focus.

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Risks Related to our Business Operations

Our business, financial condition, results of operations and ongoing clinical trials have been and could
continue to be harmed by the effects of the COVID-19 pandemic.

We are subject to various risks related to the global pandemic associated with COVID-19. For example,
many geographic regions have imposed, or in the future may impose, “shelter-in-place” orders, quarantines or
similar orders or restrictions to control the spread of COVID-19. These types of restrictions have deterred and
may continue to deter or prevent cancer patients from traveling to see their doctors and result in a decline in new
patient enrollments/new patient starts and in revenue for NERLYNX, our only commercial product. Additionally,
our commercial team, field medical and sales force have been forced to suspend the majority of their travel and
personal interactions with physicians and customers, including visits to healthcare provider offices or clinics. The
commercial team and sales force are currently limited to conducting the majority of their promotional activities
virtually. The respective commercial teams of certain of the companies to which we sub-license the commercial
rights of NERLYNX, and on which we rely for our international sales, have chosen or have been forced to take
similar action, and other sub-licensees of NERLYNX may choose or be forced to take similar action.
Furthermore, the pandemic has resulted in dramatic increases in unemployment rates, which resulted in a number
of people becoming uninsured or underinsured, and this trend may continue. These developments have had and
may continue to have an adverse effect on our revenue and thus could have an adverse effect on our ability to
satisfy the minimum revenue covenants in our loan and security agreement.

Moreover, these types of restrictions have resulted in most of our other employees working from home and

the employees of our key third-party vendors and manufacturers working from home. We rely exclusively on
third-party manufacturers to manufacture NERLYNX. Neither we, nor our suppliers or manufacturers have
significant experience operating with the majority of our respective work forces working from home, and this has
disrupted and may continue to disrupt standard operations for us or them, the magnitude of which will depend, in
part, on the length and severity of the restrictions and other limitations on our respective abilities to conduct
business in the ordinary course. In addition, this may increase our cybersecurity risk, create data accessibility
concerns and make us more susceptible to communication disruptions, any of which could adversely impact our
business operations or delay necessary interactions with local and federal regulators, ethics committees,
manufacturing sites, research or clinical trial sites and other important agencies and contractors. Our business
interruption insurance, if available at all, may be insufficient to cover losses resulting from extended business
interruptions from the COVID-19 pandemic.

Additionally, timely enrollment in our clinical trials is dependent upon global clinical trial sites, which have

been and may continue to be adversely affected by the COVID-19 pandemic. We are currently conducting
clinical trials for our product candidates in many countries, including the United States, the United Kingdom,
Spain, Italy, France, South Korea, Australia, and Israel, and may expand to other geographies. Many of these
regions have been and may continue to be affected by the COVID-19 pandemic. We have observed disruptions in
patient enrollments in the United States and our SUMMIT basket trial. If the COVID-19 pandemic continues to
spread in the geographies in which we are conducting clinical trials, we may continue to experience additional
disruptions in those clinical trials, which could have a material adverse impact on our clinical trial plans and
timelines, including:

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delays in receiving authorizations from local regulatory authorities and ethics committees to initiate
planned clinical trials;

delays or difficulties in enrolling patients in our clinical trials;

delays or difficulties in clinical site initiation, including difficulties in recruiting clinical site
investigators and clinical site staff;

delays in clinical sites receiving the supplies and materials needed to conduct our clinical trials,
including interruptions in global shipping that may affect the transport of clinical trial materials;

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diversion of healthcare resources away from the conduct of clinical trials, including the diversion of
hospitals serving as our clinical trial sites and hospital staff supporting the conduct of our clinical trials;

interruption of key clinical trial activities, such as clinical trial site monitoring, due to limitations on
travel imposed or recommended by federal or state governments, employers and others, or interruption
of clinical trial subject visits and study procedures, the occurrence of which could affect the integrity of
clinical trial data;

risk that participants enrolled in our clinical trials will contract COVID-19 while the clinical trial is
ongoing, which could impact the results of the clinical trial, including by increasing the number of
observed adverse events;

delays in necessary interactions with local regulators, ethics committees and other third parties and
contractors due to limitations in employee resources or forced furlough of government employees;

limitations in employee resources that would otherwise be focused on the conduct of our clinical trials,
including because of sickness of employees or their families or the desire of employees to avoid
contact with large groups of people; and

refusal of the FDA to accept data from clinical trials in affected geographies.

The continued spread of COVID-19 has also led to extreme disruption and volatility in the global capital

markets, which increases the cost of, and adversely impacts access to, capital and increases economic
uncertainty. While COVID-19 has had an adverse impact on our business and may continue to do so, given the
rapid and evolving nature of the virus and the uncertainty about its impact on society and the global economy, we
cannot predict the extent to which it will affect our global operations, particularly if these impacts persist or
worsen over an extended period of time. To the extent the COVID-19 pandemic adversely affects our business
and financial results, it may also affect our ability to comply with certain covenants in our loan and security
agreement or other agreements that are material to our business.

Engaging in international business subjects us to additional business and regulatory risks, and there can be
no assurance that our products will be accepted in those markets.

We have entered into exclusive sub-license agreements providing for third parties to pursue regulatory
approval and commercialize NERLYNX, if approved, in various specified regions outside of the United States.
We plan to continue to pursue commercialization of NERLYNX in additional countries outside the United States
where it has been approved. Engaging in international business inherently involves a number of difficulties and
risks, including:

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competition from established companies, many of which are well-positioned within their local markets
with longer operating histories, more recognizable names and better established distribution networks;

the availability and level of coverage and reimbursement within prevailing foreign healthcare payment
systems and the ability of patients to elect to privately pay for NERLYNX and our other products, if
approved;

difficulties in enforcing intellectual property rights;

pricing pressure;

required compliance with existing and changing foreign regulatory requirements and laws;

laws and business practices favoring local companies;

longer sales and payment cycles;

difficulties in enforcing agreements and collecting receivables through certain foreign legal systems;

political and economic instability;

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foreign currency risks that could adversely affect our financial results;

potentially adverse tax consequences, tariffs and other trade barriers;

exposure to liabilities under anti-corruption and anti-money laundering laws, including the U.S.
Foreign Corrupt Practices Act, or FCPA, and similar laws and regulations in other jurisdictions;

international terrorism and anti-American sentiment;

difficulties and costs associated with staffing and managing foreign operations; and

export restrictions and controls relating to technology.

If we or our sub-licensees or third-party manufacturers are unable to address these international risks, we

may fail to establish and maintain an international presence, and our business, financial condition and results of
operations would suffer.

The failure to comply with anti-bribery, anti-corruption, and anti-money laundering laws, including the
FCPA and similar laws associated with our activities outside of the United States, could subject us to penalties
and other adverse consequences.

We are subject to the FCPA, regulations of the U.S. Office of Foreign Assets Control, the United Kingdom

Bribery Act of 2010 and other anti-corruption, anti-bribery and anti-money laundering laws around the world
where we conduct activities, including, if approved in such countries, the sale of NERLYNX. We face significant
risks and liability if we fail to comply with the FCPA and other anti-corruption and anti-bribery laws that prohibit
companies and their employees and third-party business partners, such as distributors or resellers, from
authorizing, offering or providing, directly or indirectly, improper payments or benefits to foreign government
officials, political parties or candidates, employees of public international organizations including healthcare
professionals, or private-sector recipients for the corrupt purpose of obtaining or retaining business, directing
business to any person, or securing any advantage. We currently rely on various third parties for certain services
outside the United States, including continued development of NERLYNX and, if approved, its subsequent
commercialization. We may be held liable for the corrupt or other illegal activities of these third parties and
intermediaries, our employees, representatives, contractors, partners, and agents, even if we do not explicitly
authorize such activities.

Any violation of the FCPA, other applicable anti-bribery, anti-corruption laws, and anti-money laundering

laws could result in whistleblower, adverse media coverage, investigations, loss of export privileges, severe
criminal or civil sanctions and, in the case of the FCPA, suspension or debarment from U.S. government
contracts, which could have a material and adverse effect on our reputation, business, operating results and
prospects. In addition, responding to any enforcement action or related investigation may result in a materially
significant diversion of management’s attention and resources and significant defense costs and other
professional fees.

If we fail to comply with United States export control and economic sanctions or fail to expand and maintain
an effective sales force or successfully develop our international distribution network, our business, financial
condition and operating results may be adversely affected.

When selling any products outside of the United States, including NERLYNX, we are subject to United
States export control and economic sanctions laws, the violation of which could result in substantial penalties
being imposed against us. More broadly, if we fail to comply with export control laws, any sales could fail to
grow or could decline, and our ability to grow our business could be adversely affected.

We rely significantly on information technology and any failure, inadequacy, interruption or security lapse of
that technology, including any cybersecurity incidents, could harm us.

Our internal computer systems and those of third parties with which we contract may be vulnerable to

damage from cyber-attacks, “phishing” attacks, computer viruses, unauthorized access, natural disasters,

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terrorism, war and telecommunication and electrical failures despite the implementation of security measures.
Attacks upon information technology systems are increasing in their frequency, levels of persistence,
sophistication and intensity, and are being conducted by sophisticated and organized groups and individuals with
a wide range of motives and expertise. As a result of the COVID-19 pandemic, we may also face increased
cybersecurity risks due to our reliance on internet technology and the number of our employees who are working
remotely, which may create additional opportunities for cybercriminals to exploit vulnerabilities. Furthermore,
because the techniques used to obtain unauthorized access to, or to sabotage, systems change frequently and
often are not recognized until launched against a target, we may be unable to anticipate these techniques or
implement adequate preventative measures. We may also experience security breaches that may remain
undetected for an extended period. System failures, accidents or security breaches could cause interruptions in
our operations and could result in a material disruption of our clinical activities and business operations, in
addition to possibly requiring substantial expenditures of resources to remedy. The loss of clinical trial data could
result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the
data. To the extent that any disruption or security breach were to result in a loss of, or damage to, our data or
applications, or inappropriate disclosure of confidential or proprietary information, we could incur liability and
our research and development programs and the development of our drug candidates could be delayed.

Compliance with governmental regulation and other legal obligations related to privacy, data protection and
information security could result in additional costs and liabilities to us or inhibit our ability to collect and
process data, and the failure to comply with such requirements could have a material adverse effect on our
business, financial condition or results of operations.

Privacy and data security have become significant issues in the United States, Europe and in many other
jurisdictions where we may in the future conduct our operations. As we receive, collect, process, use and store
personal and confidential data, we are subject to diverse laws and regulations relating to data privacy and
security. In the United States, numerous federal and state laws and regulations could apply to our operations or
the operations of our partners, including state data breach notification laws, state health information privacy laws,
and federal and state consumer protection laws and regulations (e.g. Section 5 of the FTC Act), that govern the
collection, use, disclosure, and protection of health-related and other personal information. In addition, we may
obtain health information from third parties (including research institutions from which we obtain clinical trial
data) that are subject to privacy and security requirements under HIPAA. Depending on the facts and
circumstances, we could be subject to criminal penalties if we knowingly obtain, use, or disclose individually
identifiable health information maintained by a HIPAA-covered entity in a manner that is not authorized or
permitted by HIPAA.

Further, certain states have also enacted data privacy and security laws. For example, in June 2018,
California enacted the California Consumer Privacy Act, or CCPA, which went into effect on January 1, 2020.
The CCPA creates individual privacy rights for California consumers and increases the privacy and security
obligations of entities handling certain personal information. The CCPA provides for civil penalties for
violations, as well as a private right of action for data breaches that is expected to increase data breach litigation.
The CCPA may increase our compliance costs and potential liability, and similar laws have been proposed at the
federal level and in other states. Further, the California Privacy Rights Act, or the CPRA, recently passed in
California. The CPRA will impose additional data protection obligations on covered businesses, including
additional consumer rights processes, limitations on data uses, new audit requirements for higher risk data, and
opt outs for certain uses of sensitive data. It will also create a new California data protection agency authorized to
issue substantive regulations and could result in increased privacy and information security enforcement. The
majority of the provisions will go into effect on January 1, 2023, and additional compliance investment and
potential business process changes may be required. Compliance with these privacy and data security
requirements is rigorous and time-intensive and may increase our cost of doing business; despite those efforts,
there is a risk that we may be subject to fines and penalties, litigation and reputational harm, which could
materially and adversely affect our business, financial condition and results of operations.

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In addition, the regulatory framework for the receipt, collection, processing, use, safeguarding, sharing and
transfer of personal and confidential data is rapidly evolving and is likely to remain uncertain for the foreseeable
future as new global privacy rules are being enacted and existing ones are being updated and strengthened. For
example, on May 25, 2018, GDPR took effect in Europe. GDPR is directly applicable in each European Union
and EEA member state and applies to companies established in the European Union and the EEA as well as
companies that collect and use personal data to offer goods or services to, or monitor the behavior of, individuals
in the European Union and the EEA. GDPR introduces more stringent data protection obligations for processors
and controllers of personal data, and penalties and fines for failure to comply with GDPR are significant,
including fines of up to €20 million or 4% of total worldwide annual turnover, whichever is higher. Relatedly,
following the departure of the United Kingdom from the European Union after the expiry of the transition period,
companies have to comply with both the GDPR and the GDPR as incorporated into United Kingdom national
law, the latter regime having the ability to separately fine up to the greater of £17.5 million or 4% of global
turnover. On January 1, 2021, the United Kingdom became a third country for the purposes of the GDPR.

If we cannot compete successfully for market share against other drug companies, we may not achieve
sufficient product revenue and our business will suffer.

The market for our drugs and drug candidates is characterized by intense competition and rapid

technological advances. NERLYNX competes, and any of our other drug candidates that receives FDA approval
will compete, with a number of existing and future drugs and therapies developed, manufactured and marketed
by others. Existing or future competing products may provide greater therapeutic convenience or clinical or other
benefits for a specific indication than our products or may offer comparable performance at a lower cost. In
addition, a large number of companies are pursuing the development of pharmaceuticals that target the same
diseases and conditions that we are targeting. If our products fail to capture and maintain market share, we may
not achieve sufficient product revenue and our business will suffer.

We compete against fully integrated pharmaceutical companies and smaller companies that are

collaborating with larger pharmaceutical companies, academic institutions, government agencies and other public
and private research organizations. Many of these competitors have oncology compounds that have already been
approved or are in development. In addition, many of these competitors, either alone or together with their
collaborative partners, operate larger research and development programs or have substantially greater financial
resources than we do, as well as significantly greater experience in the following:

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developing drugs;

undertaking pre-clinical testing and clinical trials;

obtaining FDA and other regulatory approvals of drugs;

formulating and manufacturing drugs; and

launching, marketing and selling drugs.

We may be exposed to liability claims associated with the use of hazardous materials and chemicals.

Our research and development activities may involve the controlled use of hazardous materials and
chemicals. Although we believe that our safety procedures for using, storing, handling and disposing of these
materials comply with federal, state and local laws and regulations, we cannot completely eliminate the risk of
accidental injury or contamination from these materials. In the event of such an accident, we could be held liable
for any resulting damages and any liability could materially adversely affect our business, financial condition and
results of operations. In addition, the federal, state and local laws and regulations governing the use,
manufacture, storage, handling and disposal of hazardous or radioactive materials and waste products may
require us to incur substantial compliance costs that could materially adversely affect our business, financial
condition and results of operations.

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The loss of one or more key members of our management team could adversely affect our business.

Our success and future growth depend, to a significant degree, on the skills and continued services of our

management team, in particular Alan H. Auerbach, our Chief Executive Officer and President. If Mr. Auerbach
resigns or becomes unable to continue in his present role and is not adequately replaced, our business operations
could be materially adversely affected. We do not maintain “key man” life insurance for Mr. Auerbach.

If we are unable to hire additional qualified personnel, our ability to grow our business may be harmed.

As of December 31, 2020, we had 267 employees. Our future success depends on our ability to identify,

attract, hire, train, retain and motivate other highly skilled scientific, technical, marketing, managerial and
financial personnel. Although we will seek to hire and retain qualified personnel with experience and abilities
commensurate with our needs, there is no assurance that we will succeed despite their collective efforts.
Competition for personnel is intense, and any failure to attract and retain the necessary technical, marketing,
managerial and financial personnel would have a material adverse effect on our business, prospects, financial
condition and results of operations.

We may not successfully manage our growth.

Our success will depend upon the expansion of our operations and our ability to successfully manage our

growth. Our future growth, if any, may place a significant strain on our management and on our administrative,
operational and financial resources. Our ability to manage our growth effectively will require us to implement
and improve our operational, financial and management systems and to expand, train, manage and motivate our
employees. These demands may require the hiring of additional management personnel and the development of
additional expertise by management. Any increase in resources devoted to research and product development
without a corresponding increase in our operational, financial and management systems could have a material
adverse effect on our business, financial condition and results of operations.

We may be adversely affected by the current economic environment.

Our ability to attract and retain collaborators or customers, invest in and grow our business and meet our
financial obligations depends on our operating and financial performance, which, in turn, is subject to numerous
factors, including the prevailing economic conditions and financial, business and other factors beyond our
control, such as the rate of unemployment, the number of uninsured persons in the United States and inflationary
pressures. We cannot anticipate all the ways in which the current economic climate and financial market
conditions could adversely impact our business.

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We are exposed to risks associated with reduced profitability and the potential financial instability of our

collaborators or customers, many of which may be adversely affected by volatile conditions in the financial
markets. For example, unemployment and underemployment, and the resultant loss of insurance, may decrease
the demand for healthcare services and pharmaceuticals. If fewer patients are seeking medical care because they
do not have insurance coverage, our collaboration partners or customers may experience reductions in revenues,
profitability and/or cash flow that could lead them to modify, delay or cancel orders for our products once
commercialized. If collaboration partners or customers are not successful in generating sufficient revenue or are
precluded from securing financing, they may not be able to pay, or may delay payment of, accounts receivable
that are owed to us. This, in turn, could adversely affect our financial condition and liquidity. In addition, if
economic challenges in the United States result in widespread and prolonged unemployment, either regionally or
on a national basis, a substantial number of people may become uninsured or underinsured. To the extent
economic challenges result in fewer individuals pursuing or being able to afford our products once
commercialized, our business, results of operations, financial condition and cash flows could be adversely
affected.

We may incur substantial liabilities and may be required to limit commercialization of our products in
response to product liability lawsuits and product recalls.

The testing and marketing of medical products entail an inherent risk of product liability. If we cannot
successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required
to limit commercialization of our products. If we are unable to obtain sufficient product liability insurance at an
acceptable cost to protect against potential product liability claims, the commercialization of pharmaceutical
products we develop, alone or with collaborators, could be prevented or inhibited.

Product recalls may be issued at our discretion, or at the discretion of government agencies and other
entities that have regulatory authority for pharmaceutical sales. Any recall of NERLYNX could materially
adversely affect our business by rendering us unable to sell NERLYNX for some time and by adversely affecting
our reputation.

We may in the future engage in strategic transactions that increase our capital requirements, dilute our
stockholders, cause us to incur debt or assume contingent liabilities and subject us to other risks.

We actively evaluate various strategic transactions on an ongoing basis, including licensing or otherwise

acquiring complementary products, technologies or businesses. Any potential future acquisitions or in-licensing
transactions entail numerous risks, including but not limited to:

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risks associated with satisfying the closing conditions relating to such transactions and realizing their
anticipated benefits;

increased operating expenses and cash requirements;

difficulty integrating acquired technologies, products, operations, and personnel with our existing
business;

the potential disruption of our historical core business;

diversion of management’s attention in connection with both negotiating the acquisition or license and
integrating the business, technology or product;

retention of key employees;

difficulties in assimilating employees and corporate cultures of any acquired companies;

uncertainties in our ability to maintain key business relationships of any acquired companies;

strain on managerial and operational resources;

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difficulty implementing and maintaining effective internal control over financial reporting at
businesses that we acquire, particularly if they are not located near our existing operations;

exposure to unanticipated liabilities of acquired companies or companies in which we invest;

the potential need to write down assets or recognize impairment charges; and

potential costly and time-consuming litigation, including stockholder lawsuits.

As a result of these or other problems and risks, businesses, technologies or products we acquire or invest in

or obtain licenses to may not produce the revenues, earnings or business synergies that we anticipated, acquired
or licensed product candidates or technologies may not result in regulatory approvals, and acquired or licensed
products may not perform as expected. As a result, we may incur higher costs and realize lower revenues than we
had anticipated. We cannot assure you that any acquisitions or investments we have made or may make in the
future will be completed or that, if completed, the acquired business, licenses, investments, products, or
technologies will generate sufficient revenue to offset the negative costs or other negative effects on our
business. Failure to effectively manage our growth through acquisition or in-licensing transactions could
adversely affect our growth prospects, business, results of operations, financial condition, and cash flow.

In addition, we may spend significant amounts, issue dilutive securities, assume or incur significant debt

obligations, incur large one-time expenses and acquire intangible assets or goodwill in connection with
acquisitions and in-licensing transactions that could result in significant future amortization expense and write-
offs. Moreover, we may not be able to locate suitable acquisition opportunities and this inability could impair our
ability to grow or obtain access to technology or products that may be important to the development of our
business. Other pharmaceutical companies, many of which may have substantially greater financial, marketing
and sales resources, compete with us for these opportunities. Even if appropriate opportunities are available, we
may not be able to successfully identify them or we may not have the financial resources necessary to pursue
them, and if pursued, we may be unable to structure and execute transactions in the anticipated timeframe, or at
all.

Risks Related to our Intellectual Property

We depend significantly on intellectual property licensed from Pfizer and the termination of this license would
significantly harm our business and future prospects.

We depend significantly on our license agreement with Pfizer. Our license agreement with Pfizer may be

terminated by Pfizer if we materially breach the agreement and fail to cure our breach during an applicable cure
period. Our failure to use commercially reasonable efforts to develop and commercialize licensed products in
certain specified major market countries would constitute a material breach of the license agreement. Pfizer may
also terminate the license agreement if we become involved in bankruptcy, receivership, insolvency or similar
proceedings. In the event our license agreement with Pfizer is terminated, we will lose all of our rights to develop
and commercialize the drug candidates covered by such license, which would significantly harm our business
and future prospects.

Our proprietary rights may not adequately protect our intellectual property and potential products, and if we
cannot obtain adequate protection of our intellectual property and potential products, we may not be able to
successfully market our potential products.

Our commercial success will depend in part on obtaining and maintaining intellectual property protection

for our products, formulations, processes, methods and other technologies. We will only be able to protect these
technologies and products from unauthorized use by third parties to the extent that valid and enforceable
intellectual property rights, including patents, cover them, or other market exclusionary rights and regulatory
exclusivity periods apply. The patent positions of pharmaceutical companies, like ours, can be highly uncertain
and involve complex legal and factual questions for which important legal principles remain unresolved. No

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consistent policy regarding the breadth of claims allowed in such companies’ patents has emerged to date in the
United States. The general environment for pharmaceutical patents outside the United States also involves
significant uncertainty. Accordingly, we cannot predict the breadth of claims that may be allowed (if any are
allowed at all) or enforced, or that the scope of these patent rights could provide a sufficient degree of future
protection that could permit us to gain or keep our competitive advantage with respect to these products and
technology. For example, we cannot predict:

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the degree and range of protection any patents will afford us against competitors, including whether
third parties will find ways to make, use, sell, offer to sell or import competitive products without
infringing our patents;

if and when patents will issue;

• whether or not others will obtain patents claiming inventions similar to those covered by our patents

and patent applications; or

• whether we will need to initiate litigation or administrative proceedings in connection with patent
rights, which may be costly whether we win or lose, and the outcome of which is unpredictable.

The patents we have licensed may be challenged and could be invalidated or rendered unenforceable by
third parties. There is no guarantee that a court would agree that any of the patents we have licensed, and which
are currently in force, are valid or enforceable. Challenges to the breadth or strength of protection provided by
any patents we have licensed, or patent applications we may pursue in the future, with respect to any of our
current or future product candidates or products, could threaten our ability to commercialize any of our current or
future product candidates or products. Changes in either the patent laws or in the interpretations of patent laws in
the United States or other countries may diminish the value of our intellectual property.

The patents we have licensed may be affected by certain provisions of the America Invents Act, or AIA,

enacted in 2011. For example, under the AIA, members of the public may seek to challenge an issued patent by
petitioning the USPTO to institute a post grant proceeding, such as a Post Grant Review, or PGR, or Inter Partes
Review, or IPR. Once a post grant proceeding is instituted, the USPTO may find grounds to revoke the
challenged patent or specific claims therein. A similar procedure (known as a patent opposition) has existed in
Europe for many years and we have defended, and continue to defend, our European patents in certain of those
proceedings. We cannot predict whether any other licensed patents will become the subject of a post grant
proceeding or patent opposition. If a significant product patent is successfully challenged in a post grant
proceeding or patent opposition, it may be revoked, which would have a serious negative impact on our ability to
maintain exclusivity in the market-place for our commercial products affected by such revocation and could
adversely affect our future revenues and profitability.

In addition, others may independently develop similar or alternative products and technologies that may be
outside the scope of our intellectual property. Furthermore, others may have invented technology claimed by our
patents before we or our licensors did so, and they may have filed patents claiming such technology before we
did so, weakening our ability to obtain and maintain patent protection for such technology. Should third parties
obtain patent rights to similar products or technology, this may have an adverse effect on our business.

We may also rely on trade secrets to protect our technology, especially where we do not believe patent
protection is appropriate or obtainable. Trade secrets, however, are difficult to protect. While we believe that we
will use reasonable efforts to protect our trade secrets, our own or our strategic partners’ employees, consultants,
contractors or advisors may unintentionally or willfully disclose our information to competitors. Such disclosure
could adversely affect our ability to prevent further disclosures of our trade secrets. We seek to protect this
information, in part, through the use of non-disclosure and confidentiality agreements with employees,
consultants, advisors and others. These agreements may be breached, and we may not have adequate remedies for
a breach. In addition, we cannot ensure that those agreements will be enforceable, provide adequate protection
for our trade secrets, know-how or other proprietary information, or prevent their unauthorized use or disclosure.

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To the extent that consultants or key employees apply technological information independently developed

by them or by others to our potential products, disputes may arise as to the proprietary rights in such information,
which may not be resolved in our favor. Consultants and key employees who work with our confidential and
proprietary technologies are required to assign all intellectual property rights in their discoveries to us. However,
these consultants or key employees may terminate their relationship with us, and we cannot preclude them
indefinitely from dealing with our competitors. If our trade secrets become known to competitors with greater
experience and financial resources, the competitors may copy or use our trade secrets and other proprietary
information in the advancement of their products, methods or technologies. If we were to prosecute a claim that a
third party had illegally obtained and was using our trade secrets, it could be expensive and time consuming and
the outcome could be unpredictable. In addition, courts outside the United States are sometimes less willing to
protect trade secrets than courts in the United States. Moreover, if our competitors independently develop
equivalent knowledge, we would lack any legal or contractual claim to prevent them from using such
information, and our business could be harmed.

Following the expiration of patents and any regulatory exclusivity we are able to obtain, we expect
competitors may manufacture and sell generic versions of our products, at a lower price, which would reduce
revenues obtained from such products. Notably, legislation in some jurisdictions mandates generic substitution
for brand name drugs.

We may not be able to protect our intellectual property rights throughout the world.

Filing, prosecuting, and defending our intellectual property rights in all countries throughout the world
would be prohibitively expensive, and our intellectual property rights in some countries outside the United States
can be less extensive than those in the United States. In addition, the laws of some foreign countries do not
protect intellectual property rights to the same extent as federal and state laws in the United States. For instance,
some jurisdictions, such as China and India, do not consider methods of treating the human body as patentable.
Further, licensing partners may not prosecute patents in certain jurisdictions in which we may obtain commercial
rights, thereby precluding the possibility of later obtaining patent protection in these countries. Consequently, we
may not be able to prevent third parties from practicing our inventions in all countries outside the United States,
or from selling or importing products made using our inventions in and into the United States or other
jurisdictions. Competitors may use our technologies in jurisdictions where we have not obtained patent
protection to develop their own products and may also export infringing products to territories where we have
patent protection, but enforcement is not as strong as that in the United States. These products may compete with
our products, and our intellectual property rights may not be effective or sufficient to prevent them from
competing.

Many companies have encountered significant problems in protecting and defending intellectual property
rights in foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do
not favor the enforcement of patents, trade secrets, and other intellectual property protection, particularly those
relating to biotechnology products, which could make it difficult for us to stop the infringement of our
intellectual property rights or marketing of competing products in violation of our proprietary rights generally.
Proceedings to enforce our proprietary rights in foreign jurisdictions, whether or not successful, could result in
substantial costs and divert our efforts and attention from other aspects of our business, could put our proprietary
rights at risk of being invalidated or interpreted narrowly, could put our patent applications at risk of not issuing,
and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate,
and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our
efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant
commercial advantage from the intellectual property that we develop or license.

Certain fees, including maintenance, renewal, annuity, and other governmental fees, on patents and/or
applications are periodically due to be paid to the USPTO and various foreign governmental patent agencies at
certain stages over the lifetime of the patents and/or applications. We have systems in place and employ third-

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party firms to monitor due dates and pay these fees. We also employ law firms and other reputable professionals
to assist us in the event an inadvertent lapse can be cured by payment of a late fee or by other means according to
the applicable jurisdictional laws and rules. Non-compliance, in certain circumstances, can result in abandonment
or lapse of the patent (or patent application) and result in a partial or even complete loss of patent rights in the
particular jurisdiction. Our competitors might be able to enter the market under such circumstances, resulting in a
possible material adverse effect on our business.

Our ability to commercialize our potential products will depend on our ability to sell such products without
infringing the patent or proprietary rights of third parties. If we are sued for infringing intellectual property
rights of third parties, it will be costly and time consuming, and an unfavorable outcome in that litigation
would have a material adverse effect on our business.

