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Arena Pharmaceuticals

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FY2013 Annual Report · Arena Pharmaceuticals
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2 0 1 3   A N N U A L   R E P O R T

 
 
 
 
BUILDING ON
OUR SUCCESS:
FOCUSED ON THREE KEY VALUE DRIVERS

BELVIQ® for Chronic 
Weight Management

Lorcaserin Lifecycle 
Management Opportunities

Novel Pipeline and 
GPCR Research Programs

APPROVED PRODUCT
BELVIQ (lorcaserin HCI) CIV is approved by the US Food and Drug Administration and indicated for chronic weight management. 
We and our collaborators are seeking regulatory approval in additional countries.

LORCASERIN LIFECYCLE MANAGEMENT

Development Areas 

Status

Impact on Cardiovascular Outcomes/Conversion to Type 2 Diabetes* 

Included as Part of Ongoing CVOT

Co-Administration with Phentermine* 

Smoking Cessation* 

Once-Daily Formulation* 

12-Week Pilot Study Ongoing

12-Week Phase 2 Trial Ongoing

Evaluating for Multiple Indications

DRUG CANDIDATES IN DEVELOPMENT

Drug Candidate 

Disease Area 

Target 

Status

Temanogrel* 

Thrombotic Diseases 

APD811 

APD334 

APD371 

Pulmonary Arterial Hypertension 

Autoimmune Diseases 

Pain 

5HT2A Inverse Agonist 
PGI2 Agonist 
S1P1 Agonist 
CB2 Agonist 

Phase 1 Multiple-Ascending Dose Trial Ongoing

Phase 2 Trial Planned

Phase 1 Multiple-Ascending Dose Trial Planned

Phase 1 Single-Ascending Dose Trial Ongoing

*Development expenses shared with or funded by collaborators

DEAR STOCKHOLDERS,

Since  our  founding,  our  team  at  Arena  has  been  united  by  a 

pipeline.  As  part  of  our  evolution  as  an  organization,  we  have 

common mission: to embrace the challenge of improving health 

expanded  our  prospects  for  continued  success  by  creating  a 

by  bringing  innovative  medicines  targeting  G  Protein-Coupled 

dual track of opportunity: we will seek to discover and advance 

Receptors (GPCRs) to patients. We focus on GPCRs because they 

compounds  targeting  GPCRs  to  deliver  unique  medicines  for 

constitute a large portion of cell surface receptors, play a crucial 

unmet medical needs, as well as pursue lifecycle management 

role in many disease processes, and are targeted by a significant 

opportunities 

for 

lorcaserin, 

including  new 

indications, 

percentage of today’s approved medicines. 

formulations  and  combinations.  This  dual-track  approach  has 

resulted  in  several  active  development-stage  programs  that,  if 

In 2013, we made a major step towards realizing our mission with 

successful,  could  be  ready  for  or  in  Phase  2  or  3  clinical  trials 

the US launch of our first approved drug, BELVIQ® (lorcaserin HCl) 

by around the end of 2014. Importantly, we expect to share the 

for chronic weight management. We see the launch of BELVIQ as 

expenses of many of these programs with our collaborators.

the start of the next exciting chapter in our evolution, and we are 

extremely excited about BELVIQ’s potential to help patients. Our 

Collaborations not only contribute significant financial and other 

first marketing approval brings us increased opportunity and fuels 

resources to our pipeline development, but also provide the vehicle 

our passion and motivation to repeat this accomplishment. With 

for us to make our products available to patients and physicians 

our diverse pipeline of novel drug candidates, we believe BELVIQ 

worldwide. The approval of BELVIQ in the United States validates 

is just the first of many medicines we will deliver.

our approach to drug discovery and development, and we expect 

We  expect  BELVIQ  alone  may  provide  us  sufficient  revenue  to 

increasingly  value  our  pipeline  as  we  deliver  proof-of-concept 

support  the  advancement  of  our  cutting-edge  programs  in  our 

data for our development programs.  

that  pharmaceutical  companies  –  as  well  as  investors  –  will 

2013 MILESTONES

Announced 
launch of 
BELVIQ and 
achievement 
of $65 million 
in related 
milestone 
payments

Expanded 
 Marketing  
and Supply 
Agreement 
with Eisai  
for  BELVIQ to 
include most 
countries 
worldwide

Reported launch 
of direct-to-
consumer 
advertising 
campaign 
for BELVIQ, 
 doubling of 
BELVIQ sales 
force and an 
increase in 
 coverage to 50% 
of  people who 
are commer-
cially insured

We  see  an  extraordinary  amount  of  opportunity  this  year,  as 

well as in the long term. With the success of BELVIQ, we expect 

that  our  company  will  advance  in  a  number  of  ways.  Some 

advancements  will  be  rapid,  and  others  incremental.  However, 

we  remain  committed  to  our  vision  of  becoming  the  industry 

leader  in  the  discovery,  development  and  commercialization  of 

GPCR-directed medicines. In addition, our core values of integrity, 

excellence, teamwork and innovation will be at the center of all 

we do.

The  stories  of  how  BELVIQ  has  changed  patients’  lives  are  a 

testament  to  our  shared  commitment  of  improving  health  by 

bringing  innovative  medicines  to  patients.  As  we  reflect  on 

our journey, we are proud of the dedicated team of colleagues 

we have at Arena, and appreciate the support we receive from 

our  valued  stockholders  and  collaborators  who  believe  in  the 

Jack Lief
Co-Founder, Chairman,  
President and  
Chief Executive Officer

Dominic P. Behan, Ph.D., D.Sc.
Co-Founder,  
Executive Vice President 
and Chief Scientific Officer

potential of BELVIQ and our research and development platform. 

April 7, 2014

Together, the possibilities are endless.

Announced 
submission 
of BELVIQ 
marketing 
applications 
in Mexico, 
Canada and 
South Korea

Entered into 
Marketing 
and Supply 
Agreement 
for BELVIQ 
with CY 
Biotech in 
Taiwan

Prix Galien 
nominated 
BELVIQ for 
Best Pharma-
ceutical Agent 
Award

Completed 
study eval-
uating an 
extended- 
release, 
once-daily 
formulation of 
lorcaserin

Initiated 
12-week  
pilot study 
evaluating 
lorcaserin and 
phentermine 
when co- 
administered

Completed 
Phase 1 
multiple- 
ascending 
dose clinical 
trial  evaluating 
APD811 for 
pulmonary 
arterial 
hypertension

Completed 
Phase 1 
single- 
ascending 
dose clinical 
trial evaluating 
APD334 for 
autoimmune 
diseases

Initiated  
Phase 1 
single- 
ascending 
dose clinical 
trial evaluating 
APD371 for 
pain

Reported launch 

of direct-to-

consumer 

advertising 

campaign 

for BELVIQ, 

 doubling of 

BELVIQ sales 

force and an 

increase in 

 coverage to 50% 

of  people who 

are commer-

cially insured

2013 Form 10-K

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

FORM 10-K

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

EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2013
or

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

EXCHANGE ACT OF 1934

For the transition period from

to

COMMISSION FILE NUMBER 000-31161

ARENA PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of
incorporation or organization)

6154 Nancy Ridge Drive, San Diego, CA
(Address of principal executive offices)

23-2908305
(I.R.S. Employer
Identification No.)

92121
(Zip Code)

858.453.7200
(Registrant’s telephone number, including area code)
Securities registered pursuant to 12(b) of the Act:

Title of each class
Common Stock, $0.0001 par value

Name of each exchange on which registered
NASDAQ Global Select Market

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

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

Act. Yes È No ‘

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the

Act. Yes ‘ No 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 and posted on its corporate Web site, if any, every
Interactive Data File required to be submitted and posted 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 and post such
files). Yes È No ‘

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is
not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. È

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a
smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in
Rule 12b-2 of the Exchange Act.
Large accelerated filer È
Non-accelerated filer ‘ (Do not check if a smaller reporting company)

Accelerated filer ‘
Smaller reporting company ‘

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange

Act). Yes ‘ No È

The aggregate market value of the voting and non-voting common equity held by non-affiliates of the registrant was
approximately $1.7 billion as of June 30, 2013, based on the last sale price of the registrant’s common stock as reported on the
NASDAQ Global Select Market on such date. For purposes of this calculation, shares of the registrant’s common stock held by
directors and executive officers have been excluded. This number is provided only for purposes of this Annual Report on
Form 10-K and does not represent an admission that any particular person or entity is an affiliate of the registrant.
As of February 24, 2014, there were 219,259,995 shares of the registrant’s common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Certain information required by Part III of this Annual Report on Form 10-K is incorporated by reference from the registrant’s

definitive proxy statement for the annual meeting of stockholders to be held in June 2014, which will be filed with the Securities
and Exchange Commission within 120 days after the close of the registrant’s fiscal year ended December 31, 2013.

ARENA PHARMACEUTICALS, INC.

TABLE OF CONTENTS

PART I
Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 1.
Item 1A. Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 1B. Unresolved Staff Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 2.
Item 3.
Legal Proceedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 4. Mine Safety Disclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PART II
Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases

of Equity Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selected Financial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 6.
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations . . . . .
Item 7A. Quantitative and Qualitative Disclosures About Market Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Financial Statements and Supplementary Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 8.
Item 9.
Changes in and Disagreements With Accountants on Accounting and Financial Disclosure . . . .
Item 9A. Controls and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 9B. Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PART III
Item 10. Directors, Executive Officers and Corporate Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 11. Executive Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 12.

Security Ownership of Certain Beneficial Owners and Management and Related Stockholder

Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 13. Certain Relationships and Related Transactions, and Director Independence . . . . . . . . . . . . . . .
Item 14.
Principal Accountant Fees and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PART IV
Item 15. Exhibits, Financial Statement Schedules

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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i

INFORMATION RELATING TO FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K, or Annual Report, includes forward-looking statements, which involve a
number of risks and uncertainties. These forward-looking statements can generally be identified as such because
the context of the statement will include words such as “may,” “will,” “intend,” “plan,” “believe,” “anticipate,”
“expect,” “estimate,” “predict,” “potential,” “continue,” “likely,” or “opportunity,” the negative of these words or
other similar words. Similarly, statements that describe our future plans, strategies, intentions, expectations,
objectives, goals or prospects and other statements that are not historical facts are also forward-looking
statements. Discussions containing these forward-looking statements may be found, among other places, in
“Business” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in
this Annual Report. For such statements, we claim the protection of the Private Securities Litigation Reform Act
of 1995. Readers of this Annual Report are cautioned not to place undue reliance on these forward-looking
statements, which speak only as of the time this Annual Report was filed with the Securities and Exchange
Commission, or SEC. These forward-looking statements are based largely on our expectations and projections
about future events and future trends affecting our business, and are subject to risks and uncertainties that could
cause actual results to differ materially from those anticipated in the forward-looking statements. These risks and
uncertainties include, without limitation, those discussed in “Risk Factors” and in “Management’s Discussion
and Analysis of Financial Condition and Results of Operations” of this Annual Report. In addition, past financial
or operating performance is not necessarily a reliable indicator of future performance, and you should not use our
historical performance to anticipate results or future period trends. We can give no assurances that any of the
events anticipated by the forward-looking statements will occur or, if any of them do, what impact they will have
on our results of operations and financial condition. Except as required by law, we undertake no obligation to
update publicly or revise our forward-looking statements to reflect events or circumstances that arise after the
filing of this Annual Report or documents incorporated by reference herein that include forward-looking
statements.

Arena Pharmaceuticals®, Arena® and our corporate logo are registered service marks of Arena. CART™ is

an unregistered service mark of Arena. BELVIQ® is a registered trademark of Arena Pharmaceuticals GmbH.
Any other brand names or trademarks appearing in this Annual Report are the property of their respective
holders.

In this Annual Report, “Arena Pharmaceuticals,” “Arena,” “we,” “us” and “our” refer to Arena

Pharmaceuticals, Inc., and our wholly owned subsidiaries on a consolidated basis, unless the context otherwise
provides. “APD” is an abbreviation for Arena Pharmaceuticals Development.

BELVIQ® (pronounced “BEL-VEEK”) is the trade name for the finished drug product containing the active

pharmaceutical ingredient lorcaserin hydrochloride, or lorcaserin, that is marketed for chronic weight
management in the United States. Lorcaserin may in the future be marketed in the United States or in other
countries under a different trade name for chronic weight management. Lorcaserin may also be marketed under a
different trade name for a different indication, in a different formulation or in combination with another drug. In
this report, we use BELVIQ to refer to the finished drug product containing lorcaserin and/or, depending on the
context, the active pharmaceutical ingredient lorcaserin, and without regard to the current or potential indication,
formulation or combination.

1

Item 1.

Business.

Overview

PART I

We are a biopharmaceutical company focused on discovering, developing and commercializing novel drugs
that target G protein-coupled receptors, or GPCRs, to address unmet medical needs. BELVIQ® (lorcaserin HCl),
our internally discovered drug for chronic weight management, is our first and only drug approved by any
regulatory agency for marketing. BELVIQ was approved by the US Food and Drug Administration, or FDA, for
marketing in the United States, and was made available by prescription in June 2013 to adults who are
overweight with a comorbidity or obese. As described below, there are pending applications for the regulatory
approval of BELVIQ for marketing in a number of additional counties under our collaborations. In addition to
BELVIQ, we have drug candidates and compounds at various stages of research and development.

The key elements of our strategy are as follows:

• Make BELVIQ Available to Patients for Chronic Weight Management. We have agreements with
pharmaceutical companies that provide them rights and responsibilities to seek regulatory approval and
commercialize BELVIQ for chronic weight management throughout most of the world. Our Swiss
subsidiary, Arena Pharmaceuticals GmbH, or Arena GmbH, will manufacture BELVIQ and supply
BELVIQ to our collaborators for commercialization in the United States and, subject to applicable
regulatory approval, additional countries in the future.

• Pursue Additional BELVIQ Opportunities. We will explore with our collaborators or independently

additional indications, formulations and combinations for BELVIQ.

• Advance our Pipeline and GPCR Research. We will advance our pipeline of drug candidates
independently and through collaborations with pharmaceutical companies. In addition, our
technologies, our drug discovery infrastructure and our scientists’ integrated approach to research have
allowed us to identify and develop BELVIQ as well as a number of other novel compounds. We will
continue our research and development efforts to identify additional GPCR targets and discover and
advance new compounds.

Eisai is responsible for marketing and distributing BELVIQ in the United States under Arena GmbH’s
marketing and supply agreement with Eisai Inc., and Eisai Inc.’s parent company, Eisai Co., Ltd., which we refer
to collectively with Eisai Inc. as Eisai. Under such agreement, Arena GmbH also granted Eisai exclusive
commercialization rights for BELVIQ in all of the other countries in the world, except for South Korea, Taiwan,
Australia, New Zealand and Israel. In addition, Arena GmbH has marketing and supply agreements with Ildong
Pharmaceutical Co., Ltd., or Ildong, for BELVIQ in South Korea, and with CY Biotech Company Limited, or
CYB, in Taiwan. We intend to enter into additional collaborations for the potential regulatory approval and
commercialization of BELVIQ in Australia, New Zealand and Israel.

The marketing of BELVIQ is subject to applicable regulatory approval, and, in general, our collaborators

are responsible for regulatory activities related to obtaining marketing approval of BELVIQ in the territories
covered under the respective agreement. We or our collaborators have filed for regulatory approval in a number
of countries, and we expect our collaborators to file for regulatory approval in additional countries in the future.

We have composition of matter patents for BELVIQ issued in major jurisdictions globally that, in most
cases, are capable of continuing into 2023. We have filed applications for patent extension in the United States,
which, if granted, will extend the patent term for BELVIQ into 2026 and potentially into 2027.

As part of our research and development efforts, we are exploring BELVIQ for possible new indications,

using different formulations, and in combination with other drugs. We and Eisai have initially prioritized the
development areas of smoking cessation, a once-daily formulation, and co-administration with phentermine, as
well as exploring, including as part of the FDA-required cardiovascular outcomes trial, or CVOT, BELVIQ’s
effect on conversion to type 2 diabetes and improvements in cardiovascular outcomes.

2

In addition to BELVIQ, we also intend to utilize our GPCR focus and expertise to advance other of our

internally discovered compounds and drug candidates, which include the following clinical-stage, orally
available candidates:

• APD811, an agonist of the prostacyclin receptor intended for the treatment of pulmonary arterial
hypertension, has completed single- and multiple-ascending dose Phase 1 trials and is expected to
begin a Phase 2 trial in the first half of 2014.

• Temanogrel, an inverse agonist of the serotonin 2A receptor intended for the treatment of thrombotic

diseases, has completed single- and multiple-ascending dose Phase 1 trials. Under our Co-Development
and License Agreement with Ildong, we expect Ildong to fund and complete an additional Phase 1 trial
in healthy volunteers and potentially a Phase 2a proof-of-concept trial in patients. We expect Ildong to
initiate the Phase 1 trial in the first quarter of 2014 to evaluate the safety of co-administration of
temanogrel with aspirin and clopidogrel.

• APD334, an agonist of the sphingosine 1-phosphate subtype 1, or S1P1, receptor intended for the
treatment of a number of conditions related to autoimmune diseases, has completed a Phase 1 trial
evaluating single-ascending doses of APD334. We plan to initiate a Phase 1 multiple-ascending dose
trial of APD334 in 2014.

• APD371 is an agonist of the cannabinoid 2, or CB2, receptor intended for the treatment of pain. We

have initiated a Phase 1 single-ascending dose trial of APD371.

We have commercial rights for our programs and drug candidates, except for Eisai’s rights with respect to
BELVIQ, Ildong’s rights with respect to BELVIQ and temanogrel, and CYB’s rights with respect to BELVIQ.

Arena Pharmaceuticals, Inc., incorporated in the state of Delaware in April 1997, and is located in San
Diego, California. Our operations outside of the United States are primarily located at Arena GmbH in Zofingen,
Switzerland. Activities conducted at Arena GmbH include manufacturing, quality control, quality assurance,
development of manufacturing processes, qualifying suppliers and otherwise managing aspects of the supply
chain, regulatory compliance, distribution of finished products, alliance management, and strategic planning and
development. Arena GmbH and its wholly owned subsidiary, API Development LTD, also hold certain
intellectual property rights for BELVIQ.

3

Our Research and Development Programs

Our proprietary GPCR-based technologies and our validated drug discovery and development capabilities

and approach enable us to internally discover and develop drug candidates. We periodically conduct a review of
our programs to prioritize the use of our resources, and we are currently focusing our resources and activities on
BELVIQ and the other clinical-stage programs in the table below, as well as on earlier-stage programs that span
several therapeutic areas.

Drug Candidate

Lorcaserin*

Indication/Endpoint

Status

Impact on Cardiovascular
Outcomes/Conversion to Type 2
Diabetes

Included as Part of Ongoing CVOT

Lorcaserin*

Smoking Cessation

Upcoming Phase 2 Trial

Lorcaserin*
Co-Administration with
Phentermine

Weight Management

Ongoing Pilot Study

Lorcaserin* Extended-
Release Formulation

Multiple

Completed Initial Pharmacokinetic Study

APD811

Temanogrel

APD334

APD371

Pulmonary Arterial Hypertension

Upcoming Phase 2 Trial

Thrombotic Diseases

Upcoming Additional Phase 1 Multiple-
Ascending Dose Trial

Autoimmune Diseases

Upcoming Phase 1 Multiple-Ascending Dose Trial

Pain

Ongoing Phase 1 Single-Ascending Dose Trial

*

Lorcaserin is marketed in the United States for chronic weight management under the trade name BELVIQ. With the exception of this
table, in this report, we generally use BELVIQ to refer to the finished drug product containing lorcaserin and/or, depending on the
context, the active pharmaceutical ingredient lorcaserin, and without regard to the current or potential indication, formulation or
combination.

Clinical-Stage Programs

BELVIQ for Chronic Weight Management

According to the Centers for Disease Control and Prevention, more than one-third of US adults (35.7%) were

obese in 2009-2010. Studies have shown that a weight loss of 5% to 10% of body weight from baseline can result in
meaningful improvements in cardiovascular risk factors (e.g., lipids, blood pressure and blood glucose), quality of
life and functional capacity, and a significant reduction in the incidence of type 2 diabetes.

FDA Approval of BELVIQ and Availability in the United States

In June 2012, the FDA approved our internally discovered drug, BELVIQ, for chronic weight management
in adults who are overweight with a comorbidity or obese. The FDA’s approval was subject to the scheduling of
BELVIQ by the US Drug Enforcement Administration, or DEA. Following such scheduling, in June 2013, our
collaborator, Eisai, made BELVIQ available in the United States to patients by prescription. Eisai is focused on
physician awareness and education efforts, securing broad reimbursement coverage, and creating patient
awareness and access for BELVIQ. The BELVIQ sales force totaled approximately 400 representatives at around
the end of 2013, reimbursement coverage for BELVIQ has increased since BELVIQ’s launch, Eisai is in
discussions to further improve such coverage, and Eisai has a patient awareness and support campaign intended
to complement its physician awareness efforts.

BELVIQ is believed to decrease food consumption and promote satiety by selectively activating serotonin

2C receptors in the brain. Activation of these receptors may help a person eat less and feel full after eating
smaller amounts of food.

4

In the United States, BELVIQ is indicated as an adjunct to a reduced-calorie diet and increased physical

activity for chronic weight management in adult patients with an initial body mass index, or BMI, of:

•

•

30 kg/m2 or greater (obese), or

27 kg/m2 or greater (overweight) in the presence of at least one weight-related comorbid condition
(e.g., hypertension, dyslipidemia, type 2 diabetes).

Limitations of Use:

• The safety and efficacy of coadministration of BELVIQ with other products intended for weight loss,
including prescription drugs (e.g., phentermine), over-the-counter drugs, and herbal preparations, have
not been established.

• The effect of BELVIQ on cardiovascular morbidity and mortality has not been established.

US Postmarketing Requirements

As part of the US approval of BELVIQ, the FDA is requiring the evaluation of the effect of long-term
treatment with BELVIQ on the incidence of major adverse cardiovascular events, or MACE, in overweight and
obese patients with cardiovascular disease or multiple cardiovascular risk factors, as well as to conduct
postmarketing studies to assess the safety and efficacy of BELVIQ for weight management in obese pediatric
patients.

Eisai initiated enrollment in January 2014 of approximately 12,000 patients in the CVOT, which is also
referred to as CAMELLIA (Cardiovascular And Metabolic Effects of Lorcaserin In Overweight And Obese
Patients). CAMELLIA is a randomized, double-blind, placebo-controlled trial that will enroll patients with
cardiovascular disease or multiple cardiovascular risk factors. The trial is expected to run for approximately five
years.

The FDA required portion of CAMELLIA is designed to evaluate BELVIQ’s effect on the incidence of
MACE (non-fatal myocardial infarction, non-fatal stroke and cardiovascular death) compared to placebo, with a
non-inferiority margin for the hazard ratio of 1.4. In addition, as part of the non-FDA required portion of the trial,
CAMELLIA will also evaluate whether BELVIQ reduces the incidence of conversion to type 2 diabetes in
patients without type 2 diabetes at baseline and the incidence of MACE+ (MACE or hospitalization for unstable
angina or heart failure, or any coronary revascularization), both as compared to placebo. CAMELLIA will
include echocardiograms in a subset of the patients.

As the first of four postmarketing commitments related to adolescent and pediatric patients, we have

completed dosing in a pharmacokinetic study of BELVIQ in adolescents, and results are pending. Eight
adolescent boys and girls, aged 12-17, with a BMI of greater than or equal to the 95th percentile for age and sex,
but less than or equal to 44 kg/m2, were administered a single 10 mg dose of BELVIQ.

BELVIQ Collaborations and Regulatory Activity

Arena GmbH has granted Eisai exclusive commercialization rights for BELVIQ to all of the countries in the
world, except for South Korea, Taiwan, Australia, New Zealand and Israel. Arena GmbH also has marketing and
supply agreements with Ildong for BELVIQ in South Korea, and with CYB in Taiwan. We intend to enter into
additional collaborative agreements for the potential regulatory approval and commercialization of BELVIQ in
Australia, New Zealand and Israel.

The marketing of BELVIQ is subject to applicable regulatory approval. BELVIQ has been approved for

marketing in the United States, but currently not in any other country. In general, our collaborators are
responsible for seeking regulatory approval in the territories covered under the respective agreement. Eisai

5

filed applications for regulatory approval of BELVIQ in Mexico and Canada in March and June of 2013,
respectively, and in Brazil in February 2014. In November 2013, Ildong submitted an application for regulatory
approval of BELVIQ in South Korea. We previously filed applications for marketing approval of BELVIQ with
the regulatory authorities for the European Union and Switzerland, and these regulatory authorities notified us
that we had not yet satisfactorily addressed their concerns and that our applications would not be approved. We
expect to continue to work with Eisai in pursuing regulatory approvals for BELVIQ in Europe and other
territories outside the United States. In addition, CYB intends to file an application for regulatory approval of
BELVIQ in Taiwan.

Eisai Collaboration

In November 2013, Arena GmbH, Eisai Inc., and Eisai Inc.’s parent company, Eisai Co., Ltd., entered into
the Second Amended and Restated Marketing and Supply Agreement, or Eisai Agreement, which amended and
restated the previous agreement and expanded Eisai’s exclusive commercialization rights for BELVIQ to all of
the countries in the world, except for South Korea, Taiwan, Australia, New Zealand and Israel. Eisai’s
commercialization rights are subject to applicable regulatory approval.

Arena GmbH and Eisai entered into the original Marketing and Supply Agreement in July 2010, under
which we granted Eisai Inc. exclusive commercialization rights for BELVIQ solely in the United States and its
territories and possessions. In May 2012, Arena GmbH and Eisai Inc. amended and restated such agreement by
entering into the Amended and Restated Marketing and Supply Agreement, which expanded Eisai Inc.’s
exclusive commercialization rights to include most of North and South America.

Upfront and Milestone Payments

In connection with entering into the Eisai Agreement, we received from Eisai an upfront payment of

$60.0 million. This payment is in addition to the $50.0 million and $5.0 million in upfront payments we received
from Eisai in connection with entering into the original agreement and the first amended agreement, respectively.
We are also eligible to receive up to an aggregate of $176.5 million in additional regulatory and development
milestone payments. These milestone payments include an aggregate of $53.5 million in such potential milestone
payments that remained available for us to achieve under the first amended agreement and an aggregate of
$123.0 million in additional potential milestone payments under the Eisai Agreement.

Product Purchase Price and Purchase Price Adjustment Payments

We manufacture BELVIQ at our facility in Switzerland, and sell BELVIQ to Eisai for Eisai’s

commercialization in the United States and, subject to applicable regulatory approval, in the other territories
under the Eisai Agreement (other than Europe, China and Japan) for a purchase price starting at 31.5% and
30.75%, respectively (and starting at 27.5% in Europe, China and Japan), of Eisai’s aggregate annual net product
sales. The purchase price will increase on a tiered basis in the United States and the other territories (other than
Europe, China and Japan) to as high as 36.5% and 35.75%, respectively, on the portion of Eisai’s annual
aggregate net product sales exceeding $750.0 million in all territories other than Europe, China and Japan. The
purchase price will increase to 35% in Europe, China and Japan on the portion of Eisai’s annual aggregate net
product sales exceeding $500.0 million in such territories. The purchase price is subject to reduction (for sales in
a particular country), including in the event of generic competition in the applicable country.

In addition to payments for purchases of BELVIQ, we are eligible to receive up to an aggregate of

$1.56 billion in one-time purchase price adjustment payments and other payments. These payments include up to
an aggregate of $1.19 billion that are based on Eisai’s annual net product sales of BELVIQ in all of the territories
under the Eisai Agreement on an aggregate basis, with the first and last amounts payable with annual net product
sales of $250.0 million and $2.5 billion, respectively. Of these payments, Eisai will pay us a total of
$330.0 million for annual net product sales of up to $1.0 billion. The $1.56 billion also includes $370.0 million in

6

one-time purchase price adjustment payments we are eligible to receive based on annual net product sales in the
non-US territories, comprised of $185.0 million based on Eisai’s annual net product sales in the non-US
territories in North and South America and $185.0 million based on Eisai’s annual net product sales in the
territories outside of North and South America. The first and last amounts are payable upon first achievement of
annual net product sales of $100.0 million and $1.0 billion, respectively, with respect to each of the following
areas: (i) the non-US territories in North and South America and (ii) the territories outside of North and South
America. In addition, we are also eligible to receive certain payments by Eisai if certain annual minimum sales
requirements in Mexico, Canada and Brazil are not met during the first ten years after initial commercial sale in
such territories.

Development Payments

The below chart summarizes the general agreement regarding cost sharing between Eisai and us for
significant development activities under the Eisai Agreement. In addition, Eisai or we may from time to time
conduct approved development of BELVIQ at such party’s own expense. For example, Eisai is responsible for
the expenses of the pilot study of 12-week duration to preliminarily assess BELVIQ and phentermine when co-
administered.

Eisai Second Amended and Restated Marketing and Supply Agreement: Cost Sharing for Development

United States

Rest of
North and South America

Remaining Territories

BELVIQ for weight
management
- Pre-approval*

Not Applicable

General
Eisai: 90%; Arena: 10%

Up to total of $100.0 million -
Eisai: 50%; Arena: 50%

Certain stability work
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 100%

General
Eisai: 90%; Arena: 10%

Up to total of $50.0 million -
Eisai: 50%; Arena: 50%

Certain stability work
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 90%;
Arena: 10%

General - Eisai: 90%; Arena 10%

Non-FDA required portion of CVOT
Up to $80.0 million -
Eisai: 50%; Arena: 50%
Thereafter, Eisai: 100%

Certain pediatric studies
Eisai: 50%; Arena: 50%

Up to total of $250.0 million (as reduced by up to $80.0 million for non-FDA required portion of
CVOT) - Eisai: 50%; Arena: 50%

Up to a total of $100.0 million in the aggregate across all additional products -
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 90%; Arena: 10%

BELVIQ for weight
management
- Post-approval*

Products other than
BELVIQ for weight
management
- Pre-approval

Products other than
BELVIQ for weight
management
- Post-approval

*

Development required by a regulatory authority, with the exception of the non-FDA required portions of the CVOT.

Certain Other Terms

Eisai and we have agreed to limitations on the ability to commercialize outside of the Eisai Agreement any
weight management product or addiction disorder product in the territories under the agreement. The agreement
continues to include a stand-still provision limiting Eisai’s ability to acquire our securities and assets.

7

Eisai may terminate the Eisai Agreement with respect to any country in the territory following the later of

the expiration of all issued BELVIQ patents in such country and 12 years after the first commercial sale of
BELVIQ in such country. Arena GmbH and Eisai each has the right to terminate the agreement early in certain
circumstances in its entirety or with respect to the applicable country or product, including (a) if the other party is
in material breach, (b) for commercialization concerns, and (c) for certain intellectual property infringement.
Eisai also has the right to terminate the Agreement early in its entirety or with respect to each country in certain
circumstances, including (i) termination in a country if sales of generic equivalents of BELVIQ in such country
exceed sales of BELVIQ in that country (based on volume), and (ii) if Eisai is acquired by a company that has a
product that competes with BELVIQ. In addition, Arena GmbH can terminate the agreement early in its entirety
or with respect to each country in the non-US territories in North and South America in certain circumstances,
including termination in each country if Eisai does not satisfy certain regulatory filing and commercialization
diligence requirements in such country.

Eisai will indemnify us for losses resulting from certain third-party claims, including for (a) Eisai’s
negligence, willful misconduct or violation of law, but excluding product liability claims, (b) Eisai’s breach of
the marketing and supply agreement or related agreements, but excluding product liability claims, (c) certain uses
or misuses of BELVIQ, (d) certain governmental investigations of Eisai related to BELVIQ, and (e) infringement
relating to Eisai’s use of certain trademarks, tag lines and logos related to BELVIQ. Arena GmbH will indemnify
Eisai for losses resulting from certain third-party claims, including for (i) Arena GmbH’s negligence, willful
misconduct, failure to comply with law, breach of any agreement with a third party with respect to product
development prior to the effective date of the original agreement with Eisai, but excluding product liability
claims, (ii) Arena GmbH’s negligence or willful misconduct with respect to certain uses or misuses of BELVIQ
outside of the agreement, (iii) certain uses or misuses of BELVIQ after the term of the agreement, in any territory
no longer under the agreement or with respect to any product after the termination of the agreement with respect
to such product, (iv) Arena GmbH’s negligence, willful misconduct or violation of law, but excluding product
liability claims, (v) Arena GmbH’s breach of the marketing and supply agreement or related agreements, but
excluding product liability claims, (vi) certain infringement of intellectual rights of a third party, and
(vii) infringement relating to Eisai’s use of certain trademarks related to BELVIQ. In addition, Arena GmbH and
Eisai will, in general, share equally in losses resulting from third-party product liability claims, except where one
party’s acts or omissions did not contribute to the events or circumstances leading to such product liability claim
and the other party’s actual willful misconduct, violation of law or breach of its obligations under the Second
Amended Agreement or certain other agreements between Arena GmbH and Eisai were the sole and direct cause
of the product liability claim.

Ildong BELVIQ Collaboration: South Korea

In November 2012, Arena GmbH entered into a Marketing and Supply Agreement with Ildong for BELVIQ.

Under the agreement, we granted Ildong exclusive rights to commercialize BELVIQ in South Korea for weight
loss or weight management in obese and overweight patients, subject to regulatory approval of BELVIQ by the
South Korean Ministry of Food and Drug Safety, or MFDS.

Under the agreement, we received an upfront payment of $5.0 million, and will receive an additional $3.0

million upon the approval of BELVIQ by the MFDS. Ildong is responsible for the development, regulatory
approval and, ultimately, commercialization of BELVIQ in South Korea for weight loss or weight management
in obese and overweight patients, including related costs and expenses. We will manufacture BELVIQ at our
facility in Switzerland, and sell BELVIQ to Ildong for a purchase price starting at 35% of Ildong’s annual net
product sales. The purchase price will increase on a tiered basis up to 45% on the portion of annual net product
sales exceeding $15.0 million. If certain annual net product sales amounts are not met, we can convert Ildong’s
right to commercialize BELVIQ in South Korea to be non-exclusive.

Ildong has agreed not to conduct activities outside of our agreement related to the approval or commercialization
of any other pharmaceutical product for weight loss, weight management or obesity in South Korea. We have agreed

8

not to conduct activities outside of our agreement related to the commercialization in South Korea of any
pharmaceutical product containing BELVIQ intended for end use in weight loss or weight management in obese and
overweight patients.

Ildong will indemnify us for losses resulting from certain third-party claims, including for (a) Ildong’s
negligence, willful misconduct or violation of law, (b) Ildong’s breach of the marketing and supply agreement or
related agreements, (c) certain uses or misuses of BELVIQ (including any product liability claim and other
claims relating to sales or development of BELVIQ in South Korea), (d) certain governmental investigations of
Ildong related to BELVIQ, and (e) infringement relating to Ildong’s use of trademarks related to BELVIQ. Arena
GmbH will indemnify Ildong for losses resulting from certain third-party claims, including for (i) Arena GmbH’s
negligence, willful misconduct or violation of law, and (ii) Arena GmbH’s breach of the marketing and supply
agreement or related agreements.

Unless terminated earlier, the agreement with Ildong will continue in effect until the later of the expiration
of all issued patents relating to BELVIQ in South Korea and 12 years after the first commercial sale of BELVIQ
in South Korea. Either party has the right to terminate the agreement early in certain circumstances, including
(a) if the other party is in material breach, (b) for certain commercialization concerns, and (c) for certain
intellectual property concerns. Ildong also has the right to terminate the agreement early in certain circumstances,
including if we notify Ildong that Ildong’s right to commercialize BELVIQ in South Korea will become
non-exclusive.

CYB BELVIQ Collaboration: Taiwan

In July 2013, Arena GmbH entered into an exclusive marketing and supply agreement with CYB for

BELVIQ in Taiwan. Under the agreement, we granted CYB the rights to market and distribute BELVIQ in
Taiwan for weight loss or weight management in obese and overweight patients, subject to regulatory approval of
BELVIQ by the Taiwan Food and Drug Administration, or TFDA.

We will manufacture BELVIQ at our facility in Switzerland, and sell finished product to CYB for a
purchase price at 45% of CYB’s annual net product sales. In addition, we received from CYB a net upfront
payment of $2.0 million, and are eligible to receive purchase price adjustment payments based on CYB’s annual
net product sales, as well as a milestone payment upon approval of the first additional indication for BELVIQ by
the TFDA. CYB is responsible for the development, regulatory approval and, ultimately, marketing and
distribution of BELVIQ in Taiwan, including related costs and expenses.

Additional Development of BELVIQ

Smoking Cessation

We plan to initiate a Phase 2 clinical trial in the first half of 2014 to evaluate the potential of BELVIQ as a

drug candidate for smoking cessation. We expect to enroll approximately 600 patients in this 12-week trial.

Extended Release Once-Daily Formulation

We have completed an initial study to evaluate the safety, tolerability and pharmacokinetic properties of
different formulations of BELVIQ 20 mg extended release tablets, and selected a once-daily formulation for
further development.

Co-Administration with Phentermine

In November 2013, Eisai initiated dosing in a pilot study of 12-week duration to preliminarily assess as the
primary endpoint the safety of BELVIQ and phentermine when co-administered. This randomized, double-blind
and parallel-group study will enroll approximately 225 overweight and obese adults. Patients will be randomized

9

to one of three treatment arms in a 1:1:1 ratio, and will receive BELVIQ 10 mg twice daily, BELVIQ 10 mg
twice daily in combination with phentermine 15 mg twice daily, or BELVIQ 10 mg twice daily in combination
with phentermine 15 mg once daily.

Prior to initiating the 12-week pilot study, we completed a small pharmacokinetic study of single doses of

BELVIQ 10 mg and phentermine 15 mg when administered in combination.

BELVIQ Pre-Approval Development

BELVIQ Phase 3 Clinical Development

The three trials included in our BELVIQ Phase 3 development program are summarized in the table below.

Number of patients

Treatment groups

Patient demographics

BLOOM1

3,182

BLOSSOM2

4,008

BLOOM-DM3

604

Placebo, BELVIQ 10 mg
BID

Placebo, BELVIQ 10
mg once daily, or QD,
BELVIQ 10 mg BID

Placebo, BELVIQ 10
mg QD, BELVIQ 10 mg
BID

BMI ≥30, or ≥27 with
co-morbid condition(s);
average BMI of 36.2 and
baseline weight of 220
pounds

BMI ≥30, or ≥27 with
co-morbid condition(s);
average BMI of 35.9 and
baseline weight of 220
pounds

BMI ≥27; type 2 diabetes
mellitus; average BMI of
36.0 and baseline weight of
228 pounds

Average age 44

Average age 44

Average age 53

84% women
Caucasian (67%)
African-American (19%)
Hispanic (12%)

80% women
Caucasian (67%)
African-American (20%)
Hispanic (11%)

54% women
Caucasian (61%)
African-American (21%)
Hispanic (14%)

Duration

2 years

1 year

1 year

Echocardiographic

monitoring

Screening, every 6 months,
post-baseline

Baseline, every 6 months,
post-baseline

Baseline, every 6 months,
post-baseline

First patient enrolled

November 2006

January 2008

December 2007

Last patient completed

February 2009

July 2009

June 2010

New Drug Application

Original NDA 2009

Original NDA 2009

NDA resubmission 2011

submission

Location

USA

USA

USA

(1) BLOOM (Behavioral modification and Lorcaserin for Overweight and Obesity Management)
(2) BLOSSOM (Behavioral modification and Lorcaserin Second Study for Obesity Management)
(3) BLOOM-DM (Behavioral modification and Lorcaserin for Overweight and Obesity Management in Diabetes Mellitus)

The Phase 3 trials shared the same ordered primary efficacy endpoints: the proportion of patients achieving

5% or greater weight loss from baseline at Week 52; mean weight change from baseline at Week 52; and the
proportion of patients achieving 10% or greater weight loss from baseline at Week 52. Secondary endpoints
included changes in physical measures, serum lipids, blood pressure, HbA1c and other indicators of glycemic
control, body compositions (in BLOSSOM and BLOOM-DM), high-sensitivity C-Reactive Protein, or hs-CRP,
(in BLOOM and BLOOM-DM) and quality of life. A standardized program of diet and exercise advice was
included in each of the trials.

10

In addition to routine safety monitoring, each study included echocardiographic monitoring for valvular
regurgitation and pulmonary artery pressure. Valvular regurgitation, a measure of backflow or leakage of blood
through heart valves due to imperfect valve closing, was scored on a five-point scale (absent, trace, mild,
moderate or severe) for the mitral and aortic valves. For regulatory assessment of potential drug effects on heart
valves, the FDA defined regurgitant valvulopathy as mild or greater aortic valve regurgitation and/or moderate or
greater mitral valve regurgitation. Echocardiographic findings meeting this criterion are sometimes called
“FDA-defined valvulopathy.”

Among the pooled population enrolled in BLOOM and BLOSSOM, 22% had hypertension, 30% had
dyslipidemia, 25% had impaired fasting glucose and approximately 8% reported a history of depression. In
BLOOM-DM, all patients on BELVIQ 10 mg BID had type 2 diabetes, 61% had hypertension and approximately
6% reported a history of depression.

Patient Disposition

BLOOM. The Week 52 completion rate was higher for patients on BELVIQ (54.9%) compared to patients
on placebo (45.1%). Discontinuation rates for adverse events were 7.1% vs. 6.7% in the BELVIQ and placebo
groups, respectively, for Year 1 and approximately 3.0% for each group in Year 2.

BLOSSOM. The Week 52 completion rate was higher for patients on BELVIQ 10 mg BID (57.2%) and
10 mg QD (59.0%) compared to patients on placebo (52.0%). Discontinuation rates for adverse events were
7.2%, 6.2% and 4.6% in the BELVIQ 10 mg BID, BELVIQ 10 mg QD and placebo groups, respectively.

BLOOM-DM. The Week 52 completion rate was higher for patients on BELVIQ 10 mg BID

(66.0%) compared to patients on placebo (62.1%). Discontinuation rates for adverse events were 8.6% and 4.3%
in the BELVIQ 10 mg BID and placebo groups, respectively.