Our ability to commercialize our potential products will depend on our ability to sell such products without

infringing the patents or other proprietary rights of third parties. Third-party intellectual property rights in our
field are complicated and continuously evolving. The coverage of patents is subject to interpretation by the
courts, and this interpretation is not always consistent.

Other companies may have or may acquire intellectual property rights that could be enforced against us. If

they do so, we may be required to alter our products, formulations, processes, methods or other technologies,
obtain a license, assuming one can be obtained, or cease our product-related activities. Holders of such
intellectual property rights are not required to give us a license if one were required. If our products or
technologies infringe the intellectual property rights of others, such parties could bring legal action against us or
our licensors or collaborators claiming damages and seeking to enjoin any activities that they believe infringe
their intellectual property rights. If we are sued for patent infringement, we would need to demonstrate that our
products or methods of use either do not infringe the patent claims of the relevant patent or that the patent claims
are invalid or unenforceable, and we may not be able to do this. Proving the invalidity of a patent is particularly
difficult in the United States, since it requires a showing of clear and convincing evidence to overcome the
presumption of validity enjoyed by issued patents. If we are found to infringe a third-party patent, we may need
to cease the commercial sale of our products.

Because patent applications can take many years to issue, there may be currently pending applications

unknown to us or reissue applications that may later result in issued patents upon which our products or
technologies may infringe. There could also be existing patents of which we are unaware that our products or
technologies may infringe. In addition, if third parties file patent applications or obtain patents claiming products
or technologies also claimed by us in pending applications or issued patents, we may have to participate in
interference proceedings in the U.S. Patent and Trademark Office, or USPTO, to determine priority of invention.
If third parties file inter partes review or post-grant review petitions in the USPTO to invalidate our issued U.S.
patents, we may have to participate in such proceedings to defend such patents. If third parties file oppositions in
foreign countries, we may also have to participate in opposition proceedings in foreign tribunals to defend the
patentability of our filed foreign patent applications. The outcome of such proceedings in the United States and
foreign countries is predictable. Some of our competitors may be able to sustain the costs of such proceedings
and of complex patent litigation more effectively than we can because they have substantially greater resources.
Additionally, any uncertainties resulting from the initiation and continuation of any such proceedings or litigation
may have a material adverse effect on our ability to raise the funds necessary to continue our operations.

If a third-party claims that we infringe its intellectual property rights, it could cause our business to suffer in

a number of ways, including:

• we may become involved in time-consuming and expensive litigation, even if the claim is without

merit, the third party’s patent is ultimately invalid or unenforceable, or we are ultimately found to have
not infringed;

• we may become liable for substantial damages for past infringement if a court decides that our

technologies infringe upon a third party’s patent;

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• we may be ordered by a court to stop making, using, selling, offering for sale, importing or licensing
our products or technologies without a license from a patent holder, and such license may not be
available on commercially acceptable terms, if at all, or may require us to pay substantial royalties or
grant cross-licenses to our patents; and

• we may have to redesign our products so that they do not infringe upon others’ patent rights, which

may not be possible or could require substantial investment and/or time.

If any of these events occur, our business could suffer, and the market price of our common stock may

decline.

As is common in the biotechnology and pharmaceutical industries, we employ individuals who were
previously employed at other companies in these industries, including our competitors or potential competitors.
We may become subject to claims that these employees or we have inadvertently or otherwise used or disclosed
trade secrets or other proprietary information of their former employers, although no such claims are pending.
Litigation may be necessary to defend against these claims. Even if we successfully defend any such claims, we
may incur substantial costs in such defense, and our management may be distracted by these claims.

Risks Related to Owning our Common Stock

The price of our common stock could be subject to volatility related or unrelated to our operations.

The trading price of our common stock has been highly volatile and could continue to be subject to wide

fluctuations in response to various factors, some of which are beyond our control. These factors include:

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the level of sales of NERLYNX;

the overall demand for NERLYNX, including the customer ordering and discontinuation patterns

actual or anticipated quarterly variation in our results of operations or the results of our competitors;

announcements regarding results of any clinical trials relating to our drug candidates;

announcements of medical innovations or new products by our competitors;

developments involving our sublicensees;

issuance of new or changed securities analyst reports or recommendations for our stock;

developments or disputes concerning our intellectual property or other proprietary rights;

commencement of, or developments in, litigation involving us;

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timing and announcement of regulatory approvals;

changes in government regulation that affect us or the biopharmaceutical industry more generally;

any future sales of our common stock or other securities in connection with raising additional capital or
otherwise;

any major change to the composition of our board of directors or management; and

general economic conditions and slow or negative growth of our markets.

The stock market in general, and market prices for the securities of biotechnology companies like ours in

particular, have from time to time experienced volatility that often has been unrelated to the operating
performance of the underlying companies. These broad market and industry fluctuations may adversely affect the
market price of our common stock, regardless of our operating performance.

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We have been subject to securities litigation in the past, and volatility in the price of our common stock may
subject us to securities litigation in the future.

In the past, securities class action litigation has often been brought against a company following periods of

volatility in the market price of its securities. This risk is especially relevant for us because pharmaceutical
companies have experienced significant stock price volatility in recent years. These types of lawsuits are subject
to inherent uncertainties, and are expensive and time-consuming to investigate, defend and resolve. For instance,
in Hsu v. Puma Biotechnology, Inc., et al., the plaintiff alleged that we and certain of our executive officers made
false or misleading statements and failed to disclose material adverse facts about our business, operations,
prospects and performance in violation of the Exchange Act. In February 2019, a jury found that we had liability
on one of four alleged misstatements, and awarded a maximum of $4.50 per share in damages, representing
approximately 5% of total claimed damages. The claims challenge process is ongoing and the total amount of
aggregate class-wide damages remains uncertain. The Hsu lawsuit is described further in the section entitled
“Item 3. Legal Proceedings” below. Any other litigation to which we are a party may similarly divert our
management’s attention and financial and other resources, or result in an onerous or unfavorable judgment that
may not be reversed upon appeal or in payments of substantial monetary damages or fines. Additionally, we may
decide to settle such lawsuits on similarly unfavorable terms, which could adversely affect our business, financial
condition, results of operations or stock price.

Issuance of stock to fund our operations may dilute your investment and reduce your equity interest.

We may need to raise capital in the future to fund the development of our drug candidates or for other
purposes. Any equity financing may have a significant dilutive effect to stockholders and a material decrease in
our existing stockholders’ equity interest in us. Equity financing, if obtained, could result in substantial dilution
to our existing stockholders. At its sole discretion, our board of directors may issue additional securities without
seeking stockholder approval, and we do not know when we will need additional capital or, if we do, whether it
will be available to us.

Upon the exercise of our outstanding warrant, holders of our common stock may experience immediate
dilution and the market price of our common stock may be adversely affected.

Our founder, Chief Executive Officer and President, Alan H. Auerbach, holds a warrant for 2,116,250
shares with an exercise price of $16.00 per share. If any portion of the outstanding warrant is exercised for shares
of our common stock prior to its expiration in October 2021, our stockholders may experience immediate
dilution and the market price of our common stock may be adversely affected.

We incur increased costs and demands upon management as a result of complying with the laws and
regulations affecting public companies.

As a public company, we incur significant legal, accounting and other expenses, including costs associated
with public company reporting requirements. We also incur costs associated with current corporate governance
requirements, including requirements under Section 404 and other provisions of the Sarbanes-Oxley Act of 2002,
as amended, or the Sarbanes-Oxley Act, as well as rules implemented by the SEC, or NASDAQ or any stock
exchange or inter-dealer quotations system on which our common stock may be listed in the future. The expenses
incurred by public companies for reporting and corporate governance purposes have increased dramatically in
recent years. These rules and regulations increase our legal and financial compliance costs and make some
activities more time-consuming and costly.

These rules and regulations may also make it difficult and expensive for us to maintain the appropriate level

of director and officer insurance for a company with our market capitalization. If we are unable to maintain an
appropriate level of such insurance, we may be required to accept reduced policy limits and coverage or larger
deductible limits. As a result, it may be more difficult for us to attract and retain qualified individuals to serve on
our board of directors or as our executive officers.

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If we fail to maintain proper and effective internal controls, our ability to produce accurate and timely
financial statements could be impaired, which could harm our operating results, our ability to operate our
business and investors’ views of us.

We are subject to the rules and regulations of the SEC, including those rules and regulations mandated by

the Sarbanes-Oxley Act. Section 404 of the Sarbanes-Oxley Act requires public companies to include in their
annual report a statement of management’s responsibilities for establishing and maintaining adequate internal
control over financial reporting, together with an assessment of the effectiveness of those internal controls.
Section 404 also requires the independent auditors of certain public companies to attest to, and report on, this
management assessment. Ensuring that we have adequate internal financial and accounting controls and
procedures in place so that we can produce accurate financial statements on a timely basis is a costly and time-
consuming effort that will need to be evaluated frequently. Our failure to maintain the effectiveness of our
internal controls in accordance with the requirements of the Sarbanes-Oxley Act could have a material adverse
effect on our business. We could lose investor confidence in the accuracy and completeness of our financial
reports, which could have an adverse effect on the price of our common stock. In addition, if our efforts to
comply with new or changed laws, regulations, and standards differ from the activities intended by regulatory or
governing bodies due to ambiguities related to practice, regulatory authorities may initiate legal proceedings
against us and our business may be harmed.

If securities or industry analysts do not publish, or cease publishing, research reports about us, our business
or our market, or if they change their recommendations regarding our stock adversely, our stock price and
trading volume could decline.

The trading market for our common stock is and will be influenced by whether industry or securities
analysts publish research and reports about us, our business, our market or our competitors and, if any analysts
do publish such reports, what they publish in those reports. We may not obtain analyst coverage in the future.
Any analysts who do cover us may make adverse recommendations regarding our stock, adversely change their
recommendations from time to time, and/or provide more favorable relative recommendations about our
competitors. If any analyst who may cover us in the future were to cease coverage of our company or fail to
regularly publish reports on us, or if analysts fail to cover us or publish reports about us at all, we could lose
visibility in the financial markets, which in turn could cause our stock price or trading volume to decline.

We do not foresee paying cash dividends in the foreseeable future.

We currently intend to retain any future earnings for funding growth. We do not anticipate paying any
dividends in the foreseeable future, and the payment of dividends is also restricted under our credit facility. As a
result, you should not rely on an investment in our securities if you require dividend income. Capital
appreciation, if any, of our shares may be your sole source of gain for the foreseeable future. Moreover, you may
not be able to re-sell your shares in us at or above the price you paid for them.

Our ability to use our net operating losses and research and development credit carryforwards to offset future
taxable income may be subject to certain limitations.

In general, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, a

corporation that undergoes an “ownership change,” generally defined as a greater than 50% change (by value) in
its equity ownership over a three year period, is subject to limitations on its ability to utilize its pre-change net
operating losses, or NOLs, and its research and development credit carryforwards to offset future taxable income.
Our existing NOLs and research and development credit carryforwards may be subject to limitations arising from
previous ownership changes, and if we undergo an ownership change, our ability to utilize NOLs and research
and development credit carryforwards could be further limited by Sections 382 and 383 of the Code. Future
changes in our stock ownership, some of which might be beyond our control, could result in an ownership
change under Sections 382 and 383 of the Code. Furthermore, our ability to utilize NOLs and research and

72

development credit carryforwards of any companies we may acquire in the future may be subject to limitations,
in accordance with Sections 382 and 383 of the Code. For these reasons, in the event we experience a change of
control, we may not be able to utilize a material portion of the NOLs and research and development credit
carryforwards, even if we attain profitability.

73

ITEM 1B. UNRESOLVED STAFF COMMENTS

Not applicable.

ITEM 2.

PROPERTIES

We lease approximately 65,656 square feet of office space in the building located at 10880 Wilshire

Boulevard, Los Angeles, California for use as our corporate headquarters. This lease commenced in
December 2011 and over time has been amended to add rentable square footage. The lease terminates in March
2026. We also lease approximately 29,470 square feet of office space in the building located at 701 Gateway
Blvd, South San Francisco, California. The lease for the South San Francisco facility commenced in October
2012. The lease will terminate around March 2026, with an option to extend for an additional five-year term. We
believe that our existing office space, along with the additional office space in South San Francisco, is adequate
to meet current and anticipated future requirements and that additional or substitute space will be available as
needed to accommodate any expansions that our operations require.

ITEM 3.

LEGAL PROCEEDINGS

Hsu v. Puma Biotechnology, Inc., et. al.

On June 3, 2015, Hsingching Hsu, individually and on behalf of all others similarly situated, filed a class

action lawsuit against us and certain of our executive officers in the United States District Court for the Central
District of California (Case No. 8:15-cv-00865-AG-JCG). On October 16, 2015, lead plaintiff Norfolk Pension
Fund filed a consolidated complaint on behalf of all persons who purchased our securities between July 22, 2014
and May 29, 2015. A trial on the claims relating to four statements alleged to have been false or misleading was
held from January 15 to January 29, 2019. At trial, the jury found that three of the four challenged statements
were not false or misleading, and thus found in the defendants’ favor on those claims. The jury found liability as
to one statement and awarded a maximum of $4.50 per share in damages, which represents approximately 5% of
the total claimed damages of $87.20 per share. On September 9, 2019, the Court entered an order specifying the
rate of prejudgment interest to be awarded on any valid claims at the 52-week Treasury Bill rate. On
September 8, 2020, the claims administrator submitted its final claims report to the Court and, on October 9,
2020, the claims administrator submitted its supplemental claims report. The claims report reflects approximately
$50.5 million in claimed damages. We disagree with the amount of claimed damages. On November 27, 2020,
the Court issued an order setting out the process for challenging claims. Pursuant to that order, defendants must
decide by March 29, 2021 which claims they intend to challenge, and for which claims we need more
information to determine whether or not we will challenge those claims. Based on a review of specific claims and
subject to the outcome of the claims challenge process, we believe that total claimed damages after all claims
challenges have been adjudicated could range from $24.8 million to $51.4 million. The total amount of aggregate
class-wide damages still remains uncertain and will be ascertained only after the claims challenge process and the
exhaustion of any appeals. It is reasonably possible that the final total damages awarded will differ from these
estimates; however, the amount is not estimable at this time. A final judgment has not been entered.

Eshelman v. Puma Biotechnology, Inc., et. al.

In February 2016, Fredric N. Eshelman filed a lawsuit against our Chief Executive Officer and President,
Alan H. Auerbach, and us in the United States District Court for the Eastern District of North Carolina (Case No.
7:16-cv-00018-D). The complaint generally alleged that we and Mr. Auerbach made defamatory statements
regarding Dr. Eshelman in connection with a proxy contest. In May 2016, Dr. Eshelman filed a notice of
voluntary dismissal of the claims against Mr. Auerbach. A trial on the remaining defamation claims against us
took place from March 11 to March 15, 2019. At trial, the jury found us liable and awarded Dr. Eshelman
$15.9 million in compensatory damages and $6.5 million in punitive damages. We strongly disagree with the

74

verdict and, on April 22, 2019, filed a motion for a new trial or, in the alternative, a reduced damages award. The
Court denied that motion on March 2, 2020. We have appealed that ruling and the verdict. Additionally, after
trial, the plaintiff filed a motion seeking approximately $3.0 million in attorneys’ fees, as well as pre-judgment
interest. In the Court’s March 2 ruling, it denied the motion for attorneys’ fees but granted the request for
pre-judgment interest, bringing the total judgment to $26.3 million. On March 30, 2020, the plaintiff filed a
notice of cross-appeal and conditional cross-appeal, appealing the Court’s order denying the plaintiff’s request
for attorneys’ fees and conditionally cross-appealing a Court ruling that certain communications between
Mr. Auerbach and his attorneys were protected by attorney-client privilege and a related evidentiary ruling. We
estimate the high end of potential damages in the matter could be approximately $27.7 million; however, the
actual amount of damages payable by us is still uncertain and will be ascertained only after completion of the
appeal and any subsequent proceeding, and such amount could be greater than the amount of expense already
recognized or the high end of the estimate. The United States Court of Appeals for the Fourth Circuit has
tentatively calendared the oral argument of our appeal during the month of May 2021.

CANbridge Licensing Dispute

On July 28, 2020, we filed a request for arbitration against CANbridge Biomed Limited, or CANbridge,

before the ICC International Court of Arbitration. We asserted that CANbridge violated the terms of our
agreement with CANbridge in which we granted CANbridge an exclusive sublicense to develop and
commercialize NERLYNX throughout greater China. We sought an arbitral award, as well as damages, costs,
and attorneys’ fees. On August 26, 2020, CANbridge filed its response to our request for arbitration and brought
counterclaims, seeking damages, costs and attorneys’ fees. On February 24, 2021, we and CANbridge resolved
our dispute, with each side agreeing to dismiss our respective claims in the arbitration. The settlement is limited
to claims asserted in the arbitration, or that are related to the claims asserted in the arbitration.

Legal Malpractice Suit

On September 17, 2020, we filed a lawsuit against Hedrick Gardner Kincheloe & Garofalo, L.L.P. and
David L. Levy, the attorneys who previously represented us in Eshelman v. Puma Biotechnology, Inc., et al. in
the Superior Court of Mecklenburg County, North Carolina. We are alleging legal malpractice based on the
defendants’ negligent handling of the defense of us in Eshelman v. Puma Biotechnology, Inc., et al. as detailed
above. We are seeking recovery of the entire amount awarded in Eshelman v. Puma Biotechnology, Inc., et al. On
November 23, 2020, the defendant filed an answer to the complaint denying the allegations of negligence.

ITEM 4. MINE SAFETY DISCLOSURE

Not applicable.

75

PART II

ITEM 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER

MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

Market for Common Stock

Our common stock has been quoted on the NASDAQ Global Select Market, or NASDAQ, under the symbol
“PBYI” since January 3, 2017. Prior to January 3, 2017, shares of our common stock had been listed on the New
York Stock Exchange since October 19, 2012.

Record Holders

On February 18, 2021, we had nine holders of record of our common stock. The actual number of

stockholders is greater than this number of record holders, and includes stockholders who are beneficial owners,
but whose shares are held in street name by brokers and other nominees. This number of holders of record also
does not include stockholders whose shares may be held in trust by other entities. We believe approximately
14,500 additional owners held our common stock in “Street Name” as of February 18, 2021.

Dividends

We have never declared or paid any cash dividends on our capital stock. Currently, we anticipate that we
will retain all available funds for use in the operation and expansion of our business and do not anticipate paying
any cash dividends in the foreseeable future. Any future determination relating to dividend policy will be made at
the discretion of our board of directors and will depend on our future earnings, capital requirements, financial
condition, prospects, applicable Delaware law, which provides that dividends are only payable out of surplus or
current net profits, and other factors that our board of directors deems relevant. Additionally, we are restricted
from paying cash dividends under our credit facility with Oxford.

Securities Authorized for Issuance Under Equity Compensation Plans

The information included under Item 12 of Part III of this Annual Report, “Securities Authorized for
Issuance Under Equity Compensation Plans,” is hereby incorporated by reference into this Item 5 of Part II of
this Annual Report.

Recent Sales of Unregistered Securities

We did not make any sales of unregistered securities during fiscal year 2020.

Purchases of Equity Securities by the Issuer and Affiliated Purchasers

Neither we nor any “affiliated purchasers” within the definition of Rule 10b-18(a)(3) made any purchases of

our equity securities during the fourth quarter of 2020.

Performance Graph

The graph and table below compare the cumulative total return of our common stock from December 31,

2015, through December 31, 2020, with the cumulative total returns on (i) the Nasdaq Biotechnology Index and
(ii) the Nasdaq Composite Index. The comparison assumes investment of $100 on December 31, 2015, in our
common stock and in each index and, for each index, assumes reinvestment of all dividends.

76

The historical price performance included below is not necessarily indicative of future stock price

performance.

PBYI US Equity

XNBI Index

XCMP Index

300.00

250.00

200.00

150.00

100.00

50.00

0.00

5
1
0
2/2
1

6
1
0
2/2
1

7
1
0
2/2
1

8
1
0
2/2
1

9
1
0
2/2
1

0
2
0
2/2
1

Cumulative Total Return

Puma Biotechnology, Inc. Compared to the Nasdaq Biotechnology Index and Nasdaq Composite Index

Puma Biotechnology, Inc.
. . . . . . . . . . . . . .
Nasdaq Biotechnology Index . . . . . . . . . . . .
Nasdaq Composite Index . . . . . . . . . . . . . . .

100.00
100.00
100.00

39.16
78.65
108.87

126.08
95.67
141.13

25.96
87.19
137.12

11.16
109.08
187.44

13.09
137.90
271.64

12/31/2015

12/31/2016

12/31/2017

12/31/2018

12/31/2019

12/31/2020

*

On October 19, 2012, shares of Puma common stock were listed and began trading on the New York Stock
Exchange.

On January 3, 2017, the listing of shares of Puma common stock was moved to the Nasdaq Stock Market.

The material in this performance graph is not soliciting material, is not deemed filed with the SEC and is not

incorporated by reference in any of our filings under the Securities Act of 1933, as amended, or the Exchange
Act, whether made on, before or after the date of this filing and irrespective of any general incorporation
language in such filing.

77

ITEM 6.

SELECTED FINANCIAL DATA

The following financial data should be read in conjunction with our consolidated financial statements and

the related notes thereto appearing elsewhere in this Annual Report and with the section entitled “Management’s
Discussion and Analysis of Financial Condition and Results of Operations.”

The Consolidated Statement of Operations Data and Other Financial Data for the years ended December 31,

2020, 2019 and 2018 and the Consolidated Balance Sheet Data as of December 31, 2020 and 2019 have been
derived from our audited consolidated financial statements included elsewhere in this Annual Report. The
Consolidated Statement of Operations Data and Other Financial Data for the years ended December 31, 2017 and
2016 and the Consolidated Balance Sheet Data as of December 31, 2018, 2017 and 2016 have been derived from
our audited consolidated financial statements not included herein. Historical results are not necessarily indicative
of the results to be expected in the future, and the results for the years presented should not be considered
indicative of our future results of operations.

Statement of Operations Data:
Product revenue, net
. . . . . . . . . . . . . .
License revenue . . . . . . . . . . . . . . . . . .
Royalty revenue . . . . . . . . . . . . . . . . . .
Expenses:

$

Cost of sales . . . . . . . . . . . . . . . .
Selling, general and

administrative . . . . . . . . . . . . .
. . . . .

Research and development

Operating loss . . . . . . . . . . . . . . . . . . .

Interest income . . . . . . . . . . . . . .
Interest expense . . . . . . . . . . . . . .
Legal verdict expense . . . . . . . . .
Loss on debt extinguishment . . . .
. . . . . . .
Other income (expense)

Total other income (expense) . . . . . . .

Loss before income taxes . . . . . . . . . .
Income tax expense . . . . . . . . . . .

Net loss . . . . . . . . . . . . . . . . . . . . . . . .

Net loss attributable to common

Years Ended December 31,

2020

2019

2018

2017

2016

(in millions, except share and per share data)

$

196.7
22.7
5.7

39.4

118.4
97.7

(30.4)

0.5
(14.0)
(16.2)
—
0.3

(29.4)

(59.8)
(0.2)

(60.0)

$

211.6
60.3
0.4

36.8

141.6
132.9

(39.0)

2.8
(15.0)
(16.4)
(8.1)
0.2

(36.5)

(75.5)
(0.1)

(75.6)

200.5
50.5
—

34.6

146.2
164.9

(94.7)

1.8
(11.0)
(9.0)
—
(0.7)

(18.9)

(113.6)
—

(113.6)

$

$

26.2
1.5
—

5.6

106.7
207.8

(292.4)

1.2
(0.7)
—
—
(0.1)

0.4

(292.0)
—

(292.0)

—
—
—

—

53.8
222.8

(276.6)

1.0
—
—
—
(0.4)

0.6

(276.0)
—

(276.0)

stock . . . . . . . . . . . . . . . . . . . . . . . .

(60.0)

(75.6)

(113.6)

(292.0)

(276.0)

Net loss per common share—basic . . .
and diluted . . . . . . . . . . . . . . . . . . . . . .

Weighted-average common shares . . .
outstanding—basic and diluted . . . . . .

$

(1.52) $

(1.95) $

(2.99) $

(7.85) $

(8.29)

39,576,107

38,768,653

37,942,411

37,169,678

33,295,114

2020

2019

2018

2017

2016

As of December 31,

(in millions)

Balance Sheet Data:
Total assets . . . . . . . . . . . . . . . . . . . . .
Total liabilities . . . . . . . . . . . . . . . . . .
Total stockholders’ (deficit) equity . . .

$

$

244.2
250.2
(6.0)

$

234.9
217.4
17.5

$

259.1
224.8
34.3

$

165.5
112.2
53.3

252.8
43.0
209.8

78

Years Ended December 31,

2020

2019

2018

2017

2016

(in millions)

Other Financial Data:
Net cash provided by (used in) operating activities . . . . . . $ 0.8
23.4
Net cash provided by (used in) investing activities . . . . . .
0.1
Net cash provided by (used in) financing activities . . . . . .

$ 22.4
5.2
(67.1)

$ (24.1)
(57.6)
108.5

$(172.5)
(15.4)
75.1

$(141.7)
142.2
162.4

79

Item 7.

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
RESULTS OF OPERATIONS

This Annual Report on Form 10-K contains forward-looking statements within the meanings of the federal

securities laws. These statements are subject to risks and uncertainties that could cause actual results and events
to differ materially from those expressed or implied by such forward-looking statements. For a detailed
discussion of these risks and uncertainties, see the “Risk Factors” section in Item 1A of Part I of this Form 10-K.
We caution the reader not to place undue reliance on these forward-looking statements, which reflect
management’s analysis only as of the date of this Form 10-K. We undertake no obligation to update forward-
looking statements to reflect events or circumstances occurring after the date of this Form 10-K.

Overview

We are a biopharmaceutical company with a focus on the development and commercialization of innovative
products to enhance cancer care. We in-license from Pfizer the global development and commercialization rights
to PB272 (neratinib (oral)), PB272 (neratinib (intravenous)) and PB357. Neratinib is a potent irreversible TKI
that blocks signal transduction through the epidermal growth factor receptors, HER1, HER2 and HER4.
Currently, we are primarily focused on the development and commercialization of the oral version of neratinib,
and our most advanced drug candidates are directed at the treatment of HER2-positive breast cancer and HER2
mutated cancers. We believe neratinib has clinical application in the treatment of several other cancers as well,
including other tumor types that over-express or have a mutation in HER2, such as breast cancer, cervical cancer,
lung cancer or other solid tumors.

Prior to 2017, our efforts and resources were focused primarily on acquiring and developing our

pharmaceutical technologies, raising capital and recruiting personnel. In 2017, the FDA approved NERLYNX,
formally known as PB272 (neratinib(oral)), for the extended adjuvant treatment of adult patients with early stage
HER2-overexpressed/amplified breast cancer following trastuzumab-based therapy. In 2018, the EC granted
marketing authorization for NERLYNX in the European Union for the extended adjuvant treatment of adult
patients with early state hormone receptor positive HER-2-overexpressed/amplified breast cancer and who are
less than one year from the completion of prior adjuvant trastuzumab-based therapy.

We have entered into exclusive sub-license agreements with various parties to pursue regulatory approval, if
necessary, and commercialize NERLYNX, if approved, in various specified regions outside of the United States,
including Europe (excluding Russia and Ukraine), Australia, Canada, China, Southeast Asia, South Korea, and
various countries and territories in Central and South America. We plan to continue to pursue commercialization
of NERLYNX in other countries outside the United States, if approved.

Our expenses to date have been related to hiring staff, commencing company-sponsored clinical trials and

the build out of our corporate infrastructure and, since 2017, the commercial launch of NERLYNX. Accordingly,
our success depends not only on the safety and efficacy of our product candidates, but also on our ability to
finance product development. To date, our major sources of working capital have been proceeds from product
and license revenue, public offerings of our common stock, proceeds from our credit facility and sales of our
common stock in private placements.

Impact of COVID-19

Our priorities during the COVID-19 pandemic are protecting the health and safety of our employees while
continuing our mission to develop and commercialize innovative products to enhance cancer care. Substantially
all geographic regions in which our U.S. sales force operates have imposed, and those regions or other regions in
which our sales force operates may in the future impose, “shelter-in-place” orders, quarantines or similar orders
or restrictions to control the spread of COVID-19. These types of restrictions may deter or prevent cancer
patients from traveling to see their doctors and result in a decline in revenue for NERLYNX, our only

80

commercial product. Additionally, our commercial team and sales force have limited travel and personal
interactions with physicians and customers, including visits to healthcare provider offices due to limitations that
have been imposed at certain hospitals and medical facilities, and are currently conducting a large percentage of
promotional activities virtually. These types of restrictions have adversely impacted our ability to engage with
our customers and have adversely impacted sales of NERLYNX, our only commercial product, and they may
continue to do so. The respective commercial teams of certain of the companies to which we sub-license the
commercial rights to NERLYNX, and on which we rely for our international sales, have chosen or have been
forced to take similar action, and other sub-licensees of NERLYNX may choose or be forced to take similar
action. Furthermore, the COVID-19 pandemic has resulted in dramatic increases in unemployment rates, which
may result in a substantial number of people becoming uninsured or underinsured. Any of these developments
may have an adverse effect on our revenue. We have observed disruptions in patient enrollments in the United
States and in our SUMMIT basket trial. If the COVID-19 pandemic continues to spread in the geographies in
which we are conducting clinical trials, we may experience additional disruptions in those clinical trials, which
could have a material adverse impact on our clinical trial plans and timelines.

Our ability to continue to operate without any significant negative impacts will in part depend on the length

and severity of the COVID-19 pandemic and our ability to protect our employees and our supply chain. We
continue to follow and monitor recommended actions of government and health authorities to protect our
employees worldwide. For the year ended December 31, 2020, we and our key third-party suppliers and
manufacturers were able to broadly maintain operations. We rely exclusively on third-party manufacturers to
manufacture NERLYNX.

We intend to satisfy our near-term liquidity requirements through a combination of our existing cash and

cash equivalents and marketable securities as of December 31, 2020 and proceeds that will become available to
us through product sales, royalties and sub-license milestone payments. However, this intention is based on
assumptions that may prove to be wrong. Changes may occur that would consume our available capital faster
than anticipated, including the length and severity of the COVID-19 pandemic and measures taken to control the
spread of COVID-19, as well as changes in and progress of our development activities, the impact of
commercialization efforts, acquisitions of additional drug candidates and changes in regulation. Some of these
developments have had and may continue to have an adverse effect on our revenue and thus could have an
adverse effect on our ability to satisfy the minimum revenue covenants in our loan and security agreement.

Summary of Income and Expenses

Product revenue, net

Product revenue, net consists of revenue from sales of NERLYNX. We sell NERLYNX to a limited number

of specialty pharmacies and specialty distributors in the United States. We record revenue at the net sales price,
which includes an estimate for variable consideration for which reserves are established. Variable consideration
consists of trade discounts and allowances, product returns, provider chargebacks and discounts, government
rebates and other incentives.

License revenue

License revenue consists of consideration earned for performance obligations satisfied pursuant to our

sub-license agreements.

Royalty revenue

Royalty revenue consists of consideration earned related to product sales made by our sub-licensees in their

respective territories pursuant to our license agreements.

81

Cost of sales

Cost of sales consists of third-party manufacturing costs, freight, and indirect overhead costs associated with
sales of NERLYNX. Cost of product sales also includes period costs related to royalty charges payable to Pfizer,
the amortization of milestone payments under our license agreement with Pfizer, certain inventory manufacturing
services, inventory adjustment charges, unabsorbed manufacturing and overhead costs, and manufacturing
variances.

Selling, general and administrative expenses

Selling, general and administrative, or SG&A, expenses, consist primarily of salaries and payroll-related
costs, stock-based compensation expense, professional fees, business insurance, rent, general legal activities,
credit loss expense and other corporate expenses. We expense SG&A expenses as they are incurred.

Research and development expenses

Research and development, or R&D, expenses include costs associated with services provided by
consultants who conduct clinical services on our behalf, contract organizations for manufacturing of clinical
materials and clinical trials. During the years ended December 31, 2020, 2019 and 2018, our R&D expenses
consisted primarily of clinical research organization, or CRO, fees; fees paid to consultants; salaries and related
personnel costs; and stock-based compensation. We expense our R&D expenses as they are incurred. Internal
R&D expenses primarily consist of payroll-related costs and also include equipment costs, travel expenses and
supplies.

Results of Operations

The following summarizes our results of operations for the years ended December 31, 2020 and 2019. For

discussion related to the results of operations and changes in financial condition for the year ended December 31,
2019 compared to the year ended December 31, 2018, please refer to Item 7 of Part II, “Management’s
Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report for the Year
Ended December 31, 2019, which was filed with the United States Securities and Exchange Commission on
February 28, 2020.

Total revenue

Total revenue was approximately $225.1 million for the year ended December 31, 2020, compared to

$272.3 million for the year ended December 31, 2019.

Product revenue, net

Product revenue, net was approximately $196.7 million for the year ended December 31, 2020, compared to
$211.6 million for the year ended December 31, 2019. The decrease in product revenue, net was attributable to a
volume decrease of approximately 21% in bottles of NERLYNX sold and an increase in variable consideration
from approximately 14% of gross product revenue for the year ended December 31, 2019 to approximately 16%
of gross product revenue for the year ended December 31, 2020, partially offset by an increase in gross selling
price that occurred in the first quarter of 2020 and again in the third quarter of 2020. The increase in variable
consideration is primarily due to an increase in government rebates.

License revenue

License revenue was approximately $22.7 million for the year ended December 31, 2020, compared to
$60.3 million for the year ended December 31, 2019. The decrease in license revenue was primarily due to a

82

decrease in upfront payments that we recognized as revenue as consideration allocated to the sub-license of our
intellectual property and satisfaction of performance-based milestones related to sub-license agreements in the
year ended December 31, 2020, compared to the year ended December 31, 2019.

Royalty revenue

Royalty revenue was approximately $5.7 million for the year ended December 31, 2020, compared to
$0.4 million for the year-ended December 31, 2019. The increase was due to increased product sales by our
sub-licensees as they increased commercialization of NERLYNX in additional territories.

Cost of sales

Cost of sales was approximately $39.4 million for the year ended December 31, 2020, compared to
$36.8 million for the year ended December 31, 2019. The increase in cost of sales was primarily attributable to
increased royalty expense due to Pfizer related to the increase in royalty revenue and an increase in the
amortization of the intangible asset related to the milestone payments under our license agreement with Pfizer,
which was partially offset by decreased royalty expenses due to Pfizer related to the decrease in product revenue,
net.

Selling, general and administrative expenses:

Selling, general, and administrative expenses
(in thousands)

For the Year Ended

Change

December 31,

$

%

2020

2019

2020/2019

2020/2019

Payroll and related costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Professional fees and expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Travel and meetings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Facilities and equipment costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss on impairment of asset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Credit loss expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 41,313
42,935
4,726
5,673
—
17,778
1,000
5,063

$ 41,415
49,060
10,987
5,803
1,183
27,892
—
5,299

$

(102)
(6,125)
(6,261)
(130)
(1,183)
(10,114)
1,000
(236)

-0.2%
-12.5%
-57.0%
-2.2%
-100.0%
-36.3%
100.0%
-4.5%

$118,488

$141,639

$(23,151)

-16.3%

Total SG&A expenses decreased approximately 16.3% to $118.5 million for the year ended December 31,

2020 from $141.6 million for the year ended December 31, 2019. The decrease is primarily attributable to the
following:

•

•

•

a decrease in stock-based compensation expense of approximately $10.1 million, primarily due to a
decrease of approximately $6.9 million for stock options and restricted stock units that have fully
vested, a decrease of approximately $5.1 million from stock awards forfeited and a decrease of
approximately $2.7 million from stock award modifications partially offset by an increase of
approximately $4.8 million from new grants and other immaterial fluctuations;

a decrease in professional fees of approximately $6.1 million, consisting primarily of decreases of
approximately $6.6 million in legal fees in connection with various lawsuits and approximately
$0.9 million for professional fees primarily related to decreased consultancy efforts related to
marketing and commercialization support, partially offset by an increase of approximately $1.0 million
in insurance premiums and $0.4 million in audit and board of directors fees;

a decrease in travel and meeting related costs of approximately $6.3 million related to travel
restrictions and cancellations of on-site events due to the COVID-19 pandemic;

83

•

•

•

a loss of approximately $1.2 million for the year ended December 31, 2019 in connection with our
decision to sublease the right to use a portion of our leased office space recorded as an operating asset
in accordance with ASC 842, with no impairment loss in 2020;

a decrease in other, facilities and equipment costs for $0.4 million;

a decrease in payroll and related costs of $0.1 million;

which were partially offset by:

•

a credit loss expense of $1.0 million for the year ended December 31, 2020 for an amount owed from a
sub-license partner relating to license revenue recognized during the third quarter of 2019, compared to
no credit loss expense for the year ended December 31, 2019.

Research and development expenses:

Research and development expenses
(in thousands)

For the Year Ended

Change

December 31,

$

%

2020

2019

2020/2019

2020/2019

Clinical trial expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internal R&D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consultant and contractors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$31,428
38,736
8,689
18,797

$ 51,545
39,603
12,268
29,435

$(20,117)
(867)
(3,579)
(10,638)

-39.0%
-2.2%
-29.2%
-36.1%

$97,650

$132,851

$(35,201)

-26.5%

Total R&D expenses decreased approximately 26.5% to $97.7 million for the year ended December 31,
2020 from $132.9 million for the year ended December 31, 2019. The decrease is primarily attributable to the
following:

•

•

•

•

a decrease in stock-based compensation expense of approximately $10.6 million, primarily due to a
decrease of approximately $8.3 million for stock options and restricted stock units that have fully
vested and a decrease of approximately $4.5 million from stock awards forfeited, partially offset by an
increase of approximately $2.0 million from new grants and other immaterial fluctuations;

a decrease in internal R&D expense of approximately $0.9 million, primarily due to a decrease in
payroll and payroll-related expenses as a result of reduction in headcount;

a decrease in clinical trial expenses of approximately $20.1 million, primarily due to the close out of
certain clinical trials and a reduction in enrollments and patients for open studies; and

a decrease in consultant and contractors of approximately $3.6 million, primarily due to the close out of
certain clinical trials.

Other income and expenses:

Other income (expenses)
(in thousands)

For the Year Ended

Change

December 31,

$

%

2020

2019

2020/2019

2020/2019

Interest income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Legal verdict expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss on debt extinguishment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

489
(14,046)
(16,196)
—
367

$ 2,847
(15,019)
(16,350)
(8,103)
128

$(2,358)
973
154
8,103
239

-82.8%
-6.5%
-0.9%
100.0%
186.7%

$(29,386) $(36,497) $ 7,111

-19.5%

84

Interest income

For the year ended December 31, 2020, we recognized approximately $0.5 million in interest income
compared to approximately $2.8 million of interest income for the year ended December 31, 2019. The decrease
in interest income reflects less cash invested in money market accounts and high-yield savings accounts in 2020
compared to 2019.

Interest expense

For the year ended December 31, 2020, we recognized approximately $14.0 million in interest expense

compared to $15.0 million of interest expense for the year ended December 31, 2019. The decrease in interest
expense was primarily the result of having less borrowings outstanding in 2020 than in 2019. The decrease was
partially offset by an increase in interest expense for the milestone payments being paid to Pfizer in installments.

Legal verdict expense

For the year ended December 31, 2020, we recognized approximately $16.2 million in legal verdict expense,

which primarily represents an increase to our prior estimate of potential amounts that may be owed to class
action participants as a result of the Hsu v. Puma Biotechnology, Inc., et al. claims process. For the period ended
September 30, 2020, we changed our estimate of the legal verdict expense and the associated legal expense
accrual for the Hsu lawsuit. Our previous estimate was based on data and assumptions that were available at the
time. We obtained additional data, previously unavailable, from the claims report and amended claims report
filed with the Court. On September 8, 2020, the claims administrator submitted its final claims report to the
Court and, on October 9, 2020, the claims administrator submitted its supplemental claims report. Our estimate
of the legal verdict expense and the associated legal expense accrual for the Hsu lawsuit remained unchanged for
the quarter ended December 31, 2020. The claims report asserts $50.5 million in damages, which is larger than
the amount previously estimated. We intend to challenge these claims and estimate that the damages could range
from $24.8 million to $51.4 million. As a result, we increased our estimate of the legal accrual on a prospective
basis beginning in the third quarter of 2020 to $24.8 million, resulting in an additional $15.7 million legal verdict
expense in 2020. The total amount of aggregate class-wide damages still remains uncertain and will be
ascertained only after an extensive claims challenge process and the exhaustion of any appeals. Additionally, we
incurred approximately $0.1 million in legal verdict expense related to class action administrator services and
pre-judgment interest for the Hsu lawsuit and approximately $0.4 million in post-judgment interest for the
Eshelman lawsuit. Our estimate of the legal verdict expense and the associated legal expense accrual for the Hsu
lawsuit remained unchanged for the quarter ended December 31, 2020.

For the year ended December 31, 2019, we recognized approximately $16.4 million in legal verdict expense
related to the Eshelman v. Puma Biotechnology, Inc., et al. verdict. The legal verdict expense of $16.4 million for
the year ended December 31, 2019 was the result of our initial estimate of the total damages payable in the
matter of $22.4 million, net of $6.0 million in insurance reimbursements.

Loss on debt extinguishment

For the year ended December 31, 2019, we recognized approximately $8.1 million in loss on debt
extinguishment related to the one-time fees paid in connection with our debt refinancing during the second
quarter of 2019.

Non-GAAP Financial Measures:

In addition to our operating results, as calculated in accordance with U.S. generally accepted accounting

principles, or GAAP, we use certain non-GAAP financial measures when planning, monitoring, and evaluating
our operational performance. The following table presents our net loss and net loss per share, as calculated in

85

accordance with GAAP, as adjusted to remove the impact of stock-based compensation. For the years ended
December 31, 2020 and 2019, stock-based compensation represented approximately 61.0% and 75.8% of our net
loss, respectively. Our management believes that these non-GAAP financial measures are useful to enhance
understanding of our financial performance, are more indicative of our operational performance and facilitate a
better comparison among fiscal periods. These non-GAAP financial measures are not, and should not be viewed
as, substitutes for GAAP reporting measures.

Reconciliation of GAAP Net Loss to Non-GAAP Adjusted Net Loss and
GAAP Net Loss Per Share to Non-GAAP Adjusted Net Loss Per Share
(in thousands except share and per share data)

GAAP net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustments: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selling, general and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research and development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

For the Year Ended December 31,

2020

2019

$(59,995)

$(75,595)

17,778
18,797

27,892(1)
29,435(2)

Non-GAAP adjusted net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$(23,420)

$(18,268)

GAAP net loss per share—basic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustment to net loss (as detailed above) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Non-GAAP adjusted basic net loss per share . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

$

(1.52)
0.93

(0.59)

$

$

(1.95)
1.48

(0.47)(3)

(1) To reflect a non-cash charge to operating expense for selling, general, and administrative stock-based

compensation.

(2) To reflect a non-cash charge to operating expense for research and development stock-based compensation.
(3) Non-GAAP adjusted basic net loss per share was calculated based 39,576,107 and 38,768,653 weighted-

average shares of common stock outstanding for the years ended December 31, 2020 and 2019, respectively.

Liquidity and Capital Resources

The following table summarizes our liquidity and capital resources as of and for the years ended
December 31, 2020 and December 31, 2019 and is intended to supplement the more detailed discussion that
follows:

Liquidity and capital resources (in thousands)

As of

As of

December 31, 2020 December 31, 2019

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Marketable securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Working capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stockholders’ (deficit) equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$85,293
$ 8,096
$31,884
$ (5,951)

$60,037
$51,607
$75,459
$17,463

Cash provided by (used in):

Operating activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Investing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Financing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net increase (decrease) in cash, cash equivalents and restricted cash . . . . . .

$

773
23,403
68

$24,244

$ 22,376
5,163
(67,067)

$(39,528)

Year Ended

Year Ended

December 31, 2020 December 31, 2019

86

Operating Activities

We recorded net losses of approximately $60.0 million and $75.6 million for the years ended December 31,

2020 and 2019, respectively. We reported positive cash flows from operating activities of approximately
$0.8 million for the year ended December 31, 2020 and reported positive cash flows from operating activities of
$22.4 million for the year ended December 31, 2019.

Net cash provided by operating activities for the year ended December 31, 2020 included a net loss of

$60.0 million, adjusted for non-cash items of approximately $36.6 million for stock-based compensation
expense, approximately $10.0 million for depreciation and amortization, and $1.0 million for a provision for
credit loss expense. Further changes in cash flows from operations included an increase in accrued expenses of
approximately $19.3 million, a decrease in accounts receivable, net of approximately $2.4 million, and a decrease
in prepaid expenses and other of approximately $2.3 million. These changes were offset by a decrease in
accounts payable of approximately $7.1 million, an increase in other current assets of approximately
$3.1 million, and an increase in inventory, net of approximately $0.3 million, and other immaterial fluctuations.

Net cash used in operating activities for the year ended December 31, 2019, included a net loss of

$75.6 million adjusted for non-cash items of approximately $57.3 million for stock-based compensation expense
and approximately $8.1 million for depreciation and amortization, approximately $8.0 million for debt
extinguishment fees and a loss of approximately $1.2 million for the impairment of an operating lease asset.
Further changes in cash flows from operations included an increase in accrued expenses of approximately
$22.6 million, an increase in post-marketing commitment liability of approximately $9.0 million, a decrease in
other current assets of approximately $1.5 million and a decrease in prepaid expenses and other of approximately
$0.6 million. These changes were offset by an increase in accounts receivable, net of approximately $8.1 million,
a decrease in accounts payable of approximately $1.5 million, an increase in inventory, net of approximately
$0.5 million, and an increase in deferred rent of approximately $0.2 million.

Investing Activities

During the year ended December 31, 2020, cash provided by investing activities was approximately

$23.4 million. This included the maturity of available-for-sale securities of approximately $73.3 million, partially
offset by the purchase of available-for-sale securities of approximately $29.8 million and an increase in
intangible assets relating to the milestone achieved under our license agreement with Pfizer of $20.0 million.

During the year ended December 31, 2019, cash provided by investing activities was approximately
$5.2 million. This included the maturity of available-for-sale securities of approximately $104.6 million and the
sale of available-for-sale securities of approximately $28.1 million, partially offset by the purchase of
available-for-sale securities of approximately $127.2 million and the purchase of property and equipment of
approximately $0.3 million.

Financing Activities

During the year ended December 31, 2020, net cash was not materially changed by financing activities.

During April 2020, approximately $8.4 million was borrowed and fully repaid with no penalty or interest from
Silicon Valley Bank, or SVB, under the Paycheck Protection Program, or PPP, of the Coronavirus Aid, Relief,
and Economic Security Act.

During the year ended December 31, 2019, cash used in financing activities was approximately
$67.1 million, which consisted of $80.0 million in debt repayments, approximately $7.8 million in debt
extinguishment costs, and approximately $5.6 million in debt issuance costs, offset by $25.0 million in proceeds
from long-term debt and approximately $1.3 million in net proceeds from the exercise of stock options.

87

Loan and Security Agreement

In October 2017, we entered into a loan and security agreement with Silicon Valley Bank, or SVB, as
administrative agent, and the lenders party thereto from time to time, or the Original Lenders, including Oxford
and SVB. Pursuant to the terms of the credit facility provided for by the loan and security agreement, or the
Original Credit Facility, we borrowed $50 million. In May 2018, we entered into an amendment to the loan and
security agreement, which provided for an amended credit facility, or the Amended Credit Facility. Under the
Amended Credit Facility, the Original Lenders agreed to make term loans available to us in an aggregate amount
of $155 million, consisting of (i) a term loan in an aggregate amount of $125 million, the proceeds of which, in
part, were used to repay the $50 million we borrowed under the Original Credit Facility, and (ii) a term loan in an
aggregate amount of $30 million that we drew in December 2018, which was available to us under the Amended
Credit Facility as a result of achieving a specified minimum revenue milestone. We were in compliance with all
applicable financial covenants during the entire term of the Amended Credit Facility.

On June 28, 2019, or the Effective Date, we entered into a new credit facility, or the New Credit Facility,
with Oxford, as collateral agent, and the lenders party thereto from time to time, including Oxford, pursuant to
which we repaid the $155.0 million outstanding under the Amended Credit Facility, as well as all applicable exit
and prepayment fees owed to the Original Lenders under the Amended Credit Facility, using cash on hand and
$100.0 million in new borrowings from the New Credit Facility. Under the New Credit Facility, we issued to
Oxford new and/or replacement secured promissory notes in an aggregate principal amount for all such
promissory notes of $100.0 million evidencing the New Credit Facility. No additional capacity remains available
to us under the New Credit Facility.

The New Credit Facility is secured by substantially all of our personal property other than our intellectual

property. We also pledged 65% of the issued and outstanding capital stock of our subsidiaries, Puma
Biotechnology Ltd. and Puma Biotechnology B.V. The New Credit Facility limits our ability to grant any interest
in our intellectual property to certain permitted licenses and permitted encumbrances set forth in the agreement.

The term loans under the New Credit Facility bear interest at an annual rate equal to the greater of (i) 9.0%

and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the
month that immediately precedes the month in which the interest will accrue, plus (b) 3.5%. We are required to
make monthly interest-only payments on each term loan under the New Credit Facility commencing on the first
calendar day of the calendar month following the funding date of such term loan, and continuing on the first
calendar day of each calendar month thereafter through August 1, 2021, or the Amortization Date. Commencing
on the Amortization Date, and continuing on the first calendar day of each calendar month thereafter, we will
make consecutive equal monthly payments of principal, together with applicable interest, in arrears to each
lender under the New Credit Facility, calculated pursuant to the New Credit Facility. All unpaid principal and
accrued and unpaid interest with respect to each term loan under the New Credit Facility is due and payable in
full on June 1, 2024, or the Maturity Date. Upon repayment of such term loans, we are also required to make a
final payment to the new lenders equal to 7.5% of the aggregate principal amount of such term loans outstanding
as of the Effective Date. The effective interest rate as of December 31, 2020 was 12.75%.

At our option, we may prepay the outstanding principal balance of any term loan in whole but not in part,
subject to a prepayment fee of 3.0% of the amount prepaid if the prepayment occurs through and including the
first anniversary of the funding date of such term loan, 2.0% of the amount prepaid if the prepayment occurs after
the first anniversary of the funding date of such term loan through and including the second anniversary of the
funding date of such term loan, and 1.0% of the amount prepaid if the prepayment occurs after the second
anniversary of the funding date of such term loan and prior to the Maturity Date.

The New Credit Facility includes affirmative and negative covenants applicable to us, our current
subsidiaries and any subsidiaries we create in the future. The affirmative covenants include, among others,
covenants requiring us to maintain our legal existence and governmental approvals, deliver certain financial

88

reports, maintain insurance coverage and satisfy certain requirements regarding deposit accounts. We must also
achieve certain product revenue targets, measured as of the last day of each fiscal quarter on a trailing year to
date basis. New minimum revenue levels will be established for each fiscal year by mutual agreement of us,
Oxford, as collateral agent, and the lenders under the New Credit Facility. The negative covenants include,
among others, restrictions on our transferring collateral, incurring additional indebtedness, engaging in mergers
or acquisitions, paying dividends or making other distributions, making investments, creating liens, selling assets
and suffering a change in control, in each case subject to certain exceptions.

The New Credit Facility also includes events of default, the occurrence and continuation of which could

cause interest to be charged at the rate that is otherwise applicable plus 5.0% and would provide Oxford, as
collateral agent, with the right to exercise remedies against us and the collateral securing the New Credit Facility,
including foreclosure against the property securing the New Credit Facility, including our cash. These events of
default include, among other things, our failure to pay principal or interest due under the New Credit Facility, a
breach of certain covenants under the New Credit Facility, our insolvency, a material adverse change, the
occurrence of any default under certain other indebtedness in an amount greater than $500,000 and one or more
judgments against us in an amount greater than $500,000 individually or in the aggregate that remains
unsatisfied, unvacated, or unstayed for a period of 10 days after its entry.

On February 27, 2020, we entered into an amendment of the New Credit Facility with Oxford to establish
the minimum revenue thresholds for the trailing year to date periods ending March 31, June 30, September 30,
and December 31, 2020 and the fiscal year 2021. On August 5, 2020, we entered into an amendment of the New
Credit Facility with Oxford to amend the minimum revenue thresholds for the trailing year to date periods ending
September 30 and December 31, 2020. On February 3, 2021, we entered into an amendment of the New Credit
Facility with Oxford to establish the minimum revenue thresholds for the trailing year to date periods ending
March 31, June 30, September 30, and December 31, 2021.

As of December 31, 2020, there was $100.0 million in principal amounts outstanding under the New Credit

Facility, representing all of our debt outstanding as of that date, and we were in compliance with all applicable
covenants under the New Credit Facility.

Current and Future Financing Needs

We did not receive or record any product revenues until the third quarter of 2017. We have spent, and

expect to continue to spend, substantial amounts in connection with implementing our business strategy,
including our planned product development efforts, our clinical trials, our R&D efforts and our
commercialization efforts.

We may choose to begin new R&D efforts or we may choose to launch additional marketing efforts. These

efforts may require funding in addition to the cash and cash equivalents totaling approximately $85.3 million and
$8.1 million in marketable securities available at December 31, 2020. While our consolidated financial
statements have been prepared on a going concern basis, we expect to continue incurring significant losses for
the foreseeable future and will need to generate significant revenue to sustain operations and successfully
commercialize neratinib. While we have been successful in raising financing in the past, there can be no
assurance that we will be able to do so in the future. Our ability to obtain funding may be adversely impacted by
uncertain market conditions, including the global COVID-19 pandemic, our success in commercializing
neratinib, unfavorable decisions of regulatory authorities or adverse clinical trial results. The outcome of these
matters cannot be predicted at this time. We believe that our existing cash and cash equivalents and marketable
securities as of December 31, 2020 and proceeds that will become available to us through product sales and
sub-license payments are sufficient to satisfy our operating cash and capital needs for at least one year after the
filing of this Annual Report.

89

In addition, we have based our estimate of capital needs on assumptions that may prove to be wrong.
Changes may occur that would consume our available capital faster than anticipated, including changes in and
progress of our development activities, the impact of commercialization efforts, acquisitions of additional drug
candidates and changes in regulation. Potential sources of financing include strategic relationships, public or
private sales of equity or debt and other sources of funds. We may seek to access the public or private equity
markets when conditions are favorable due to our long-term capital requirements. If we raise funds by selling
additional shares of common stock or other securities convertible into common stock, the ownership interests of
our existing stockholders will be diluted. If we are not able to obtain financing when needed, we may be unable
to carry out our business plan. As a result, we may have to significantly limit our operations, and our business,
financial condition and results of operations would be materially harmed. In such an event, we will be required to
undertake a thorough review of our programs, and the opportunities presented by such programs, and allocate our
resources in the manner most prudent.

Off-Balance Sheet Arrangements

We do not have any “off-balance sheet arrangements,” as defined by the SEC regulations.

Contractual Obligations

Contractual obligations represent future cash commitments and liabilities under agreements with third
parties and exclude contingent liabilities for which we cannot reasonably predict future payment. Our contractual
obligations result from leases for office space and office equipment and the principal and interest owed under our
credit facility. We also have unrecognized tax benefits that, if recognized, would affect the effective tax rate at
December 31, 2020. We do not have tax positions for which it is reasonably possible that the total amounts of
unrecognized tax benefit will significantly increase or decrease within 12 months of the reporting date.
Additionally, the expected timing of payment of the obligations presented below is estimated based on current
information.

The following table represents our contractual obligations as of December 31, 2020, aggregated by type (in

thousands):

Contractual Obligations

Total

Operating lease obligations . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . .
Debt obligations (principal and interest)

$ 29,776
126,509

Less than
1 year

$ 5,365
23,194

1 - 3
years

3 - 5
years

More than
5 years

$11,114
78,214

$13,297
25,101

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$156,285

$28,559

$89,328

$38,398

—
—

—

Although we do have obligations for CRO services, the table above excludes potential payments we may be

required to make under our agreements with CROs because timing of payments and actual amounts paid under
those agreements may be different depending on the timing of receipt of goods or services or changes to agreed-
upon terms or amounts for some obligations, and those agreements are cancelable upon written notice by us and
therefore, not long-term liabilities. The contracts also contain variable costs and milestones that are hard to

90

predict as they are based on such things as patients enrolled and clinical trial sites, which can vary and therefore,
are also not included in the table above. The contracts held by us as of December 31, 2020, are summarized as
follows (in thousands):

Indication

HER2 Overexpressed/Amplified Breast Cancer (Extension)
. . . . . . . . . . . . . . . . . . . . .
HER2 Overexpressed/Amplified Breast Cancer (Licensor Legacy Clinical Trials) . . . .
HER2 Mutated Breast Cancer and HER2 Mutated Breast Cancer with Brain

Metastases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metastatic & Adjuvant Breast Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pre-Clinical Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Post-Clinical Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HER2 Mutated Solid Tumors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Estimated
Contractual
Obligation
as of
December 31,
2020

$ 5,242
371

456
10,399
22,003
1,256
2,645
24,849

Months
Remaining
on Contract

12
3

24
5
14
11
10
15

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$67,221

In regard to our contractual obligations in relation to the Pfizer in-license agreement, as consideration for
the license, we are required to make substantial payments upon the achievement of certain milestones totaling
approximately $187.5 million if all such milestones are achieved. The remaining milestone amounts were not
included in the table above as the timing of when or if these payments will be made is uncertain. In connection
with the FDA approval of NERLYNX in July of 2017, we triggered a one-time milestone payment pursuant to
the agreement. In June 2020, we entered into a letter agreement with Pfizer relating to the method of payment
associated with a milestone payment under our license agreement with Pfizer (see Note 14-Commitments and
Contingencies in the accompanying notes to the financial statements). Should we commercialize any more of the
compounds licensed from Pfizer or any products containing any of these compounds, we will be obligated to pay
to Pfizer annual royalties at a fixed rate in the low to mid-teens of net sales of all such products, subject to certain
reductions and offsets in some circumstances. Our royalty obligation continues, on a product-by-product and
country-by-country basis, until the later of (i) the last to expire licensed patent covering the applicable licensed
product in such country, or (ii) the earlier of generic competition for such licensed product reaching a certain
level in such country or expiration of a certain time period after first commercial sale of such licensed product in
such country. In the event that we sublicense the rights granted to us under the license agreement with Pfizer to a
third party, the same milestone and royalty payments are required. We can terminate the license agreement at
will, or for safety concerns, in each case upon specified advance notice.

See Note 13—Income Taxes and Note 14—Commitments and Contingencies in the accompanying notes to

the financial statements for a summary of our uncertain tax positions and contracts held by us as of December 31,
2020. As of December 31, 2020, the amount of unrecognized tax benefit was $3.3 million, and is also not
included in the table above as the timing of when or if these payments will be made is uncertain.

Critical Accounting Policies

The discussion and analysis of our consolidated financial condition and results of operations are based upon

our consolidated financial statements, which have been prepared in conformity with GAAP. The preparation of
these consolidated financial statements requires us to make estimates and assumptions that affect the reported
amounts of assets, liabilities, and expenses, and related disclosure of contingent assets and liabilities reported in
our consolidated financial statements. The estimation process requires assumptions to be made about future
events and conditions and, as a result, is inherently subjective and uncertain. Actual results could differ
materially from our estimates.