BELVIQ Phase 3 Results

Efficacy

In each of the Phase 3 trials, BELVIQ 10 mg BID was superior to placebo for each of the ordered primary

endpoints using a modified intent-to-treat population with last observation carried forward imputation for
missing values, or ITT-LOCF, analysis, as summarized in the table below. Patients who completed one year of
study participation experienced significantly greater efficacy according to each of the three co-primary endpoints.

ITT/LOCF
% Losing ≥5% weight . . . . . . . . . . . . . . . . . . . . .
Mean weight change (%) . . . . . . . . . . . . . . . . . . .
% Losing ≥10% weight . . . . . . . . . . . . . . . . . . . .
Per Protocol/Completers*
% Losing ≥5% weight . . . . . . . . . . . . . . . . . . . . .
Mean weight change (%) . . . . . . . . . . . . . . . . . . .
% Losing ≥10% weight . . . . . . . . . . . . . . . . . . . .

BLOOM

BLOSSOM

BLOOM-DM

Placebo

BELVIQ
10 BID

Placebo

BELVIQ
10 BID

Placebo

BELVIQ
10 BID

20.3% 47.5% 25.0% 47.2% 16.1% 37.5%
1.5%
2.2%
4.5%
5.8%
4.4% 16.3%
7.7% 22.6%

2.8%
5.9%
9.7% 22.6%

32.1% 66.4% 34.9% 63.2% 17.9% 44.6%
1.7%
3.4%
5.5%
7.9%
5.8% 20.8%
13.6% 36.2% 16.1% 35.1%

8.2%

3.9%

*

These results are reported for the per protocol populations in BLOOM and BLOSSOM, and for the completers population in
BLOOM-DM. The particular statistical analysis reported for each trial was pre-specified in the statistical analysis plan for that trial.

At the end of Year 2 of BLOOM, significantly more patients who took BELVIQ for two years maintained at
least 5% weight loss achieved in Year 1 than did patients who took BELVIQ during Year 1 and were changed to
placebo for Year 2.

11

BELVIQ demonstrated similar effects on secondary efficacy variables in BLOOM and BLOSSOM. A

pooled analysis of changes from baseline to Week 52 showed significant improvements relative to placebo in
waist circumference, BMI, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, systolic blood
pressure, diastolic blood pressure and heart rate. In BLOOM, significant improvements relative to placebo were
also observed for hsCRP, fasting insulin and HOMA-IR (a measure of insulin resistance); these variables were
not assessed in BLOSSOM. In BLOSSOM, BELVIQ significantly decreased body fat content relative to placebo;
this variable was not assessed in BLOOM. In BLOOM-DM, which included only patients with type 2 diabetes,
significant improvements with respect to patients on BELVIQ 10 mg BID relative to those on placebo occurred
in HbA1c (-0.9% and -0.4%, respectively) and fasting glucose (-27.4 mg/dL and -11.9 mg/dL, respectively).

At baseline in BLOOM-DM, approximately 90% of patients were taking metformin and approximately 50%

of patients were taking sulfonylureas with or without metformin. Weight loss and reductions in HbA1c and
fasting plasma glucose were greater with BELVIQ treatment compared to placebo whether patients were treated
with metformin or sulfonylureas. Fewer patients on BELVIQ 10 mg BID compared to placebo (13.3% vs. 21.8%,
respectively) increased and more patients on BELVIQ 10 mg BID compared to placebo (16.8% vs. 11.5%,
respectively) decreased use of anti-diabetic medication during the trial.

Safety and Tolerability Profile

BLOOM and BLOSSOM Pooled Analysis

Under the BLOOM and BLOSSOM pooled analysis, the most common adverse events reported in Year 1

and their incidences for BELVIQ 10 mg BID and placebo patients, respectively, were as follows: headache
(16.8% vs. 10.1%), dizziness (8.5% vs. 3.8%), fatigue (7.2% vs. 3.6%), nausea (8.3% vs. 5.3%), dry mouth
(5.3% vs. 2.3%) and constipation (5.8% vs. 3.9%). Adverse events of depression, anxiety and suicidal ideation
were infrequent and were reported by a similar proportion of each treatment group.

BLOOM-DM

In BLOOM-DM, the most common adverse events reported and their incidences for BELVIQ 10 mg BID

and placebo patients, respectively, were as follows: hypoglycemia (biochemical, symptomatic or asymptomatic)
(29.3% vs. 21.0%), headache (14.5% vs. 7.1%), back pain (11.7% vs. 7.9%), cough (8.2% vs. 4.4%) and fatigue
(7.4% vs. 4.0%). Adverse events of depression, anxiety and suicidal ideation were infrequent and were reported
by a similar proportion of each treatment group.

Echocardiographic Analysis

Echocardiograms were evaluated to assess whether there was an association between BELVIQ and valvular

insufficiency. Incidences of new FDA-defined valvulopathy were as follows for BELVIQ 10 mg BID and
placebo:

Dose

Week 24 Week 52 Week 104

BLOOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BELVIQ 10 mg BID

BLOSSOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BELVIQ 10 mg BID

BLOOM-DM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BELVIQ 10 mg BID

Pooled analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BELVIQ 10 mg BID

Placebo

Placebo

Placebo

Placebo

2.6%
2.7%

2.7%
2.1%
2.3%
1.9%
2.0% —
2.3%
2.0% —
1.8%
2.9% —
2.5%
1.9%
0.5% —
2.20% 2.37% —
1.88% 2.04% —

BELVIQ Prior Clinical Development

Prior to initiating our Phase 3 clinical trial program, we completed multiple Phase 1 and Phase 2 clinical

trials of BELVIQ.

12

Our Phase 2a clinical trial included 352 obese patients dosed for 28 days, and our Phase 2b clinical trial

included 469 obese patients dosed for 12 weeks. Significant weight loss was observed in both Phase 2 clinical
trials. The most common adverse events occurring in the Phase 2a and Phase 2b clinical trials included headache,
nausea and dizziness.

Our Phase 1 clinical trials included a three-part Phase 1a clinical trial of BELVIQ that established a
maximum tolerated dose for the drug candidate and a multiple-dose Phase 1b clinical trial of BELVIQ in obese
volunteers. The most common adverse events reported in the Phase 1 clinical trials were related to the central
nervous system and the gastrointestinal system. Dose escalation was terminated at the 40 mg QD dose in the
Phase 1a trial, a dose that resulted in euphoria and other central nervous system, or CNS, adverse effects. In each
of the Phase 1a and 1b trials, serial echocardiograms supported further development of BELVIQ.

BELVIQ Intellectual Property

As of February 17, 2014, we owned issued patents that cover compositions of matter for the BELVIQ new
chemical entity and related compounds and methods of treatment utilizing BELVIQ and related compounds in
69 jurisdictions, including the United States, Japan, Germany, France, China, Italy, Spain, Canada, the United
Kingdom, Russia, Australia, India, and South Korea, and had applications pending in two other jurisdictions, of
which the one with the largest pharmaceutical market was Brazil. Based on sales statistics provided by IMS
Health, the jurisdictions where BELVIQ patents have been issued accounted for more than 93% of global
pharmaceutical sales in 2011, while other jurisdictions where BELVIQ patents remain pending accounted for
more than 2% of global pharmaceutical sales in that same year. The patents on BELVIQ issued by the US Patent
and Trademark Office have serial numbers US 6,953,787; US 7,514,422; US 7,977,329; US 8,207,158;
US 8,273,734; US 8,575,149; and US 8,546,379, while the corresponding patent granted by the European Patent
Office has serial number EP 1 411 881 B9. Other of our BELVIQ issued patents and patent applications,
including those directed to the HCl salt of BELVIQ (e.g., US 8,367,657), the hemihydrate of the HCl salt of
BELVIQ as well as its crystalline forms (e.g., US 8,168,624 and EP 1 838 677 B1), and synthetic routes and
intermediates useful in the manufacturing of BELVIQ, are all present in a lesser number of commercially
important jurisdictions. The earliest priority date for the patents on BELVIQ is 2002. The terms of these patents
are capable of continuing into 2023 in most jurisdictions without taking into account any patent term adjustment
or extension regimes of any country or any additional term of exclusivity we might obtain by virtue of the later
filed patent applications. With respect to the United States, we have filed applications for patent extension,
which, if granted, will extend the patent term for one of our BELVIQ composition of matter patents into 2026
and potentially into 2027.

As of February 17, 2014, we owned registered trademarks on the use of the name BELVIQ in Class 5 for the

sale and marketing of pharmaceutical preparations for weight management, weight loss, the treatment of obesity
and the maintenance of weight loss in 101 jurisdictions, including the United States, Japan, Germany, France,
China, Italy, Spain, the United Kingdom, Russia, Australia and South Korea, and had trademark applications
pending in 42 other jurisdictions, of which the three with the largest pharmaceutical markets were Canada, Brazil
and India. The trademark on the name BELVIQ registered by the US Patent and Trademark Office has serial
number US 4,080,253, while the corresponding trademark registered by the European Union’s Office for
Harmonization in the Internal Market has serial number CTM 010224905. Other of our BELVIQ registered
trademarks and trademark applications, including those in classes 9, 16, 41 and 44 for downloadable
publications, publications, educational services and medical services, respectively, directed to weight
management, weight loss and the maintenance of weight loss are all present in a lesser number of commercially
important jurisdictions. As of February 17, 2014, we have also filed trademark applications in Class 5 on one or
more transliterations of the name BELVIQ in the local character set or alphabet of 24 jurisdictions, including
Japan, China, Russia and South Korea.

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APD811 Program

APD811, an orally available agonist of the prostacyclin, or IP, receptor, is an internally discovered
investigational drug candidate intended for the treatment of pulmonary arterial hypertension, or PAH. We are
planning to initiate a Phase 2 clinical trial of APD811 in the first half of 2014.

PAH is a progressive, life-threatening disorder characterized by increased pressure in the arteries that carry

blood from the heart to the lungs. The increased pressure strains the heart, which can limit physical activity,
result in heart failure and reduce life expectancy. Based on data from the Registry to EValuate Early And
Long-term PAH disease management (REVEAL) of patients in the United States, there is an estimated five-year
survival rate of 57% from diagnosis.

Treatment with IP agonists, which can slow disease progression and improve exercise tolerance in
PAH patients, is considered standard of care for advanced PAH. Currently available IP agonists belong to the
prostanoid class of molecules, and the majority of these products need to be administered frequently or
continuously through intravenous, subcutaneous or inhaled delivery methods. We believe that an orally available,
non-prostanoid IP agonist that provides clinical benefits similar to currently available IP agonists has the
potential to improve the standard of care for PAH. APD811’s oral bioavailability and approximately 20 to
26 hour half-life may provide advantages over other IP agonists, including improved receptor coverage given
long half-life and the potential for once-daily oral dosing.

APD811 Development

In October 2012, we initiated a multiple-dose, randomized, double-blind and placebo-controlled Phase 1

clinical trial evaluating multiple-ascending doses of APD811 in healthy volunteers. In this trial, 40 healthy
volunteers received APD811 and 15 received placebo, and the safety profile of APD811 was characteristic of IP
receptor agonists. One serious adverse event, transient atrial fibrillation, occurred in a single patient, and the
study investigator considered it to be possibly treatment related, and the most frequent treatment-emergent
adverse events were headache, nausea and jaw pain.

Prior to the multiple-dose clinical trial, in December 2010, we initiated a Phase 1 clinical trial to evaluate

the safety, tolerability and pharmacokinetics of single-ascending doses of APD811. The randomized,
double-blind and placebo-controlled trial evaluated 32 healthy volunteers in four cohorts of eight participants
each, with six randomized to APD811 and two to placebo. APD811 was rapidly absorbed and demonstrated
dose-proportional pharmacokinetic exposure over the tested dose range. Consistent with the expected
pharmacology of APD811, the most common adverse events were headache, vomiting, nausea, jaw pain and
flushing.

APD811 Intellectual Property

As of February 17, 2014, we owned pending patent applications and patents covering compositions of
matter for APD811 and related compounds and methods of treatment utilizing APD811 and related compounds,
synthetic routes and intermediates useful in the manufacturing of APD811, and various solid state forms of
APD811 filed in 19 jurisdictions, including the United States, Europe, Japan, China, Canada, Brazil, Russia,
Australia, India, and South Korea. Based on sales statistics provided by IMS Health, the jurisdictions where
APD811 patents have been filed accounted for more than 95% of global pharmaceutical sales in 2011. The
earliest priority date for the patents on APD811 is 2008. The terms of any patents that may issue from these
patent applications should be capable of continuing into 2029 in most jurisdictions without taking into account
any patent term adjustment or extension regimes of any country or any additional term of exclusivity we might
obtain by virtue of later filed patent applications.

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Temanogrel Program

Temanogrel, an orally available inverse agonist of the serotonin 2A receptor, is an internally discovered
investigational drug candidate intended for the treatment of thrombotic diseases. We believe temanogrel has the
potential to inhibit serotonin-mediated platelet aggregation and vasoconstriction. Temanogrel’s dual mechanism
may be therapeutically useful for the treatment or prevention of thrombotic diseases.

Thrombosis is the formation of a clot, or thrombus, inside a blood vessel. Thrombus formation that occurs in

the arteries leading to the heart or brain can lead to serious thrombotic diseases including myocardial infarction,
acute coronary syndrome and stroke. One of the initial events in thrombus formation is the activation of platelets,
which then aggregate and adhere to one another as they release certain factors, including high concentrations of
serotonin. Serotonin promotes further platelet aggregation and also causes constriction, or narrowing, of the
blood vessels. Elevated serotonin levels have been associated with increased cardiovascular risk. The
prothrombotic effects of serotonin on platelets and blood vessels are mediated by the serotonin 2A receptor, and
inverse agonists of the serotonin 2A receptor have the potential to inhibit this activity.

As described below, temanogrel has completed single- and multiple-ascending dose Phase 1 trials in healthy

volunteers. Under our Co-Development and License Agreement, Ildong will be responsible for funding and
conducting the next two planned clinical trials in this program: an additional Phase 1 trial in healthy volunteers
and a Phase 2a proof-of-concept trial in patients. We expect Ildong to initiate a Phase 1 trial in the first quarter of
2014 to evaluate the safety of co-administration of temanogrel with aspirin and clopidogrel.

Temanogrel Development

In July 2007, we initiated a randomized, double-blind, placebo-controlled, single-ascending dose Phase

1a clinical trial evaluating temanogrel in 90 healthy male and female volunteers. Doses originally intended for
study ranged from 1 mg to 160 mg, but due to favorable tolerability the maximum dose was increased to 320 mg.
In this trial, a maximum tolerated dose could not be defined despite achieving high concentrations in blood.
Temanogrel was rapidly absorbed, and exposures were generally related to dose. Terminal half-life (t1/2) of parent
plus active metabolites was also related to dose, reaching approximately 11 hours at the higher doses.
Dose-dependent inhibition of serotonin-mediated amplification of platelet aggregation was demonstrated,
supporting the preclinical data generated around temanogrel and establishing initial clinical validation for
temanogrel’s novel mechanism of action.

The Phase 1b clinical trial, initiated in January 2008, was a randomized, double-blind, placebo-controlled,
multiple-ascending dose trial in 50 healthy male and female volunteers. This trial evaluated safety, tolerability,
pharmacokinetics and pharmacodynamics of multiple-ascending doses of temanogrel over a period of one week.
Total daily doses ranged from 15 mg to 80 mg. Temanogrel was rapidly absorbed and exposures were related to
dose. The most frequently reported adverse event was headache, which was more common in the placebo group
than in any temanogrel dose group. None of the adverse events occurred in a dose-related fashion with the
exception of epistaxis (nose bleed), which occurred in two of the volunteers who received the 80 mg dose, a dose
above the anticipated therapeutic range. Dose-dependent inhibition of serotonin-mediated amplification of
platelet aggregation was demonstrated starting at the 15 mg dose and may permit the identification of exposure
ranges that produce minimal, moderate and near-complete inhibition of serotonin-amplified platelet aggregation.

Ildong Temanogrel Collaboration

In November 2012, we entered into a Co-Development and License Agreement with Ildong for temanogrel.

Under the agreement, we granted Ildong exclusive rights to commercialize temanogrel in South Korea for
myocardial infarction, acute coronary syndrome, stroke, peripheral artery disease and other cardiovascular
diseases, subject to further development and regulatory approval of temanogrel. Initially, Ildong will be
responsible for funding and conducting, under the direction of a joint steering committee, the next two planned
clinical trials in this program: an additional Phase 1 trial in healthy volunteers and a Phase 2a proof-of-concept
trial in patients.

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We will maintain ownership of temanogrel outside of South Korea, and have the rights to use data generated

by Ildong for the development and potential commercialization of temanogrel outside of South Korea by us or
other Arena licensees. In addition, Ildong has agreed to pay us a $2.0 million development milestone if the
planned additional Phase 1 and Phase 2a clinical trials conducted by Ildong support continued development and
we or another Arena licensee initiates a Phase 2b clinical trial of temanogrel. We are also eligible to receive a
royalty on net product sales of temanogrel in South Korea, while Ildong is eligible to receive a share of future
payments received by us related to licensing transactions and sales of temanogrel in other territories.

Ildong will indemnify us for losses resulting from certain third-party claims, including for (a) Ildong’s
negligence, willful misconduct or violation of law, (b) Ildong’s breach of the agreement, (c) certain uses or
misuses of temanogrel (including any product liability claim and other claims relating to sales or development of
temanogrel in South Korea), and (d) certain governmental investigations of Ildong related to temanogrel. We will
indemnify Ildong for losses resulting from certain third-party claims, including for (i) our negligence, willful
misconduct or violation of law, and (ii) our breach of the agreement.

Unless terminated earlier or extended, the agreement will continue in effect until the later of the expiration

of all issued patents relating to temanogrel in South Korea and 10 years after the first commercial sale of
temanogrel in South Korea. Either party has the right to terminate the agreement early in certain circumstances,
including (a) if the other party is in material breach, (b) for certain commercialization concerns, and (c) for
certain intellectual property concerns.

Temanogrel Intellectual Property

As of February 17, 2014, we owned issued patents that cover compositions of matter for temanogrel and
related compounds and methods of treatment utilizing temanogrel and related compounds in 83 jurisdictions,
including the United States, Japan, Germany, France, China, Canada, Italy, Spain, the United Kingdom, Russia,
Australia, and South Korea, and had applications pending in 17 other jurisdictions, of which the largest
pharmaceutical markets were Brazil and India. Based on sales statistics provided by IMS Health, the jurisdictions
where temanogrel patents have been issued accounted for more than 92% of global pharmaceutical sales in 2011,
while other jurisdictions where temanogrel patents remain pending accounted for more than 6% of global
pharmaceutical sales in that same year. The patent on temanogrel issued by the US Patent and Trademark Office
has serial number US 7,884,101, while the corresponding patent granted by the European Patent Office has serial
number EP 1 833 799 B1. Other of our temanogrel issued patents and patent applications, including those
directed to the temanogrel HCl salt as well as its crystalline forms, synthetic routes and intermediates useful in
the manufacturing of temanogrel, and the active metabolites of temanogrel have all been filed in a lesser number
of commercially important jurisdictions. The earliest priority date for the patents on temanogrel is 2004. The
terms of these patents are capable of continuing into 2025 in most jurisdictions without taking into account any
patent term adjustment or extension regimes of any country or any additional term of exclusivity we might obtain
by virtue of the later filed patent applications.

APD334 Program

APD334, an orally available agonist of the S1P1 receptor, is an internally discovered investigational drug

candidate intended for the potential treatment of a number of conditions related to autoimmune diseases,
including multiple sclerosis, psoriasis and rheumatoid arthritis. S1P1 receptors have been demonstrated to be
involved in the modulation of several biological responses, including lymphocyte trafficking from lymph nodes
to the peripheral blood. By isolating lymphocytes in lymph nodes, fewer immune cells are available in the
circulating blood to effect tissue damage. We have optimized APD334 as a potent and selective small molecule
S1P1 receptor agonist that reduces the severity of disease in preclinical autoimmune disease models. We have
completed a Phase 1 single-ascending dose trial, as described below, and we plan to initiate a Phase 1
multiple-ascending dose trial of APD334 in 2014.

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APD334 Development

We have completed a Phase 1 single-ascending dose clinical trial of APD334. This randomized, double-blind

and placebo-controlled trial evaluated the safety, tolerability and pharmacokinetics of single-ascending doses of
APD334 in 40 healthy adult volunteers. In the trial, APD334 demonstrated favorable pharmacokinetic and
pharmacodynamic effects, a dose-responsive reduction in blood lymphocyte count, and a slowing of heart rate
(bradycardia) that appears comparable to other S1P1 agonists. The terminal half-life was approximately 35 hours.