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The SEC defines critical accounting policies as those that are, in management’s view, most important to the
portrayal of our financial condition and results of operations and most demanding of our judgment. We consider
the following policies to be critical to an understanding of our consolidated financial statements and the
uncertainties associated with the complex judgments made by us that could impact our results of operations,
financial position, and cash flows.

Revenue Recognition

Under Accounting Standards Codification, or ASC, Topic 606—Revenue from Contracts with Customers, or

ASC 606, we recognize revenue when a customer obtains control of the promised goods or services, in an
amount that reflects the consideration which we expect to be entitled in exchange for those goods or services. We
had no contracts with customers until the FDA approved NERLYNX on July 17, 2017. Subsequent to receiving
FDA approval, we entered into a limited number of arrangements with specialty pharmacies and specialty
distributors in the United States to distribute NERLYNX. These arrangements are our initial contracts with
customers. We have determined that these sales channels with customers are similar.

Product Revenue, Net:

We sell NERLYNX to a limited number of specialty pharmacies and specialty distributors in the United

States. These customers subsequently resell our products to patients and certain medical centers or hospitals. In
addition to distribution agreements with these customers, we enter into arrangements with health care providers
and payors that provide for government mandated and/or privately negotiated rebates, chargebacks and discounts
with respect to the purchase of our products.

We recognize revenue on product sales when the specialty pharmacy or specialty distributor, as applicable,

obtains control of our product, which occurs at a point in time (upon delivery). Product revenue is recorded net of
applicable reserves for variable consideration.

Shipping and handling costs for product shipments occur prior to the customer obtaining control of the

goods and are recorded in cost of sales.

Reserves for Variable Consideration:

Revenue from product sales are recorded at the net sales price (transaction price), which includes estimates
of variable consideration for which reserves are established. Components of variable consideration include trade
discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor
rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within
contracts between us and our customers, payors, and other indirect customers relating to the sale of our products.
These reserves, as detailed below, are based on the amounts earned, or to be claimed on the related sales, and are
classified as reductions of accounts receivable or a current liability. These estimates take into consideration a
range of possible outcomes which are probability-weighted in accordance with the expected value method in
ASC 606 for relevant factors such as current contractual and statutory requirements, specific known market
events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves
reflect our best estimates of the amount of consideration to which it is entitled based on the terms of the
respective underlying contracts.

The amount of variable consideration which is included in the transaction price may be constrained, and is
included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the
cumulative revenue recognized under the contract will not occur in a future period. Our analyses also
contemplated application of the constraint in accordance with the guidance, under which it determined a
significant reversal of revenue would not occur in a future period for the estimates detailed below as of
December 31, 2020 and, therefore, the transaction price was not reduced further during the year ended

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December 31, 2020. Actual amounts of consideration ultimately received may differ from our estimates. If actual
results in the future vary from our estimates, we will adjust these estimates, which would affect net product
revenue and earnings in the period such variances become known.

Trade Discounts and Allowances:

We generally provide customers with discounts which include incentive fees that are explicitly stated in our

contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized. In
addition, we compensate (through trade discounts and allowances) our customers for sales order management,
data, and distribution services. However, we have determined such services received to date are not distinct from
our sale of products to the customer and, therefore, these payments have been recorded as a reduction of revenue
within the statement of operations.

Product Returns:

Consistent with industry practice, we offer the specialty pharmacies and specialty distributors limited
product return rights for damaged and expiring products, provided it is within a specified period around the
product expiration date as set forth in the applicable individual distribution agreement. We estimate the amount
of our product sales that may be returned by our customers and record this estimate as a reduction of revenue in
the period the related product revenue is recognized, as well as a reduction to accounts receivables, net on the
consolidated balance sheets. We currently estimate product returns using our sales information, including our
visibility into the inventory remaining in the distribution channel. We have an insignificant amount of returns to
date and believe that returns of our products will continue to be minimal.

Provider Chargebacks and Discounts:

Chargebacks for fees and discounts to providers represent the estimated obligations resulting from
contractual commitments to sell products to qualified healthcare providers at prices lower than the list prices
charged to customers who directly purchase the product from us. Customers charge us for the difference between
what they pay for the product and the ultimate selling price to the qualified healthcare providers. These reserves
are established in the same period that the related revenue is recognized, resulting in a reduction of product
revenue and a reduction to accounts receivable, net on the consolidated balance sheets. Chargeback amounts are
generally determined at the time of resale to the qualified healthcare provider by customers, and we generally
issue credits for such amounts within a few weeks of the customer’s notification to us of the resale. Chargebacks
consist of credits that we expect to issue for units that remain in the distribution channel at each reporting period
end that we expect will be sold to qualified healthcare providers, and chargebacks that customers have claimed,
but for which we have not yet issued a payment.

Government Rebates:

We are subject to discount obligations under state Medicaid programs and Medicare. These reserves are
recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the
establishment of a current liability which is included in accrued expenses on the consolidated balance sheets. Our
liability for these rebates consists of invoices received for claims from prior quarters that have not been paid or
for which an invoice has not yet been received, estimates of claims for the current quarter, and estimated future
claims that will be made for product that has been recognized as revenue, but which remains in the distribution
channel at the end of each reporting period.

Payor Rebates:

We contract with certain private payor organizations, primarily insurance companies and pharmacy benefit

managers, for the payment of rebates with respect to utilization of its products. We estimate these rebates and

93

record such estimates in the same period the related revenue is recognized, resulting in a reduction of product
revenue and the establishment of a current liability.

Other Incentives:

Other incentives which we offer include voluntary patient assistance programs, such as the co-pay assistance

program, which are intended to provide financial assistance to qualified commercially-insured patients with
prescription drug co-payments required by payors. The calculation of the accrual for co-pay assistance is based
on an estimate of claims and the cost per claim that we expect to receive associated with product that has been
recognized as revenue, but remains in the distribution channel at the end of each reporting period. The
adjustments are recorded in the same period the related revenue is recognized, resulting in a reduction of product
revenue and the establishment of a current liability which is included as a component of accrued expenses on the
consolidated balance sheets.

License Revenue:

We recognize license revenue under certain of our sub-license agreements that are within the scope of ASC
606. The terms of these agreements may contain multiple performance obligations, which may include licenses
and research and development activities. We evaluate these agreements under ASC 606 to determine the distinct
performance obligations. Non-refundable, up-front fees that are not contingent on any future performance and
require no consequential continuing involvement by us, are recognized as revenue when the license term
commences and the licensed data, technology or product is delivered. We defer recognition of non-refundable
upfront license fees if the performance obligations are not satisfied.

Prior to recognizing revenue, we make estimates of the transaction price, including variable consideration

that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the
extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur
and when the uncertainty associated with the variable consideration is subsequently resolved. Variable
consideration may include nonrefundable upfront license fees, payments for research and development activities,
reimbursement of certain third-party costs, payments based upon the achievement of specified milestones, and
royalty payments based on product sales derived from the collaboration.

If there are multiple distinct performance obligations, we allocate the transaction price to each distinct
performance obligation based on its relative standalone selling price. The standalone selling price is generally
determined based on the prices charged to customers or using expected cost-plus margin. Revenue is recognized
by measuring the progress toward complete satisfaction of the performance obligations using an input measure.

Royalty Revenue:

For sub-license agreements that are within the scope of ASC 606, we recognize revenue when the related

sales occur in accordance with the sales-based royalty exception under ASC 606-10-55-65. Royalty revenue
consists of consideration earned related to international sales of NERLYNX made by our sub-licensees in their
respective territories. We recognize royalty revenue when the performance obligations have been satisfied.

Legal Contingencies and Expense

For legal contingencies, we accrue a liability for an estimated loss if the potential loss from any claim or
legal proceeding is considered probable and the amount can be reasonably estimated. Legal fees and expenses are
expensed as incurred based on invoices or estimates provided by legal counsel. We periodically evaluate
available information, both internal and external, relative to such contingencies and adjust the accrual as
necessary. We determine whether a contingency should be disclosed by assessing whether a material loss is

94

deemed reasonably possible. In determining whether a loss should be accrued, we evaluate, among other factors,
the degree of probability of an unfavorable outcome and the ability to make a reasonable estimate of the amount
of the loss (see Note 14-Commitments and Contingencies in the accompanying notes to the financial statements).

Recently Issued Accounting Standards

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326):
Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires that credit losses be reported
using an expected losses model rather than the incurred losses model that is currently used, and establishes
additional disclosures related to credit risks. For trade accounts receivable, we recognize credit losses based on
lifetime expected losses using the probability of default method. For available-for-sale debt securities with
unrealized losses, this standard now requires allowances to be recorded instead of reducing the amortized cost of
the investment. These amendments under ASU 2016-13 are effective for interim and annual fiscal periods
beginning after December 15, 2019. We adopted ASU 2016-13, and the adoption did not have a material effect
on our current financial position, results of operations or financial statement disclosures.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure

Framework-Changes to the Disclosure Requirements for Fair Value Measurement. As of January 1, 2020, we
adopted the amendments in ASU 2018-13, which modifies the disclosure requirements on fair value
measurements. The removed and modified disclosures were adopted on a retrospective basis and the new
disclosures were adopted on a prospective basis. The adoption of ASU 2018-13 did not have a material effect on
our current financial position, results of operations or financial statement disclosures.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the
Accounting for Income Taxes, as part of its Simplification Initiative to reduce the cost and complexity in
accounting for income taxes. The amendments in ASU 2019-12 remove certain exceptions related to the
approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and
the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also amends other aspects of
the guidance to help simplify and promote consistent application of GAAP. The guidance is effective for interim
and annual periods beginning after December 15, 2020, with early adoption permitted. We do not expect ASU
2019-12 to have a material effect on our current financial position, results of operations or financial statement
disclosures.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Some of the securities in which we invest have market risk in that a change in prevailing interest rates may
cause the principal amount of the cash equivalents to fluctuate. Financial instruments that potentially subject us
to significant concentrations of credit risk consist primarily of cash and cash equivalents. We invest our excess
cash primarily in cash equivalents such as money market investments as of December 31, 2020. The primary
objectives of our investment activities are to ensure liquidity and to preserve principal while at the same time
maximizing the income we receive from our cash and cash equivalents without significantly increasing risk.
Additionally, we established guidelines regarding approved investments and maturities of investments, which are
designed to maintain safety and liquidity.

Because of the short-term maturities of our cash equivalents, we do not believe that a 10% increase in

interest rates would have a material effect on the realized value of our cash equivalents.

We also have interest rate exposure as a result of our outstanding term loans. As of December 31, 2020, the

aggregate outstanding principal amounts of the term loans was $100 million. The term loans bear interest at an
annual rate equal to the greater of (i) 9.00% and (ii) the sum of (a) the “prime rate,” as reported in The Wall
Street Journal on the last business day of the month that immediately precedes the month in which the interest

95

will accrue, plus (b) 3.5%. If overall interest rates had increased by 100 basis points during the year ended
December 31, 2020 our interest expense would not have been materially affected.

ITEM 8.

FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

All financial statements and supplementary data required by this Item are listed in Part IV, Item 15 of this

Annual Report and are presented beginning on Page F-1.

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND

FINANCIAL DISCLOSURE

Not applicable.

ITEM 9A. CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

We maintain disclosure controls and procedures that are designed to ensure that information required to be

disclosed in our reports under the Exchange Act, is recorded, processed, summarized and reported within the
timelines specified in the SEC’s rules and forms, and that such information is accumulated and communicated to
our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow
timely decisions regarding required disclosures. In designing and evaluating the disclosure controls and
procedures, management recognized that any controls and procedures, no matter how well designed and
operated, can only provide reasonable assurance of achieving the desired control objectives and in reaching a
reasonable level of assurance, management necessarily was required to apply its judgment in evaluating the cost-
benefit relationship of possible controls and procedures.

Under the supervision and with the participation of our management, including our Chief Executive Officer

and Chief Financial Officer, we have evaluated the effectiveness of our disclosure controls and procedures (as
defined under Exchange Act Rule 13a-15(e)), as of December 31, 2020. Based on that evaluation, our Chief
Executive Officer and Chief Financial Officer have concluded that these disclosure controls and procedures were
effective as of December 31, 2020.

Changes in Internal Control over Financial Reporting

There was no change in our internal control over financial reporting that occurred during the year ended
December 31, 2020, that has materially affected, or is reasonably likely to materially affect, our 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, as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act. Internal control over financial
reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and
the preparation of financial statements for external purposes in accordance with accounting principles generally
accepted in the United States of America.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect
misstatements. Also, 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.

96

Under the supervision and with the participation of our management, including our Chief Executive Officer

and Chief Financial Officer, we conducted an evaluation of the effectiveness of our internal control over
financial reporting as of December 31, 2020. Management based its assessment on the criteria set forth by the
Committee of Sponsoring Organizations of the Treadway Commission in Internal Control—Integrated
Framework—2013 (COSO 2013 framework). Based on this evaluation, our management concluded that, as of
December 31, 2020, our internal control over financial reporting was effective.

Our internal control over financial reporting as of December 31, 2020 has been audited by KPMG LLP, our

independent registered public accounting firm, as stated in their report, which expresses an unqualified opinion
on the effectiveness of our internal control over financial reporting as of December 31, 2020.

97

Report of Independent Registered Public Accounting Firm

To the Stockholders and Board of Directors
Puma Biotechnology, Inc.:

Opinion on Internal Control Over Financial Reporting

We have audited Puma Biotechnology, Inc. and subsidiaries’ (the Company) internal control over financial
reporting as of December 31, 2020, based on criteria set forth by the Committee of Sponsoring Organizations of
the Treadway Commission in Internal Control – Integrated Framework (2013). In our opinion, the Company
maintained, in all material respects, effective internal control over financial reporting as of December 31, 2020,
based on criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in
Internal Control – Integrated Framework (2013).

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board

(United States) (PCAOB), the consolidated balance sheets of the Company as of December 31, 2020 and 2019,
the related consolidated statements of operations, comprehensive loss, stockholders’ (deficit) equity, and cash
flows for each of the years in the three-year period ended December 31, 2020, and the related notes (collectively,
the consolidated financial statements), and our report dated March 1, 2021 expressed an unqualified opinion on
those consolidated financial statements.

Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial
reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the
accompanying Management’s Report on Internal Control over Financial Reporting. Our responsibility is to
express an opinion on the Company’s internal control over financial reporting based on our audit. We are a
public accounting firm registered with the 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 audit in accordance with the standards of the PCAOB. Those standards require that we

plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial
reporting was maintained in all material respects. Our audit of internal control over financial reporting included
obtaining an understanding of internal control over financial reporting, assessing the risk that a material
weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on
the assessed risk. Our audit also included performing such other procedures as we considered necessary in the
circumstances. We believe that our audit provides a reasonable basis for our opinion.

Definition and Limitations of Internal Control Over Financial Reporting

A company’s internal control over financial reporting is a process designed 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. A company’s internal control over financial reporting
includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail,
accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable
assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance
with generally accepted accounting principles, and that receipts and expenditures of the company are being made
only in accordance with authorizations of management and directors of the company; and (3) 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.

98

Because of its inherent limitations, internal control over financial reporting may not prevent or detect
misstatements. Also, 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.

/s/ KPMG LLP

Los Angeles, California
March 1, 2021

99

ITEM 9B. OTHER INFORMATION

Entry Into a Material Definitive Agreement.

On February 24, 2021, we and Pierre Fabre Medicament SAS, or Pierre Fabre, entered into a second
amendment to the sub-license agreement, dated March 29, 2019, by and between us and Pierre Fabre, as
amended November 25, 2019, to extend Pierre Fabre’s commercial rights for NERLYNX to Greater China,
which includes mainland China, Taiwan, Hong Kong and Macao, or the Second Pierre Fabre Amendment. Under
the terms of the Second Pierre Fabre Amendment, we will receive an upfront payment of $50.0 million, as well
as additional regulatory and sales-based milestone payments that could add up to an additional $240.0 million.
These milestones will be based solely on regulatory and sales achievements in Greater China. In addition, we are
entitled to receive double-digit tiered royalties on the sales of NERLYNX in Greater China.

The foregoing description of the Second Pierre Fabre Amendment is qualified in its entirety by reference to
the Second Pierre Fabre Amendment, a copy of which will be filed as an exhibit to our Quarterly Report on Form
10-Q for the quarter ended March 31, 2021.

Termination of a Material Definitive Agreement.

As described further in the section entitled “Item 3. Legal Proceedings” above, in July 2020, we filed a
request for arbitration against CANbridge BIOMED Limited, or CANbridge, in connection with the sub-license
agreement, or the CANbridge Agreement, dated January 30, 2018, by and between us and CANbridge, to
commercialize NERLYNX in Greater China. On February 24, 2021, we and CANbridge mutually agreed to
terminate the CANbridge Agreement and all other related agreements. Subject to the terms of a termination
agreement between us and CANbridge, or the CANbridge Termination Agreement, we agreed to pay CANbridge
a one-time termination fee of $20.0 million to return all rights to NERLYNX in Greater China back to us and
assist with the transfer of such rights to us.

The foregoing description of the CANbridge Termination Agreement is qualified in its entirety by reference
to the CANbridge Termination Agreement, a copy of which will be filed as an exhibit to our Quarterly Report on
Form 10-Q for the quarter ended March 31, 2021.

Part III

ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

The information required by this Item will be included in our 2021 Proxy Statement, which will be filed

with the SEC, and is incorporated by reference herein.

ITEM 11. EXECUTIVE COMPENSATION

The information required by this Item will be included in our 2021 Proxy Statement, which will be filed

with the SEC, and is incorporated by reference herein.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

AND RELATED STOCKHOLDER MATTERS

The information required by this Item will be included in our 2021 Proxy Statement, which will be filed

with the SEC, and is incorporated by reference herein.

100

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR

INDEPENDENCE

The information required by this Item will be included in our 2021 Proxy Statement, which will be filed

with the SEC, and is incorporated by reference herein.

ITEM 14. PRINCIPAL ACCOUNTING FEES AND SERVICES

The information required by this Item will be included in our 2021 Proxy Statement, which will be filed

with the SEC, and is incorporated by reference herein.

Part IV

ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES

Reference is made to the Index to Consolidated Financial Statements beginning on Page F-1 hereof.

Consolidated Financial Statement Schedules

(a) Documents Filed as Part of Report

(1) Consolidated Financial Statements

•
•
•

•

•

•

•

Report of Independent Registered Public Accounting Firm . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Balance Sheets at December 31, 2020 and 2019 . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Operations for the Years Ended December 31, 2020, 2019

and 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consolidated Statements of Comprehensive Loss for the Years Ended December 31,

2020, 2019 and 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consolidated Statements of Stockholders’ (Deficit) Equity for the Years Ended

December 31, 2020, 2019 and 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consolidated Statements of Cash Flows for the Years Ended December 31, 2020, 2019

F-2
F-5

F-6

F-7

F-8

and 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Notes to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

F-9
F-10

(2) Consolidated Financial Statement Schedules

Consolidated Financial Statement Schedules have been omitted because they are either not required or not

applicable, or because the information required to be presented is included in the consolidated financial
statements or the notes thereto included in this Annual Report.

(3) Exhibits

The exhibits listed on the accompanying Exhibit Index are filed or incorporated by reference as part of this

Annual Report and such Exhibit Index is incorporated by reference herein.

ITEM 16. Form 10-K SUMMARY

None.

101

Exhibit
Number

2.1

3.1

3.2

3.3

3.4

4.1

4.2#

4.3

EXHIBIT INDEX

Description

Agreement and Plan of Merger, dated September 29, 2011, by and among Innovative Acquisitions
Corp., IAC Merger Corporation, a Delaware corporation and wholly-owned subsidiary of the
Company, and Puma Biotechnology, Inc., a Delaware corporation (filed as Exhibit 2.1 to the
Company’s Current Report on Form 8-K filed with the SEC on October 4, 2011 and incorporated
herein by reference)

Certificate of Merger relating to the merger of IAC Merger Corporation with and into Puma
Biotechnology, Inc., filed with the Secretary of State of Delaware on October 4, 2011 (filed as
Exhibit 3.1 to the Company’s Current Report on Form 8-K filed with the SEC on October 11, 2011
and incorporated herein by reference)

Certificate of Ownership and Merger relating to the merger of Puma Biotechnology, Inc. with and
into Innovative Acquisitions Corp., filed with the Secretary of State of the State of Delaware on
October 4, 2011 (filed as Exhibit 3.2 to the Company’s Current Report on Form 8-K filed with the
SEC on October 11, 2011 and incorporated herein by reference)

Second Amended and Restated Certificate of Incorporation of the Company, as filed with the
Secretary of State of the State of Delaware on June 14, 2016 (filed as Exhibit 3.1 to the Company’s
Current Report on Form 8-K filed with the SEC on June 15, 2016 and incorporated herein by
reference)

Third Amended and Restated Bylaws of the Company (filed as Exhibit 3.1 to the Company’s Current
Report on Form 8-K filed with the SEC on May 28, 2019 and incorporated herein by reference)

Form of Common Stock Certificate (filed as Exhibit 4.1 to the Company’s Registration Statement on
Form S-1/A filed with the SEC on February 1, 2012 and incorporated herein by reference)

Warrant to Purchase Shares of Common Stock of Puma Biotechnology, Inc., dated October 4, 2011,
issued to Alan H. Auerbach (filed as Exhibit 4.2 to the Company’s Current Report on Form 8-K filed
with the SEC on October 11, 2011 and incorporated herein by reference)

Description of the Company’s Securities Registered Pursuant to Section 12 of the Securities
Exchange Act of 1934 (filed as Exhibit 4.3 to the Company’s Annual Report on Form 10-K filed
with the SEC on February 28, 2020 and incorporated herein by reference)

10.1(a)* License Agreement, dated August 18, 2011, by and between the Company, as successor to Puma

Biotechnology, Inc., and Pfizer Inc. (filed as Exhibit 10.1 to the Company’s Current Report on Form
8-K/A filed with the SEC on December 16, 2011 and incorporated herein by reference)

10.1(b)* Amendment No. 1 to License Agreement dated July 18, 2014, between the Company and Pfizer Inc.

(filed as Exhibit 10.1 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on
November 10, 2014 and incorporated herein by reference)

10.1(c)** Pfizer Letter Agreement dated June 8, 2020, by and between the Company and Pfizer Inc. (filed as

Exhibit 10.2 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on August 6, 2020
and incorporated herein by reference)

10.1(d)+**Amendment No. 2 to License Agreement dated October 29, 2020, between the Company and Pfizer

Inc.

10.2(a)# Puma Biotechnology, Inc. 2011 Incentive Award Plan (filed as Exhibit 10.4 to the Company’s

Current Report on Form 8-K filed with the SEC on October 11, 2011 and incorporated herein by
reference)

102

Exhibit
Number

Description

10.2(b)# First Amendment to Puma Biotechnology, Inc. 2011 Incentive Award Plan (filed as Appendix A to

the Company’s Proxy Statement on Form DEFR14A filed with the SEC on June 4, 2014 and
incorporated herein by reference)

10.2(c)# Second Amendment to Puma Biotechnology, Inc. 2011 Incentive Award Plan (filed as Exhibit 10.1

to the Company’s Quarterly Report on Form 10-Q filed with the SEC on August 10, 2015 and
incorporated herein by reference)

10.2(d)# Third Amendment to Puma Biotechnology, Inc. 2011 Incentive Award Plan (filed as Exhibit 10.1 to

the Company’s Current Report on Form 8-K filed with the SEC on June 14, 2017 and incorporated
herein by reference)

10.2(e)# Fourth Amendment to Puma Biotechnology, Inc. 2011 Incentive Award Plan (filed as Exhibit 10.2 to

the Company’s Current Report on Form 8-K filed with the SEC on June 14, 2017 and incorporated
herein by reference)

10.2(f)# Puma Biotechnology, Inc. 2017 Employment Inducement Incentive Award Plan (filed as Exhibit

99.1 to the Company’s Registration Statement on Form S-8 filed with the SEC on May 31, 2017 and
incorporated herein by reference)

10.2(g)# First Amendment to Puma Biotechnology, Inc. 2017 Employment Inducement Incentive Award Plan

(filed as Exhibit 99.2 to the Company’s Registration Statement on Form S-8 filed with the SEC on
February 28, 2020 and incorporated herein by reference)

10.2(h)# Form of Stock Option Grant Notice and Stock Option Agreement, issued pursuant to the 2011

Incentive Award Plan (filed as Exhibit 10.5 to the Company’s Annual Report on Form 10-K filed
with the SEC on March 29, 2012 and incorporated herein by reference)

10.2(i)# Form of Chief Executive Officer Stock Option Grant Notice and Stock Option Agreement, issued

pursuant to the 2011 Incentive Award Plan (filed as Exhibit 10.6 to the Company’s Annual Report on
Form 10-K filed with the SEC on March 29, 2012 and incorporated herein by reference)

10.2(j)# Form of Performance Share Award Agreement, issued pursuant to the 2011 Incentive Award Plan

(filed as Exhibit 10.2(d) to the Company’s Annual Report on Form 10-K filed with the SEC on
March 3, 2014 and incorporated herein by reference)

10.2(k)# Form of Restricted Stock Unit Award Agreement, issued pursuant to the 2011 Incentive Award Plan
(filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on
October 17, 2016 and incorporated herein by reference)

10.2(l)# Form of Stock Option Grant Notice and Stock Option Agreement, issued pursuant to the 2017

Employment Inducement Incentive Award Plan (filed as Exhibit 10.2(k) to the Company’s Annual
Report on Form 10-K filed with the SEC on March 1, 2019 and incorporated herein by reference)

10.3(a) Registration Rights Agreement, dated October 4, 2011, by and among Puma, the investors listed on
Exhibit A attached thereto and the Company (filed as Exhibit 10.5 to the Company’s Current Report
on Form 8-K/A filed with the SEC on December 16, 2011 and incorporated herein by reference)

10.3(b) Amendment No. 1 to Registration Rights Agreement (filed as Exhibit 10.2 to the Company’s Current
Report on Form 8-K filed with the SEC on November 23, 2011 and incorporated herein by reference)

10.4(a) Office Lease by and between the Company and CA – 10880 Wilshire Limited Partnership, executed
on December 7, 2011 (filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with
the SEC on December 13, 2011 and incorporated herein by reference)

10.4(b)

First Amendment to the Office Lease, dated as of November 28, 2012, by and between the Company
and CA – 10880 Wilshire Limited Partnership (filed as Exhibit 10.13(b) to the Company’s Annual
Report on Form 10-K filed with the SEC on April 1, 2013 and incorporated herein by reference)

103

Exhibit
Number

10.4(c)

10.4(d)

10.4(e)

10.5#

10.6(a)

10.6(b)

10.6(c)

10.6(d)

10.7#

10.8#

10.9#

Description

Second Amendment to the Office Lease, dated as of December 3, 2013, by and between the
Company and CA – 10880 Wilshire Limited Partnership (filed as Exhibit 10.6(c) to the Company’s
Annual Report on Form 10-K filed with the SEC on March 3, 2014 and incorporated herein by
reference)

Third Amendment to the Office Lease, dated as of March 18, 2014, by and between the Company
and CA – 10880 Wilshire Limited Partnership (filed as Exhibit 10.5(d) to the Company’s Annual
Report on Form 10-K filed with the SEC on March 2, 2015 and incorporated herein by reference)

Fourth Amendment to the Office Lease, dated as of July 31, 2015, by and between the Company and
CA – 10880 Wilshire Limited Partnership (filed as Exhibit 10.1 to the Company’s Quarterly Report
on Form 10-Q filed with the SEC on November 9, 2015 and incorporated herein by reference)

Employment Agreement, dated January 19, 2012, by and between the Company and Alan H.
Auerbach (filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on
January 24, 2012 and incorporated herein by reference)

Office Lease by and between DWF III Gateway, LLC and the Company, executed June 7, 2012 (filed
as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on June 13, 2012
and incorporated herein by reference)

First Amendment to Lease, dated as of May 19, 2014, by and between DWF III Gateway, LLC and
Puma Biotechnology, Inc. (filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed
with the SEC on May 23, 2014 and incorporated herein by reference)

Second Amendment to Lease, dated as of June 10, 2014, by and between DWF III Gateway, LLC
and Puma Biotechnology, Inc. (filed as Exhibit 10.2 to the Company’s Quarterly Report on Form
10-Q filed with the SEC on August 10, 2015 and incorporated herein by reference)

Third Amendment to Lease, dated as of July 21, 2015, by and between PR 707 Gateway, LLC (as
sucessor in interest to DWF III Gateway, LLC) and the Company (filed as Exhibit 10.2 to the
Company’s Quarterly Report on Form 10-Q filed with the SEC on November 9, 2015 and
incorporated herein by reference)

Letter Agreement, dated May 2, 2012, between the Company and Richard P. Bryce (filed as Exhibit
10.1 to the Company’s Current Report on Form 8-K filed with the SEC on June 26, 2012 and
incorporated herein by reference)

Form of Indemnification Agreement (filed as Exhibit 10.17 to the Company’s Registration Statement
on Form S-1/A filed with the SEC on October 15, 2012 and incorporated herein by reference)

Amended Non-Employee Director Compensation Program (filed as Exhibit 10.3 to the Company’s
Quarterly Report on Form 10-Q filed with the SEC on May 7, 2020 and incorporated herein by
reference)

10.10(a)* License Agreement, dated November 20, 2017, by and between the Company and Specialised

Therapeutics Asia Pte Ltd. (filed as Exhibit 10.13 to the Company’s Annual Report on Form 10-K
filed with the SEC on March 9, 2018 and incorporated herein by reference)

10.10(b)* Amendment No. 1, dated April 20, 2018, to the License Agreement by and between the Company

and Specialised Therapeutics Asia Pte Ltd. (filed as Exhibit 10.2 to the Company’s Quarterly Report
on Form 10-Q filed with the SEC on August 9, 2018 and incorporated herein by reference)