APD334 Intellectual Property

As of February 17, 2014, we owned issued patents that cover compositions of matter for APD334 and
related compounds, methods of treatment utilizing APD334 and related compounds, and various salts of APD334
and crystalline forms thereof in 5 jurisdictions, including the United States and Japan, and had applications
pending in 11 other jurisdictions, of which the largest pharmaceutical markets were Europe, China, Canada,
Brazil, Russia, Australia, India, and South Korea. Based on sales statistics provided by IMS Health, the
jurisdictions where APD334 patents have been issued accounted for more than 50% of global pharmaceutical
sales in 2011, while other jurisdictions where APD334 patents remain pending accounted for more than 44% of
global pharmaceutical sales in that same year. The patent on APD334 issued by the US Patent and Trademark
Office has serial number US 8,580,841. Other of our APD334 pending patent applications, including those
directed to synthetic routes and intermediates useful in the manufacturing of APD334 have all been filed in a
lesser number of commercially important jurisdictions. The earliest priority date for the patents on APD334 is
2008. The terms of any patents that may issue from these patent applications should be capable of continuing into
2029 in most jurisdictions without taking into account any patent term adjustment or extension regimes of any
country or any additional term of exclusivity we might obtain by virtue of the later filed patent applications.

APD371 Program

APD371, an orally available agonist of the CB2 receptor, is an internally discovered investigational drug
candidate intended for the treatment of pain. Currently available CB receptor agonists have been limited in utility
by the psychotropic effects associated with the activation of the CB1, but not CB2, receptor subtype. We have
identified several novel, potent, CB2-selective, lead compounds that are intended to retain the analgesic activity
of the CB receptor agonists while avoiding the limiting psychotropic side effects. Preclinical efficacy with these
CB2 receptor agonists has been established in animal models of pain.

In December 2013, we initiated dosing in a randomized, double-blind and placebo-controlled Phase 1 trial to

evaluate the safety, tolerability and pharmacokinetics of single-ascending doses of APD371 in up to 56 healthy
adult volunteers.

APD371 Intellectual Property

As of February 17, 2014, we owned pending patent applications and patents covering compositions of
matter for APD371 and related compounds and methods of treatment utilizing APD371 and related compounds,
synthetic routes and intermediates useful in the manufacturing of APD371, and various solid state forms of
APD371 filed in 23 jurisdictions, including the United States, Europe, Japan, China, Canada, Brazil, Russia,
Australia, India, and South Korea. Based on sales statistics provided by IMS Health, the jurisdictions where
APD371 patents have been filed accounted for more than 96% of global pharmaceutical sales in 2011. Other of
our APD371 patent applications, including those directed methods useful in the manufacturing of APD371 and
various solid state forms of APD371 have all been filed in a similar number of commercially important
jurisdictions. The earliest priority date for the patents on APD371 is 2009. The terms of any patents that may
issue from these patent applications should be capable of continuing into 2030 in most jurisdictions without
taking into account any patent term adjustment or extension regimes of any country or any additional term of
exclusivity we might obtain by virtue of later filed patent applications.

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Other Research and Development Programs

We are continuing our efforts to discover and develop additional novel compounds that target GPCRs to

address unmet medical needs, including programs that are in the early research stage. The extent we devote
research and developments efforts to these programs will depend on our available resources and prioritization
decisions.

Our GPCR Focus, Technologies and Programs

Our drug candidates have resulted from our validated GPCR-focused drug discovery and development
approach, specialized expertise and technologies, including Constitutively Activated Receptor Technology, or
CART, and our Melanophore technology. GPCRs are categorized as “known” when their naturally occurring, or
native, ligands have been identified. Scientists have used molecular cloning in combination with the sequencing
of the human genome to identify both additional receptor subtypes of known GPCRs as well as hundreds of
novel GPCRs. GPCRs are categorized as “orphan” GPCRs when their native ligands have not been identified.
We believe both orphan and known GPCRs offer significant promise for the development of novel GPCR-based
therapeutics.

Our drug discovery approach, specialized expertise and technologies allow us to identify drug leads that act
as receptor activators, or agonists, which increase the detected biological response, or act as receptor inhibitors,
which decrease the detected response. We can also identify inverse agonists, which inhibit ligand-independent, as
well as ligand-dependent, receptor activity.

We believe that our drug discovery approach, specialized expertise and technologies offer several
advantages for drug discovery, including: (a) eliminating the need to identify the native ligand for an orphan
receptor; (b) enhancing the detection of, and allowing us to simultaneously identify, both receptor inhibitor and
receptor activator drug leads; (c) allowing for the identification of drug leads that inhibit both ligand-independent
and ligand-dependent activity; and (d) providing the ability to discover novel and improved therapeutics directed
at known receptors.

Intellectual Property

Our success depends in large part on our ability to protect our proprietary technologies, compounds and
information, and to operate without infringing the proprietary rights of third parties. We rely on a combination of
patent, trade secret, copyright, and trademark laws, as well as confidentiality, licensing and other agreements, to
establish and protect our proprietary rights. We seek patent protection for our key inventions, including drug
candidates we identify, routes for chemical synthesis, pharmaceutical formulations and drug screening
technologies.

There is no assurance that any of our patent applications will issue, or that any of the patents will be
enforceable or will cover a drug or other commercially significant product or method. In addition, we regularly
review our patent portfolio to identify patents and patent applications for potential abandonment that we deem to
have relatively low value to our ongoing business operations. There is also no assurance that we will correctly
identify which of our patents and patent applications should be maintained and which should be abandoned. The
term of most of our other current patents commenced, and most of our future patents, if any, will commence, on
the date of issuance and terminate 20 years from the earliest effective filing date of the patent application.
Because any marketing and regulatory approval for a drug often occurs several years after the related patent
application is filed, the resulting market exclusivity afforded by any patent on our drug candidates and
technologies will likely be substantially less than 20 years.

In the United States, patent term extensions are available for certain delays in either patent office

proceedings or marketing and regulatory approval processes. Under the Drug Price Competition and Patent Term
Restoration Act of 1984, or the Hatch-Waxman Act, the term of a patent that covers an FDA-approved drug may
also be eligible for patent term extension, or PTE. PTE permits patent term restoration of a US patent as

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compensation for the patent term lost during product development and the FDA regulatory review process. The
Hatch-Waxman Act permits a PTE of up to five years beyond the expiration of the patent. This period is
generally one-half the time between the effective date of an Investigational New Drug, or IND (falling after
issuance of the patent), and the submission date of a New Drug Application, or NDA, plus the time between the
submission date of an NDA and the approval of that application, provided the sponsor acted with diligence. A
PTE cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval
and only one patent applicable to an approved drug may be extended. The application for PTE is subject to
approval by the US Patent and Trademark Office in conjunction with the FDA. We believe it currently takes
about two years to obtain approval of the application for PTE.

Outside of the United States, similar provisions may be available in the European Union, Japan, South
Korea and some other jurisdictions to extend the term of a patent that covers an approved drug. The length of any
such extension would vary by country. Our European patents may be eligible for supplemental protection
certificates of up to five years in one or more countries.

However, due to the specific requirements for obtaining these extensions, there is no assurance that our

patents will be afforded extensions even if we encounter significant delays in patent office proceedings or
marketing and regulatory approval.

In addition to patent protection, we rely on trade secrets, proprietary know-how, and continuing

technological advances to develop and maintain our competitive position. To maintain the confidentiality of our
trade secrets and proprietary information, all of our employees are required to enter into and adhere to an
employee confidentiality and invention assignment agreement, laboratory notebook policy, and invention
disclosure procedures as a condition of employment. Additionally, our employee confidentiality and invention
assignment agreements require that our employees not bring to us, or use without proper authorization, any
third-party proprietary technology. We also require our consultants and collaborators that have access to
proprietary property and information to execute confidentiality and invention rights agreements in our favor
before beginning their relationship with us. While such arrangements are intended to enable us to better control
the use and disclosure of our proprietary property and provide for our ownership of proprietary technology
developed on our behalf, they may not provide us with meaningful protection for such property and technology
in the event of unauthorized use or disclosure.

Competition

The biotechnology and pharmaceutical industries are highly competitive and are subject to rapid and
significant change. We face significant competition from organizations with drugs or drug candidates that do or
may compete with BELVIQ or drug candidates we are developing. We may not be able to compete successfully
against these organizations, which include many large, well-financed and experienced pharmaceutical and
biotechnology companies, as well as academic and research institutions and government agencies.

The focus of our scientific and business strategy is on GPCRs. We believe that many pharmaceutical and

biotechnology companies and other organizations also have internal drug discovery and development programs
focused on GPCRs. In addition, other companies have attempted to overcome the problems associated with
traditional drug screening by embarking on a variety of alternative strategies. Developments by others may
render our drug candidates or technologies obsolete or noncompetitive.

Our present competitors with respect to BELVIQ include Hoffmann-La Roche Inc., the US prescription
drug unit of the Roche Group, which markets with Genentech USA, Inc., orlistat under the brand name Xenical,
GlaxoSmithKline Consumer Healthcare which markets an over-the-counter low-dose version of orlistat in the
United States under the brand name alli, and VIVUS Inc., which markets a combination of phentermine and
topiramate under the brand name Qsymia. Another competitor is phentermine, which is a generic drug sold by a
number of companies. Prescribers may also prescribe other drugs, including in combination or off label, that

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would compete with BELVIQ. We also face competition from other approaches for weight loss, including
behavior modification (such as diet and exercise), surgical approaches (such as gastric bypass surgery and gastric
banding), and herbal or other supplements.

There are also potentially competing drug candidates and other approaches for weight loss being developed

by various pharmaceutical and medical device companies and other entities. For example, Orexigen
Therapeutics, Inc., announced that it submitted applications for EU and US regulatory approval of its drug
candidate for a similar indication in October and December 2013, respectively. In addition, Novo Nordisk
announced that it submitted applications in December 2013 for US and EU regulatory approval of its drug
currently approval for patients with type 2 diabetes for the treatment of obesity. Some programs in discovery,
preclinical or other stages of development may include serotonin 2C programs.

Many of our existing and potential competitors have substantially greater drug development capabilities and
financial, scientific and marketing resources than we do. Additional consolidation in the pharmaceutical industry
may result in even more resources being concentrated with our competitors. As a result, our competitors may be
able to devote greater resources than we can to the research, development, marketing and promotion of
therapeutic products or drug discovery techniques, or to adapt more readily to technological advances than we
can. Accordingly, our competitors may succeed in obtaining patent protection, receiving regulatory approval or
commercializing drugs before we do.

We expect to encounter significant competition in the therapeutic areas targeted by our principal drug
candidates. Companies that complete clinical trials, obtain regulatory approvals and commence commercial sales
of their drug candidates before us may achieve a significant competitive advantage. Furthermore, we may be
competing against companies with substantially greater manufacturing, marketing, distribution and selling
capabilities, and any drug candidate that we successfully develop may compete with existing therapies that have
long histories of safe and effective use.

We may rely on collaborators for support of development programs and for the manufacturing and
marketing of drug candidates. Such collaborators may be conducting multiple drug development efforts within
the same disease areas that are the subject of their agreements with us, which may negatively impact the
development of drugs that are subject to our agreements. In addition, we face and will continue to face intense
competition from other companies for such collaborative arrangements, and technological and other
developments by others may make it more difficult for us to establish such relationships.

Government Regulation

We and our collaborators are subject to significant governmental regulation. The FDA and comparable
regulatory agencies in state and local jurisdictions and in foreign countries impose substantial requirements upon
the preclinical and clinical development, pre-market approval, manufacture, marketing and distribution of
pharmaceutical products. These agencies and other regulatory agencies regulate research and development
activities and the testing, approval, manufacture, quality control, safety, effectiveness, labeling, storage, tracking,
recordkeeping, advertising, pricing and promotion of drug candidates and commercialized drugs. Failure to
comply with applicable FDA or other regulatory requirements may result in inspectional notices of violation,
warning letters, civil or criminal penalties, suspension or delays in clinical development, recall or seizure of
products, partial or total suspension of production, withdrawal of a product from the market or other negative
consequences.

In the United States. In the United States, the FDA regulates drug products under the Federal Food, Drug,

and Cosmetic Act, or FD&C Act, and its implementing regulations. The process required by the FDA before
drug candidates may be marketed in the United States generally involves the following:

•

completion of extensive preclinical laboratory tests and preclinical animal studies, many of which are
required to be performed in accordance with the FDA’s Good Laboratory Practice, or GLP, regulations;

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•

•

•

•

•

•

submission to the FDA of an IND, which must become effective before human clinical trials may begin
and be updated annually;

performance of adequate and well-controlled human clinical trials to establish the safety and efficacy
of the drug candidate for each proposed indication;

submission to the FDA of an NDA after completion of adequate and well-controlled human clinical
trials, generally accompanied by payment of a substantial user fee to the FDA;

a determination by the FDA within 60 days of its receipt of the NDA to file the NDA for review;

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

FDA review and approval of the NDA prior to any commercial marketing or sale of the drug in the
United States. Prior to commercialization, centrally acting drugs may be subject to review and potential
scheduling by the DEA.

In cases where a drug will not be approved based on the information provided in the NDA, the FDA will
issue a CRL outlining the deficiencies in the application to which the sponsor must provide a complete response
for the application to be further considered.

The development and approval process requires substantial expertise, time, effort and financial resources,
and we cannot be certain that any approvals for our drug candidates will be granted on a timely basis, if at all.

The results of preclinical tests (which include laboratory evaluation as well as GLP studies to evaluate

toxicity in animals) for a particular drug candidate, together with related manufacturing information and
analytical data, are submitted as part of an IND to the FDA. The IND automatically becomes effective 30 days
after receipt by the FDA, unless the FDA institutes a clinical hold within the 30-day time period because of
concerns or questions about the conduct of the clinical trial, including concerns that human research subjects will
be exposed to unreasonable health risks. In such a case, the IND sponsor and the FDA must resolve any
outstanding concerns before the clinical trial can begin. IND submissions may not result in FDA authorization to
commence a clinical trial. A separate submission to an existing IND must also be made for each successive
clinical trial conducted during product development. Further, an independent institutional review board, or IRB,
for each medical center proposing to conduct the clinical trial must review and approve the plan for any clinical
trial before it commences at that center and it must monitor the study until completed. The FDA, the IRB or the
sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects or
patients are being exposed to an unacceptable health risk. Clinical testing also must satisfy extensive Good
Clinical Practice, or GCP, regulations and regulations for informed consent and privacy of individually
identifiable information.

Clinical Trials. For purposes of NDA submission and approval, clinical trials are typically conducted in the

following sequential phases, which may overlap:

• Phase 1 Clinical Trials. Studies are initially conducted in a limited population to test the drug

candidate for safety, dose tolerance, absorption, metabolism, distribution and excretion, typically in
healthy volunteers, but in some cases in patients.

• Phase 2 Clinical Trials. Studies are generally conducted in a limited patient population to identify

possible adverse effects and safety risks, explore the initial efficacy of the product for specific targeted
indications and to determine dose range or pharmacodynamics. Multiple Phase 2 clinical trials may be
conducted by the sponsor to obtain information prior to beginning larger and more expensive Phase 3
clinical trials.

• Phase 3 Clinical Trials. These are commonly referred to as pivotal studies or adequate and well-controlled
studies. When Phase 2 evaluations demonstrate that a dose range of the product is effective and has an

21

acceptable safety profile, Phase 3 clinical trials are undertaken in large patient populations to further evaluate
dosage, provide substantial evidence of clinical efficacy and further test for safety in an expanded and
diverse patient population at multiple, geographically dispersed clinical trial centers.

• Phase 4 Clinical Trials. The FDA may approve an NDA for a drug candidate, but require that the

sponsor conduct additional clinical trials to further assess the drug after NDA approval under a post-
approval commitment. In addition, a sponsor may decide to conduct additional clinical trials after the
FDA has approved an NDA. Post-approval trials are typically referred to as Phase 4 clinical trials.

New Drug Applications. The results of drug development, preclinical studies and clinical trials are submitted

to the FDA as part of an NDA. NDAs also must contain extensive chemistry, manufacturing and control, or
CMC, information. An NDA is usually accompanied by a significant user fee. Once the submission has been
accepted for filing, the FDA’s goal is to review applications within 10 months from its acceptance of the filing
or, if the application relates to an unmet medical need in a serious or life-threatening indication, 6 months from
its acceptance of the filing. The review process can be significantly extended by FDA requests for additional
information or clarification. The FDA may refer the application to a preestablished advisory committee for
review, evaluation and recommendation as to whether the application should be approved. The FDA is not bound
by the recommendation of an advisory committee. The FDA may deny approval of an NDA by issuing a
Complete Response Letter, or CRL, if the applicable regulatory criteria are not satisfied. A CRL may require
additional clinical data and/or an additional pivotal Phase 3 clinical trial(s), and/or other significant, expensive
and time-consuming requirements related to clinical trials, preclinical studies or manufacturing. Data are not
always conclusive and the FDA may interpret data differently than we or our collaborators interpret data.
Approval may occur with Risk Evaluation and Mitigation Strategies, or REMS, that may limit the labeling,
distribution or promotion of a drug product. Once issued, 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 4 clinical trials, and surveillance programs to monitor the safety
effects of approved products which have been commercialized, and the FDA has the power to prevent or limit
further marketing of a product based on the results of these postmarketing programs or other information.

Other US Regulatory Requirements. Products manufactured or distributed pursuant to FDA approvals are

subject to continuing regulation by the FDA, including recordkeeping, annual product quality review and
reporting requirements. Adverse event experience with the product must be reported to the FDA in a timely
fashion and pharmacovigilance programs to proactively look for these adverse events are mandated by the FDA.
Drug manufacturers and their subcontractors are required to register their establishments with the FDA and
certain state agencies, and are subject to periodic inspections (which may be unannounced) by the FDA and
certain state agencies for compliance with ongoing regulatory requirements, including current Good
Manufacturing Practice, or cGMPs, regulations, which impose certain procedural and documentation
requirements upon us and our third-party manufacturers. Following such inspections, the FDA may issue notices
on Form FDA 483 and warning letters that could cause us to modify certain activities. A Form FDA 483 notice,
if issued at the conclusion of an FDA inspection, can list conditions the FDA investigators believe may have
violated cGMP or other FDA regulations. FDA guidelines specify that a warning letter be issued only for
violations of “regulatory significance,” also known as Official Action Indicated, or OAI. Failure to adequately
and promptly correct the observation(s) can result in regulatory action. In addition to Form FDA 483 notices and
warning letters, failure to comply with the statutory and regulatory requirements can subject a manufacturer to
possible legal or regulatory action, such as suspension of manufacturing, seizure of product, injunctive action or
possible civil or criminal penalties.

The FDA closely regulates the post-approval marketing and promotion of drugs, 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 their approved indications and in accordance with the provisions of the approved label. Further,
modifications to the drug may require us to develop additional data or conduct additional preclinical studies and
clinical trials and we may be required to submit and obtain FDA approval of a new or supplemental NDA,

22

including changes in indications, labeling, or manufacturing processes or facilities. Failure to comply with these
requirements can subject a manufacturer to possible legal or regulatory action, such as warning letters, corrective
advertising, suspension of manufacturing, seizure of product, injunctive action or potential civil and criminal
penalties.

Physicians may prescribe legally available drugs for uses that are not described in the product’s labeling and

that differ from those tested by us and approved by the FDA, if in their professional medical judgment the
physicians deem such use to be appropriate. Such off-label uses are common across certain medical specialties.
The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however,
impose stringent restrictions on manufacturers’ communications regarding off-label use.

To distribute products commercially, we or our collaborators, as applicable, must comply with state laws
that require the registration of manufacturers and wholesale distributors of pharmaceutical products in a state,
including, in certain states, manufacturers and distributors who ship products into the state even if such
manufacturers or distributors have no place of business within the state. Some states also impose requirements on
manufacturers and distributors to establish the pedigree of product in the chain of distribution.

DEA Regulation. The DEA regulates drugs that are controlled substances. Controlled substances are those
drugs that appear on one of the five schedules promulgated and administered by the DEA under the Controlled
Substances Act, or CSA. The CSA governs, among other things, the inventory, distribution, recordkeeping,
handling, security and disposal of controlled substances. Any drug that acts on the central nervous system has the
potential to become a controlled substance based on an evaluation of its abuse potential, and scheduling by the
DEA is a separate process that may delay the commercial launch of a drug even after FDA approval of the NDA.
Companies with a scheduled drug are subject to periodic and ongoing inspections by the DEA and similar state
drug enforcement authorities to assess ongoing compliance with the DEA’s regulations. Any failure to comply
with these regulations could lead to a variety of sanctions, including the revocation or a denial of renewal of any
DEA registration, injunctions, or civil or criminal penalties.

Outside of the United States. Outside of the United States, the 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.

Hatch-Waxman Exclusivity and Patent Term Extension. Market exclusivity provisions of the

Hatch-Waxman Act can delay the submission or approval of applications seeking to rely upon the FDA’s
findings of safety and effectiveness for a previously approved NDA. A new chemical entity subject to an NDA,
such as BELVIQ, is entitled to a five-year period of non-patent marketing exclusivity in the United States. 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 a
505(b)(2) NDA submitted 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, such an application may be
submitted after four years if it contains a certification of patent invalidity or non-infringement of patents listed
with the FDA by the NDA holder. The Hatch-Waxman Act also provides three years of marketing exclusivity for
an NDA, or supplement to an existing NDA, if new clinical investigations, other than bioavailability studies, that
were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the
application. This three-year exclusivity covers only the conditions of use associated with the new clinical
investigations and does not prohibit the FDA from approving ANDAs for drugs containing the original active
ingredient. 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 preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and
effectiveness.