10.11(a)**Amended and Restated Loan and Security Agreement dated June 28, 2019, by and among the
Company and Oxford Finance LLC, as collateral agent and lender (filed as Exhibit 10.1 to the
Company’s Quarterly Report on Form 10-Q filed with the SEC on August 9, 2019 and incorporated
herein by reference)

104

Exhibit
Number

Description

10.11(b)** First Amendment to Amended and Restated Loan and Security Agreement, dated February 27,

2020, by and between the Company and Oxford Finance LLC, as collateral agent and lender (filed
as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on March 4, 2020
and incorporated herein by reference)

10.11(c)

Second Amendment to Amended and Restated Loan and Security Agreement, dated July 6, 2020,
by and between the Company and Oxford Finance LLC, as collateral agent and Lender (filed as
Exhibit 10.3 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on August 6,
2020 and incorporated herein by reference)

10.11(d)** Third Amendment to Amended and Restated Loan and Security Agreement, dated August 5, 2020,

by and between the Company and Oxford Finance LLC, as collateral agent and Lender (filed as
Exhibit 10.4 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on August 6,
2020 and incorporated herein by reference)

10.12#

Letter Agreement, dated December 8, 2017, between the Company and Douglas Hunt (filed as
Exhibit 10.15 to the Company’s Annual Report on Form 10-K filed with the SEC on March 9, 2018
and incorporated herein by reference)

10.13(a)* Collaboration and License Agreement, dated January 30, 2018, between the Company and

CANbridge Biomed Limited (as successor in interest to CANbridgepharma Limited) (filed as
Exhibit 10.1 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on May 10, 2018
and incorporated herein by reference)

10.13(b)* Side Letter Agreement, dated November 19, 2018, between the Company and CANbridge Biomed

Limited (as successor in interest to CANbridgepharma Limited) (filed as Exhibit 10.15(b) to the
Company’s Annual Report on Form 10-K filed with the SEC on March 1, 2019 and incorporated
herein by reference)

10.14*

10.15*

10.16#

License Agreement, dated March 30, 2018, between the Company and Pint Pharma International
SA (filed as Exhibit 10.2 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on
May 10, 2018 and incorporated herein by reference)

Supply Agreement, dated April 20, 2018, by and between the Company and Specialised
Therapeutics Asia Pte. Ltd. (filed as Exhibit 10.3 to the Company’s Quarterly Report on Form 10-Q
filed with the SEC on August 9, 2018 and incorporated herein by reference)

Letter Agreement, dated September 28, 2018, between the Company and Maximo F. Nougues (filed
as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on November 9,
2018 and incorporated herein by reference)

10.17(a)* License Agreement, dated January 9, 2019, by and between the Company and Knight Therapeutics
Inc. (filed as Exhibit 10.19 to the Company’s Annual Report on Form 10-K filed with the SEC on
March 1, 2019 and incorporated herein by reference)

10.17(b)** Amendment to the License Agreement, dated December 18, 2019, by and between the Company

and Knight Therapeutics, Inc. (filed as Exhibit 10.17(b) to the Company’s Annual Report on Form
10-K filed with the SEC on February 28, 2020 and incorporated herein by reference)

10.18(a)** License Agreement, dated March 29, 2019, by and between the Company and Pierre Fabre

Medicament SAS (filed as Exhibit 10.3 to the Company’s Quarterly Report on Form 10-Q filed
with the SEC on May 10, 2019 and incorporated herein by reference)

105

Exhibit
Number

10.18(b)**

10.18(c)**

Description

First Amendment to the License Agreement, dated September 17, 2019, by and between the
Company and Pierre Fabre Medicament SAS (filed as Exhibit 10.18(b) to the Company’s
Annual Report on Form 10-K filed with the SEC on February 28, 2020 and incorporated herein
by reference)

Second Amendment to the License Agreement, dated November 25, 2019, by and between the
Company and Pierre Fabre Medicament SAS (filed as Exhibit 10.18(c) to the Company’s
Annual Report on Form 10-K filed with the SEC on February 28, 2020 and incorporated herein
by reference)

10.19#+**

Letter Agreement, dated February 13, 2020, by and between the Company and Jeff J. Ludwig

21.1+

23.1+

24.1+

31.1+

31.2+

32.1++

32.2++

Subsidiaries

Consent of KPMG LLP

Power of Attorney (included on signature page)

Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act
of 2002

Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act
of 2002

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

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

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 Document

101.PRE+

Inline XBRL Taxonomy Extension Linkbase Document

104+

Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101)

+

++

*

**

#

Filed herewith

Furnished herewith

Portions of this exhibit (indicated by asterisks) have been omitted pursuant to a request for
confidential treatment pursuant to Rule 24b-2 under the Securities Exchange Act of 1934.

Portions of this exhibit (indicated by asterisks) have been omitted pursuant to Regulation S-K,
Item 601(b)(10). Such omitted information is not material and would likely cause competitive
harm to the registrant if publicly disclosed. Additionally, certain schedules and attachments to
certain of these exhibits have been omitted pursuant to Regulation S-K, Item 601(a)(5).

Management contract or compensatory plan or arrangement.

106

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, on March 1, 2021.

Signatures

PUMA BIOTECHNOLOGY, INC.

By: /s/ Alan H. Auerbach

Alan H. Auerbach
President & Chief Executive Officer
(Principal Executive Officer)

KNOWN BY ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below

constitutes and appoints Alan H. Auerbach and Maximo Nougues, or either of them, as his or her true and lawful
attorneys-in-fact and agents, with full power of substitution and resubstitution, for him and in his name, place and
stead, in any and all capacities, to sign any and all amendments to this Annual Report on Form 10-K and any
documents related to this report and filed pursuant to the Securities Exchange Act of 1934, and to file the same, with
all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, full power and authority to do and perform each and every act and
thing requisite and necessary to be done in connection therewith as fully to all intents and purposes as he or she
might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or their
substitute or substitutes may lawfully do or cause to be done by virtue hereof. This power of attorney shall be
governed by and construed with the laws of the State of Delaware and applicable federal securities laws.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed by the

following persons in the capacities and on the dates indicated.

Signature

Title

Date

/s/ Alan H. Auerbach
Alan H. Auerbach

/s/ Maximo Nougues
Maximo Nougues

/s/ Ann C. Miller
Ann C. Miller

/s/ Michael P. Miller
Michael P. Miller

/s/

Jay M. Moyes
Jay M. Moyes

/s/ Hugh O’Dowd
Hugh O’Dowd

/s/ Adrian M. Senderowicz
Adrian M. Senderowicz

/s/ Brian M. Stuglik
Brian M. Stuglik

/s/ Troy E. Wilson
Troy E. Wilson

Chairman of the Board of Directors, President and
Chief Executive Officer (Principal Executive Officer)

March 1, 2021

Chief Financial Officer (Principal Financial Officer
and Principal Accounting Officer)

March 1, 2021

Director

Director

Director

Director

Director

Director

Director

107

March 1, 2021

March 1, 2021

March 1, 2021

March 1, 2021

March 1, 2021

March 1, 2021

March 1, 2021

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES
INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting Firm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Balance Sheets at December 31, 2020 and 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Operations for the Years Ended December 31, 2020, 2019, and 2018 . . . . . . .
Consolidated Statements of Comprehensive Loss for the Years Ended December 31, 2020, 2019, and

Page

F-2
F-5
F-6

2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Stockholders’ (Deficit) Equity for the Years Ended December 31, 2020, 2019,
F-8
and 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Cash Flows for the Years Ended December 31, 2020, 2019, and 2018 . . . . . . .
F-9
Notes to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-10

F-7

F-1

Report of Independent Registered Public Accounting Firm

To the Stockholders and Board of Directors
Puma Biotechnology, Inc.:

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of Puma Biotechnology, Inc. and subsidiaries
(the Company) as of December 31, 2020 and 2019, the related consolidated statements of operations,
comprehensive loss, stockholders’ (deficit) equity, and cash flows for each of the years in the three-year period
ended December 31, 2020, and the related notes (collectively, the consolidated financial statements). In our
opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the
Company as of December 31, 2020 and 2019, and the results of its operations and its cash flows for each of the
years in the three-year period ended December 31, 2020, in conformity with U.S. generally accepted accounting
principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board
(United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2020,
based on criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in
Internal Control – Integrated Framework (2013), and our report dated March 1, 2021 expressed an unqualified
opinion on the effectiveness of the Company’s internal control over financial reporting.

Change in Accounting Principle

As discussed in Note 2 to the consolidated financial statements, the Company has changed its method of
accounting for Leases as of January 1, 2019, due to the adoption of Financial Accounting Standards Boards
Accounting Standards Codification (ASC) Topic 842, Leases.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility
is to express an opinion on these consolidated financial statements based on our audits. We are a public
accounting firm registered with the 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 audit to obtain reasonable assurance about whether the consolidated financial statements are free
of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the
risks of material misstatement of the consolidated 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 consolidated 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 consolidated financial statements. We believe that our audits provide a reasonable
basis for our opinion.

Critical Audit Matters

The critical audit matters communicated below are matters arising from the current period audit of the
consolidated 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 consolidated financial statements
and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical

F-2

audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole,
and we are not, by communicating the critical audit matters below, providing separate opinions on the critical
audit matters or on the accounts or disclosures to which they relate.

Estimate of variable consideration related to net product sales

As discussed in Note 2 to the consolidated financial statements, the Company recognizes product revenue,
which includes estimates of variable consideration. For the year ended December 31, 2020, the Company
recorded product revenue, net of $196.7 million. The components of variable consideration include trade
discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor
rebates, and other incentives. These estimates take into consideration a range of possible outcomes that are
probability-weighted in accordance with the expected value method in ASC 606, Revenue from Contracts
with Customers. The range of possible outcomes is driven by relevant factors such as current contractual and
statutory requirements, specific known market events and trends, industry data, and forecasted customer
buying and payment patterns.

We identified the estimate of variable consideration for provider chargebacks and government rebates,
including consideration of the constraint on variable consideration, related to product sales, net as a critical
audit matter. Evaluating the key assumptions of forecasted patient buying and payment pattern assumptions
underlying the estimate for provider chargebacks and government rebates involved especially challenging
auditor judgment. We performed a sensitivity analysis in order to identify the key assumptions used to
estimate the Company’s variable consideration. These assumptions relate to estimating which of the
Company’s revenue transactions will ultimately be subject to a related provider chargeback or government
rebate.

The following are the primary procedures we performed to address this critical audit matter. We evaluated
the design and tested the operating effectiveness of certain internal controls related to the development of
the key assumptions used to determine estimated claims for provider chargebacks and government rebates.
We evaluated the forecasted patient buying and payment patterns estimate for the provider chargebacks and
government rebates by comparing them to the Company’s internal data, statutory information, and executed
third-party contracts. We assessed the Company’s estimate of the forecasted patient buying and payment
patterns by independently recalculating historical actual patient buying and payment pattern rates based on
historical actual claim data and compared current period forecasts to historical actual rates. We evaluated
the Company’s ability to accurately estimate provider chargebacks and government rebates, including
consideration of the constraint on variable consideration, by comparing historically recorded accruals to the
actual amount that was ultimately paid by the Company.

Assessment of the accrued legal verdict expense

As discussed in notes 2, 9, 14 and 16 to the consolidated financial statements, the Company is named as a
defendant in various legal proceedings, including the Hsu vs. Puma Biotechnology, Inc., et al. (Hsu) matter,
and has recorded an accrued legal verdict expense of $24.8 million as of December 31, 2020. The Company
records a liability in the consolidated financial statements for loss contingencies when a loss is known or
considered probable and the amount can be reasonably estimated. If the reasonable estimate of a known or
probable loss is a range, and no amount within the range is a better estimate than any other, the minimum
amount of the range is accrued. If a loss is reasonably possible but not known or probable, and can be
reasonably estimated, the estimated loss or range of loss is disclosed.

We identified the assessment of the accrued legal verdict expense for the Hsu matter as a critical audit
matter. This proceeding involves significant judgment by management when assessing the likelihood of a
loss being incurred and when determining whether a reasonable estimate of the loss or range of loss for each
claim can be made. The assessment of the accrued legal verdict expense required especially significant
auditor judgment, subjectivity, and effort in performing procedures and evaluating management’s

F-3

assessment of assumptions and estimate associated with the contingency and evaluation of possible
outcomes. Changes to the outcomes could have a significant effect on the estimated amount of the accrued
legal verdict expense.

The following are the primary procedures we performed to address this critical audit matter. We tested the
effectiveness of controls related to the Company’s evaluation of the liability related to the class action legal
proceedings, including internal controls over the Company’s determination of accrued legal verdict expense
related to the Hsu matter. We evaluated the reasonableness of Management’s assessment regarding the
extent of claimed damages for which an unfavorable outcome is reasonably possible or probable and
reasonably estimable and assessed the amounts accrued by performing legal inquiries and reading letters
received directly from the Company’s external legal counsel that discussed the Company’s legal matters,
including the Hsu matter. We read available court filings for litigation matters to corroborate certain
assumptions made by management regarding the extent of claimed damages and to search for contradictory
information. We obtained the claims report and amended claims report specific to the Hsu matter submitted
to the court by third parties and agreed the information to management’s accrued legal verdict expense
calculation. We evaluated the Company’s litigation contingencies disclosure of the Hsu matter for
consistency with our knowledge of the Company’s litigation matters.

/s/ KPMG LLP

We have served as the Company’s auditor since 2017.

Los Angeles, California
March 1, 2021

F-4

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES
CONSOLIDATED BALANCE SHEETS
(in thousands, except share and per share data)

December 31,
2020

December 31,
2019

ASSETS
Current assets:

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Marketable securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts receivable, net of allowance for credit loss of $1,000 and $0 . . . . . . .
Inventory, net
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses, current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred rent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restricted cash, current
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lease right-of-use assets, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Property and equipment, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intangible assets, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restricted cash, long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other, long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

85,293
8,096
25,543
3,454
11,262
198
8,850
3,443

146,139
16,404
2,481
74,140
3,311
1,745

60,037
51,607
28,896
3,170
13,259
154
8,850
323

166,296
18,522
3,304
40,461
4,323
1,999

Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

244,220

$

234,905

LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY
Current liabilities:

Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued expenses, current
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued in-licensed rights, current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Post-marketing commitment liability, current . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lease liabilities, current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of long-term debt

$

Total current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued expenses, long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lease liabilities, long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Post-marketing commitment liability, long-term . . . . . . . . . . . . . . . . . . . . . . . . .
Long-term debt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

12,076
61,325
20,993
2,481
3,094
14,286

114,255
25,963
19,549
6,379
84,025

250,171

19,183
69,030
—
—
2,624
—

90,837
—
22,643
9,000
94,962

217,442

Commitments and contingencies (Note 14)
Stockholders’ (deficit) equity:

Common stock—$.0001 par value per share; 100,000,000 shares authorized;

40,086,387 shares issued and outstanding at December 31, 2020 and
39,203,304 issued and outstanding at December 31, 2019 . . . . . . . . . . . . . . .
Additional paid-in capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated other comprehensive income . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated deficit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4
1,331,676
—

(1,337,631)

4
1,295,033
62
(1,277,636)

Total stockholders’ (deficit) equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(5,951)

17,463

Total liabilities and stockholders’ (deficit) equity . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

244,220

$

234,905

See Accompanying Notes to the Consolidated Financial Statements

F-5

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES
CONSOLIDATED STATEMENTS OF OPERATIONS
(in thousands, except share and per share data)

Revenue:

Product revenue, net
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
License revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Royalty revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating costs and expenses:

Cost of sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selling, general and administrative . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research and development

Total operating costs and expenses . . . . . . . . . . . . . . . . . . . . . . . . . . .

For the Year Ended December 31,

2020

2019

2018

$

$

196,728
22,700
5,682

225,110

39,374
118,488
97,650

255,512

211,619
60,250
391

272,260

36,815
141,639
132,851

311,305

200,491
50,500
—

250,991

34,621
146,171
164,854

345,646

Loss from operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(30,402)

(39,045)

(94,655)

Other income (expenses):

Interest income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Legal verdict expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss on debt extinguishment . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other income (expenses) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total other expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

489
(14,046)
(16,196)
—
367

(29,386)

2,847
(15,019)
(16,350)
(8,103)
128

(36,497)

1,796
(10,985)
(9,000)
—
(714)

(18,903)

Loss before income taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

(59,788) $

(75,542) $ (113,558)

Income tax expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(207)

(53)

(17)

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net loss applicable to common stockholders . . . . . . . . . . . . . . . . . . .

Net loss per share of common stock—basic and diluted . . . . . . . . . .

$

$

$

(59,995) $

(75,595) $ (113,575)

(59,995) $

(75,595) $ (113,575)

(1.52) $

(1.95) $

(2.99)

Weighted-average shares of common stock outstanding—basic and

diluted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

39,576,107

38,768,653

37,942,411

See Accompanying Notes to the Consolidated Financial Statements

F-6

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
(in thousands)

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other comprehensive (loss) income:

Unrealized (loss) gain on available-for-sale securities, net of tax of $0,

For the Year Ended December 31,

2020

2019

2018

$(59,995) $(75,595) $(113,575)

$0, and $0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(65)

Reclassifications of gain on available-for-sale securities, included in

“Other income (expenses)”, net of tax of $0, $0, and $0 . . . . . . . . . . . .

3

72

2

(12)

—

Comprehensive loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$(60,057) $(75,521) $(113,587)

See Accompanying Notes to the Consolidated Financial Statements

F-7

Balance at December 31, 2018 . . . 38,325,037

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES
CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ (DEFICIT) EQUITY
(in thousands, except share and per share data)

Common Stock

Shares

Amount

Additional
Paid-in
Capital

Receivables
from
Exercises
of Options

Accumulated
Other
Comprehensive
Income (Loss)

Accumulated
Deficit

Total

Balance at December 31, 2017 . . . 37,594,851 $

— —

4 $1,142,213
86,939

$(449)
—

$—
—

$(1,088,466) $ 53,302
86,939

—

Stock-based compensation . . .
Shares issued or restricted
stock units vested under
employee stock plans . . . . .

Unrealized loss on

available-for- sale
securities . . . . . . . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . .

Stock-based compensation . . .
Shares issued or restricted
stock units vested under
employee stock plans . . . . .

Reclassification of gain on

available-for-sale
securities . . . . . . . . . . . . . .

Unrealized gain on

available-for- sale
securities . . . . . . . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . .

Stock-based compensation . . .
Shares issued or restricted
stock units vested under
employee stock plans . . . . .

Reclassification of gain on

available-for-sale
securities . . . . . . . . . . . . . .

Unrealized loss on available-

for-sale securities . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . .

730,186 —

7,203

449

—

— —
— —

4
— —

—
—

1,236,355
57,327

—
—

—
—

(12)
—

(12)
—

878,267 —

1,351

—

—

— —

— —
— —

4
— —

—

—
—

1,295,033
36,575

—

—
—

—
—

2

72

—

62
—

883,083 —

68

—

—

— —

— —
— —

—

—
—

—

—
—

3

(65)
—

—

—

(113,575)

(1,202,041)

—

—

—

7,652

(12)
(113,575)

34,306
57,327

1,351

2

—
(75,595)

72
(75,595)

(1,277,636)

—

—

—

17,463
36,575

68

3

—
(59,995)

(65)
(59,995)

Balance at December 31, 2019 . . . 39,203,304

Balance at December 31, 2020 . . . 40,086,387 $

4 $1,331,676

$ —

$—

$(1,337,631) $

(5,951)

See Accompanying Notes to the Consolidated Financial Statements

F-8

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES
CONSOLIDATED STATEMENTS OF CASH FLOWS
(in thousands)

Operating activities:

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustments to reconcile net loss to net cash provided by
(used in) operating activities:
Depreciation and amortization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Provision for credit loss expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disposal of property and equipment
Loss on impairment of asset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss on debt extinguishment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Debt modification fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changes in operating assets and liabilities:

Accounts receivable, net
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inventory, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued expenses and other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred rent
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Post-marketing commitment liability . . . . . . . . . . . . . . . . . . . . . . . .
Net cash provided by (used in) operating activities . . . . . . . . . . . . . . . . . . . . .
Investing activities:

Purchase of property and equipment
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expenditures for leasehold improvements . . . . . . . . . . . . . . . . . . . . . . . .
Purchase of available-for-sale securities . . . . . . . . . . . . . . . . . . . . . . . . .
Sale of available-for-sale securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maturity of available-for-sale securities . . . . . . . . . . . . . . . . . . . . . . . . .
Purchase of intangible assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net cash provided by (used in) investing activities . . . . . . . . . . . . . . . . . . . . .
Financing activities:

Net proceeds from shares issued under employee stock plans . . . . . . . .
Proceeds from debt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Payment of debt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Payment of debt extinguishment costs . . . . . . . . . . . . . . . . . . . . . . . . . . .
Payment of debt issuance costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net cash provided by (used in) financing activities . . . . . . . . . . . . . . . . . . . . .
Net increase (decrease) in cash, cash equivalents and restricted cash . . . . . . .
Cash, cash equivalents and restricted cash, beginning of period . . . . . . . . . . .
Cash, cash equivalents and restricted cash, end of period . . . . . . . . . . . . . . . .

Supplemental disclosures of non-cash investing and financing
activities:

For the Year Ended December 31,

2020

2019

2018

$(59,995) $ (75,595) $(113,575)

10,033
36,575
1,000
—
—
—
—

2,353
(284)
2,251
(3,120)
(7,107)
19,251
(44)
(140)
773

8,077
57,327
—
54
1,183
8,047
—

(8,123)
(545)
568
1,464
(1,526)
22,599
(154)
9,000
22,376

7,384
86,939
—
—
—
—
289

(11,103)
(596)
(840)
(1,787)
(7,008)
15,783
409
—
(24,105)

(46)
—
(29,826)
—
73,275
(20,000)
23,403

(306)
—

(127,198)
28,135
104,532

—
5,163

(439)
(170)
(107,502)

—
50,488
—
(57,623)

68
8,444
(8,444)
—
—
68
24,244
73,210
$ 97,454

1,351
25,000
(80,000)
(7,793)
(5,625)
(67,067)
(39,528)
112,738
$ 73,210

7,652
105,000
—
—
(4,201)
108,451
26,723
86,015
$ 112,738

Intangibles in accrued expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Property and equipment purchases in accounts payable . . . . . . . . . . . . .

$
$ 20,000
$ — $

— $
$
25

—
—

Supplemental disclosure of cash flow information:

Interest paid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Income taxes paid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 9,703
207
$

$ 11,739
53
$

$
$

8,055
17

See Accompanying Notes to the Consolidated Financial Statements

F-9

PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Note 1—Business and Basis of Presentation:

Business:

Puma Biotechnology, Inc., or the Company, is a biopharmaceutical company based in Los Angeles,
California with a focus on the development and commercialization of innovative products to enhance cancer
care. The Company in-licenses from Pfizer Inc., or Pfizer, the global development and commercialization rights
to PB272 (neratinib (oral)), PB272 (neratinib (intravenous)) and PB357. Neratinib is a potent irreversible
tyrosine kinase inhibitor that blocks signal transduction through the epidermal growth factor receptors HER1,
HER2 and HER4. Currently, the Company is primarily focused on the development and commercialization of the
oral version of neratinib, and its most advanced drug candidates are directed at the treatment of HER2-positive
breast cancer and HER2 mutated cancers. The Company believes neratinib has clinical application in the
treatment of several other cancers as well, including other tumor types that over-express or have a mutation in
HER2, such as breast cancer, cervical cancer, lung cancer or other solid tumors.

The Company has two subsidiaries, Puma Biotechnology Ltd., a United Kingdom company, and Puma

Biotechnology, B.V., a Netherlands company. These subsidiaries were established for the purpose of legal
representation in the United Kingdom and the European Union.

Basis of Presentation:

The Company has incurred significant operating losses since its inception. The Company believes that it
will continue to incur net losses and may incur negative net cash flows from operating activities through the drug
development process and global commercialization. In 2017, the Company received U.S. Food and Drug
Administration, or FDA, approval for its first product, NERLYNX® (neratinib), formerly known as PB272
(neratinib, oral), for the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/
amplified breast cancer following adjuvant trastuzumab-based therapy. Following FDA approval in July 2017,
NERLYNX became available by prescription in the United States, and the Company commenced
commercialization.

In February 2020, NERLYNX was also approved by the FDA in combination with capecitabine for the
treatment of adult patients with advanced or metastatic HER2-positive breast cancer who have received two or
more prior anti-HER2-based regimens in the metastatic setting.

In 2018, the European Commission, or EC, granted marketing authorization for NERLYNX in the European

Union for the extended adjuvant treatment of adult patients with early stage hormone receptor positive HER2-
overexpressed/amplified breast cancer and who are less than one year from the completion of prior adjuvant
trastuzumab-based therapy.

The Company is required to make substantial payments to Pfizer upon the achievement of certain

milestones and has contractual obligations for clinical trial contracts.

The Company has entered into other exclusive sub-license agreements with various parties to pursue

regulatory approval, if necessary, and commercialize NERLYNX, if approved, in many regions outside the
United States, including Europe (excluding Russia and Ukraine), Australia, Canada, China, Southeast Asia,
Israel, South Korea, and various countries and territories in Central and South America. The Company plans to
continue to pursue commercialization of NERLYNX in other countries outside the United States, if approved.

The Company has reported a net loss of approximately $60.0 million and cash flows from operations of

F-10

approximately $0.8 million for the year ended December 31, 2020. The Company’s commercialization, research
and development or marketing efforts may require funding in addition to the cash and cash equivalents totaling
approximately $85.3 million and marketable securities totaling approximately $8.1 million available at
December 31, 2020. The Company believes that its existing cash and cash equivalents and marketable securities
as of December 31, 2020 and proceeds that will become available to the Company through product sales and
sub-license payments are sufficient to satisfy its operating cash needs for at least one year after the filing of the
Annual Report on Form 10-K in which these financial statements are included. The Company continues to
remain dependent on its ability to obtain sufficient funding to sustain operations and continue to successfully
commercialize neratinib in the United States. While the Company has been successful in raising capital in the
past, there can be no assurance that it will be able to do so in the future. The Company’s ability to obtain funding
may be adversely impacted by uncertain market conditions, including the global COVID-19 pandemic, the
Company’s success in commercializing neratinib, unfavorable decisions of regulatory authorities or adverse
clinical trial results. The outcome of these matters cannot be predicted at this time. Additionally, the terms of the
Company’s loan and security agreement place restrictions on the Company’s ability to operate the business and
on the Company’s financial flexibility, and the Company may be unable to achieve the revenue necessary to
satisfy the minimum revenue covenants as specified in the agreement.

Since its inception through December 31, 2020, the Company’s financing has primarily been proceeds from

product, royalty, and license revenue, public offerings of its common stock, private equity placements, and
borrowings under its loan and security agreement.

Note 2—Significant Accounting Policies:

The significant accounting policies followed in the preparation of these consolidated financial statements

are as follows:

Principles of Consolidation:

The consolidated financial statements include the accounts of the Company and its wholly owned

subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Certain prior year amounts have been reclassified to conform to the current year presentation, the effect of

which was not material to the Company’s consolidated financial statements.

Segment Reporting:

Management has determined that the Company operates in one business segment, which is the development

and commercialization of innovative products to enhance cancer care.

Use of Estimates:

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting

principles, or GAAP, requires management to make estimates and assumptions that affect reported amounts of
assets and liabilities, and disclosure of contingent assets and liabilities at the date of the balance sheet, and
reported amounts of revenues and expenses for the period presented. Accordingly, actual results could differ
from those estimates.

Significant estimates include estimates for variable consideration for which reserves were established. These

estimates are included in the calculation of net revenues and include trade discounts and allowances, product
returns, provider chargebacks and discounts, government rebates, payor rebates, and other incentives, such as
voluntary patient assistance, and other allowances that are offered within contracts between the Company and its
customers, payors, and other indirect customers relating to the Company’s sale of its products.

F-11

Change in Estimate:

During the three-month period ended September 30, 2020, the Company changed its estimate of the legal

verdict expense and the associated legal expense accrual for the Hsu v. Puma Biotechnology, Inc., et al. class
action lawsuit. The previous estimate was based on data and assumptions that were the best available information
at the time. In September and October 2020, the Company obtained additional data, previously unavailable, from
the claims report and amended claims report filed with the Court. Our estimate of the legal verdict expense and
the associated legal expense accrual for the Hsu lawsuit remained unchanged for the quarter ended December 31,
2020. The new data indicate that the settlement is expected to be larger than previously estimated. As a result, the
Company has changed its estimate of the legal accrual on a prospective basis beginning in the third quarter of
2020. This change resulted in an increase of approximately $15.7 million in legal verdict expense and the
associated accrued expense, long-term, for the year ended December 31, 2020. For the year ended December 31,
2020, the change in estimate has no impact on revenue from operations and reduces net income by approximately
$15.7 million. The change in accounting estimate increased the net loss per share by approximately $0.40 for the
year ended December 31, 2020.

Net Loss per Share of Common Stock:

Basic net loss per share of common stock is computed by dividing net loss applicable to common

stockholders by the weighted average number of shares of common stock outstanding during the periods
presented, as required by Accounting Standards Codification, or ASC, 260 Earnings per Share. For purposes of
calculating diluted loss per share of common stock, the denominator includes both the weighted average number
of shares of common stock outstanding and the number of dilutive common stock equivalents, such as stock
options, restricted stock units, or RSUs, and warrants. A common stock equivalent is not included in the
denominator when calculating diluted earnings per common share if the effect of such common stock equivalent
would be anti-dilutive. For the year ended December 31, 2020, potentially dilutive securities excluded from the
calculations were 5,009,342 shares issuable upon exercise of options, 2,116,250 shares issuable upon exercise of
a warrant, and 1,854,205 shares underlying RSUs that were subject to vesting and were anti-dilutive. For the year
ended December 31, 2019, potentially dilutive securities excluded from the calculations were 5,042,325 shares
issuable upon exercise of options, 2,116,250 shares issuable upon exercise of a warrant, and 1,991,125 shares
underlying RSUs that were subject to vesting and were anti-dilutive. For the year ended December 31, 2018,
potentially dilutive securities excluded from the calculations were 5,708,544 shares issuable upon exercise of
options, 2,116,250 shares issuable upon exercise of a warrant, and 1,838,670 shares underlying RSUs that were
subject to vesting and were anti-dilutive.