23

Drug Product Manufacturing. In Zofingen, Switzerland, our Swiss subsidiary, Arena GmbH operates a drug
product manufacturing facility. Swissmedic, a public service organization of the Swiss federal government, is the
central Swiss agency for the authorization and supervision of therapeutic products. Our Swiss manufacturing
facility has been inspected by the competent regional authorities (Regionales Heilmittelinspektorat der
Nordostschweiz, Basel, Switzerland), acting on behalf of Swissmedic, which issued GMP and production
licenses to Arena GmbH for the production of drugs. The FDA conducted a PAI of this facility in July 2010,
which resulted in No Actions Indicated, and classified this facility as acceptable. Consistent with FDA practice,
we expect a routine FDA inspection in the 2014/2015 timeframe.

Prescription Drug Reimbursement. In the United States and markets in other countries, sales of prescription

drug products depend in part on the availability of reimbursement from third-party payers. Third-party payers
include government health administrative authorities, managed care organizations, private health insurers and
other organizations. The process for determining whether a payer will provide coverage for a drug product may
be separate from the process for setting the price or reimbursement rate that the payer will pay for the drug
product. Third-party payers may limit coverage to specific drug products on an approved list, or formulary,
which might not include all of the FDA-approved drug products for a particular indication. Third-party payers are
increasingly challenging the price and examining the medical necessity and cost-effectiveness of medical
products and services, in addition to their safety and efficacy. We may need to conduct expensive
pharmacoeconomic studies to demonstrate the cost-effectiveness of our products. A payer’s decision to provide
coverage for a drug product does not imply that an adequate reimbursement rate will be approved. Adequate
third-party reimbursement may not be available to enable us to maintain price levels sufficient to realize an
appropriate return on our investment in product development. Patients who are prescribed medications for the
treatment of their conditions, and their prescribing physicians, generally rely on third-party payers to reimburse
all or part of the costs associated with their prescription drugs. Patients are less likely to use our products unless
coverage is provided and reimbursement is adequate to cover a significant portion of the cost of our products.
Therefore, coverage and adequate reimbursement are important to new product acceptance.

If a drug is reimbursed by Medicare or Medicaid, pricing and rebate programs must comply with, as
applicable, the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 as well as the
Medicaid rebate requirements of the Omnibus Budget Reconciliation Act of 1990 and the Veterans Health Care
Act of 1992, or VHCA, each as amended. If products are made available to authorized users of the Federal
Supply Schedule of the General Services Administration, additional laws and requirements apply. Under the
VHCA, drug companies are required to offer certain drugs at a reduced price to a number of federal agencies
including US Department of Veterans Affairs and US Department of Defense, the Public Health Service and
certain private Public Health Service designated entities in order to participate in other federal funding programs
including Medicare and Medicaid. Participation under the VHCA requires submission of pricing data and
calculation of discounts and rebates pursuant to complex statutory formulas, as well as the entry into government
procurement contracts governed by the Federal Acquisition Regulations.

The containment of healthcare costs has become a priority of federal, state and foreign governments, and the

prices of drugs have been a focus in this effort. In addition, emphasis on managed care in the United States has
increased and we expect will continue to increase the pressure on drug pricing. Coverage policies, third-party
reimbursement rates and drug pricing regulation may change at any time. In particular, the Patient Protection and
Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively
PPACA, was enacted in the United States in March 2010 and contains provisions that may reduce the
profitability of drug products, including, for example, increased rebates for drugs sold to Medicaid programs,
extension of Medicaid rebates to Medicaid managed care plans, mandatory discounts for certain Medicare Part D
beneficiaries and annual fees based on pharmaceutical companies’ share of sales to federal healthcare programs.
Even if favorable coverage and reimbursement status is attained for our products, less favorable coverage
policies and reimbursement rates may be implemented in the future. In the case of BELVIQ, Medicare explicitly
excludes coverage of drugs for weight loss.

24

In markets outside the United States, pricing of pharmaceutical products may be subject to governmental
control. Evaluation criteria used by many government agencies for the purposes of pricing and reimbursement
typically focus on a product’s degree of innovation and its ability to meet a clinical need unfulfilled by currently
available therapies. Some jurisdictions operate positive and negative list systems under which products may only
be marketed once a reimbursement price has been agreed. To obtain reimbursement or pricing approval, some of
these countries may require the completion of clinical trials that compare the cost-effectiveness of a particular
drug candidate to currently available therapies. Other member states allow companies to fix their own prices for
medicines, but monitor and control company profits. In addition, in some countries, cross-border imports from
low-priced markets exert a commercial pressure on pricing within a country. There can be no assurance that any
country that has price controls or reimbursement limitations for drug products will allow favorable
reimbursement and pricing arrangements for any of our products.

Healthcare Fraud and Abuse. Pharmaceutical companies are subject to various federal and state laws
pertaining to healthcare fraud and abuse, including, but not limited to, anti-kickback and false claims laws. We
have a commercial compliance program and have adopted the voluntary Code on Interactions with Healthcare
Professionals, or PhRMA Code, promulgated by the Pharmaceutical Research and Manufacturers of America and
revised in 2009. The PhRMA Code provides guidelines for interactions with respect to marketed products and
related pre- and post-launch activities and reinforces the intention that industry interactions with healthcare
professionals are professional exchanges designed to benefit patients and to enhance the practice of medicine.

The Federal Anti-Kickback Statute makes it illegal for any person or entity, including a prescription drug

manufacturer, or a party acting on its behalf, to knowingly and willfully solicit, offer, receive or provide any
remuneration, directly or indirectly, in exchange for, or to induce, the referral of business, including the purchase,
order, lease of any good, facility, service or item, including the prescription of a particular drug, for which
payment may be made under federal healthcare programs such as Medicare and Medicaid. Some of the state
prohibitions are broader in scope and apply to referral of patients for healthcare services reimbursed by any
source, not only the Medicare and Medicaid programs.

In the course of practicing medicine, physicians may legally prescribe FDA-approved drugs for an
indication that has not been approved by the FDA and which, therefore, is not described in the product’s
approved labeling, so-called “off-label use,” if deemed appropriate in the physicians’ professional medical
judgment. The FDA does not ordinarily regulate the behavior of physicians in their choice of treatments. The
FDA and other government agencies do, however, restrict communications on the subject of off-label use by a
manufacturer or those acting on behalf of a manufacturer. Companies may not promote FDA-approved drugs for
off-label uses. The FDA and other governmental agencies do permit a manufacturer (and those acting on its
behalf) to engage in some limited, non-misleading, non-promotional exchanges of scientific information
regarding unapproved indications.

There are numerous federal false claims laws and civil monetary penalty laws that forbid, among other

things, anyone from knowingly presenting, or causing to be presented for payment to third-party payers
(including Medicare and Medicaid) claims for reimbursed drugs or services that are false or fraudulent, claims
for items or services not provided as claimed or claims for medically unnecessary items or services.

Violations of fraud and abuse laws may be punishable by criminal, civil and/or administrative sanctions,
including individual imprisonment, disgorgement, criminal fines and civil monetary penalties, as well as possible
exclusion from federal healthcare programs (including Medicare and Medicaid). In addition, under certain
healthcare fraud and abuse laws, there is an ability for private individuals to bring similar actions. Additionally,
many states have analogous fraud and abuse laws, some of which may be broader in scope. Further, there are an
increasing number of state laws that require pharmaceutical companies to establish marketing compliance
programs, file periodic reports with the state, make periodic public disclosures on sales, marketing, pricing,
clinical trials and other activities, or register their sales representatives, as well as prohibiting certain other sales
and marketing practices. Beginning August 1, 2013, a federal disclosure requirement will require certain

25

manufacturers (which are known as “applicable manufacturers”) to track and report to the federal government
information about certain payments made to US-licensed physicians and teaching hospitals. If applicable to a
manufacturer, the law may affect operational activities by imposing administrative and compliance burdens to
track and report certain payments. Additionally, recent federal legislation imposes additional obligations on
certain pharmaceutical manufacturers, among others, regarding drug product tracking and tracing.

Our activities are also potentially subject to federal and state consumer protection and unfair competition

laws. We are also subject to the US Foreign Corrupt Practices Act, or the FCPA, which prohibits companies and
individuals from engaging in specified activities to obtain or retain business or to influence a person working in
an official capacity. Under the FCPA, it is illegal to pay, offer to pay, or authorize the payment of anything of
value to any foreign government official, governmental staff members, political party or political candidate in an
attempt to obtain or retain business or to otherwise influence a person working in an official capacity.

Healthcare Privacy and Security Laws. Federal and state laws protect the confidentiality of certain health

information, in particular, individually identifiable information, and restrict the use and disclosure of that
information. At the federal level, the Department of Health and Human Services promulgated health information
privacy and security rules under the Health Insurance Portability and Accountability Act of 1996, or HIPAA. In
addition, many state laws apply to the use and disclosure of health information. We may be subject to, or our or
our collaborators’ marketing activities may be limited by, HIPAA, and its implementing regulations, which
established uniform standards for certain “covered entities” (healthcare providers, health plans and healthcare
clearinghouses) governing the conduct of certain electronic healthcare transactions and protecting the security
and privacy of protected health information. The American Recovery and Reinvestment Act of 2009, commonly
referred to as the economic stimulus package, included sweeping expansion of HIPAA’s privacy and security
standards called the Health Information Technology for Economic and Clinical Health Act, or HITECH, which
became effective on February 17, 2010. Among other things, the law makes HIPAA’s privacy and security
standards directly applicable to “business associates,” which are independent contractors or agents of covered
entities that receive or obtain protected health information in connection with providing a service on behalf of a
covered entity. HITECH also increased the civil and criminal penalties that may be imposed against covered
entities, business associates and possibly other persons, and gave state attorneys general new authority to file
civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorney’s
fees and costs associated with pursuing federal civil actions.

Manufacturing and Sources and Availability of Raw Materials, Intermediates and Clinical Supplies

In January 2008, we acquired from Siegfried certain drug product facility assets, including manufacturing

facility production licenses, fixtures, equipment, other personal property and real estate assets in Zofingen,
Switzerland. We are using this facility to manufacture and package BELVIQ as well as certain drug products for
Siegfried. From time to time, we may also use this facility to manufacture and package tablets and capsules for
other of our programs.

All of our manufacturing services revenues are attributable to Siegfried, which is our only customer for such
services. Our revenues of $81.4 million for the year ended December 31, 2013, included $2.7 million, or 3.3% of
our total revenues, from Siegfried. Our revenues of $27.6 million for the year ended December 31, 2012,
included $3.8 million, or 13.8%, of our total revenues, from Siegfried. Our revenues of $12.7 million for the year
ended December 31, 2011, included $5.3 million, or 41.9%, of our total revenues, from Siegfried.

We purchase raw materials, starting materials, intermediates, API, excipients and other materials from
commercial sources. To decrease the risk of an interruption to our supply, when we believe it is reasonable for us
to do so, we source these materials from multiple suppliers so that, in general, the loss of any one source of
supply would not have a material adverse effect on commercial production, project timelines or inventory of
supplies for our studies or clinical trials. However, currently we have only one or a limited number of suppliers
for some of these materials for BELVIQ and for other of our programs. The loss of a primary source of supply

26

would potentially delay our production of BELVIQ or our development projects and potentially those of current
or future collaborators. We intend to maintain a safety stock of certain of these materials to help avoid delays in
production, but we do not know whether such stock will be sufficient. Our facility in Zofingen is the only
manufacturer of finished drug product for BELVIQ. We intend to have a second source of supply for finished
drug product of BELVIQ, but we believe that it could take two years or longer to secure another source.

Eisai is our only customer for commercial sales of BELVIQ. Eisai purchases BELVIQ from Arena GmbH,

and is the exclusive distributor of BELVIQ in the United States, which is the only jurisdiction for which
BELVIQ has received regulatory approval for marketing. Our revenues of $81.4 million for the year ended
December 31, 2013, included $78.1 million, or 96.0% of our total revenues, from Eisai. Our revenues of
$27.6 million for the year ended December 31, 2012, included $23.6 million, or 85.6%, of our total revenues,
from Eisai. Our revenues of $12.7 million for the year ended December 31, 2011, included $6.8 million, or
53.2%, of our total revenues, from Eisai.

Compliance with Environmental Regulations

Our research and development programs involve the controlled use of hazardous materials, chemicals,
biological materials and various radioactive compounds. In the United States, we are subject to regulation under
the Occupational Safety and Health Act, the Environmental Protection Act, US Environmental Protection
Agency, California Environmental Protection Agency, the Toxic Substances Control Act, the Resource
Conservation and Recovery Act, the CSA and other federal, state or local regulations.

With regard to Arena GmbH’s drug product manufacturing facility, Arena GmbH has contracted with
Siegfried to provide safety, health and environmental services and assess compliance, train personnel and oversee
Arena GmbH’s compliance with the applicable safety, health and environmental regulations. Arena GmbH is
subject to regulation under the Environmental Protection Act (Umweltschutzgesetz, USG), the Chemicals Act
(Chemikaliengesetz, ChemG), and the Federal Act on the Protection of Waters (Gewässerschutzgesetz, GSchG),
which refer to several ordinances such as the Ordinance on Air Pollution Control (Luftreinhalteverordnung,
LRV), the Ordinance on Incentive Taxes on Volatile Organic Compounds (Verordnung über die Lenkungsabgabe
auf flüchtigen organischen Verbindungen, VOCV), the Water Protection Ordinance (Gewässerschutzverordnung,
GSchV), the Ordinance of the Handling of Wastes (Verordnung über den Verkehr mit Abfällen, VeVA), the
Chemicals Ordinance (Chemikalienverordnung, ChemV), the Ordinance on Chemical Risk Reduction
(Chemikalien-Risikoreduktions-Verordnung, ChemRRV) and the Ordinance on Protection against Major
Accidents (Störfallverordnung, StFV). The competent authorities in Switzerland for the implementation of
environmental regulations are BAFU (Bundesamt für Umwelt / Federal Office for the Environment), which is the
Swiss federal agency for the environment, and the respective authorities of the Canton of Aargau (Abteilung für
Umwelt, AfU). Furthermore, the BAFU and the BAG (Bundesamt für Gesundheit / Federal Office of Public
Health) share authorities with regard to the implementation and, together with the respective authority of the
Canton of Aargau (Amt für Verbraucherschutz), the supervision of compliance with the laws and regulations
related to chemicals. Occupational health and safety is regulated, in particular, by the EKAS (Eidgenössische
Koordinationskommission für Arbeitssicherheit) guideline No. 6508 (ASA), governing the evaluation of worker
safety and the reporting to the relevant authorities. The competent authority for the implementation of
occupational health and safety regulations is the Canton of Aargau (Amt für Wirtschaft und Arbeit), whereby
exposure limits are set by SUVA (Schweizerische Unfallversicherungsanstalt), which is the Swiss Accident
Insurance Fund.

We may be subject to further such regulations in the future. Although we believe that our operations comply

in all material respects with the applicable environmental laws and regulations, the risk of accidental
contamination or injury from these materials cannot be eliminated. In the event of such an accident, we could be
held liable for any damages that result, and the extent of that liability could exceed our resources. Our
compliance with these laws and regulations has not had, and is not expected to have, a material effect upon our
capital expenditures, results of operations or competitive position.

27

Research and Development Expenses

Research and development activities are the primary source of our expenses. Our research and development

expenses include personnel costs, research supplies, facility and equipment costs, clinical and preclinical study
fees, and manufacturing costs for non-commercial products. Such expenses totaled $66.5 million for the year
ended December 31, 2013, $54.1 million for the year ended December 31, 2012, and $58.7 million for the year
ended December 31, 2011. We include research and development sponsored by collaborators in our total research
and development expenses. We estimate that such expenses totaled $2.0 million, $27,000 and $3.3 million in
2013, 2012 and 2011, respectively.

Employees

As of February 24, 2014, we had a total of 310 employees, including 254 in research, development and
manufacturing and 56 in administration, which includes finance, legal, facilities, information technology and
other general support areas.

Available Information

Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and all
amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act
of 1934, or the Exchange Act, are available free of charge on our website (www.arenapharm.com) as soon as
reasonably practicable after they are electronically filed with, or furnished to, the SEC.

Item 1A. Risk Factors.

RISK FACTORS

Investment in our stock involves a high degree of risk. You should consider carefully the risks described

below, together with other information in this Annual Report on Form 10-K and other public filings, before
making investment decisions regarding our stock. If any of the following events actually occur, our business,
operating results, prospects or financial condition could be materially and adversely affected. This could cause
the trading price of our common stock to decline and you may lose all or part of your investment. Moreover, the
risks described below are not the only ones that we face. Additional risks not presently known to us or that we
currently deem immaterial may also affect our business, operating results, prospects or financial condition.

BELVIQ® (pronounced “BEL-VEEK”) is the trade name for the finished drug product containing the active

pharmaceutical ingredient lorcaserin hydrochloride, or lorcaserin, that is marketed for chronic weight
management in the United States. Lorcaserin may in the future be marketed in the United States or in other
countries under a different trade name for chronic weight management. Lorcaserin may also be marketed under
a different trade name for a different indication, in a different formulation or in combination with another drug.
In this report, we use BELVIQ to refer to the finished drug product containing lorcaserin and/or, depending on
the context, the active pharmaceutical ingredient lorcaserin, and without regard to the current or potential
indication, formulation or combination.

Risks Relating to Our Business

Our prospects are highly dependent on the success of BELVIQ, our first and only FDA-approved drug. To
the extent BELVIQ is not commercially successful, our business, financial condition and results of
operations may be materially adversely affected and the price of our common stock may decline.

Our prospects are highly dependent on the success of BELVIQ, which was approved for chronic weight
management by the US Food and Drug Administration, or FDA, and is our first and only drug approved by any
regulatory agency. We believe our prospects are highly dependent on, and a significant portion of the value of
our company relates to, the successful commercialization of BELVIQ in the United States and potentially in
additional territories. The marketing approval and successful commercialization of BELVIQ is subject to many

28

risks, including the risks identified in other risk factors. As we have granted rights to commercialize BELVIQ to
collaborators for most of the territories in the world, we are highly dependent on collaborators for obtaining
marketing approval and commercializing BELVIQ. We do not know whether or when BELVIQ will be approved
for sale or commercialized in any territories outside of the United States, and BELVIQ may not receive
marketing approval from any other regulatory agency or be commercialized in any other territories. If the results
or timing of regulatory filings, the regulatory process, regulatory developments, commercialization, clinical trials
or preclinical studies, or other activities, actions or decisions related to BELVIQ do not meet our, your, analysts’
or others’ expectations, the market price of our common stock could decline significantly.

BELVIQ became available in June 2013 to patients in the United States by prescription, and is being
marketed in the United States by Eisai under a marketing and supply agreement, among our wholly owned
subsidiary, Arena Pharmaceuticals GmbH, or Arena GmbH, Eisai Inc., and Eisai Inc.’s parent company, Eisai
Co., Ltd. (collectively with Eisai Inc., Eisai). The FDA approval of BELVIQ includes the following limitations
of use: (i) the safety and efficacy of coadministration of BELVIQ with other products intended for weight loss
including prescription drugs (e.g., phentermine), over-the-counter drugs, and herbal preparations have not been
established, and (ii) the effect of BELVIQ on cardiovascular morbidity and mortality has not been established.

Under the marketing and supply agreement with Eisai, Arena GmbH also granted Eisai exclusive rights to

market and distribute BELVIQ in all of other the countries in the world, except for South Korea, Taiwan,
Australia, New Zealand and Israel. In addition, Arena GmbH has entered into marketing and supply agreements
with Ildong Pharmaceutical Co., or Ildong, for South Korea and with CY Biotech Company Limited, or CYB, for
Taiwan, granting them exclusive rights to market and distribute BELVIQ in the respective territories for weight
loss or weight management in obese and overweight patients, subject to applicable regulatory approval. We refer
collectively to all of these marketing and supply agreements as the BELVIQ Agreements.

We expect that revenues under the marketing and supply agreement with Eisai (and, to a lesser extent, the

marketing and supply agreements with Ildong and CYB) will constitute the majority of our revenues over the
next several years, and future payments to us under the BELVIQ Agreements will substantially depend on
BELVIQ product sales and the achievement of milestones, and potentially on other BELVIQ products, if any.
Each of the BELVIQ Agreements may be terminated early in certain circumstances, in which case we may not
receive additional milestone or other payments under the terminated agreement. We cannot guarantee future
BELVIQ product sales or achievement of any other milestones under the BELVIQ Agreements.

We and our collaborators have pending applications for regulatory approval for BELVIQ outside of the
United States, and we expect our collaborators will seek regulatory approval for BELVIQ in additional territories
in the future. There is no assurance that any pending or future regulatory applications will be approved. For
example, we withdrew our Marketing Authorization Application, or MAA, for BELVIQ in the European Union,
and we were notified that our MAA for BELVIQ in Switzerland would not be approved. We also plan to enter
into marketing and supply agreements or similar arrangements with one or more pharmaceutical companies to
commercialize BELVIQ in the territories not already under collaboration, but there is no assurance that we will
be able to do so at all or on terms that you or others view as favorable.

In the United States, the degree of market acceptance and commercial success of BELVIQ, and our
revenues, will depend on a number of factors, including the following, as well as risks identified in other risk
factors:

•

•

the successful commercial introduction (or launch) of BELVIQ and growth of commercial sales;

the number of patients with the potential to use BELVIQ, the number of patients receiving BELVIQ
treatment and the results achieved by such patients;

• market acceptance of BELVIQ, which may depend on the public’s view of BELVIQ, the timing and
impact of current or new competition and BELVIQ’s perceived advantages or disadvantages over
alternative treatments (including relative convenience, ease of administration, and prevalence and
severity of any adverse events, including any unexpected adverse events);

29

•

•

•

•

•

•

the actual and perceived safety and efficacy of BELVIQ on both a short- and long-term basis among
actual or potential patients, healthcare providers and others in the medical community, regulatory
agencies and insurers and other payers, including related decisions by any such entity or individual;

incidence and severity of any side effects, including as a result of off-label use or in combination with
one or more drugs;

new data relating to BELVIQ, including as a result of additional studies, trials or analyses of BELVIQ
or related drugs or drug candidates (such as BELVIQ in combination with another drug or using
another formulation);

physicians may not prescribe, and patients may not take, BELVIQ until at least results from our
required postmarketing studies are available or other long-term efficacy and safety data exists;

the claims, limitations, warnings and other information in BELVIQ’s current or future labeling;

the current or future scheduling designation for BELVIQ by the US Drug Enforcement Administration,
or DEA;

• Eisai’s maintenance of an effective sales force, marketing team and strategy and medical affairs group
and related functions, and its sales, marketing and other representatives accurately describing BELVIQ
consistent with its approved labeling;

• BELVIQ’s commercial price (including discounting or other promotions) and perceived cost-

effectiveness;

•

•

•

•

•

•

the placement of BELVIQ on third-party payer formularies, and the ability of patients and physicians
and other providers to obtain and maintain adequate reimbursement, if any, by third-party payers,
including government payers;

the ability and desire of group purchasing organizations, or GPOs, including distributors and other
network providers, to sell BELVIQ to their constituencies;

introduction of counterfeit or unauthorized versions of BELVIQ;

the development of the market for weight-management medications;

to the extent BELVIQ is approved and marketed in a jurisdiction with a significantly lower price than
in another jurisdiction, the impact of the lower pricing in the higher-priced territory, including on the
pricing of reimbursement, if available, and by the diversion of lower-priced BELVIQ into the higher-
priced territory; and

the establishment and maintenance of adequate commercial manufacturing capabilities ourselves or
through third-party manufacturers, our ability to meet commercial demand for BELVIQ, and supply
chain issues.

If BELVIQ is approved in territories outside the United States, the degree of market acceptance and
commercial success of BELVIQ in these territories, and our revenues, will depend on similar factors as in the
United States, as well as territory-specific risks.

We cannot predict with certainty the extent to which BELVIQ will be accepted or utilized by patients,
physicians, healthcare insurers, maintenance organizations or the medical community in general. The potential
population of patients eligible for treatment with BELVIQ may be reduced, including due to the limitations for
use in the product label, which may be more restrictive in different territories. Efforts to educate the medical
community and third-party payers regarding the benefits of BELVIQ will require significant resources and may
not be successful in achieving the objectives. If BELVIQ does not achieve sufficient market acceptance in the
United States, and ultimately in other territories, the revenues we generate from sales will be limited and we may
not be profitable.

30

BELVIQ or any of our future drugs may not be commercially successful if not widely covered and adequately
reimbursed by third-party payers, and we may depend on others to obtain and maintain third-party payer
access; inadequate third-party coverage and reimbursement could make entering into agreements with
pharmaceutical companies to collaborate or commercialize our drugs more difficult and diminish our revenues.

Our and our collaborators’ ability to commercialize any of our drugs that have been or may be approved will

depend in part on government regulation and the availability of coverage and adequate reimbursement from
third-party payers, including private health insurers and government payers, such as the Medicaid and Medicare
programs, increases in government-run, single-payer health insurance plans and compulsory licenses of drugs.
Government and third-party payers are increasingly attempting to contain healthcare costs by limiting coverage
and reimbursement levels for new drugs. In March 2010, the Patient Protection and Affordable Care Act, as
amended by the Health Care and Education Reconciliation Act, or collectively, PPACA (also referred to as
“Obamacare”), was passed, which has the potential to significantly affect the pharmaceutical industry. In
addition to extending coverage to patients otherwise uninsured, PPACA includes, among several other provisions
relating to pharmaceuticals, measures that enhance remedies against healthcare fraud and abuse, add new
transparency requirements, impose a new annual nondeductible fee on certain branded drugs based on market
share in government healthcare programs, increases in rebates for government programs such as Medicaid,
expanded manufacturers’ rebate liability under the Medicaid Drug Rebate Program by increasing the minimum
rebate for both branded and generic drugs, established the Medicare Part D coverage gap discount program by
requiring manufacturers to provide a 50% point-of-sale discount off the negotiated price 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, and the creation of a new Patient-Centered Outcomes Research
Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with
funding for such research. In addition, many countries outside of the United States have nationalized healthcare
systems in which the government pays for all such products and services and must approve product pricing.

The ability to successfully commercialize any drug depends, in part, on the extent to which coverage and
reimbursement for the drug is available from government and health administration authorities, private health
insurers, managed care programs and other third-party payers. It is increasingly difficult to obtain coverage and
adequate reimbursement levels from third-party payers, and significant uncertainty exists as to the coverage and
reimbursement of newly approved prescription drug products. We or our collaborators also face competition in
negotiating for coverage from pharmaceutical companies and others with competitive drugs or other treatment,
and such competitors may have significantly more negotiating leverage or success with respect to the individual
payers than we or our collaborators may have.

With respect to BELVIQ, we depend on Eisai and our other collaborators for the achievement of third-party
payer coverage and acceptable reimbursement and negotiating with individual payers. In the United States, even
if a third-party payer ultimately elects to cover and reimburse for BELVIQ, most payers will not reimburse 100%
of the cost, but rather require patients to pay a portion of the cost through a co-payment. Thus, even if
reimbursement is available, the percentage of drug cost required to be borne by the patients may make use of
BELVIQ financially difficult or impossible for certain patients, which would have a negative impact on sales of
BELVIQ. For example, payers may approve coverage for BELVIQ in tiers requiring unacceptably high patient
co-payments or only as a second- or later-line treatment. Since launch, several third-party payers have approved
coverage for BELVIQ with limitations, including co-pays that may be unacceptably high for certain patients
regardless of the availability of any coupon, voucher or other discount program. Failure to improve coverage or
the reduction or loss of coverage could materially harm the ability to successfully market BELVIQ. Achieving
coverage and acceptable reimbursement levels typically involves negotiating with individual payers and is a
time-consuming and costly process. In addition, Medicare explicitly excludes coverage for drugs for weight loss.
While new legislation may in the future remove this exclusion, there is no assurance any such legislation will be
approved, and Medicare may continue to exclude drugs for weight loss from its coverage.

Given the continuing discussion regarding the cost of healthcare, managed care, universal healthcare
coverage and other healthcare reform measures proposed or yet to be proposed, we cannot predict with certainty

31

what additional healthcare initiatives, if any, will be implemented or the effect any future legislation or regulation
will have on our business. PPACA and any additional legislation or regulations may limit our commercial
opportunities by reducing the amount a potential collaborator is willing to pay to license our programs or drug
candidates in the future due to a reduction in the potential revenues from drug sales. Moreover, legislation and
regulations affecting the pricing of pharmaceuticals may change before regulatory agencies approve our drug
candidates for marketing. Adoption of such legislation and regulations could further limit pricing approvals for,
and reimbursement of, drugs. A government or third-party payer decision not to approve pricing for, or provide
adequate coverage and reimbursements of, our drugs, if any, could limit market acceptance of and demand for
our drugs.

We expect that the PPACA, as well as other federal and state healthcare reform measures that have and may

be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on
the price that we may receive for any approved product, and could seriously decrease our future revenues. Any
reduction in reimbursement from Medicare, Medicaid or other government programs may result in a similar
reduction in payments from private payers. The implementation of cost containment measures or other healthcare
reforms may prevent us from being able to generate revenue, attain profitability, commercialize our products or
establish and maintain collaborations.

The full impact of these new laws, as well as laws and other reform measures that may be proposed and
adopted in the future, remains uncertain, but may continue the downward pressure on pharmaceutical pricing,
and may also increase our regulatory burdens and operating costs, which could have a material adverse effect on
our business operations.

Forecasting of BELVIQ sales will be difficult, and if BELVIQ projections are inaccurate, our business
may be harmed and our stock price may be adversely affected.

Our business planning requires us to forecast demand and revenues for BELVIQ despite numerous
uncertainties, which may be increased because we rely to a large extent on our collaborators, particularly Eisai,
conducting commercial activities and providing us with accurate and timely information. Actual results may
deviate materially from projected results for various reasons, including the following, as well as risks identified
in other risk factors:

•

•

•

•

•

•

•

•

the rate of adoption in the United States;

pricing (including discounting or other promotions), reimbursement, product returns or recalls,
competition, labeling, DEA scheduling, adverse events and others items that impact commercialization;

lack of patient and physician familiarity with BELVIQ;

lack of patient use and physician prescribing history;

lack of commercialization experience with BELVIQ, in particular, and weight loss or management
drugs, in general;

actual sales to patients may significantly differ from expectations based on sales to wholesalers;

our collaborators under the BELVIQ Agreements control the commercialization of BELVIQ in all of
the countries in the world, except for Australia, New Zealand and Israel, including related strategy and
their allocation of resources, and we expect that any future collaborators for BELVIQ will similarly
control the commercialization in the applicable territory; and

uncertainty relating to when BELVIQ may become commercially available to patients and rate of
adoption in other territories.

The extent to which any of these or other factors individually or in the aggregate may impact sales of
BELVIQ is uncertain and difficult to predict. This may lead to lower than expected revenue, increased difficulty

32

in operational planning and higher than desired expenditures. Revenue shortfalls would have a negative impact
on our cash flow and on our business in general. We expect that our revenues from BELVIQ will continue to be
based in part on estimates, judgment and accounting policies, and incorrect estimates or regulators’ or others’
disagreement regarding such estimates or accounting policies may result in changes to guidance or previously
reported results. For example, with respect to the commercialization of BELVIQ in the United States, our
revenues are based on information we receive from Eisai, including their estimates of deductions for certain
items, such as taxes, credits, allowances, discounts, rebates, chargebacks and returns, which are subject to
significant judgment. We expect to continue to recognize revenues upon Eisai’s sales to wholesalers. As
BELVIQ is sold through to patients, if the actual level of deductions differ materially from Eisai’s estimates, this
could have a material impact on our revenues. In addition, expected and actual product sales and quarterly and
other results may greatly fluctuate, including in the near-term, and such fluctuations can adversely affect the
market price of our common stock, perceptions of our ability to forecast demand and revenues, and our ability to
maintain and fund our operations.

Data generated or analyzed with respect to product use in the market or required postmarketing or other
studies may result in decreased demand, lower sales, product recall or regulatory action.

A New Drug Application, or NDA, holder is responsible for assessing and monitoring the safety of a drug

that has been approved for marketing. Eisai is the NDA holder of BELVIQ, and we expect that Eisai and other of
our collaborators will hold the BELVIQ regulatory approvals, if any, in territories outside of the United States.
Eisai, we and others will assess and monitor the safety of BELVIQ in the marketplace, and will receive reports of
adverse safety events. In addition, as a condition to obtaining FDA approval of BELVIQ, the FDA required the
conduct of postmarketing studies, including evaluation of the effect of long-term treatment with BELVIQ on the
incidence of major adverse cardiovascular events in overweight and obese subjects with cardiovascular disease or
multiple cardiovascular risk factors. The FDA required portion of the trial is designed to evaluate BELVIQ’s
effect on the incidence of major adverse cardiovascular events, or MACE, (non-fatal myocardial infarction, non-
fatal stroke and cardiovascular death) compared to placebo, with a non-inferiority margin for the hazard ratio of
1.4. The trial will also include FDA-required echocardiographic assessments. Along with the FDA-required
portion of the trial, we expect that the trial will include the non-FDA required evaluation of whether lorcaserin
reduces the incidence of conversion to type 2 diabetes in patients without type 2 diabetes at baseline and the
incidence of MACE+ (MACE or hospitalization for unstable angina or heart failure, or any coronary
revascularization), both as compared to placebo. We expect that the trial (including the non-FDA required
portion) will run approximately five years. In addition, we expect that, from time to time, we or others will
conduct additional studies, clinical trials or analyses of BELVIQ, including in connection with seeking regulatory
approval of BELVIQ outside of the United States, in combination with other drugs, for other indications or using
different formulations.

New data relating to BELVIQ, including from adverse event reports, required postmarketing and other
studies and trials in the United States, and registration and other studies and trials in territories outside the United
States, may result in label changes, may adversely affect sales or result in withdrawal of BELVIQ from the
market and may adversely affect prospects of developing or commercializing BELVIQ in combination with other
drugs, for other indications or using different formulations. Foreign regulatory agencies may also consider the
new data in reviewing BELVIQ marketing applications in their territories or impose post-approval requirements
that require significant additional expenditures. Furthermore, the discovery of significant problems with a
product or class of products similar to BELVIQ could have an adverse effect on the BELVIQ program, including
commercialization.

In addition, new data or other information, including information about product misuse, may lead

government agencies, professional societies, practice management groups or organizations involved in various
diseases to publish guidelines or recommendations related to the use of BELVIQ or place greater restrictions on
sales. Such guidelines or recommendations may lead to lower sales of BELVIQ.

33

We will need to further collaborate or obtain additional funds to conduct our planned research,
development and commercialization efforts; we may not be able to further collaborate or obtain adequate
funds, your ownership may be substantially diluted if we do obtain additional funds, and you may not
agree with the manner in which we allocate our available resources; and we may not be profitable.

We have accumulated a large deficit since inception that has primarily resulted from the significant research

and development expenditures we have made in seeking to identify and validate new drug targets and develop
compounds that could become marketed drugs. We expect that our losses and operating expenses will continue to
be substantial for at least the short term.

Cash we may generate in the future from sales of BELVIQ or otherwise is uncertain and difficult to predict.
All of our other programs are in the research or early development stage, and we may not have adequate funds to
develop our compounds into marketed drugs. We intend to explore BELVIQ’s therapeutic potential for other
indications, in combination with other drugs or using different formulations, and from time to time we expect to
collaborate with Eisai or others, or, possibly, to work independently, on related studies and trials. We also intend
to advance other of our drug candidates and preclinical compounds in our pipeline. It takes many years and
potentially hundreds of millions of dollars to successfully develop a drug candidate or preclinical compound into
a marketed drug, and our efforts may not result in marketed drugs.

We cannot assure you that any additional payments we may receive under the BELVIQ Agreements will be

sufficient to fund our planned research and development and other activities. We expect to enter into marketing
and supply agreements or other arrangements with one or more pharmaceutical companies to commercialize
BELVIQ in territories not already under collaboration and to research, develop and commercialize other drug
candidates in our pipeline. We may not be able to enter into any such agreement on terms that we or third parties,
including investors or analysts, view as favorable, if at all.

Our ability to enter into new collaborations for BELVIQ or any of our drug candidates may depend on the
outcomes of regulatory applications for marketing approval or additional preclinical and clinical testing. We do
not control these outcomes.

For example, if we experience a significant setback or delay, particularly any relating to BELVIQ, we may
seek to obtain additional funding from the capital markets or we may eliminate, scale back or delay some or all
of our research or development programs. Any such reductions or failure to apply our resources effectively may
narrow, slow or otherwise adversely impact the development and commercialization of our pipeline, which we
believe would reduce our opportunities for success and have a material adverse effect on our business and
prospects.

We may allocate our resources in ways that do not improve our results of operations or enhance the value of

our assets, and our stockholders and others may also not agree with the manner in which we choose to allocate
our resources or obtain additional funding. Any failure to apply our resources effectively, how we obtain
additional funding and the related views of stockholders or others could have a material adverse effect on our
business or the development of our drug candidates and cause the market price of our common stock to decline.
In addition, we cannot assure you that we will be profitable or, if we are profitable for any particular time period,
that we will be profitable in the future.

If BELVIQ is not approved for marketing outside the United States, or if any such approval is significantly
delayed or limited, our results of operations and business may be materially adversely affected and our
stock price may decline.

We or our collaborators have pending applications for regulatory approval of BELVIQ outside of the United
States, and we expect that our current or future collaborators or we will seek regulatory approval for the marketing
of BELVIQ in additional territories. The FDA’s approval of a drug does not assure or predict with any certainty that

34

any other regulatory authority will grant marketing approval for such drug. For example, as described below, we
withdrew our MAA for BELVIQ in the European Union. As another example, VIVUS, Inc., announced in October
2012 that, despite the FDA’s approval of its drug candidate for the treatment of obesity, the Committee for
Medicinal Products for Human Use, or CHMP, of the European Medicines Agency, or EMA, recommended against
approval of its MAA for such drug candidate. We cannot assure or predict with any certainty that BELVIQ will be
approved in any additional territories or the expected timeframe of any such approval. The review and potential
approval of BELVIQ carries many risks and uncertainties, and our or others’ BELVIQ regulatory submissions may
not be satisfactory to the applicable regulatory authorities, including with regard to demonstrating adequate safety
and efficacy for regulatory approval. We have made, and expect to make in the future, assumptions, estimations,
calculations and decisions as part of our analyses of data and regulatory submissions, and the applicable regulatory
authorities may not accept or agree with our assumptions, estimations, calculations, decisions or analyses or may
interpret or weigh the importance of data differently.

Furthermore, as was the case with FDA approval, other regulatory approvals, even if obtained, may be
limited to specific indications, limit the type of patients in which the drug may be used, or otherwise require
specific warning or labeling language, any of which might reduce the commercial potential of BELVIQ. As with
the FDA’s approval of BELVIQ, regulatory authorities in other territories may condition BELVIQ marketing
approval on the conduct of specific postmarketing studies to further evaluate safety and efficacy, in either
particular or general patient populations or both. The results of these studies, discovery of previously unknown
issues involving safety or efficacy or failure to comply with post-approval regulatory requirements, including
requirements with respect to manufacturing practices, reporting of adverse effects, advertising, promotion and
marketing, may result in restrictions on the marketing of BELVIQ or the withdrawal of BELVIQ from the
market.

With respect to the European Union, in 2013, the EMA’s CHMP identified major objections related to
nonclinical and clinical issues, including tumors in rats, valvulopathy and psychiatric events, and the CHMP
requested that we further justify BELVIQ’s overall benefit-risk balance taking these issues into consideration.
The major objections needed to be addressed before the CHMP could have recommended BELVIQ for marketing
approval in the European Union. We did not believe we could resolve the major objections related to the results
of nonclinical studies prior to the time we expected the CHMP to issue its final opinion, and, therefore, we
withdrew the BELVIQ MAA for the European Union. We expect Eisai to potentially submit for regulatory
approval in Europe at a later date, but BELVIQ may not be submitted for regulatory approval in Europe when
expected or ever.

With respect to Switzerland, Swissmedic provided feedback to our MAA in the form of a list of questions
with major objections, which include objections that are similar to those identified with respect to our MAA for
the European Union. We responded to the list of questions in writing, and we subsequently received a
determination from Swissmedic that those concerns have not yet been satisfied and that our application would
not be approved. While we expect to continue to work with Eisai to pursue regulatory approval in Switzerland,
BELVIQ may not be approved for marketing in Switzerland when expected or ever.

We cannot assure you that our collaborator’s or our past or any future responses or submissions will be
sufficient to the applicable regulatory authority or others, that the applicable regulatory authority or others will
consider our BELVIQ program or data, including with regard to BELVIQ’s efficacy or safety, as sufficient, or
that any other regulatory authority will ever approve BELVIQ.

Our commercialization and continuing development of BELVIQ may be adversely impacted by
cardiovascular side effects associated with drugs used for the treatment of obesity.

We developed BELVIQ to more selectively stimulate the serotonin 2C receptor than did fenfluramine or
dexfenfluramine because we believe this may avoid the cardiovascular side effects associated with fenfluramine
and dexfenfluramine (often used in combination with phentermine, the combination of which was commonly
referred to as “fen-phen”). These two drugs were serotonin-releasing agents and non-selective serotonin receptor

35

agonists, and were withdrawn from the market in 1997 after reported incidences of heart valve disease and
pulmonary hypertension associated with their usage. In in vitro studies examining affinity, activity and serotonin
receptor subtype specificity, BELVIQ demonstrated affinity for, and activity at, serotonin 2A, 2B and
2C receptors, but demonstrated greater affinity, activity and selectivity for the serotonin 2C receptor than for the
serotonin 2A and 2B receptors. Activation of the latter two receptors has been associated with undesirable
effects. Activation of the 2A receptor has been associated with central nervous system, or CNS, effects, including
altered perception, mood and abuse potential, and activation of the 2B receptor has been associated with cardiac
valvulopathy.