Revenue Recognition:

Under ASC Topic 606, Revenue from Contracts with Customers, or ASC 606, the Company recognizes

revenue when its customer obtains control of the promised goods or services, in an amount that reflects the
consideration which the entity expects to be entitled in exchange for those goods or services. The Company had
no contracts with customers until the FDA approved NERLYNX on July 17, 2017. Subsequent to receiving FDA
approval, the Company entered into a limited number of arrangements with specialty pharmacies and specialty
distributors in the United States to distribute NERLYNX. These arrangements are the Company’s initial contracts
with customers. The Company has determined that these sales channels with customers are similar.

Product Revenue, Net:

The Company sells NERLYNX to a limited number of specialty pharmacies and specialty distributors in the

United States. These customers subsequently resell the Company’s products to patients and certain medical
centers or hospitals. In addition to distribution agreements with these customers, the Company enters into
arrangements with health care providers and payors that provide for government mandated and/or privately
negotiated rebates, chargebacks and discounts with respect to the purchase of the Company’s products.

F-12

The Company recognizes revenue on product sales when the specialty pharmacy or specialty distributor, as

applicable, obtains control of the Company’s product, which occurs at a point in time (upon delivery). Product
revenue is recorded net of applicable reserves for variable consideration, including discounts and allowances.
The Company’s payment terms range between 10 and 68 days.

Shipping and handling costs for product shipments occur prior to the customer obtaining control of the

goods and are recorded in cost of sales.

If taxes should be collected from customers relating to product sales and remitted to governmental

authorities, they will be excluded from revenue. The Company expenses incremental costs of obtaining a contract
when incurred, if the expected amortization period of the asset that the Company would have recognized is one
year or less. However, no such costs were incurred during the year ended December 31, 2020.

For the period ended December 31, 2020, two major customers represented approximately 33% and 21%,

respectively, of the Company’s total product revenue. For the period ended December 31, 2019, two major
customers accounted for approximately 34% and 22%, respectively, of the Company’s total product revenue. For
the period ended December 31, 2018, two major customers accounted for approximately 39% and 25%,
respectively, of the Company’s total product revenue.

Reserves for Variable Consideration:

Revenue from product sales is recorded at the net sales price (transaction price), which includes estimates of

variable consideration for which reserves are established. Components of variable consideration include trade
discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor
rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within
contracts between the Company and its customers, payors, and other indirect customers relating to the
Company’s sale of its products. These reserves, as detailed below, are based on the related sales, and are
classified as reductions of accounts receivable, net when the right of offset exists in accordance with ASU
2013-1, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities,
or as a current liability. These estimates take into consideration a range of possible outcomes that are probability-
weighted in accordance with the expected value method in ASC 606 for relevant factors such as current
contractual and statutory requirements, specific known market events and trends, industry data, and forecasted
customer buying and payment patterns. Overall, these reserves reflect the Company’s best estimates of the
amount of consideration to which it is entitled based on the terms of the respective underlying contracts.

The amount of variable consideration that is included in the transaction price may be constrained, and is
included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the
cumulative revenue recognized under the contract will not occur in a future period. The Company’s analyses also
contemplated application of the constraint in accordance with the guidance, under which it determined a
significant reversal of revenue would not occur in a future period for the estimates detailed below as of
December 31, 2020 and, therefore, the transaction price was not reduced further during the year ended
December 31, 2020. Actual amounts of consideration ultimately received may differ from the Company’s
estimates. If actual results in the future vary from the Company’s estimates, the Company will adjust these
estimates, which would affect net product revenue and earnings in the period such variances become known.

Trade Discounts and Allowances:

The Company generally provides customers with discounts, which include incentive fees that are explicitly

stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product
revenue is recognized. The reserve for discounts is established in the same period that the related revenue is
recognized, together with reductions to accounts receivables, net on the consolidated balance sheets. In addition,
the Company compensates its customers for sales order management, data, and distribution services. The

F-13

Company has determined such services received to date are not distinct from the Company’s sale of products to
its customers and, therefore, these payments have been recorded as a reduction of revenue within the statement of
operations.

Product Returns:

Consistent with industry practice, the Company offers the specialty pharmacies and specialty distributors

that are its customers limited product return rights for damaged and expiring product, provided it is within a
specified period around the product expiration date as set forth in the applicable individual distribution
agreement. The Company estimates the amount of its product sales that may be returned by its customers and
records this estimate as a reduction of revenue in the period the related product revenue is recognized, as well as
a reduction to accounts receivables, net on the consolidated balance sheets. The Company currently estimates
product returns using its own sales information, including its visibility into the inventory remaining in the
distribution channel. The Company has an insignificant amount of returns to date and believes that returns of its
products will continue to be minimal.

Provider Chargebacks and Discounts:

Chargebacks for fees and discounts to providers represent the estimated obligations resulting from
contractual commitments to sell products to qualified healthcare providers at prices lower than the list prices
charged to its customers who directly purchase the product from the Company. Customers charge the Company
for the difference between what they pay for the product and the ultimate selling price to the qualified healthcare
providers. The reserve for chargebacks is established in the same period that the related revenue is recognized,
resulting in a reduction of product revenue and a reduction to accounts receivable, net on the consolidated
balance sheets. Chargeback amounts are generally determined at the time of resale to the qualified healthcare
provider by customers, and the Company generally issues credits for such amounts within a few weeks of the
customer’s notification to the Company of the resale. Chargebacks consist of credits the Company expects to
issue for units that remain in the distribution channel at each reporting period end that the Company expects will
be sold to qualified healthcare providers and chargebacks that customers have claimed, but for which the
Company has not yet issued a payment.

Government Rebates:

The Company is subject to discount obligations under state Medicaid programs and Medicare. These
reserves are recorded in the same period the related revenue is recognized, resulting in a reduction of product
revenue and the establishment of a current liability, which is included in accrued expenses on the consolidated
balance sheets. The Company’s liability for these rebates consists of invoices received for claims from prior
quarters that have not been paid or for which an invoice has not yet been received, estimates of claims for the
current quarter, and estimates of future claims that will be made for product that has been recognized as revenue,
but which remains in the distribution channel at the end of each reporting period.

Payor Rebates:

The Company contracts with certain private payor organizations, primarily insurance companies and
pharmacy benefit managers, for the payment of rebates with respect to utilization of its products. The Company
estimates these rebates and records such estimates in the same period the related revenue is recognized, resulting
in a reduction of product revenue, net and the establishment of a current liability, which is included in accrued
expenses on the consolidated balance sheets.

Other Incentives:

Other incentives the Company offers include voluntary patient assistance programs, such as the co-pay
assistance program, which are intended to provide financial assistance to qualified commercially-insured patients

F-14

with prescription drug co-payments required by payors. The calculation of the accrual for co-pay assistance is
based on an estimate of claims and the cost per claim that the Company expects to receive associated with
product that has been recognized as revenue, but remains in the distribution channel at the end of each reporting
period. The adjustments are recorded in the same period the related revenue is recognized, resulting in a
reduction of product revenue and the establishment of a current liability, which is included as a component of
accrued expenses on the consolidated balance sheets.

License Revenue:

The Company also recognizes license revenue under certain of the Company’s sub-license agreements that
are within the scope of ASC 606. The terms of these agreements may contain multiple performance obligations,
which may include licenses and research and development activities. The Company evaluates these agreements
under ASC 606 to determine the distinct performance obligations. Non-refundable, upfront fees that are not
contingent on any future performance and require no consequential continuing involvement by the Company, are
recognized as revenue when the license term commences and the licensed data, technology or product is
delivered. The Company defers recognition of non-refundable upfront license fees if the performance obligations
are not satisfied. The Company’s payment terms range between the execution date of the sub-license agreement
and 45 days.

Prior to recognizing revenue, the Company makes estimates of the transaction price, including variable
consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction
price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized
will not occur and when the uncertainty associated with the variable consideration is subsequently resolved.

If there are multiple distinct performance obligations, the Company allocates the transaction price to each

distinct performance obligation based on its relative standalone selling price. The standalone selling price is
generally determined based on the prices charged to customers or using expected cost-plus margin. Revenue is
recognized by measuring the progress toward complete satisfaction of the performance obligations using an input
measure.

Since 2018, the Company has entered into sub-license agreements with certain sub-licensees in territories

outside of the United States. These sub-licensing agreements grant certain intellectual property rights and set
forth various respective obligations with respect to actions such as development, pursuit and maintenance of
regulatory approvals, commercialization and supply of NERLYNX in the sub-licensees’ respective territories.

License fees under the sub-license agreements include one-time upfront payments when each sub-license

agreement was executed and potential additional one-time milestone payments due to the Company upon
successful completion of certain performance obligations, such as achieving regulatory approvals or sales target
thresholds, and potential double-digit royalties on sales of the licensed product, calculated as a percentage of net
sales of the licensed product throughout each sub-licensee’s respective territory. For the year ended
December 31, 2020, pursuant to the sub-license agreements, the Company recognized as license revenue, upfront
payments totaling $0.5 million and development-based milestone payments totaling $22.2 million. The beginning
balance of accounts receivable, net on the Company’s consolidated balance sheet for license revenue from the
sub-license agreements for the twelve months ended December 31, 2020 was $2.5 million. As of December 31,
2020, $2.5 million in license revenue from the sub-license agreements is included in accounts receivable, net and
$1.0 million in the allowance for credit loss on the consolidated balance sheet. As of December 31, 2020, the
total potential milestone payments that would be due to the Company upon achievement of all respective
performance obligations under the sub-license agreements is approximately $536.5 million. At this time, the
Company cannot estimate if or when these milestone-related performance obligations might be achieved.

F-15

Royalty Revenue:

For sub-license agreements that are within the scope of ASC 606, the Company recognizes revenue when
the related sales occur in accordance with the sales-based royalty exception under ASC 606-10-55-65. Royalty
revenue consists of consideration earned related to international sales of NERLYNX made by the Company’s
sub-licensees in their respective territories. The Company recognizes royalty revenue when the performance
obligations have been satisfied. The Company’s payment terms range between 30 and 90 days.

Legal Contingencies and Expense:

For legal contingencies, the Company accrues a liability for an estimated loss if the potential loss from any

claim or legal proceeding is considered probable and the amount can be reasonably estimated. Legal fees and
expenses are expensed as incurred based on invoices or estimates provided by legal counsel. The Company
periodically evaluates available information, both internal and external, relative to such contingencies and adjusts
the accrual as necessary. The Company determines whether a contingency should be disclosed by assessing
whether a material loss is deemed reasonably possible. In determining whether a loss should be accrued, the
Company evaluates, among other factors, the degree of probability of an unfavorable outcome and the ability to
make a reasonable estimate of the amount of the loss (see Note 14-Commitments and Contingencies).

Royalty Expenses:

Royalties incurred in connection with the Company’s license agreement with Pfizer, as disclosed in Note
14—Commitments and Contingencies, are expensed to cost of sales as revenue from product sales is recognized.

Research and Development Expenses:

Research and development, or R&D, expenses are charged to operations as incurred. The major components

of research and development costs include clinical manufacturing costs, clinical trial expenses, consulting and
other third-party costs, salaries and employee benefits, stock-based compensation expense, supplies and
materials, and allocations of various overhead costs. Clinical trial expenses include, but are not limited to,
investigator fees, site costs, comparator drug costs, and clinical research organization, or CRO, costs. In the
normal course of business, the Company contracts with third parties to perform various clinical trial activities in
the ongoing development of potential products. The financial terms of these agreements are subject to negotiation
and variations from contract to contract and may result in uneven payment flows. Payments under the contracts
depend on factors such as the achievement of certain events, the successful enrollment of patients and the
completion of portions of the clinical trial or similar conditions. The Company’s accruals for clinical trials are
based on estimates of the services received and efforts expended pursuant to contracts with numerous clinical
trial sites, cooperative groups and CROs. As actual costs become known, the Company adjusts its accruals in that
period.

In instances where the Company enters into agreements with third parties for clinical trials and other

consulting activities, upfront amounts are recorded to prepaid expenses and other in the accompanying
consolidated balance sheets and expensed as services are performed or as the underlying goods are delivered. If
the Company does not expect the services to be rendered or goods to be delivered, any remaining capitalized
amounts for non-refundable upfront payments are charged to expense immediately. Amounts due under such
arrangements may be either fixed fee or fee for service, and may include upfront payments, monthly payments
and payments upon the completion of milestones or receipt of deliverables.

Costs related to the acquisition of technology rights and patents for which development work is still in

process are charged to operations as incurred and considered a component of research and development costs.

F-16

Stock-Based Compensation:

Stock option awards:

ASC Topic 718, Compensation-Stock Compensation, or ASC 718, requires the fair value of all share-based
payments to employees and non-employees, including grants of stock options, to be recognized in the statement
of operations over the requisite service period. Under ASC 718, employee and non-employee option grants are
generally valued at the grant date and those valuations do not change once they have been established. The fair
value of each option award is estimated on the grant date using the Black-Scholes Option Pricing Method. As
allowed by ASC 718, the Company’s estimate of expected volatility is based on its average volatilities using its
past eight years of publicly traded history. The risk-free rate for periods within the contractual life of the option is
based on the U.S. Treasury yield curve in effect at the time of grant valuation. Option forfeitures are estimated
when the option is granted to reduce the option expense to be recognized over the life of the award. The
estimated forfeiture rate considers historical employee turnover rates stratified into employee pools, actual
forfeiture experience and other factors. The option expense is adjusted upon the actual forfeiture of a stock option
grant and the Company periodically revises the estimated forfeiture rate in subsequent periods if actual
forfeitures differ from those estimates. Due to its limited history of stock option exercises, the Company uses the
simplified method to determine the expected life of the option grants. Compensation expense related to modified
stock options is measured based on the fair value for the awards as of the modification date. Any incremental
compensation expense arising from the excess of the fair value of the awards on the modification date compared
to the fair value of the awards immediately before the modification date is recognized at the modification date or
ratably over the requisite service period, as appropriate.

Restricted stock units:

RSUs are valued on the grant date and the fair value of the RSUs is equal to the market price of the

Company’s common stock on the grant date. The RSU expense is recognized over the requisite service period in
the statement of operations. When the requisite service period begins prior to the grant date (because the service
inception date occurs prior to the grant date), the Company is required to begin recognizing compensation cost
before there is a measurement date (i.e., the grant date). The service inception date is the beginning of the
requisite service period. If the service inception date precedes the grant date, accrual of compensation cost for
periods before the grant date shall be based on the fair value of the award at the reporting date. In the period in
which the grant date occurs, cumulative compensation cost shall be adjusted to reflect the cumulative effect of
measuring compensation cost based on fair value at the grant date rather than the fair value previously used at the
service inception date (or any subsequent reporting date). RSU forfeitures are estimated when the RSU is granted
to reduce the RSU expense to be recognized over the life of the award. The estimated forfeiture rate considers
historical employee turnover rates stratified into employee pools, actual forfeiture experience and other factors.
The RSU expense is “trued-up” upon the actual forfeiture of a RSU grant and the Company periodically revises
the estimated forfeiture rate in subsequent periods if actual forfeitures differ from those estimates. Compensation
expense related to modified restricted stock units is measured based on the fair value for the awards as of the
modification date. Any incremental compensation expense arising from the excess of the fair value of the awards
on the modification date compared to the fair value of the awards immediately before the modification date is
recognized at the modification date or ratably over the requisite service period, as appropriate.

Warrants:

Warrants (refer to Note 11 for further details) granted to employees and non-employees are normally valued

at the fair value of the instrument on the grant date and are recognized in the statement of operations over the
requisite service period. When the requisite service period precedes the grant date and a market condition exists
in the warrant, the Company values the warrant using the Monte Carlo Simulation Method. When the terms of
the warrant become fixed, the Company values the warrant using the Black-Scholes Option Pricing Method. As
allowed by ASC 718, the Company’s estimate of expected volatility is based on its average volatilities using its
past eight years of publicly traded history. The risk-free rate for periods within the contractual life of the warrant
is based on the U.S. Treasury yield curve in effect at the time of grant valuation. In determining the value of the

F-17

warrant until the terms are fixed, the Company factors in the probability of the market condition occurring and
several possible scenarios. When the requisite service period precedes the grant date and is deemed to be
complete, the Company records the fair value of the warrant at the time of issuance as an equity stock-based
compensation transaction. The grant date is determined when all pertinent information, such as exercise price and
quantity are known.

Income Taxes:

The Company follows ASC Topic 740, Income Taxes, or ASC 740, which requires recognition of deferred

tax assets and liabilities for the expected future tax consequences of events that have been included in the
consolidated financial statements or tax returns. Under this method, deferred tax assets and liabilities are based
on the differences between the consolidated financial statement and tax basis of assets and liabilities using
enacted tax rates in effect for the year in which the differences are expected to reverse. Deferred tax assets are
reduced by a valuation allowance to the extent management concludes it is more likely than not that the asset will
not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to
taxable income in the years in which those temporary differences are expected to be recovered or settled.

The standard addresses the determination of whether tax benefits claimed or expected to be claimed on a tax
return should be recorded in the consolidated financial statements. Under ASC 740, the Company may recognize
the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be
sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefits
recognized in the consolidated financial statements from such a position should be measured based on the largest
benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. ASC 740 also provides
guidance on de-recognition, classification, interest and penalties on income taxes, accounting in interim periods
and requires increased disclosures. As of December 31, 2020, the Company’s uncertain tax position includes a
reserve for its R&D credits.

Financial Instruments

The carrying value of financial instruments, such as cash equivalents, accounts receivable and accounts
payable, approximate their fair value because of their short-term nature. The carrying value of long-term debt
approximates its fair value as the principal amounts outstanding are subject to variable interest rates that are
based on market rates which are regularly reset.

Cash and Cash Equivalents:

The Company classifies all highly liquid instruments with an original maturity of three months or less as

cash equivalents.

Restricted Cash:

Restricted cash represents cash held at financial institutions that are pledged as collateral for stand-by letters

of credit for lease and legal verdict commitments. The lease related letters of credit will lapse at the end of the
respective lease terms through 2026. At December 31, 2020 and 2019, the Company had restricted cash in the
amount of $12.2 million and $13.2 million, respectively.

Investment Securities:

The Company classifies all investment securities (short-term and long-term) as available-for-sale, as the sale

of such securities may be required prior to maturity to implement management’s strategies. These securities are
carried at fair value, with the unrealized gains and losses, reported as a component of accumulated other
comprehensive income (loss) in stockholders’ (deficit) equity until realized. Realized gains and losses from the

F-18

sale of available-for-sale securities, if any, are determined on a specific identification basis. In accordance with
ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial
Instruments, credit losses on available-for-sale securities are reported using an expected loss model and recorded
to an allowance. No credit loss on available-for-sale securities was recognized in the year ending December 31,
2020. Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to
yield using the straight-line method. Interest income is recognized when earned.

Assets Measured at Fair Value on a Recurring Basis:

ASC Topic 820, Fair Value Measurement, or ASC 820, provides a single definition of fair value and a
common framework for measuring fair value as well as disclosure requirements for fair value measurements used
in financial statements. Under ASC 820, fair value is determined based upon the exit price that would be received
by a company to sell an asset or paid by a company to transfer a liability in an orderly transaction between
market participants, exclusive of any transaction costs. Fair value measurements are determined by either the
principal market or the most advantageous market. The principal market is the market with the greatest level of
activity and volume for the asset or liability. Absent a principal market to measure fair value, the Company uses
the most advantageous market, which is the market from which the Company would receive the highest selling
price for the asset or pay the lowest price to settle the liability, after considering transaction costs. However,
when using the most advantageous market, transaction costs are only considered to determine which market is
the most advantageous and these costs are then excluded when applying a fair value measurement. ASC 820
creates a three-level hierarchy to prioritize the inputs used in the valuation techniques to derive fair values. The
basis for fair value measurements for each level within the hierarchy is described below, with Level 1 having the
highest priority and Level 3 having the lowest.

Level 1:

Quoted prices in active markets for identical assets or liabilities.

Level 2:

Quoted prices for similar assets or liabilities in active markets; quoted prices for identical
or similar instruments in markets that are not active; and model-derived valuations in
which all significant inputs are observable in active markets.

Level 3:

Valuations derived from valuation techniques in which one or more significant inputs are
unobservable.

Following are the major categories of assets measured at fair value on a recurring basis as of December 31,
2020 and 2019, using quoted prices in active markets for identical assets (Level 1), significant other observable
inputs (Level 2), and significant unobservable inputs (Level 3) (in thousands):

December 31, 2020

Level 1

Level 2

Level 3

Total

Cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commercial paper

$59,919
—

$11,798
8,096

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$59,919

$19,894

$—
—

$—

$71,717
8,096

$79,813

December 31, 2019

Level 1

Level 2

Level 3

Total

Cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Corporate bonds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
U.S. government securities . . . . . . . . . . . . . . . . . . . . . . . . .

$41,295
—
10,050

$ —
41,557
—

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$51,345

$41,557

$—
—
—

$—

$41,295
41,557
10,050

$92,902

The Company’s investments in commercial paper, corporate bonds and U.S. government securities are
exposed to price fluctuations. The fair value measurements for commercial paper, corporate bonds and U.S.
government securities are based upon the quoted prices of similar items in active markets multiplied by the
number of securities owned.

F-19

The following tables summarize the Company’s short-term investments (in thousands):

December 31, 2020

Maturity
(in years)

Amortized
cost

Unrealized

Gains Losses

Estimated
fair value

Cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commercial paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Less than 1

$71,717

$— $— $71,717
8,096

—

8,096 —

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$79,813

$— $— $79,813

December 31, 2019

Maturity
(in years)

Amortized
cost

Unrealized

Gains Losses

Estimated
fair value

Cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Corporate bonds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Less than 1
U.S. government securities . . . . . . . . . . . . . . . . . . . . . . . . . . . Less than 1

$41,295
41,507
10,038

$— $— $41,295
41,557
10,050

50 —
12 —

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$92,840

$ 62

$— $92,902

Concentration of Risk:

Financial instruments, which potentially subject the Company to concentrations of credit risk, principally
consist of cash and cash equivalents, marketable securities, and accounts receivable, net. The Company’s cash
and cash equivalents and restricted cash in excess of the Federal Deposit Insurance Corporation and the
Securities Investor Protection Corporation insured limits at December 31, 2020, were approximately
$101.8 million. The Company does not believe it is exposed to any significant credit risk due to the quality
nature of the financial instruments in which the money is held. Pursuant to the Company’s internal investment
policy, investments must be rated A-1/P-1 or better by Standard and Poor’s Rating Service and Moody’s
Investors Service at the time of purchase.

The Company sells its products in the United States primarily through specialty pharmacies and specialty

distributors. Therefore, wholesale distributors and large pharmacy chains account for a large portion of its
accounts receivables, net and product revenues, net. The creditworthiness of its customers is continuously
monitored, and the Company has internal policies regarding customer credit limits. The Company estimates an
allowance for credit loss primarily based on the credit worthiness of its customers, historical payment patterns,
aging of receivable balances and general economic conditions. The Company recorded $1.0 million and $0 as an
allowance for credit loss and the related credit loss expense in the years ended December 31, 2020 and 2019,
respectively.

The Company’s success depends on its ability to successfully commercialize NERLYNX. The Company

currently has a single product with limited commercial sales experience, which makes it difficult to evaluate its
current business, predict its future prospects and forecast financial performance and growth. The Company has
invested a significant portion of its efforts and financial resources in the development and commercialization of
the lead product, NERLYNX, and expects NERLYNX to constitute the vast majority of product revenue for the
foreseeable future.

The Company relies exclusively on third parties to formulate and manufacture NERLYNX and its drug
candidates. The commercialization of NERLYNX and any other drug candidates, if approved, could be stopped,
delayed or made less profitable if those third parties fail to provide sufficient quantities of product or fail to do so
at acceptable quality levels or prices. The Company has no experience in drug formulation or manufacturing and
does not intend to establish its own manufacturing facilities. The Company lacks the resources and expertise to
formulate or manufacture NERLYNX and other drug candidates. While the drug candidates were being
developed by Pfizer, both the drug substance and drug product were manufactured by third-party contractors. The
Company is using the same third-party contractors to manufacture, supply, store and distribute drug supplies for

F-20

clinical trials and the commercialization of NERLYNX. If the Company is unable to continue its relationships
with one or more of these third-party contractors, it could experience delays in the development or
commercialization efforts as it locates and qualifies new manufacturers. The Company intends to rely on one or
more third-party contractors to manufacture the commercial supply of drugs.

Inventory:

The Company values its inventories at the lower of cost and estimated net realizable value. The Company
determines the cost of its inventories, which includes amounts related to materials and manufacturing overhead,
on a first-in, first-out basis. The Company performs an assessment of the recoverability of capitalized inventory
during each reporting period, and it writes down any excess and obsolete inventories to their estimated realizable
value in the period in which the impairment is first identified. Such impairment charges, should they occur, are
recorded within the cost of sales in the consolidated statements of operations. The determination of whether
inventory costs will be realizable requires estimates by management. If actual market conditions are less
favorable than projected by management, additional write-downs of inventory may be required, which would be
recorded as a cost of sales in the consolidated statements of operations.

The Company capitalizes inventory costs associated with the Company’s products after regulatory approval,

if any, when, based on management’s judgment, future commercialization is considered probable and the future
economic benefit is expected to be realized. Inventory that can be used in either the production of clinical or
commercial product is recorded as research and development expense when selected for use in a clinical trial.
Starter kits, provided to patients prior to insurance approval, are expensed by the Company to selling, general and
administrative expense as incurred.

As of December 31, 2020, the Company’s inventory balance consisted primarily of raw materials purchased

subsequent to FDA approval of NERLYNX.

Property and Equipment, Net:

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is

computed using the straight-line method over the useful lives of the assets, which is generally three years for
computer hardware and software, three years for phone equipment, and seven years for furniture and fixtures.
Leasehold improvements are amortized using the straight-line method over the lesser of the useful life or the
lease term. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are
eliminated from the accounts and any resulting gain or loss is credited or charged to operations. Repairs and
maintenance costs are expensed as incurred.

The Company reviews its long-lived assets used in operations for impairment whenever events or changes in

circumstances indicate that the carrying amount of an asset may not be recoverable, as required by ASC Topic
360, Property, Plant, and Equipment, or ASC 360. The Company performs a recoverability test by comparing the
sum of the estimated undiscounted cash flows over the life of the asset to its carrying value on the consolidated
balance sheet. If the undiscounted cash flows used in the recoverability test are less than the carrying value, the
Company would then determine the fair value of the long-lived asset and recognize an impairment loss for the
amount in excess of the carrying value.

Leases:

ASC Topic 842, Leases, as adopted in the first quarter of 2019, requires lessees to recognize most leases on

the balance sheet with a corresponding right-of-use asset, or ROU asset. ROU assets represent the Company’s
right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to
make lease payments arising from the lease. The assets and lease liabilities are recognized at the lease
commencement date based on the estimated present value of fixed lease payments over the lease term. ROU

F-21

assets are evaluated for impairment using the long-lived assets impairment guidance, as required by ASC 360. A
significant indication of impairment of an ROU asset would include a change in the extent or manner in which
the asset is being used. The Company must make assumptions which underlie the most significant and subjective
estimates in determining whether any impairment exists. Those estimates, and the underlying assumptions,
include estimates of future cash flow utilizing market lease rates and determination of fair value. If an ROU asset
related to an operating lease is impaired, the carrying value of the ROU asset post-impairment should be
amortized on a straight-line basis through the earlier of the end of the useful life of the ROU asset or the end of
the lease term. Post impairment, a lessee must calculate the amortization of the ROU asset and interest expense
on the lease liability separately, although the sum of the two continues to be presented as a single lease cost. If a
lease is planned to be abandoned with no intention of subleasing, the ROU asset should be assessed for
impairment.

Leases are classified as financing or operating, which will drive the expense recognition pattern. The
Company elects to exclude short-term leases if and when the Company has them. For additional information, see
Note 7—Leases.

The Company leases office space and copy machines, all of which are operating leases. Most leases include
the option to renew and the exercise of the renewal options is at the Company’s sole discretion. Options to extend
or terminate a lease are considered in the lease term to the extent that the option is reasonably certain of exercise.
The leases do not include options to purchase the leased property. The depreciable life of assets and leasehold
improvements is limited by the expected lease term. Covenants imposed by the leases include letters of credit
required to be obtained by the lessee.

The incremental borrowing rate, or IBR, represents the rate of interest the Company would expect to pay on
a collateralized basis to borrow an amount equal to the lease payments under similar terms. When determinable,
the Company uses the rate implicit in the lease to determine the present value of lease payments. As the
Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the
information available at the commencement date in determining the present value of lease payments. The
Company’s average IBR for existing leases as of December 31, 2020 was 10.9%.

The Company decided to cease the use of a portion of its leased office space in 2019. In connection with the
decreased need for the right to use the ROU asset, the Company entered into a sublease for the underlying asset,
in which the sublease income is less than the original lease payments, indicating impairment. In performing the
recoverability test on the effective date, the undiscounted future estimated cash flows and carrying value were
identified for the subleased portion of the leased building, as an individual asset group, defined under ASC 360.
A reduction to the carrying value of the ROU asset of approximately $1.2 million was recorded, representing the
fair value amount in excess of the carrying value, with a corresponding impairment charge recorded as selling,
general and administration expense, in the consolidated statements of operations for the year ended
December 31, 2019. There were no indications for impairment during the year ended December 31, 2020.

License Fees and Intangible Assets:

The Company expenses amounts paid to acquire licenses associated with products under development when
the ultimate recoverability of the amounts paid is uncertain and the technology has no alternative future use when
acquired. Acquisitions of technology licenses are charged to expense or capitalized based upon the asset
achieving technological feasibility in accordance with management’s assessment regarding the ultimate
recoverability of the amounts paid and the potential for alternative future use. The Company has determined that
technological feasibility for its product candidates is reached when the requisite regulatory approvals are
obtained to make the product available for sale. The Company capitalizes technology licenses upon reaching
technological feasibility.

F-22

The Company maintains definite-lived intangible assets related to the license agreement with Pfizer. These
assets are amortized over their remaining useful lives, which are estimated based on the shorter of the remaining
patent life or the estimated useful life of the underlying product. Intangible assets are amortized using the
economic consumption method if anticipated future revenues can be reasonably estimated. The straight-line
method is used when future revenues cannot be reasonably estimated. Amortization costs are recorded as part of
cost of sales.

The Company assesses its intangible assets for impairment if indicators are present or changes in

circumstance suggest that impairment may exist. Events that could result in an impairment, or trigger an interim
impairment assessment, include the receipt of additional clinical or non-clinical data regarding one of the
Company’s drug candidates or a potentially competitive drug candidate, changes in the clinical development
program for a drug candidate, or new information regarding potential sales for the drug. If impairment indicators
are present or changes in circumstance suggest that impairment may exist, the Company performs a
recoverability test by comparing the sum of the estimated undiscounted cash flows of each asset group to its
carrying value on the consolidated balance sheet. If the undiscounted cash flows used in the recoverability test
are less than the carrying value, the Company would determine the fair value of the intangible asset and
recognize an impairment loss if the carrying value of the intangible asset exceeds its fair value. In connection
with the FDA approval of NERLYNX in July 2017, the Company triggered a one-time milestone payment
pursuant to its license agreement with Pfizer. In June 2020, the Company entered into a letter agreement with
Pfizer relating to the method of payment associated with a milestone payment under the Company’s license
agreement with Pfizer (see Note 14-Commitments and Contingencies). The Company capitalized the milestone
payments as an intangible asset and is amortizing the asset to cost of sales on a straight-line basis over the
estimated useful life of the licensed patent through 2030. The Company recorded amortization expense related to
its intangible asset of $6.3 million, $3.9 million and $3.9 million for the years ended December 31, 2020, 2019
and 2018, respectively. As of December 31, 2020, estimated future amortization expense related to the
Company’s intangible asset was approximately $8.0 million for each year starting 2021 through 2029, and
$2.0 million for 2030.

Recently Issued Accounting Standards:

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326):
Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires that credit losses be reported
using an expected losses model rather than the incurred losses model that is currently used, and establishes
additional disclosures related to credit risks. For trade accounts receivable, the Company recognizes credit losses
based on lifetime expected losses. For available-for-sale debt securities with unrealized losses, this standard now
requires allowances to be recorded instead of reducing the amortized cost of the investment. These amendments
under ASU 2016-13 are effective for interim and annual fiscal periods beginning after December 15, 2019. The
Company adopted ASU 2016-13, and the adoption did not have a material effect on the Company’s current
financial position, results of operations or financial statement disclosures.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure

Framework-Changes to the Disclosure Requirements for Fair Value Measurement. As of January 1, 2020, the
Company adopted the amendments in ASU 2018-13, which modifies the disclosure requirements on fair value
measurements. The removed and modified disclosures were adopted on a retrospective basis and the new
disclosures were adopted on a prospective basis. The adoption of ASU 2018-13 did not have a material effect on
the Company’s current financial position, results of operations or financial statement disclosures.

In December 2019, the FASB issued ASU No 2019-12, Income Taxes (Topic 740): Simplifying the
Accounting for Income Taxes, as part of its Simplification Initiative to reduce the cost and complexity in
accounting for income taxes. The amendments in ASU 2019-12 removes certain exceptions related to the
approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and
the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also amends other aspects of

F-23

the guidance to help simplify and promote consistent application of GAAP. The guidance is effective for interim
and annual periods beginning after December 15, 2020, with early adoption permitted. The Company does not
expect ASU 2019-12 to have a material effect on the Company’s current financial position, results of operations
or financial statement disclosures.

Note 3—Accounts Receivable, Net:

Accounts receivable, net consisted of the following (in thousands):

December 31,
2020

December 31,
2019

Trade accounts receivable . . . . . . . . . . . . . . . . . . . . .
License revenue receivable . . . . . . . . . . . . . . . . . . . .
Royalty revenue receivable . . . . . . . . . . . . . . . . . . . .

Total accounts receivable . . . . . . . . . . . . . . . . . . . . . .
Allowance for credit losses . . . . . . . . . . . . . . . . . . . .

$21,515
2,500
2,528

$26,543
(1,000)

Total accounts receivable, net

. . . . . . . . . . . . . . . . . .

$25,543

$26,180
2,500
216

$28,896
—

$28,896

Trade accounts receivable consist entirely of amounts owed from the Company’s customers related to
product sales. License revenue receivable represents an amount owed from a sub-licensee under a sub-license
agreement. Royalty revenue receivable represents amounts owed related to royalty revenue recognized based on
the Company’s sub-licensees’ sales in their respective territories in the years ended December 31, 2020 and
2019.

For all accounts receivable, the Company recognized credit losses based on lifetime expected losses. In
determining estimated credit losses, the Company evaluated its historical loss rates, current economic conditions
and reasonable and supportable forecasts of future economic conditions. During the fourth quarter of 2020, the
Company became aware of new information regarding the collectability of the amount owed from a sub-licensee
relating to license revenue recognized during the third quarter of 2019. Based on this new information, the
Company determined that a portion of the receivable may be uncollectible and the Company recorded a credit
loss expense of $1.0 million to selling, general and administration expense in the consolidated statements of
operations for the year ended December 31, 2020. The Company recorded $1.0 million and $0 as a credit loss
expense in the years ended December 31, 2020 and 2019, respectively. The rollforward of the allowance for
credit losses is as follows:

Allowance for credit losses (in thousands):

Beginning balance at January 1, 2020 . . . . . . . . . . . . . . .
Impact of adopting ASC 326 . . . . . . . . . . . . . . . . . . . . . .
Provision for credit loss expense . . . . . . . . . . . . . . . . . . .
Accounts receivable written-off . . . . . . . . . . . . . . . . . . . .
Recoveries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ —
—
(1,000)
—
—

Total ending allowance balance as December 31, 2020 . . . . . .

$(1,000)

Note 4—Prepaid Expenses and Other:

Prepaid expenses and other consisted of the following at December 31 (in thousands):

F-24

Current:

CRO services . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
Other clinical development
Insurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Professional fees . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other

Long-term:

CRO services . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
Other clinical development
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other

December 31,
2020

December 31,
2019

$ 1,550
2,718
3,708
651
2,635

11,262

518
437
790

1,745

$ 4,810
2,043
3,452
544
2,410

13,259

400
468
1,131

1,999

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$13,007

$15,258

Other current prepaid amounts consist primarily of deposits, signing bonuses, licenses, subscriptions and

software. Other long-term prepaid amounts consist primarily of deposits, signing bonuses, licenses,
subscriptions, software, a capitalized sublease commission and a sublease tenant improvement allowance, net of
amortization.

Note 5—Other Current Assets:

Other current assets consisted of the following at December 31 (in thousands):

Deposit for manufacturing costs . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$3,376
67

$3,443

$—
323

$323

December 31,
2020

December 31,
2019

Other current asset amounts consist primarily of capitalized sublease commission and a sublease tenant

improvement allowances, net of amortization.

Note 6—Property and Equipment:

Property and equipment consisted of the following at December 31 (in thousands):

Leasehold improvements . . . . . . . . . . . . . . . . . . . . . .
Computer equipment . . . . . . . . . . . . . . . . . . . . . . . . .
Telephone equipment . . . . . . . . . . . . . . . . . . . . . . . . .
Furniture and fixtures . . . . . . . . . . . . . . . . . . . . . . . . .

Less: accumulated depreciation . . . . . . . . . . . . . . . . .

December 31,
2020

December 31,
2019

$ 3,779
2,192
302
2,359

8,632
(6,151)

$ 3,779
2,698
340
2,346

9,163
(5,859)

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 2,481

$ 3,304

F-25

For the years ended December 31, 2020, 2019, and 2018, the Company incurred depreciation expense of

$0.9 million, $0.9 million, and $1.1 million, respectively.

Note 7—Leases:

In December 2011, the Company entered into a non-cancelable operating lease for office space in Los
Angeles, California, which lease was subsequently amended in November 2012, December 2013, March 2014,
July 2015, and December 2017. The initial term of the lease was for seven years and commenced on
December 10, 2011. As amended, the Company rents approximately 65,656 square feet. The term of the lease
runs until March 2026, and rent amounts payable by the Company increase approximately 3% per year.
Concurrent with the execution of the lease, the Company provided the landlord an automatically renewable
stand-by letter of credit in the amount of $2.0 million. The stand-by letter of credit is collateralized by a high-
yield savings account which is classified as restricted cash on the accompanying consolidated balance sheets.

In June 2012, the Company entered into a long-term lease agreement for office space in South San

Francisco, California, which was subsequently amended in May 2014 and July 2015. As amended, the Company
rents approximately 29,470 square feet. The term of this lease runs until March 2026, with the option to extend
for an additional five-year term, and rents payable by the Company increase approximately 3% per year. The
Company provided the landlord an automatically renewable stand-by letter of credit in the amount of
$1.1 million. The stand-by letter of credit is collateralized by a high-yield savings account which is classified as
restricted cash on the accompanying consolidated balance sheets.

The Company also leases copier equipment for use in the office spaces. Components of lease expense

include fixed lease expense and variable lease expense of approximately $4.7 million and $0.4 million,
respectively, for the year ended December 31, 2020. Rent expense for each of the respective years ended
December 31, 2019 and 2018 was approximately $4.7 million. For purposes of determining straight-line rent
expense, the lease term is calculated from the date the Company first takes possession of the facility, including
any periods of free rent and any renewal option periods that the Company is reasonably certain of exercising. The
Company’s office and equipment leases generally have contractually specified minimum rent and annual rent
increases are included in the measurement of the ROU asset and related lease liability. Additionally, under these
lease arrangements, the Company may be required to pay directly, or reimburse the lessors, for real estate taxes,
insurance, utilities, maintenance and other operating costs. Such amounts are generally variable and therefore not
included in the measurement of the ROU asset and related lease liability but are instead recognized as variable
lease expense in selling, general and administrative costs in the consolidated statements of operations when they
are incurred.

The future minimum lease payments under ASC 842 as of December 31, 2020 were as follows (in

thousands):

2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2025 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thereafter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Amount

5,365
5,483
5,631
5,805
5,983
1,509

Total minimum lease payments . . . . . . . . . . . . . . . . . . . . . .

$29,776

Less: imputed interest

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(7,133)

Total lease liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$22,643

F-26

In February 2019, the Company entered into a long-term sublease agreement for 12,429 square feet of the
office space in Los Angeles, California. The term of the lease runs until March 2026, and rent amounts payable
to the Company increase approximately 3% per year. The Company recorded operating sublease income of
$0.4 million, $0.2 million and $0 for the years ended December 31, 2020, 2019 and 2018, respectively, in other
income (expenses) in the consolidated statements of operations.

The future minimum lease payments to be received as of December 31, 2020 were as follows (in

thousands):

2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2025 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thereafter

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Amount

$ 467
481
495
510
525
133

$2,611

Supplemental cash flow information related to leases for the year ended December 31, 2020:

Operating cash flows used for operating leases (in

thousands) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$5,569

Right-of-use assets obtained in exchange for new operating

lease liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Weighted average remaining lease term (in years) . . . . . . . . . .
Weighted average discount rate . . . . . . . . . . . . . . . . . . . . . . . . .

—
5.2
10.9%

Note 8—Intangible Assets:

Intangible assets consisted of the following at December 31 (in thousands):

Acquired and in-licensed rights . . . . . . . . . . . . . . . . .
Less: accumulated amortization . . . . . . . . . . . . . . . . .

$ 90,000
(15,860)

Total intangible asset, net

. . . . . . . . . . . . . . . . . . . . .

$ 74,140

$50,000
(9,539)

$40,461

December 31,
2020

December 31,
2019

Estimated future intangible amortization expense as of December 31, 2020 is as follows (in thousands):

2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2025 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thereafter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 8,015
8,015
8,015
8,015
8,015
34,065

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$74,140

F-27

Note 9—Accrued Expenses:

Accrued expenses consisted of the following at December 31 (in thousands):

Current:

Accrued legal verdict expense . . . . . . . . . . . . . .
Accrued royalties . . . . . . . . . . . . . . . . . . . . . . . .
Accrued CRO services . . . . . . . . . . . . . . . . . . . .
Accrued variable consideration . . . . . . . . . . . . .
Accrued bonus . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued compensation . . . . . . . . . . . . . . . . . . . .
. . . . . . . . .
Accrued other clinical development
Accrued professional fees . . . . . . . . . . . . . . . . .
Accrued legal fees . . . . . . . . . . . . . . . . . . . . . . .
Accrued manufacturing costs . . . . . . . . . . . . . . .
Accrued other . . . . . . . . . . . . . . . . . . . . . . . . . . .

Long-term:

Accrued legal verdict expense . . . . . . . . . . . . . .
Accrued CRO services . . . . . . . . . . . . . . . . . . . .
Accrued other . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,
2020

December 31,
2019

$22,724
8,604
3,474
9,014
7,788
4,820
1,904
1,420
383
752
442

61,325

24,822
908
233

25,963

$31,350
8,866
8,502
7,978
1,618
4,138
2,546
1,775
266
869
1,122

69,030

—
—
—

—

Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$87,288

$69,030

Accrued CRO services, accrued other clinical development expenses, and accrued legal fees represent the

Company’s estimates of such costs and are recognized as incurred. Accrued royalties represent royalties incurred
in connection with the Company’s license agreement with Pfizer. Accrued compensation includes accrued
commissions and accrued vacation, which is accrued at the rate the employee earns vacation and reduced as
vacation is used by the employee. Accrued variable consideration represents estimates of adjustments to product
revenue, net for which reserves are established.

Current accrued legal verdict expense represents an estimate of $22.7 million that may be owed to the
plaintiff as a result of the jury verdict in Eshelman v. Puma Biotechnology, Inc., et al. The Company estimates
the high end of potential damages in the matter could be approximately $27.7 million; however, the actual
amount of damages payable by the Company is still uncertain and will be ascertained only after completion of
the appeal and any subsequent proceeding, and such amount could be greater than the amount of expense already
recognized or the high end of the estimate. Other accrued expenses consist primarily of business license fees, one
half of the portion of employer Social Security payroll taxes deferred under the Coronavirus Aid, Relief, and
Economic Security Act, or the CARES Act, and other taxes, insurance, and marketing fees.

Long-term accrued legal verdict expense represents the Company’s estimate of $24.8 million that may be
owed to class action participants as a result of the jury verdict in Hsu v. Puma Biotechnology, Inc., et al. While
the final claims report received in Hsu reflects a total of $50.5 million in claimed damages, the Company intends
to challenge these claims and estimates that actual claims could be as low as $24.8 million. The actual amount
and timing of payment of damages in Hsu is uncertain and will be ascertained only after an extensive claims
challenge process, the completion of post-trial proceedings and the exhaustion of any appeals. As a result, the
Company has estimated the legal verdict expense for Hsu to be $24.8 million and has been classified as long-
term. Actual damages in the Hsu matter may be higher than the Company’s estimate. In addition, on
September 9, 2019, the Court entered an order specifying the rate of prejudgment interest to be awarded on any

F-28

valid claims at the 52-week Treasury Bill rate. Other long-term accrued expenses consist primarily of one half of
the portion of employer Social Security payroll taxes deferred under the CARES Act, accrued compensation, and
deposit from a sublessee.

Note 10—Debt:

Long-term debt consisted of the following at December 31, 2020 (in thousands):

Total debt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accretion of final interest payment
. . . . . . . . . . . . .
Less: current portion of long-term debt . . . . . . . . . .
Less: deferred financing costs . . . . . . . . . . . . . . . . .

Maturity Date

June 1, 2024

December 31,
2020

$100,000
3,313
(14,286)
(5,002)

Total long-term debt, net

. . . . . . . . . . . . . . . . . . . . .

$ 84,025

In October 2017, the Company entered into a loan and security agreement with Silicon Valley Bank, or
SVB, as administrative agent, and the lenders party thereto from time to time, or the Original Lenders, including
Oxford Finance LLC, or Oxford, and SVB. Pursuant to the terms of the credit facility provided for by the loan
and security agreement, or the Original Credit Facility, the Company borrowed $50.0 million.

In May 2018, the Company entered into an amendment to the loan and security agreement, which provided
for an amended credit facility, or the Amended Credit Facility. Under the Amended Credit Facility, the Original
Lenders agreed to make term loans available to the Company in an aggregate amount of $155.0 million,
consisting of (i) an aggregate amount of $125.0 million, the proceeds of which, in part, were used to repay the
$50.0 million borrowed under the Original Credit Facility, and (ii) an aggregate amount of $30.0 million that the
Company drew in December 2018, which was available under the Amended Credit Facility as a result of
achieving a specified minimum revenue milestone. The Company was in compliance with all applicable financial
covenants during the entire term of the Amended Credit Facility.

Prior to the amendment and restatement of the loan and security agreement in June 2019, which provided

for a new credit facility, or the New Credit Facility, the term loans under the Amended Credit Facility bore
interest at an annual rate equal to the greater of (i) 8.25% and (ii) the sum of (a) the “prime rate,” as reported in
The Wall Street Journal on the last business day of the month that immediately preceded the month in which the
interest accrued, plus (b) 3.5%. The Company was required to make monthly interest-only payments on each
term loan commencing on the first calendar day of the calendar month following the funding date of such term
loan, and continuing on the first calendar day of each calendar month thereafter through July 1, 2020.
Commencing on July 1, 2020, and continuing on the first calendar day of each calendar month thereafter, the
Company would have been required to make consecutive equal monthly payments of principal, together with
applicable interest, in arrears to each original lender, calculated pursuant to the Amended Credit Facility. All
unpaid principal and accrued and unpaid interest with respect to each term loan would have been due and payable
in full on May 1, 2023. Upon repayment of the term loans, the Company was also required to make a final
payment to the Original Lenders equal to 7.5% of the original principal amount of term loans funded.

The Company was also permitted to prepay the outstanding principal balance of any term loan under the

Amended Credit Facility, in whole but not in part, subject to a prepayment fee of 3.0% of the amount prepaid if
the prepayment were to occur through and including the first anniversary of the funding date of such term loan,
2.0% of any amount prepaid if the prepayment were to occur after the first anniversary of the funding date of
such term loan through and including the second anniversary of the funding date of such term loan, and 1.0% of
the amount prepaid if the prepayment were to occur after the second anniversary of the funding date of such term
loan and prior to May 1, 2023.

F-29

On June 28, 2019, or the Effective Date, the Company entered into the New Credit Facility with Oxford, as

collateral agent, and the lenders party thereto from time to time, including Oxford, pursuant to which the
Company repaid the $155.0 million outstanding under the Amended Credit Facility, as well as all applicable exit
and prepayment fees owed to the Original Lenders under the Amended Credit Facility, using cash on hand and
$100.0 million in new borrowings from the New Credit Facility. Under the New Credit Facility, the Company
issued to Oxford new and/or replacement secured promissory notes in an aggregate principal amount for all such
promissory notes of $100.0 million evidencing the New Credit Facility. No additional capacity remains available
to the Company under the New Credit Facility.

The New Credit Facility is secured by substantially all of the Company’s personal property other than its

intellectual property. The Company also pledged 65% of the issued and outstanding capital stock of its
subsidiaries, Puma Biotechnology Ltd. and Puma Biotechnology B.V. The New Credit Facility limits the
Company’s ability to grant any interest in its intellectual property to certain permitted licenses and permitted
encumbrances set forth in the agreement.

The term loans under the New Credit Facility bear interest at an annual rate equal to the greater of (i) 9.0%

and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the
month that immediately precedes the month in which the interest will accrue, plus (b) 3.5%. The Company is
required to make monthly interest-only payments on each term loan under the New Credit Facility commencing
on the first calendar day of the calendar month following the funding date of such term loan, and continuing on
the first calendar day of each calendar month thereafter through August 1, 2021 or, the Amortization Date.
Commencing on the Amortization Date, and continuing on the first calendar day of each calendar month
thereafter, the Company will make consecutive equal monthly payments of principal, together with applicable
interest, in arrears to each lender under the New Credit Facility, calculated pursuant to the New Credit Facility.
All unpaid principal and accrued and unpaid interest with respect to each term loan under the New Credit Facility
is due and payable in full on June 1, 2024, or the Maturity Date. Upon repayment of such term loans, the
Company is also required to make a final payment to the lenders equal to 7.5% of the aggregate principal amount
of such term loans outstanding as of the Effective Date. The effective interest rate as of December 31, 2020 was
12.75%.

At the Company’s option, the Company may prepay the outstanding principal balance of any term loan in

whole but not in part, subject to a prepayment fee of 3.0% of the amount prepaid if the prepayment occurs
through and including the first anniversary of the funding date of such term loan, 2.0% of the amount prepaid if
the prepayment occurs after the first anniversary of the funding date of such term loan through and including the
second anniversary of the funding date of such term loan, and 1.0% of the amount prepaid if the prepayment
occurs after the second anniversary of the funding date of such term loan and prior to the Maturity Date.

The New Credit Facility includes affirmative and negative covenants applicable to the Company, its current

subsidiaries and any subsidiaries the Company creates in the future. The affirmative covenants include, among
others, covenants requiring the Company to maintain its legal existence and governmental approvals, deliver
certain financial reports, maintain insurance coverage and satisfy certain requirements regarding deposit
accounts. The Company must also achieve certain product revenue targets, measured as of the last day of each
fiscal quarter on a trailing year to date basis. New minimum revenue levels will be established for each
subsequent fiscal year by mutual agreement of the Company, Oxford, as collateral agent, and the new lenders.
The negative covenants include, among others, restrictions on the Company’s transferring collateral, incurring
additional indebtedness, engaging in mergers or acquisitions, paying dividends or making other distributions,
making investments, creating liens, selling assets and suffering a change in control, in each case subject to certain
exceptions.

The New Credit Facility also includes events of default, the occurrence and continuation of which could

cause interest to be charged at the rate that is otherwise applicable plus 5.0% and would provide Oxford, as
collateral agent, with the right to exercise remedies against the Company and the collateral securing the New

F-30

Credit Facility, including foreclosure against the property securing the New Credit Facility, including the
Company’s cash. These events of default include, among other things, the Company’s failure to pay principal or
interest due under the New Credit Facility, a breach of certain covenants under the New Credit Facility, the
Company’s insolvency, a material adverse change, the occurrence of any default under certain other indebtedness
in an amount greater than $500,000 and one or more judgments against the Company in an amount greater than
$500,000 individually or in the aggregate that remains unsatisfied, unvacated, or unstayed for a period of 10 days
after its entry.

On February 27, 2020, the Company and Oxford amended the New Credit Facility to establish the
Company’s minimum revenue thresholds for the trailing year-to-date periods ending March 31, June 30,
September 30 and December 31, 2020 and the fiscal year 2021. On August 5, 2020 the Company and Oxford
amended the New Credit Facility to amend the minimum revenue thresholds for the trailing year-to-date periods
ending September 30 and December 31, 2020. On February 3, 2021, the Company and Oxford amended the New
Credit Facility to establish the Company’s minimum revenue thresholds for the trailing year-to-date periods
ending March 31, June 30, September 30 and December 31, 2021.

As of December 31, 2020, there were $100.0 million in principal amounts outstanding under the New Credit
Facility, representing all of the Company’s debt outstanding as of that date, and the Company was in compliance
with all applicable covenants under the New Credit Facility.

The future minimum principal payments under the New Credit Facility as of December 31, 2020 were as

follows (in thousands):

2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thereafter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Amount

$ 14,286
34,286
34,286
17,142
—

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$100,000

Deferred Financing Costs

Deferred financing costs consisted of the following (in thousands):

Deferred financing costs . . . . . . . . . . . . . . . . . . . . . .
Less: accumulated amortization . . . . . . . . . . . . . . . . .

$ 8,668
(3,666)

Included in long-term debt . . . . . . . . . . . . . . . . . . . . .

$ 5,002

$ 8,668
(1,701)

$ 6,967

December 31,
2020

December 31,
2019

Deferred financing costs are financing costs related to the Company’s outstanding debt. Amortization of

debt issuance costs is expensed using the effective interest method and is included in interest expense in the
consolidated statements of operations. For the years ended December 31, 2020, 2019 and 2018, the Company
recorded approximately $2.0 million, $1.5 million and $0.9 million, respectively, of interest expense related to
the amortization of debt issuance costs in the consolidated statements of operations.

F-31

Note 11—Stockholders’ (Deficit) Equity:

Common Stock:

The Company issued 18,202, 87,625, and 200,743 shares of common stock upon exercise of stock options

during the years ended December 31, 2020, 2019 and 2018, respectively. The Company issued 864,881, 790,642,
and 529,443 shares of common stock upon vesting of RSUs during the years ended December 31, 2020, 2019
and 2018, respectively.

Authorized Shares:

The Company has 100,000,000 shares of stock authorized for issuance, all of which are common stock, par

value $0.0001 per share.

Warrants:

In October 2011, the Company issued an anti-dilutive warrant to Alan Auerbach, the Company’s founder

and Chief Executive Officer. The warrant was issued to provide Mr. Auerbach with the right to maintain
ownership of at least 20% of the Company’s common stock in the event that the Company raised capital through
the sale of its securities in the future.

In connection with the closing of a public offering in October 2012, the exercise price and number of shares

underlying the warrant issued to Mr. Auerbach were established and, accordingly, the final value of the warrant
became fixed. Pursuant to the terms of the warrant, Mr. Auerbach may exercise the warrant to acquire 2,116,250
shares of the Company’s common stock at $16 per share until October 4, 2021.

Stock Options and Restricted Stock Units:

The Company’s 2011 Incentive Award Plan, or the 2011 Plan, was adopted by the Company’s Board of
Directors on September 15, 2011. Pursuant to the 2011 Plan, the Company may grant incentive stock options and
nonqualified stock options, as well as other forms of equity-based compensation. Incentive stock options may be
granted only to employees, while consultants, employees, officers and directors are eligible for the grant of
nonqualified options under the 2011 Plan. The maximum term of stock options granted under the 2011 Plan is 10
years and the awards generally vest over a three-year period. The exercise price of incentive stock options
granted under the 2011 Plan must be at least equal to the fair value of such shares on the date of grant. As of
December 31, 2020, a total of 12,529,412 shares of the Company’s common stock have been reserved for
issuance under the 2011 Plan.

As of December 31, 2020, 5,620,045 shares of the Company’s common stock are issuable upon the exercise

of outstanding awards granted under the 2011 Plan and 2,387,923 shares of the Company’s common stock are
available for future issuance under the 2011 Plan. The Company awarded only “plain vanilla options” as
determined by the SEC Staff Accounting Bulletin 107, or Share Based Payment. The fair value of options
granted to employees and non-employees was estimated using the Black-Scholes Option Pricing Method (see
Note 2) with the following weighted-average assumptions used during the years ended December 31:

Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected volatility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk-free interest rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected life in years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2020

2019

0.0% 0.0%
100.6% 99.9%
0.9% 2.5%
5.81

5.76

The Company’s 2017 Employment Inducement Incentive Award Plan, or the 2017 Plan, was adopted by the

Company’s Board of Directors on April 27, 2017. Pursuant to the 2017 Plan, the Company may grant stock

F-32

options and restricted stock units, as well as other forms of equity-based compensation to employees, as an
inducement to join the Company. The maximum term of stock options granted under the 2017 Plan is 10 years
and the awards generally vest over a three-year period. The exercise price of stock options granted under the
2017 Plan must be at least equal to the fair market value of such shares on the date of grant. As of December 31,
2020, a total of 2,000,000 shares of the Company’s common stock have been reserved for issuance under the
2017 Plan. As of December 31, 2020, 1,243,502 shares of the Company’s common stock are issuable upon the
exercise of outstanding stock options and vesting of RSUs granted under the 2017 Plan, and 434,540 shares of
the Company’s common stock are available for future issuance under the 2017 Plan.

Stock-based compensation expense was as follows for the years ended December 31 (in thousands):

For the Year Ended
December 31,

2020

2019

2018

Stock-based compensation:

Options -

Selling, general, and administrative . . . . . . . . . .
Research and development . . . . . . . . . . . . . . . . .

$ 3,937
3,018

$ 9,044
7,452

$14,063
26,456

Restricted stock units -

Selling, general, and administrative . . . . . . . . . .
Research and development . . . . . . . . . . . . . . . . .

13,841
15,779

18,848
21,983

20,851
25,569

Total stock-based compensation expense . . . . . . . . . . . . .

$36,575

$57,327

$86,939

Activity with respect to options granted under the 2011 and 2017 Plan is summarized as follows:

Outstanding at December 31, 2017 . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . .
Expired . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outstanding at December 31, 2018 . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . .
Expired . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outstanding at December 31, 2019 . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . .
Expired . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outstanding at December 31, 2020 . . . . . . . . . .
Nonvested at December 31, 2020 . . . . . . . . . . .