We may not be correct in our belief that more selectively stimulating the serotonin 2C receptor will avoid

these undesired side effects, or BELVIQ’s selectivity profile may not be adequate to avoid these side effects.
BELVIQ’s selectivity profile and the potential relationship between the activity of BELVIQ and the activity of
fenfluramine and dexfenfluramine may result in increased FDA or other regulatory scrutiny of the safety of
BELVIQ, may raise potential adverse publicity and may affect enrollment of any future clinical trials or product
sales. In addition, we cannot guarantee that any other regulatory authority will find our safety data to be
sufficient to approve BELVIQ for marketing outside of the United States.

As a condition to obtaining FDA approval of BELVIQ, the FDA required the conduct of postmarketing
studies to, among other things, evaluate the effect of long-term treatment with BELVIQ on the incidence of
major adverse cardiovascular events in overweight and obese subjects with cardiovascular disease or multiple
cardiovascular risk factors. As described above, this trial will include echocardiographic assessments in a subset
of the patients as well as non-FDA required evaluations. The results of such trial and assessments may be
unfavorable. Unfavorable results from these studies or other studies we or others conduct, including for related
development programs, could negatively impact the commercialization of BELVIQ, limit the revenues we
generate from sales, result in BELVIQ’s withdrawal from the market, and preclude us from being profitable.

We are dependent on marketing and supply agreements for BELVIQ and the failure to maintain such
agreements, or poor performance under such agreements, could negatively impact our business.

Eisai has primary responsibility for the marketing and distribution of BELVIQ in all of the countries in the

world, except for South Korea, Taiwan, Australia, New Zealand and Israel, and Ildong and CYB have primary
responsibility for the regulatory approval and, ultimately, marketing and distribution of BELVIQ in South Korea
and Taiwan, respectively. We have limited or no control over the amount and timing of resources that any of
these collaborators will dedicate to such activities. In addition, they are responsible for compliance with certain
regulatory requirements.

We are subject to a number of other risks associated with our dependence on the BELVIQ Agreements,

including:

•

•

•

•

our collaborators may not comply with applicable regulatory guidelines with respect to BELVIQ,
which could adversely impact the commercialization or development of BELVIQ;

there could be disagreements regarding the agreements or the study or development of BELVIQ that
delay or terminate the commercialization, research, study or development of BELVIQ, delay or
eliminate potential payments under the agreements or increase our costs under or outside of the
agreements;

our collaborators may not allocate adequate resources or otherwise support BELVIQ or may have
limited experience in a particular territory; and

our collaborators may not perform as expected, including with regard to making any required
payments, and the agreements may not provide adequate protection or may not be effectively enforced.

We and our collaborators have the right to terminate the BELVIQ Agreements in certain circumstances. We

could also agree with a collaborator to amend the terms of our agreement, and we or others, including investors

36

and analysts, may not view any amendments as favorable. If any of the BELVIQ Agreements is terminated early,
we may not be able to find another company to further develop and commercialize BELVIQ in the covered
territory on acceptable terms, if at all, and even if we elected to pursue further development or commercialization
of BELVIQ on our own, we might not have the funds or otherwise be able to do so successfully.

We may enter into additional agreements for the commercialization of BELVIQ or one or more of our drug

candidates, and may be similarly dependent on the performance of third parties with similar and potentially
company-specific risks.

We are responsible for supplying BELVIQ under the BELVIQ Agreements, including for commercial sale.
We rely to an extent on other companies, including third-party manufacturers and sole-source suppliers,
and we or such other companies may encounter failures or difficulties or not receive or provide adequate
supply, which could adversely affect the commercial production of BELVIQ or the clinical development or
regulatory approval of our drug candidates.

Under each of the BELVIQ Agreements, we are the exclusive supplier of BELVIQ. Our Swiss subsidiary
owns and operates a drug product manufacturing facility in Switzerland that will produce finished drug product
of BELVIQ and potentially of one or more of our drug candidates. Such facility is currently our only source for
finished drug product of BELVIQ. Accordingly, we must either rely on third-party manufacturers for such
production or develop or acquire such facilities, which, in either case, would require substantial time and funds.
With respect to BELVIQ, we estimate that it could take two years or longer and a substantial amount of financial
and other resources to secure another source for finished drug product.

In addition, we do not own or operate manufacturing facilities that can produce active pharmaceutical
ingredient, or API, intermediates and other material required to make BELVIQ and our drug candidates, or
finished drug product for all of our drug candidates. Instead, we currently contract with other companies to
supply API, intermediates and other materials. Certain of these materials are available from only one or a small
number of suppliers, and using a new supplier, if available, for finished drug product, API and certain of the
other materials could result in substantial delay and greater cost. We expect Siegfried AG, or Siegfried, will be
the only source of BELVIQ API for at least the short term. Our dependence on one source of finished drug
product and API, as well as our dependence on other third parties in the supply chain, may adversely affect our
ability to develop and deliver drug products on a timely and competitive basis, or at all.

Any performance failure on the part of us or a third-party manufacturer could delay or otherwise adversely
affect the sales of BELVIQ or the clinical development or regulatory approval of BELVIQ or one or more of our
drug candidates. We or third-party manufacturers may encounter difficulties involving production yields,
regulatory compliance, lot release, quality control and quality assurance, as well as shortages of qualified
personnel. Approval of BELVIQ, as well as one or more of our drug candidates, could be delayed, limited or
denied if the applicable regulatory authority does not approve our processes or facilities or those of a third-party
manufacturer. Moreover, the ability to adequately and timely manufacture and supply drug product is dependent
on the uninterrupted and efficient operation of the manufacturing facilities, which is impacted by many
manufacturing variables, including:

•

•

•

•

•

availability or contamination of raw materials and components used in the manufacturing process,
particularly those for which we have no other source or supplier;

capacity of our facilities or those of our contract manufacturers;

having the ability to adjust to changes in actual or anticipated use of the facility, including with respect
to having sufficient capacity and a sufficient number of qualified personnel;

facility contamination by microorganisms or viruses or cross contamination;

compliance with regulatory requirements, including inspectional notices of violation and warning
letters;

37

• maintenance and renewal of any required licenses or certifications;

•

•

•

•

changes in actual or forecasted demand;

timing and number of production runs;

production success rates and bulk drug yields; and

timing and outcome of product quality testing.

In addition, we or our third-party manufacturers may encounter delays and problems in manufacturing our

drug candidates or drugs for a variety of reasons, including accidents during operation, failure of equipment,
delays in receiving materials, natural or other disasters, political or governmental unrest or changes, social unrest,
intentional misconduct or other factors inherent in operating complex manufacturing facilities. Supply chain
management is complex, and involves sourcing from a number of different companies and foreign countries.
Commercially available starting materials, reagents and excipients may be or become scarce or more expensive
to procure, and we may not be able to obtain favorable terms in agreements with subcontractors. We or our
third-party manufacturers may not be able to operate our respective manufacturing facilities in a cost-effective
manner or in a time frame that is consistent with our expected future manufacturing needs. If we or our
third-party manufacturers cease or interrupt production or if our third-party manufacturers and other service
providers fail to supply materials, products or services to us for any reason, such interruption could delay
progress on our programs, or interrupt the commercial supply, with the potential for additional costs and lost
revenues. If this were to occur, we may also need to seek alternative means to fulfill our manufacturing needs.

We may not be able to enter into or maintain agreements for the manufacture of BELVIQ or one or more of

our drug candidates with manufacturers whose facilities and procedures comply with applicable law.
Manufacturers are subject to ongoing periodic inspection (which may be unannounced) by the FDA, the DEA,
corresponding state and foreign authorities and other regulatory authorities to ensure strict compliance with
Current Good Manufacturing Practices, or cGMPs, regulations and other applicable government regulations and
corresponding foreign standards. We do not have control over a third-party manufacturer’s compliance with
these regulations and standards. In addition, we have contracted with Siegfried to provide to us certain business
and technical services, including safety, health and environmental services. We are, therefore, relying at least in
part on Siegfried’s judgment, experience and expertise. We intend to reduce or eliminate our dependence on
Siegfried for such business and technical services, and any changes may result in increased cost, additional risk
or otherwise negatively impact our operations. If we or one of our manufacturers fail to maintain compliance or
otherwise experience setbacks, we or they could be subject to civil or criminal penalties, the production of
BELVIQ or one or more of our drug candidates could be interrupted or suspended, or our product could be
recalled or withdrawn, resulting in delays, additional costs and potentially lost revenues.

Negative US and global economic conditions may pose challenges to our business strategy, which relies on
funding from collaborators or the financial markets, and creates other financial risks for us.

Negative conditions in the US or global economy, including financial markets, may adversely affect our

business and the business of our current and prospective collaborators, distributors and licensees, which we
sometimes refer to generally as our collaborators, and others with which we do or may conduct business. The
duration and severity of these conditions is uncertain. If negative economic conditions persist or worsen, we may
be unable to secure funding to sustain our operations or to find suitable collaborators to advance our internal
programs, even if we achieve positive results from our research and development or business development
efforts. Such negative conditions could also impact commercialization of BELVIQ or any other drugs we
develop as well as our financial condition.

From time to time, we may maintain a portfolio of investments in marketable debt securities, which are

recorded at fair value. Although we have established investment guidelines relative to diversification and
maturity with the objectives of maintaining safety of principal and liquidity, we rely on credit rating agencies to
help evaluate the riskiness of investments, and such agencies may not accurately predict such risk. In addition,

38

such agencies may reduce the credit quality of our individual holdings, which could adversely affect their value.
Lower credit quality and other market events, such as changes in interest rates and further deterioration in the
credit markets, may have an adverse effect on the fair value of our investment holdings and cash position.

We and certain of our current and former employees and directors have been named as defendants in
litigation that could result in substantial costs and divert management’s attention.

Beginning in September 2010, a number of lawsuits were filed against us and certain of our employees and

directors on behalf of certain purchasers of our common stock. The lawsuits in general include allegations that
we and certain of our employees and directors violated laws by making materially false and misleading
statements regarding our BELVIQ trials, thereby artificially inflating the price of our common stock. The
plaintiffs are seeking unspecified monetary damages and other relief.

There is no guarantee that we will be successful in defending these lawsuits. Also, our insurance coverage

may be insufficient, our assets may be insufficient to cover any amounts that exceed our insurance coverage, and
we may have to pay damage awards or otherwise may enter into settlement arrangements in connection with such
claims. A settlement of any of these lawsuits could involve the issuance of common stock or other equity, which
may dilute your ownership interest. Any payments or settlement arrangements could have material adverse
effects on our business, operating results, financial condition or your ownership interest. Even if the plaintiffs’
claims are not successful, this litigation could result in substantial costs and significantly and adversely impact
our reputation and divert management’s attention and resources, which could have a material adverse effect on
our business, operating results or financial condition. In addition, such lawsuits may make it more difficult to
finance our operations, obtain certain types of insurance (including directors’ and officers’ liability insurance),
and attract and retain qualified executive officers, other employees and directors.

Our stock price could decline significantly based on the results and timing of clinical trials and preclinical
studies of, and decisions affecting, BELVIQ or one or more of our drug candidates.

The results and timing of clinical trials and preclinical studies, as well as related decisions, can affect our
stock price. Preclinical studies include experiments performed in test tubes, in animals, or in cells or tissues from
humans or animals. These studies, which are sometimes referred to as nonclinical studies, include all drug studies
except those conducted in human subjects, and may occur before or after initiation of clinical trials for a
particular compound. Results of clinical trials and preclinical studies of BELVIQ or one or more of our drug
candidates (including development programs related to BELVIQ) may not be viewed favorably by us or third
parties, including investors, analysts, current or potential collaborators, the academic and medical communities,
and regulators. The same may be true of decisions regarding the focus and prioritization of our research and
development efforts, how we design individual studies, trials and development programs of BELVIQ as well as
for any of our drug candidates, and regulatory decisions (including by us or regulatory authorities) affecting our
programs. Stock prices of companies in our industry have declined significantly when such results and decisions
were unfavorable or perceived negatively or when a drug candidate or product did not otherwise meet
expectations.

From time to time we have drug programs in clinical trials. In addition to successfully completing clinical

trials, to conduct long-term clinical trials and gain regulatory approval to commercialize drug candidates,
regulatory authorities require that all drug candidates complete short- and long-term preclinical toxicity and
carcinogenicity studies. These preclinical, animal studies are required to help us and regulatory authorities assess
the potential risk that drug candidates may be toxic or cause cancer in humans. The results of clinical trials and
preclinical studies are uncertain and subject to different interpretations, and the design of these trials and studies
(which may change significantly and be more expensive than anticipated depending on results and regulatory
decisions) may also be viewed negatively by us, regulatory authorities or other third parties and adversely impact
the development and opportunities for regulatory approval and commercialization of our drug candidates and
those under collaborative agreements.

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As a condition to obtaining FDA approval of BELVIQ, the FDA required the conduct of postmarketing
studies to assess the safety and efficacy of BELVIQ for weight management in obese pediatric patients, as well
as to evaluate the effect of long-term treatment with BELVIQ on the incidence of major adverse cardiovascular
events in overweight and obese patients with cardiovascular disease or multiple cardiovascular risk factors. As
described above, this trial will include echocardiographic assessments in a subset of the patients as well as non-
FDA required evaluations. In addition, we may decide or need to conduct additional studies, clinical trials or
analyses of BELVIQ, including in connection with seeking regulatory approval of BELVIQ outside of the United
States. Unfavorable results from these studies, trials or analyses could negatively impact market acceptance of
BELVIQ, limit the revenues we generate from sales, result in BELVIQ’s withdrawal from the market, and
preclude us from being profitable.

We may not be successful in initiating or completing our studies or trials or advancing our programs on our

projected timetable, if at all. Any failure to initiate or delays in our studies, trials or development programs, or
unfavorable results or decisions or negative perceptions regarding any of our programs, could cause our stock
price to decline significantly. This is particularly the case with respect to BELVIQ (including related
development programs).

We may report top-line data from time to time, which is based on a preliminary analysis of then-available

efficacy and safety data, and such findings and conclusions are subject to change following a more
comprehensive review of the data related to the particular study or trial. In addition, we make assumptions,
estimations and calculations as part of our analyses of data, and others, including regulatory agencies, may not
accept or agree with our assumptions, estimations, calculations 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 drug candidate or drug and our company in general.

If we do not seek regulatory approval or commercialize BELVIQ with one or more collaborators, our lack
of corporate experience and resources may negatively impact our ability to commercialize BELVIQ
independently.

Subject to applicable regulatory approval, we expect our collaborators to commercialize BELVIQ under the
BELVIQ Agreements. We may not be able to maintain the BELVIQ Agreements or enter into new agreements in
the few territories outside of such agreements on acceptable terms, if at all. If we are unable to maintain or enter
into agreements to commercialize BELVIQ and we develop or acquire our own capabilities to commercialize
BELVIQ in any territory independently, we may require additional capital to develop such capabilities, and the
marketing and sale of BELVIQ in such territory may be delayed or otherwise impeded by our lack of resources.
We may not be successful in developing the requisite capabilities to commercialize BELVIQ without a
collaborator. Even if we were able to do so, we have not previously commercialized a drug, and our limited
experience may make us less effective at commercial planning, marketing and selling than a more experienced
pharmaceutical company. Our lack of corporate experience and adequate resources may impede our efforts to
successfully commercialize BELVIQ independently.

If our competitors are able to establish commercialization arrangements with companies who have

substantially greater resources than we have (or, with respect to commercializing BELVIQ in a territory under an
existing marketing and supply agreement, than our collaborator has), our competitors may be more successful in
marketing and selling their drugs, and our ability to successfully commercialize BELVIQ will be limited.

Our drug candidates are subject to extensive regulation, and we may not receive required regulatory
approvals, or timely approvals, for any of our drug candidates.

The preclinical and clinical development, manufacturing, labeling, packaging, storage, recordkeeping,
advertising, promotion, export, marketing and distribution, and other possible activities relating to BELVIQ and
our drug candidates are, and any other resulting drugs will be, subject to extensive regulation by the FDA and

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other regulatory agencies. We are subject to periodic inspections (which may be unannounced) by the FDA, the
DEA and other regulatory agencies, including inspections at Arena GmbH by the FDA and other regulatory
agencies. Failure to comply with applicable regulatory requirements may, either before or after product approval,
subject us to administrative or judicially imposed sanctions that may negatively impact the commercialization of
BELVIQ or approval of one or more of our drug candidates or otherwise negatively impact our business.
Regulatory agencies have in the past inspected certain aspects of our business in the United States and
Switzerland, and we were provided with observations of objectionable conditions or practices with respect to our
business in the United States. We believe we satisfactorily addressed such observations, but there is no assurance
that regulatory agencies will not provide us with observations in future inspections or that we satisfactorily
addressed observations provided to us in past inspections.

Neither collaborators nor we are permitted to market a drug candidate in the United States until the

particular drug candidate is approved for marketing by the FDA. Specific preclinical data, chemistry,
manufacturing and controls data, a proposed clinical trial protocol and other information must be submitted to the
FDA as part of an investigational new drug, or IND, application, and clinical trials may commence only after the
IND application becomes effective. To market a new drug in the United States, we must submit to the FDA and
obtain FDA approval of an NDA. An NDA must be supported by extensive clinical and preclinical data, as well
as extensive information regarding chemistry, manufacturing and controls to demonstrate the safety and
effectiveness of the drug candidate. Following its review of an NDA or a response to a Complete Response
Letter, or CRL, the FDA may approve the NDA or issue a CRL.

Obtaining approval of an NDA can be a lengthy, expensive and uncertain process. As part of the
Prescription Drug User Fee Act, or PDUFA, the FDA has a goal to review and act on a percentage of all
submissions in a given time frame. The FDA’s review goals are subject to change, and it is unknown whether any
particular FDA review will be completed within the FDA’s review goals or will be delayed. Moreover, the
duration of the FDA’s review may depend on the number and types of other submissions with the FDA around
the same time period.

As with BELVIQ, any drug that acts on the CNS has the potential to be scheduled as a controlled substance
by the DEA. DEA scheduling is a separate process that can delay when a drug may become available to patients
beyond an NDA approval date, and the timing and outcome of such DEA process is uncertain. For example, the
FDA approved the NDA for BELVIQ in June 2012, subject to the final scheduling of BELVIQ by the DEA. The
DEA’s final rule placing BELVIQ into Schedule IV of the Controlled Substances Act was not effective until June
2013. The scheduling designation can also change after it has been finalized. DEA scheduling ranges from I to V,
with I being the most tightly controlled category. If BELVIQ were to be rescheduled into a different category,
such scheduling could negatively impact the ability or willingness to prescribe or dispense BELVIQ, the
likelihood that patients will use it and other aspects of our and Eisai’s ability to commercialize it.

Regulatory approval of an NDA is not guaranteed. The number and types of preclinical studies and clinical

trials that will be required for FDA approval varies depending on the drug candidate, the disease or condition that
the drug candidate is designed to target and the regulations applicable to any particular drug candidate. Despite
the time and expense exerted in preclinical and clinical studies, failure can occur at any stage, and we could
encounter problems that cause us to abandon clinical trials or to repeat or perform additional preclinical studies
and clinical trials. The FDA can delay, limit or deny approval of a drug candidate for many reasons, including:

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a drug candidate may not be deemed adequately safe and effective;

FDA officials may not find the data from preclinical studies and clinical trials sufficient;

the FDA’s interpretation and our interpretation of data from preclinical studies and clinical trials may
differ significantly;

our or our contractors’ or collaborators’ failure to comply with applicable FDA and other regulatory
requirements, including those identified in other risk factors;

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the FDA may not approve the manufacturing processes or facilities;

the FDA may change its approval policies or adopt new regulations; or

the FDA may not accept an NDA or other submission due to, among other reasons, the content or
formatting of the submission.

Even if approved, drug candidates may not be approved for all indications requested and such approval may

be subject to limitations on the indicated uses for which the drug may be marketed, restricted distribution
methods or other limitations, such as those required by a Risk Evaluation and Mitigation Strategies, or REMS.

With the exception of our regulatory submissions for BELVIQ, we have not previously submitted an

application for marketing approval in the United States or any other jurisdiction. This lack of corporate
experience may impede our ability to obtain regulatory approval in a timely manner, if at all, for BELVIQ in
territories in which regulatory approval is our responsibility or for any of our drug candidates. Our preclinical
and clinical data, other information and procedures relating to a drug candidate may not be sufficient to support
approval by the FDA or any other US or foreign regulatory authority, or regulatory interpretation of these data
and procedures may be unfavorable. Our business and reputation may be harmed by any failure or significant
delay in receiving regulatory approval for the sale of any drugs resulting from our drug candidates. As a result,
we cannot predict when or whether regulatory approval will be obtained for any drug we or our collaborators
develop.

To market any drugs outside of the United States, we and our current or future collaborators must comply

with numerous and varying regulatory requirements of other countries. Approval procedures vary among
countries and can involve additional product testing and additional administrative review periods. The time
required to obtain approval in other countries might differ from that required to obtain FDA approval. The
regulatory approval process in other countries may include all of the risks associated with FDA approval as well
as additional risks, some of which may be unanticipated. With respect to our BELVIQ collaborations, our
collaborators are responsible for regulatory filings, and we will depend on their capabilities, plans and diligence
in obtaining regulatory approval.