Weighted
Average
Exercise
Price

$ 87.91
$ 59.13
$ 51.96
$ 35.88
$116.96
$ 87.49
$ 15.40
$ 38.71
$ 15.42
$104.76
$ 82.42
$ 10.03
$
3.75
$ 90.51
$ 71.42
$ 11.18

Shares

6,134,513
315,566
(183,837)
(200,743)
(356,955)
5,708,544
340,241
(128,406)
(87,625)
(790,429)
5,042,325
700,853
(18,202)
(715,634)
5,009,342
899,672

Exercisable . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4,109,670

$ 84.61

Weighted
Average
Remaining
Contractual
Term
(years)

7.2
9.3

6.1
8.6

5.2
9.2

5.1
9.1

4.3

Aggregate
Intrinsic
Value
(in thousands)

$220,060

$

$

$

$

$

$

$

5,063

7,762

995

1,951

119

3,458
1,106

2,352

At December 31, 2020, total estimated unrecognized compensation cost related to non-vested stock options

granted prior to that date was approximately $5.9 million, which is expected to be recognized over a weighted-
average period of 1.9 years. At December 31, 2020, the total estimated unrecognized compensation cost related

F-33

to non-vested RSUs was approximately $16.6 million, which is expected to be recognized over a weighted-
average period of 1.5 years. The weighted-average grant date fair value of options granted during the years ended
December 31, 2020, 2019 and 2018, was $7.81, $12.08 and $45.62 per share, respectively. The weighted average
grant date fair value of RSUs awarded during the year ended December 31, 2020, 2019 and 2018 was $10.47,
$14.72, and $41.42, respectively.

Stock Option Rollforward

Nonvested shares at December 31, 2018 . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested/Issued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonvested shares at December 31, 2019 . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested/Issued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shares

779,292
340,241
(551,933)
(128,406)
439,194
700,853
(240,375)

Nonvested shares at December 31, 2020 . . . . . . . . . . . . .

899,672

Restricted Stock Unit Rollforward

Nonvested shares at December 31, 2017 . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested/Issued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonvested shares at December 31, 2018 . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested/Issued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonvested shares at December 31, 2019 . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested/Issued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shares

1,637,662
1,175,231
(529,443)
(444,780)
1,838,670
1,472,417
(790,642)
(529,320)
1,991,125
1,234,616
(864,881)
(506,655)

Nonvested shares at December 31, 2020 . . . . . . . . . . . . .

1,854,205

Weighted
Average
Grant-Date
Fair Value

$33.75
12.08
33.56
26.27
19.38
7.81
25.57

$ 8.71

Weighted
Average
Grant-Date
Fair Value

$85.58
41.42
79.98
80.99
60.08
14.72
62.98
51.63
27.63
10.47
36.86
21.72

$13.51

Note 12—401(k) Savings Plan:

During 2012, the Company adopted a 401(k) savings plan for the benefit of its employees. The Company is

required to make matching contributions to the 401(k) plan equal to 100% of the first 3% of wages deferred by
each participating employee and 50% on the next 2% of wages deferred by each participating employee. The
Company incurred expenses for employer matching contributions of approximately $1.4 million, $1.5 million
and $ 1.9 million for the years ended December 31, 2020, 2019 and 2018, respectively.

F-34

Note 13—Income Taxes:

Income tax expense was as follows for the years ended December 31 (in thousands):

Current:

Federal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Deferred:

Federal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2020

2019

2018

$—
124
83

207

$—
53
—

53

$—
17
—

17

—
—

—

—
—

—

—
—

—

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$207

$ 53

$ 17

The provision for income taxes in the accompanying consolidated statements of operations differs from the

amount calculated by applying the statutory income tax rate to loss from continuing operations before income
taxes. Approximately $13.2 million of tax expense for the year ended December 31, 2020 is due to stock-based
compensation expense shortfall and the expiration of vested stock options. Approximately $5.2 million of the tax
benefit for the year-ended December 31, 2020 is due to R&D tax credits, net of an approximate $1.3 million
reserve related to unrecognized tax benefits for the method of allocation of expenses used in the R&D tax credits
calculation.. The primary components of such differences are as follows as of December 31 (in thousands):

Tax computed at the federal statutory rate . . . . . . . . . . .
State taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Permanent items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R&D credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prior year adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . .
Change in valuation allowance . . . . . . . . . . . . . . . . . . .

2020

2019

2018

$(12,540)
(2,304)
83
13,660
(5,231)
(2,116)
8,655

$(15,830)
(2,453)
—
21,834
(14,946)
(2,792)
14,240

$(23,771)
(2,791)
—
10,932
(5,630)
15,750
5,527

Total provision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

207

$

53

$

17

Temporary differences between the carrying amounts of assets and liabilities for financial reporting
purposes and the amounts used for income tax purposes give rise to the Company’s deferred income taxes. The
components of the Company’s net deferred tax assets are as follows as of December 31 (in thousands):

2020

2019

Deferred tax assets:

Net operating loss carryforwards . . . . . . . . . . . . . . .
Business credit carryforwards . . . . . . . . . . . . . . . . . .
Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . .
Accrued legal verdict
Carryforward of disallowed interest . . . . . . . . . . . . .
Accrued expenses . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lease liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other deferred tax assets . . . . . . . . . . . . . . . . . . . . . .

$261,472
55,574
58,112
11,880
3,093
561
5,657
804

$260,555
50,343
60,967
7,624
2,839
9
6,145
13

Subtotal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

397,153

388,495

F-35

2020

2019

Deferred tax liabilities:

Lease right-of-use assets . . . . . . . . . . . . . . . . . . . . .
Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other deferred tax liabilities . . . . . . . . . . . . . . . . . .

(4,099)
(21)
(464)

(4,505)
—
(76)

Subtotal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . .
Valuation allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(4,584)
392,569
(392,569)

(4,581)
383,914
(383,914)

Net deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . .

$

—

$

—

As the ultimate realization of the potential benefits of the Company’s deferred tax assets is considered
unlikely by management, the Company has offset the deferred tax assets attributable to those potential benefits
through valuation allowances. Accordingly, the Company did not recognize any benefit from income taxes in the
accompanying consolidated statements of operations to offset its pre-tax losses. The valuation allowance
increased $8.7 million and $14.2 million for the years ended December 31, 2020 and 2019, respectively. At
December 31, 2020, the Company had federal and state net operating loss carryforwards, respectively, of
approximately $961.0 million and $884.3 million, which will begin to expire in 2033. At December 31, 2020, the
Company also has federal research and development credit carryforwards of approximately $37.1 million. If not
utilized, the carryforwards will begin to expire in 2033. The Company has state research and development credit
carryforwards of approximately $21.7 million which do not expire. Pursuant to the Internal Revenue Code,
Sections 382 and 383, use of the Company’s net operating loss and credit carryforwards could be limited if a
cumulative change in ownership of more than 50% occurs within a three-year period. The Company has not yet
performed an assessment on the potential limitation on net operating loss and credit carryforwards.

The following is a tabular reconciliation of the total amounts of unrecognized tax benefits at December 31

(in thousands):

Unrecognized tax benefits—January 1 . . . . . . . . . . . . . . . . . .
Gross decreases—tax positions in a prior period . . . . . . . . . .
Gross increases—tax positions in a current period . . . . . . . . .

$1,968
—
1,308

$ 8,777
(8,422)
1,613

$7,151
—
1,626

Unrecognized tax benefits—December 31 . . . . . . . . . . . . . . .

$3,276

$ 1,968

$8,777

2020

2019

2018

During the year ended December 31, 2019, the Company completed an R&D credit study. As a result of the

study, the Company assessed that the Company qualified under safe harbor rules, which when applied
consistently results in a more conservative approach of calculating the amount of R&D credit. The Company
concluded that a release of uncertain tax benefits was appropriate and released a portion of previously recorded
uncertain tax positions reserve. There were no releases of uncertain tax position reserves in the year ended
December 31, 2020. Current year increases in the R&D credit relate to R&D support department costs that were
allocated to various research projects based upon a reasonable methodology. The uncertain tax position is related
to the method of allocating these costs.

The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the

normal course of business, the Company is subject to examination by the federal and state jurisdictions where
applicable. There are currently no pending income tax examinations. The Company’s tax years for 2009 and
forward are subject to examination by the federal and California tax authorities due to the carryforward of
unutilized net operating losses and research and development credits.

F-36

Note 14—Commitments and Contingencies:

License Agreement:

In August 2011, the Company entered into an agreement pursuant to which Pfizer agreed to grant it a
worldwide license for the development, manufacture and commercialization of PB272 neratinib (oral), PB272
neratinib (intravenous) and PB357, and certain related compounds. The license is exclusive with respect to
certain patent rights owned by or licensed to Pfizer. Under the agreement, the Company is obligated to
commence a new clinical trial for a product containing one of these compounds within a specified period of time
and to use commercially reasonable efforts to complete clinical trials and to achieve certain milestones as
provided in a development plan. From the closing date of the agreement through December 31, 2011, Pfizer
continued to conduct the existing clinical trials on behalf of the Company at the Licensor’s sole expense. At the
Company’s request, Pfizer agreed to continue to perform certain services in support of the existing clinical trials
at the Company’s expense. These services will continue through the completion of the transitioned clinical trials.
The license agreement “capped” the out of pocket expense the Company would be responsible to complete the
then existing clinical trials. All agreed upon costs incurred by the Company above the “cost cap” would be
reimbursed by Pfizer. The Company exceeded the “cost cap” during the fourth quarter of 2012. In accordance
with the license agreement, the Company billed Pfizer for agreed upon costs above the “cost cap” until
December 31, 2013.

On July 18, 2014, the Company entered into an amendment to the license agreement with Pfizer. The
amendment amends the agreement to (i) reduce the royalty rate payable by the Company to Pfizer on sales of
licensed products; (ii) release Pfizer from its obligation to pay for certain out-of-pocket costs incurred or accrued
on or after January 1, 2014 to complete certain ongoing clinical studies; and (iii) provide that Pfizer and the
Company will continue to cooperate to effect the transfer to the Company of certain records, regulatory filings,
materials and inventory controlled by Pfizer as promptly as reasonably practicable.

As consideration for the license, the Company is required to make substantial payments upon the

achievement of certain milestones totaling approximately $187.5 million if all such milestones are achieved. In
connection with the FDA approval of NERLYNX in July of 2017, the Company triggered a one-time milestone
payment pursuant to the agreement. In June 2020, the Company entered into a letter agreement, or the Letter
Agreement, with Pfizer relating to the method of payment associated with a one-time milestone payment under
the license agreement with Pfizer. The Letter Agreement permits the Company to make the milestone payment in
installments with portions of the amount payable to Pfizer (including interest) made in June and November 2020
for approximately $20.6 million in the aggregate and the remaining portion to be made in September 2021 for
approximately $21.9 million. Unpaid portions of the milestone payment will accrue interest at 6.25% per annum
until paid. The installment payments and accrued interest are included in accrued in-licensed rights on the
accompanying consolidated balance sheets. The Company may trigger additional milestone payments in the
future. Should the Company commercialize any more of the compounds licensed from Pfizer or any products
containing any of these compounds, the Company will be obligated to pay to Pfizer annual royalties at a fixed
rate in the low to mid-teens of net sales of all such products, subject to certain reductions and offsets in some
circumstances. The Company’s royalty obligation continues, on a product-by-product and country-by-country
basis, until the later of (i) the last to expire licensed patent covering the applicable licensed product in such
country, or (ii) the earlier of generic competition for such licensed product reaching a certain level in such
country or expiration of a certain time period after first commercial sale of such licensed product in such country.
In the event that the Company sublicenses the rights granted to the Company under the license agreement with
Pfizer to a third party, the same milestone and royalty payments are required. The Company can terminate the
license agreement at will, or for safety concerns, in each case upon specified advance notice.

Clinical Trial Contracts:

The Company engages with clinical research organizations and contract manufacturing organizations, or

CMOs, in addition to engaging in contracts for the management of its ongoing clinical trials and

F-37

pre-commercialization efforts. The Company may cancel these agreements with a 30 to 45 day written notice to
the outside vendor. The Company would be obligated to pay for services rendered up to that point. The contracts
also contain variable costs that are hard to predict as they are based on such things as patients enrolled and
clinical trial sites, which can vary, and therefore, are not included in the table below. The contracts held by the
Company as of December 31, 2020, are summarized as follows (in thousands):

Indication

Estimated
Contractual
Obligation
as of
December 31,
2020

Months
Remaining
on Contract

HER2 Overexpressed/Amplified Breast Cancer

(Extension) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 5,242

HER2 Overexpressed/Amplified Breast Cancer

(Licensor Legacy Clinical Trials)

. . . . . . . . . . . . . .

371

HER2 Mutated Breast Cancer and HER2 Mutated

Breast Cancer with Brain Metastases . . . . . . . . . . . .
Metastatic & Adjuvant Breast Cancer . . . . . . . . . . . . .
Pre-Clinical Research . . . . . . . . . . . . . . . . . . . . . . . . . .
Post-Clinical Research . . . . . . . . . . . . . . . . . . . . . . . . .
HER2 Mutated Solid Tumors . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

456
10,399
22,003
1,256
2,645
24,849

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$67,221

12

3

24
5
14
11
10
15

Included in the above are payments to be made when milestones are reached. As of December 31, 2020,
Company obligations for potential milestone payments totaled approximately $18.4 million. This amount will be
paid by the Company if all milestones are reached and would reduce the overall contractual obligation if one or
more milestone is never reached.

Legal Proceedings

The Company and certain of its executive officers were named as defendants in the lawsuits detailed below.

The Company records a liability in the consolidated financial statements for loss contingencies when a loss is
known or considered probable and the amount can be reasonably estimated. If the reasonable estimate of a
known or probable loss is a range, and no amount within the range is a better estimate than any other, the
minimum amount of the range is accrued. If a loss is reasonably possible but not known or probable, and can be
reasonably estimated, the estimated loss or range of loss is disclosed. When determining the estimated loss or
range of loss, significant judgment is required to estimate the amount and timing of a loss to be recorded.
Currently, the Company has accrued estimated losses of $24.8 million related to Hsu v. Puma Biotechnology,
Inc., et al., and $22.7 million related to Eshelman v. Puma Biotechnology, Inc., et al. as detailed below. For
certain legal expenses related to the verdicts listed below, the Company has received reimbursements from its
insurers.

Hsu v. Puma Biotechnology, Inc., et al.

On June 3, 2015, Hsingching Hsu, individually and on behalf of all others similarly situated, filed a class
action lawsuit against the Company and certain of its executive officers in the United States District Court for the
Central District of California (Case No. 8:15-cv-00865-AG-JCG). On October 16, 2015, lead plaintiff Norfolk
Pension Fund filed a consolidated complaint on behalf of all persons who purchased the Company’s securities
between July 22, 2014 and May 29, 2015. A trial on the claims relating to four statements alleged to have been
false or misleading was held from January 15, 2019 to January 29, 2019. At trial, the jury found that three of the
four challenged statements were not false or misleading, and thus found in the defendants’ favor on those claims.

F-38

The jury found liability as to one statement and awarded a maximum of $4.50 per share in damages, which
represents approximately 5% of the total claimed damages of $87.20 per share. On September 9, 2019, the Court
entered an order specifying the rate of prejudgment interest to be awarded on any valid claims at the 52-week
Treasury Bill rate. On September 8, 2020, the claims administrator submitted its final claims report to the Court
and, on October 9, 2020, the claims administrator submitted its supplemental claims report. The claims report
reflects approximately $50.5 million in claimed damages. The Company disagrees with the amount of claimed
damages. On November 27, 2020, the Court issued an order setting out the process for challenging claims.
Pursuant to that order, defendants must decide by March 29, 2021 which claims they intend to challenge, and for
which claims the Company needs more information to determine whether or not it will challenge those claims.
Based on a review of specific claims and subject to the outcome of the claims challenge process, the Company
believes that total claimed damages after all claims challenges have been adjudicated could range from
$24.8 million to $51.4 million. The total amount of aggregate class-wide damages still remains uncertain and will
be ascertained only after the claims challenge process and the exhaustion of any appeals. It is reasonably possible
that the final total damages awarded will differ from these estimates; however, the amount is not estimable at this
time. A final judgment has not yet been entered.

Eshelman v. Puma Biotechnology, Inc., et al.

In February 2016, Fredric N. Eshelman filed a lawsuit against the Company’s Chief Executive Officer and

President, Alan H. Auerbach, and the Company in the United States District Court for the Eastern District of
North Carolina (Case No. 7:16-cv-00018-D). The complaint generally alleged that Mr. Auerbach and the
Company made defamatory statements regarding Dr. Eshelman in connection with a proxy contest. In May 2016,
Dr. Eshelman filed a notice of voluntary dismissal of the claims against Mr. Auerbach. A trial on the remaining
defamation claims against the Company took place from March 11 to March 15, 2019. At trial, the jury found the
Company liable and awarded Dr. Eshelman $15.9 million in compensatory damages and $6.5 million in punitive
damages. The Company strongly disagrees with the verdict and, on April 22, 2019, filed a motion for a new trial
or, in the alternative, a reduced damages award. The Court denied that motion on March 2, 2020. The Company
has appealed that ruling, and the verdict. Additionally, after trial, the plaintiff filed a motion seeking
approximately $3.0 million in attorneys’ fees, as well as prejudgment interest. In the Court’s March 2 ruling, it
denied the motion for attorneys’ fees but granted the request for prejudgment interest, bringing the total judgment
to $26.3 million. On March 30, 2020, the plaintiff filed a notice of cross-appeal and conditional cross-appeal,
appealing the Court’s order denying the plaintiff’s request for attorneys’ fees and conditionally cross-appealing a
Court ruling that certain communications between Mr. Auerbach and his attorneys were protected by attorney-
client privilege and a related evidentiary ruling. The Company estimates the high end of potential damages in the
matter could be approximately $27.7 million; however, the actual amount of damages payable by the Company is
still uncertain and will be ascertained only after completion of the appeal and any subsequent proceedings, and
such amount could be greater than the amount of expense already recognized or the high end of the estimate. Due
to the appeal, the Company secured a bond for the potential damages, which is collateralized by an automatically
renewable stand-by letter of credit in the amount of $8.9 million. The stand-by letter of credit is collateralized by
a high-yield savings account, which is classified as restricted cash, current on the accompanying consolidated
balance sheets. The United States Court of Appeals for the Fourth Circuit has tentatively calendared the oral
argument of the Company’s appeal during the month of May 2021.

CANbridge Licensing Dispute

On July 28, 2020, the Company filed a request for arbitration against CANbridge Biomed Limited, or
CANbridge, before the ICC International Court of Arbitration. The Company asserted that CANbridge violated
the terms of the Company’s agreement with CANbridge in which it granted CANbridge an exclusive sublicense
to develop and commercialize NERLYNX throughout greater China. The Company sought an arbitral award, as
well as damages, costs, and attorneys’ fees. On August 26, 2020, CANbridge filed its response to the Company’s
request for arbitration and brought counterclaims, seeking damages, costs and attorneys’ fees. On February 24,
2021, the parties resolved their dispute, with each side agreeing to dismiss their respective claims in the

F-39

arbitration. The settlement is limited to claims asserted in the arbitration, or that are related to the claims asserted
in the arbitration.

Legal Malpractice Suit

On September 17, 2020, the Company filed a lawsuit against Hedrick Gardner Kincheloe & Garofalo,

L.L.P. and David L. Levy, the attorneys who previously represented the Company in Eshelman v. Puma
Biotechnology, Inc., et al. in the Superior Court of Mecklenburg County, North Carolina. The Company is
alleging legal malpractice based on the defendants’ negligent handling of the defense of the Company in
Eshelman v. Puma Biotechnology, Inc., et al. as detailed above. The Company is seeking recovery of the entire
amount awarded in Eshelman v. Puma Biotechnology, Inc., et al. On November 23, 2020, the defendant filed an
answer to the complaint denying the allegations of negligence.

Note 15—Quarterly Financial Data:

Quarterly financial data (in thousands except share and per share data):
(unaudited)

Three Months Ended

March 31,

June 30,

September 30, December 31,

2020

Revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . $
Net (loss) income . . . . . . . . . . . . . . . . . . . .
Net (loss) income attributable to common

stock . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net (loss) income per share—basic . . . . . . . $
Net (loss) income per share—diluted . . . . . $
Weighted-average shares of common stock
outstanding—basic . . . . . . . . . . . . . . . . .
Weighted-average shares of common stock
outstanding—diluted . . . . . . . . . . . . . . . .

51,217 $
(16,933)

70,582 $
3,395

50,754 $
(31,463)

52,557
(14,994)

(16,933)

(0.43) $
(0.43) $

3,395
0.09 $
0.08 $

(31,463)

(0.79) $
(0.79) $

(14,994)
(0.38)
(0.38)

39,291,162

39,432,030

39,695,444

39,881,131

39,291,162

39,997,571

39,695,444

39,881,131

2019

Revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . $
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net loss attributable to common stock . . . .
Net loss per share—basic and diluted . . . . . $
Weighted-average shares of common stock
outstanding—basic and diluted . . . . . . . .

99,067 $
(10,087)
(10,087)

(0.26) $

53,919 $
(37,424)
(37,424)

(0.97) $

56,352 $
(16,885)
(16,885)

(0.44) $

62,922
(11,199)
(11,199)
(0.29)

38,481,824

38,647,775

38,893,757

39,043,706

2018

Revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . $
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net loss attributable to common stock . . . .
Net loss per share—basic and diluted . . . . . $
Weighted-average shares of common stock
outstanding—basic and diluted . . . . . . . .

66,516 $
(24,345)
(24,345)

(0.65) $

50,767 $
(44,335)
(44,335)

(1.17) $

62,629 $
(14,201)
(14,201)

(0.37) $

71,079
(30,694)
(30,694)
(0.80)

37,699,024

37,819,767

38,043,174

38,201,056

Note 16—Subsequent Events:

Pierre Fabre Amendment and CANbridge Termination of License Agreement and Related Agreements

On February 24, 2021, the Company entered into a second amendment, or the Second Pierre Fabre

Amendment, to the sub-license agreement with Pierre Fabre Medicament SAS, or Pierre Fabre, to extend Pierre
Fabre’s commercial rights for NERLYNX to Greater China, which includes mainland China, Taiwan, Hong
Kong and Macao. Under the terms of the Second Pierre Fabre Amendment, the Company will receive an upfront

F-40

payment of $50.0 million, as well as additional regulatory and sales-based milestone payments that could add up
to an additional $240.0 million. These milestones will be based solely on regulatory and sales achievements in
Greater China. In addition, the Company is entitled to receive double-digit tiered royalties on the sales of
NERLYNX in Greater China. Also on February 24, 2021, the Company and CANbridge BIOMED Limited, or
CANbridge, have mutually agreed to terminate the sub-license agreement, by and between the Company and
CANbridge, to commercialize NERLYNX in Greater China and all other related agreements. Subject to the terms
of a termination agreement between CANbridge and the Company, the Company agreed to pay CANbridge a
one-time termination fee of $20.0 million to return all rights to NERLYNX in Greater China back to the
Company and assist with the transfer of such rights to the Company.

F-41

Exhibit 31.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Alan H. Auerbach, certify that:

1. I have reviewed this Annual Report on Form 10-K of Puma Biotechnology, Inc. for the year ended

December 31, 2020;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to

state a material fact necessary to make 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;

3. 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;

4. 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) 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;

(b) 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;

(c) 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

(d) 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) 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

(b) 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 1, 2021

/s/ Alan H. Auerbach

Alan H. Auerbach
Principal Executive Officer

Exhibit 31.2

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER
PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Maximo F. Nougues, certify that:

1. I have reviewed this Annual Report on Form 10-K of Puma Biotechnology, Inc. for the year ended

December 31, 2020;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to

state a material fact necessary to make 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;

3. 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;

4. 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) 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;

(b) 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;

(c) 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

(d) 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) 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

(b) 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 1, 2021

/s/ Maximo F. Nougues

Maximo F. Nougues
Principal Financial and Accounting Officer

Exhibit 32.1

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

The following certification is being furnished solely to accompany the Annual Report on Form 10-K of Puma
Biotechnology, Inc. for the year ended December 31, 2020, pursuant to 18 U.S.C. § 1350 and in accordance with
SEC Release No. 33-8238. This certification shall not be deemed “filed” for purposes of Section 18 of the
Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference in any filing of Puma
Biotechnology, Inc. under the Securities Act of 1933, as amended, whether made before or after the date hereof,
regardless of any general incorporation language in such filing.

Certification of Principal Executive Officer

I, Alan H. Auerbach, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that the Annual Report on Form 10-K of Puma Biotechnology, Inc. for the year
ended December 31, 2020, fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the
Securities Exchange Act of 1934, as amended, and that the information contained in such report fairly presents,
in all material respects, the financial condition and results of operations of Puma Biotechnology, Inc.

Date: March 1, 2021

/s/ Alan H. Auerbach

Alan H. Auerbach
Principal Executive Officer

A signed original of this written statement required by Section 906 has been provided to Puma Biotechnology,
Inc. and will be retained by Puma Biotechnology, Inc. and furnished to the Securities and Exchange Commission
or its staff upon request.

Exhibit 32.2

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

The following certification is being furnished solely to accompany the Annual Report on Form 10-K of Puma
Biotechnology, Inc. for the year ended December 31, 2020, pursuant to 18 U.S.C. § 1350 and in accordance with
SEC Release No. 33-8238. This certification shall not be deemed “filed” for purposes of Section 18 of the
Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference in any filing of Puma
Biotechnology, Inc. under the Securities Act of 1933, as amended, whether made before or after the date hereof,
regardless of any general incorporation language in such filing.

Certification of Principal Financial Officer

I, Maximo F. Nougues, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that the Annual Report on Form 10-K of Puma Biotechnology, Inc. for the year
ended December 31, 2020, fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the
Securities Exchange Act of 1934, as amended, and that the information contained in such report fairly presents,
in all material respects, the financial condition and results of operations of Puma Biotechnology, Inc.

Date: March 1, 2021

/s/ Maximo F. Nougues

Maximo F. Nougues
Principal Financial and Accounting Officer

A signed original of this written statement required by Section 906 has been provided to Puma Biotechnology,
Inc. and will be retained by Puma Biotechnology, Inc. and furnished to the Securities and Exchange Commission
or its staff upon request.

COMPANY LEADERSHIP

BOARD OF DIRECTORS

Alan H. Auerbach 
Chairman, Chief Executive Officer and President  
Puma Biotechnology, Inc.

Ann C. Miller, M.D. 
Vice President, Marketing, Global Marketing (retired)  
Sanofi S.A.

Michael P. Miller 
Executive Vice President U.S. Commercial (retired) 
Jazz Pharmaceuticals plc

Jay M. Moyes 
Chief Financial Officer 
Sera Prognostics, Inc.

Hugh O’Dowd 
President and Chief Executive Officer 
Neon Therapeutics

Adrian M. Senderowicz, M.D. 
Senior Advisor  
Constellation Pharmaceuticals

Brian Stuglik, R.Ph. 
Chief Executive Officer 
Verastem, Inc.

Troy E. Wilson, Ph.D., J.D. 
President, Chief Executive Officer and Chairman 
Kura Oncology, Inc.

CORPORATE OFFICERS

Alan H. Auerbach 
Chairman, Chief Executive Officer and President 

Maximo F. Nougues 
Chief Financial Officer

Jeff J. Ludwig 
Chief Commercial Officer

Douglas Hunt 
Senior Vice President, Regulatory Affairs, 
Medical Writing and Project Management

Alvin Wong, Pharma.D. 
Senior Vice President, Clinical Science 
and Pharmacology

STOCKHOLDER INFORMATION

Corporate Headquarters 
Puma Biotechnology, Inc. 
10880 Wilshire Blvd., Suite 2150 
Los Angeles, CA  90024 
424-248-6500

Investor Relations 
Securities analysts, investment professionals and stockholders 
should direct inquiries to Investor Relations at 424-248-6500 
Ext. 2011 or ir@pumabiotechnology.com.

For additional information about Puma, please visit 
our website at www.pumabiotechnology.com.

Common Stock 
Puma’s common stock is listed on The NASDAQ 
Stock Market under the trading symbol “PBYI.”

Transfer Agent 
EQ Shareowner Services SM

Mail: 
P.O. Box 64854 
St. Paul, MN 55164

Courier: 
1110 Centre Pointe Curve, Suite 101 
Mendota Heights, MN  55120--4100

Telephone: 
800-468-9716 
651-450-4064

Website: www.shareowneronline.com

Annual Meeting 
The 2021 Annual Meeting of Stockholders will be held at  
1:00 p.m. PDT on Tuesday, June 15, 2021 at  
Puma Biotechnology, Inc. 
10880 Wilshire Boulevard, Suite 2150 
Los Angeles, CA 90024

Independent Registered Public Accounting Firm 
KPMG LLP 
550 South Hope St. 
Suite 1500 
Los Angeles, CA 90071

Forward-Looking Statements

This document contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, including, but not limited to, statements regarding 
the commercialization of NERLYNX®, the potential indications of the Company’s drug candidates and the development of those drug candidates, and the announcement of data relative to the 
Company’s clinical trials. These statements are often, but not always, made through the use of words or phrases such as “anticipates,” “estimates,” “expects,” “plans,” “projects,” “continuing,” 
“ongoing,” “believes,” “intends,” and similar words or phrases. Discussions containing these forward-looking statements may be found throughout this document, including the sections entitled 
“Item 1. Business” and “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations” in the Company’s Annual Report on Form 10-K for the fiscal year 
ended December 31, 2020. All forward-looking statements included in this document involve risks and uncertainties that could cause the Company’s actual results to differ materially from the 
anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions, and actual outcomes 
and results could differ materially from these statements due to a number of factors, which include, but are not limited to any adverse impact on the Company’s business or the global economy 
and financial markets, generally, from the global COVID-19 pandemic, and the risk factors disclosed in the periodic and current reports filed by the Company with the Securities and Exchange 
Commission from time to time, including the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020, which is included herein. Readers are cautioned not to 
place undue reliance on these forward-looking statements, which speak only as of the date hereof. The Company assumes no obligation to update these forward-looking statements, except 
as required by law.

Puma Biotechnology, Inc. 
10880 Wilshire Blvd., Suite 2150 
Los Angeles, CA  90024 
pumabiotechnology.com

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