With respect to our previously filed MAA for BELVIQ in the European Union, we did not believe we could

resolve the major objections identified by the CHMP prior to the time we expected the CHMP to issue its final
opinion, and, therefore, we withdrew the MAA. We expect Eisai to potentially submit for regulatory approval of
BELVIQ in Europe at a later date. If such an application is submitted, the regulatory authority could determine
that the application and data from our BELVIQ studies and trials is not sufficient for approval in such territory.
The approval requirements in the European Union are different than in the United States. For example, the EMA
guidelines provide that clinical trials assessing drug candidates intended for weight control should subject
patients to a weight reducing diet run-in period, and our Phase 3 clinical trials did not include a run-in period.
Such EMA guidelines also provide primary and alternative primary efficacy criteria for weight loss drug
candidates. We believe BELVIQ will satisfy the EMA’s alternative primary efficacy criterion, which is the
proportion of responders achieving more than 10% weight loss at the end of a 12-month period. However, we do
not believe BELVIQ meets the more stringent EMA primary efficacy criterion, which requires demonstrating
weight loss of at least 10% of baseline weight that is also at least 5% greater than that associated with placebo.
Also, with respect our previously filed MAA for BELVIQ in the European Union, the EMA raised questions
regarding the dropout rate in our clinical trials and how this affects the analysis of efficacy in those trials.

We also submitted an MAA with Swissmedic for the marketing approval of BELVIQ in Switzerland. In
February 2013, Swissmedic provided feedback to our MAA in the form of a list of questions with major objections,
which include objections that are similar to those identified with respect to the MAA we previously submitted for
the European Union. We responded to the list of questions in writing, and we subsequently received a determination
from Swissmedic that those concerns have not yet been satisfied and that our application would not be approved.
While we expect to continue to work with Eisai to pursue regulatory approval in Switzerland, BELVIQ may not be

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approved for marketing in Switzerland when expected or ever. In addition, Eisai filed regulatory applications for
marketing approval of BELVIQ in Mexico, Canada and Brazil, and Ildong filed a regulatory application for
marketing approval in South Korea. We expect that we or our collaborators will submit applications for regulatory
approval of BELVIQ in additional territories in the future, but there is no guarantee that we or any of our
collaborators will submit any additional regulatory applications.

We cannot assure you that our collaborator’s or our past or any future responses or submissions will be
sufficient to the applicable regulatory authority or others, that the applicable regulatory authority or others will
consider our BELVIQ program or data, including with regard to BELVIQ’s efficacy or safety, as sufficient, or
that any other regulatory authority will ever approve BELVIQ.

Regulatory approval of a drug in one territory does not ensure additional regulatory approval in such territory
(such as approval of the drug in combination with other drugs, for other indications or using different formulations)
or regulatory approval in another territory, but a failure or delay in obtaining regulatory approval may negatively
impact other regulatory processes. Failure to obtain regulatory approval in a territory, any delay or setback in
obtaining such approval, or our regulatory strategy or decisions could adversely affect the regulatory approval or
commercialization of our drug candidates in other territories, including that our drug candidates may not be
approved for all indications requested, that such approval may be subject to limitations on the indicated uses for
which the drug may be marketed, and with regard to the pricing or reimbursement of any approved drugs.

Our drugs will still be subject to extensive postmarketing regulation if approved.

Following regulatory approval of any of our drug candidates, we and our collaborators will be subject to
ongoing obligations and continued regulatory review from the FDA and other applicable regulatory agencies,
such as continued adverse event reporting requirements. As with BELVIQ, there may also be additional
postmarketing obligations imposed by the FDA or other regulatory agencies. These obligations may result in
significant expense and limit the ability to commercialize such drugs.

The FDA or other regulatory agencies may also require that the sponsor of the NDA or foreign equivalent,

as applicable, conduct additional clinical trials to further assess approved drugs after approval under a post-
approval commitment. Such additional studies may be costly and may impact the commercialization of the drug.
For example, as part of the approval of BELVIQ, the FDA required the conduct of postmarketing studies to
assess the safety and efficacy of BELVIQ for weight management in obese pediatric patients, as well as to
evaluate the effect of long-term treatment with BELVIQ on the incidence of major adverse cardiovascular events
in overweight and obese subjects with cardiovascular disease or multiple cardiovascular risk factors. As
described above, this trial will include echocardiographic assessments in a subset of the patients and other
FDA-required as well as non-FDA required evaluations. Along with being costly and time consuming,
unfavorable results from these trials could negatively impact market acceptance of BELVIQ; limit the revenues
we generate from sales; result in BELVIQ’s withdrawal from the market; negatively impact the potential
approval of BELVIQ in other territories for weight management, for other indications, in combination with other
drugs or using different formulations; and preclude us from being profitable.

The FDA or other regulatory agencies may also impose significant restrictions on the indicated uses for
which a drug may be marketed. Additionally, the FDA may require a REMS, including in connection with a
drug’s approval, to help ensure that the benefits of the drug outweigh its risks. A REMS may be required to
include various elements, such as a medication guide or patient package insert, a communication plan to educate
healthcare providers of the drug’s risks, limitations on who may prescribe or dispense the drug, requirements that
patients enroll in a registry or undergo certain health evaluations or other measures that the FDA deems
necessary to ensure the safe use of the drug.

With regard to BELVIQ and any of our drug candidates that receive regulatory approval, the labeling,
packaging, adverse event reporting, storage, advertising and promotion for the drug will be subject to extensive
regulatory requirements. We and the manufacturers of our products are also required to comply with cGMP

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regulations, which include requirements relating to quality control and quality assurance, as well as the
corresponding maintenance of records and documentation. Further, regulatory agencies must approve these
manufacturing facilities before they can be used to manufacture our products, and these facilities are subject to
ongoing regulatory inspections. In addition, regulatory agencies subject a drug, its manufacturer and the
manufacturer’s facilities to continual review and inspections. The subsequent discovery of previously unknown
problems with a drug, including adverse events of unanticipated severity or frequency, or problems with the
facility where the drug is manufactured, may result in restrictions on the marketing of that drug, up to and
including withdrawal of the drug from the market. In the United States, the DEA and comparable state-level
agencies also heavily regulate the manufacturing, holding, processing, security, recordkeeping and distribution of
drugs that are considered controlled substances.

The DEA has placed BELVIQ into Schedule IV of the Controlled Substances Act, which subjects us to the
DEA’s regulations. The scheduling designation can change after finalization. If BELVIQ were to be rescheduled
into a different category, such scheduling could negatively impact the ability or willingness to prescribe or
dispense BELVIQ, the likelihood that patients will use it and other aspects of our and Eisai’s ability to
commercialize it. The DEA periodically inspects facilities for compliance with its rules and regulations.

If our manufacturing facilities or those of our suppliers fail to comply with applicable regulatory

requirements, such noncompliance could result in regulatory action and additional costs to us. Failure to comply
with applicable FDA and other regulatory requirements may, either before or after product approval, if any,
subject us to administrative or judicially imposed sanctions, including:

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issuance of inspectional notices of violation or warning letters by any regulatory agency;

imposition of fines and other civil penalties;

criminal prosecutions;

injunctions, suspensions or revocations of regulatory approvals;

suspension of any ongoing clinical trials;

total or partial suspension of manufacturing;

delays in commercialization;

refusal by any regulatory agency to approve pending applications or supplements to approved
applications filed by us or collaborators;

refusals to permit drugs or related materials to be imported into or exported from the United States or
other countries;

restrictions on operations, including costly new manufacturing requirements; and

product recalls or seizures.

The FDA’s and other regulatory agencies’ policies may change and additional government regulations may

be enacted that could prevent or delay regulatory approval of our drug candidates or further restrict or regulate
post-approval activities. We cannot predict the likelihood, nature or extent of adverse government regulation that
may arise from future legislation or administrative action, either in the United States or abroad. If we are not able
to maintain regulatory compliance, we or our collaborators might not be permitted to market our drugs and our
business could suffer.

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Our ability to generate revenues from BELVIQ or any of our drug candidates that receive regulatory
approval will be subject to a variety of risks, many of which are out of our control.

BELVIQ or any of our drug candidates that may be approved for marketing may not gain market acceptance
among patients, healthcare providers, healthcare payers or the medical community. We believe that the degree of
market acceptance and our ability to generate revenues from such products will depend on a number of factors,
including:

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timing of market introduction of our drugs and competitive drugs and alternative treatments;

actual and perceived efficacy and safety of our drug candidates;

incidence and severity of any side effects;

potential or perceived advantages or disadvantages as compared to alternative treatments;

strength of sales, marketing and distribution support;

price of our future products, both in absolute terms and relative to alternative treatments;

the general marketplace for the particular drug;

the effect of current and future healthcare laws on our drug candidates;

availability of coverage and reimbursement from government and other third-party payers; and

product labeling or product insert requirements of the FDA or other regulatory authorities.

If our approved drugs fail to achieve market acceptance, we may not be able to generate significant revenues

to be profitable.

Drug development programs are expensive, time consuming, uncertain and susceptible to change,
interruption, delay or termination.

Drug development programs are very expensive, time consuming and difficult to design and implement. Our
drug candidates are in various stages of research and development and are prone to the risks of failure inherent in
drug development. In addition, the FDA or other regulatory authority may require us to, or we or others may
decide to, conduct additional research and development of any of our approved drugs. For example, the FDA is
requiring the conduct of postmarketing studies of BELVIQ, and we or others may from time to time conduct
additional studies or trials of BELVIQ alone or in combination with other drugs. Clinical trials and preclinical
studies are needed to demonstrate that drug candidates are safe and effective to the satisfaction of the FDA and
similar non-US regulatory authorities. These trials and studies are expensive and uncertain processes that may
take years to complete. Failure can occur at any stage of the process, and successful early preclinical studies or
clinical trials do not ensure that later studies or trials will be successful. In addition, the commencement or
completion of our planned preclinical studies or clinical trials could be substantially delayed or prevented by
several factors, including the following:

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limited number of, and competition for, suitable patients required for enrollment in our clinical trials or
animals to conduct our preclinical studies;

limited number of, and competition for, suitable sites to conduct our clinical trials or preclinical
studies;

delay or failure to obtain approval or agreement from the applicable regulatory authority to commence
a clinical trial or approval of a study protocol;

delay or failure to obtain sufficient supplies of drug candidates, drugs or other materials for the trial or study;

delay or failure to reach agreement on acceptable agreement terms or protocols; and

delay or failure to obtain institutional review board, or IRB, approval to conduct a clinical trial at a
prospective site.

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Even if the results of our development programs are favorable, the development programs of our most
advanced drug candidates, including those being developed by collaborators, may take significantly longer and
cost more than expected to complete. In addition, the FDA, other regulatory authorities, collaborators, or we may
suspend, delay or terminate our development programs at any time for various reasons, including:

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lack of effectiveness of any drug candidate during clinical trials;

side effects experienced by study participants or other safety issues;

slower than expected rates of patient recruitment and enrollment or lower than expected patient
retention rates;

delays or inability to manufacture or obtain sufficient quantities of materials for use in clinical trials;

inadequacy of or changes in our manufacturing process or compound formulation;

delays in obtaining regulatory approvals to commence a study, or “clinical holds,” or delays requiring
suspension or termination of a study by a regulatory authority, such as the FDA, after a study is
commenced;

changes in applicable regulatory policies and regulations;

delays in identifying and reaching agreement on acceptable terms with prospective clinical trial sites;

uncertainty regarding proper dosing;

unfavorable results from ongoing clinical trials or preclinical studies;

failure of our clinical research organizations to comply with all regulatory and contractual requirements
or otherwise perform their services in a timely or acceptable manner;

scheduling conflicts with participating clinicians and clinical institutions;

failure to design appropriate clinical trial protocols;

insufficient data to support regulatory approval;

termination of clinical trials by one or more clinical trial sites;

inability or unwillingness of medical investigators to follow our clinical protocols;

difficulty in maintaining contact with subjects during or after treatment, which may result in
incomplete data;

lack of sufficient funding to continue clinical trials or preclinical studies; or

changes in business priorities or perceptions of the value of the program.

There is typically a high rate of attrition from the failure of drug candidates proceeding through clinical
trials, and many companies have experienced significant setbacks in advanced development programs even after
promising results in earlier studies or trials. We have experienced setbacks in our internal and partnered
development programs and expect to experience additional setbacks from time to time in the future. If we or our
collaborators abandon or are delayed in our development efforts related to BELVIQ or any drug candidate, we
may not be able to generate sufficient revenues to continue our operations at the current level or be profitable,
our reputation in the industry and in the investment community would likely be significantly damaged, additional
funding may not be available to us or may not be available on terms we or others believe are favorable, and our
stock price may decrease significantly.

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The results of preclinical studies and completed clinical trials are not necessarily predictive of future
results, and our current drug candidates or any approved drugs may not have favorable results in later
studies or trials.

Preclinical studies and Phase 1 and Phase 2 clinical trials are not primarily designed to test the efficacy of a
drug candidate, but rather to test safety, to study pharmacokinetics and pharmacodynamics, and to understand the
drug candidate’s side effects at various doses and schedules. Favorable results in early studies or trials may not
be repeated in later studies or trials, including continuing preclinical studies and large-scale clinical trials, and
our drug candidates or drugs in later-stage trials may fail to show desired safety and efficacy despite having
progressed through earlier-stage trials. Unfavorable results from ongoing preclinical studies or clinical trials
could result in delays, modifications or abandonment of ongoing or future clinical trials, or abandonment of a
program. Preclinical and clinical results are frequently susceptible to varying interpretations that may delay, limit
or prevent regulatory approvals or commercialization. Negative or inconclusive results or adverse medical events
during a clinical trial could cause a clinical trial to be delayed, repeated or terminated; a program to be
abandoned; or negatively impact a related marketed drug.

Many of our research and development programs are in early stages of development, and may not result in
the commencement of clinical trials.

Many of our research and development programs are in the discovery or preclinical stage of development.

The process of discovering compounds with therapeutic potential is expensive, time consuming and
unpredictable. Similarly, the process of conducting preclinical studies of compounds that we discover requires
the commitment of a substantial amount of our technical and financial resources and personnel. We may not
discover additional compounds with sufficient therapeutic potential, and any of our preclinical compounds may
not result in the commencement of clinical trials. We cannot be certain that results sufficiently favorable to
justify commencement of Phase 1 clinical trials will be obtained in these preclinical investigations. Even if such
favorable preclinical results are obtained, our financial resources may not allow us to commence Phase 1 clinical
trials. If we are unable to identify and develop new drug candidates, we may not be able to maintain a clinical
development pipeline or generate revenues.

We may participate in new strategic transactions that could impact our liquidity, increase our expenses,
present significant distractions to our management and be viewed as unfavorable.

From time to time we consider strategic transactions, such as out-licensing or in-licensing of compounds or
technologies, acquisitions of companies and asset purchases. Additional potential transactions we may consider
include a variety of different business arrangements, such as strategic collaborations, joint ventures, spin-offs,
restructurings, divestitures, business combinations and investments. In addition, another entity may pursue us as
an acquisition target. Any such transaction may be viewed as unfavorable by our stockholders or others and may
require us to incur non-recurring or other charges, may create potential liabilities, may increase our near- and
long-term expenditures and may pose significant integration challenges, require additional expertise or disrupt
our management or business, which could harm our operations and financial results.

As part of an effort to enter into significant transactions, we conduct business, legal and financial due
diligence with the goal of identifying and evaluating material risks involved in the transaction. Despite our
efforts, we ultimately may be unsuccessful in ascertaining or evaluating all such risks and, as a result, might not
realize the intended advantages of the transaction. If we fail to realize the expected benefits from any transaction
we may consummate, whether as a result of unidentified risks, integration difficulties, regulatory setbacks or
other events, our business, results of operations and financial condition could be adversely affected.

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Drug discovery and development is intensely competitive in the therapeutic areas on which we focus. If our
competitors increase or they develop treatments that are approved faster, marketed better, less expensive
or demonstrated to be more effective or safer than our drugs or drug candidates, our commercial
opportunities will be reduced or eliminated.

Many of the drugs we or our collaborators are or may attempt to discover and develop may compete with

existing therapies in the United States and other territories. In addition, many companies are pursuing the
development of new drugs that target the same diseases and conditions that we target.

For example, with regard to BELVIQ, VIVUS announced the US market availability of its drug for chronic

weight management in September 2012. We also face competition from other drugs that may be indicated or
used off label or otherwise for weight loss and from other approaches for weight loss, including behavior
modification (such as diet and exercise), surgical approaches (such as gastric bypass surgery and gastric
banding), and herbal or other supplements. With respect to future weight-loss treatments, we expect that
companies and others may allocate resources to discover and develop additional drugs, additional drug
candidates may be approved and competition may increase. For example, in December 2013, Orexigen
Therapeutics, Inc., announced that it resubmitted with the FDA an NDA for its drug candidate for a similar
indication, and it has also filed an MAA for the approval of such drug candidate in the European Union; and, in
December 2013, Novo Nordisk announced that it has filed submissions for regulatory approval in the United
States and Europe of its drug candidate for the treatment of obesity that is currently approved for the treatment of
type 2 diabetes.

Our competitors, particularly large pharmaceutical companies, may have substantially greater research,

development and marketing capabilities and greater financial, scientific and human resources than we do.
Companies that complete clinical trials, obtain required regulatory agency approvals and commence commercial
sale of their drugs before we do for the same indication may achieve a significant competitive advantage, including
certain patent and marketing exclusivity rights. In addition, our competitors’ drugs may have fewer side effects,
more desirable characteristics (such as efficacy, route of administration or frequency of dosing), or be viewed more
favorably by patients, healthcare providers, healthcare payers, the medical community, the media or others than our
drug candidates or drugs, if any, for the same indication. Our competitors may also market generic or other drugs
that compete with our drugs at a lower price than our drugs, which may negatively impact our drug sales, if any.
Any results from our research and development efforts, or from our joint efforts with our existing or any future
collaborators, may not compete successfully with existing or newly discovered products or therapies.

Collaborative relationships may lead to disputes and delays in drug development and commercialization,
and we may not realize the full commercial potential of our drug candidates.

We may have conflicts with our prospective, current or past collaborators, such as conflicts concerning
rights and obligations under our agreements, the interpretation of preclinical or clinical data, the achievement of
milestone or other payments, the ownership of intellectual property, or research and development, regulatory,
commercialization or other strategy. Collaborators may stop supporting our drug candidates or drugs, including if
they no longer view the program as in their best financial or other interests or they develop or obtain rights to
competing drug candidates or drugs. In addition, collaborators may fail to effectively develop, obtain approval
for or commercialize our drugs, which may result in us not realizing their full commercial potential. If any
conflicts arise with any of our current, past or prospective collaborators, the other party may act in a manner that
is adverse to our interests. Any such disagreement could result in one or more of the following, each of which
could delay, or lead to termination of, development or commercialization of our drug candidates or drugs, and in
turn prevent us from generating revenues:

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•

unwillingness on the part of a collaborator to pay for studies or other research, milestones, royalties or
other payments that we believe are due to us under a collaboration;

uncertainty regarding ownership of intellectual property rights arising from our collaborative activities,
which could prevent us from entering into additional collaborations;

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unwillingness on the part of a collaborator to keep us informed regarding the progress of its
development, regulatory, commercialization, pharmacovigilance or other activities or to permit public
disclosure of the results of those activities;

slowing or cessation of a collaborator’s research, development, regulatory or commercialization efforts
with respect to our drug candidates or drugs; or

litigation or arbitration.

Setbacks and consolidation in the pharmaceutical and biotechnology industries could make entering into
agreements with pharmaceutical companies to collaborate or commercialize our drugs more difficult and
diminish our revenues.

Setbacks in the pharmaceutical and biotechnology industries, such as those caused by safety concerns
relating to drugs like Meridia, Avandia, Vioxx and Celebrex, or drug candidates, as well as competition from
generic drugs, litigation, and industry consolidation, may have an adverse effect on us, including by making it
more difficult to enter into agreements with pharmaceutical companies to collaborate or commercialize our drugs
and diminishing our revenues. For example, the FDA may be more cautious in approving our drug candidates
based on safety concerns relating to these or other drugs or drug candidates, or pharmaceutical companies may be
less willing to enter into new collaborations or continue existing collaborations if they are integrating a new
operation as a result of a merger or acquisition or if their therapeutic areas of focus change following a merger.

We and our collaborators may from time to time rely on third parties to conduct clinical trials and
preclinical studies. If those parties do not comply with regulatory and contractual requirements,
successfully carry out their contractual duties or meet expected deadlines, our drug candidates may not
advance in a timely manner or at all.

In the course of our discovery, preclinical testing and clinical trials, we and our collaborators may from time

to time rely on third parties, including laboratories, investigators, clinical research organizations and
manufacturers, to perform critical services. For example, we rely on third parties to conduct our clinical trials and
many of our preclinical studies. Clinical research organizations are responsible for many aspects of the trials,
including finding and enrolling subjects for testing and administering the trials. Although we rely on these third
parties to conduct our clinical trials, we are responsible for ensuring that each of our clinical trials is conducted in
accordance with its investigational plan and protocol. Moreover, the FDA and foreign regulatory authorities
require us to comply with regulations and standards, commonly referred to as Good Clinical Practices, or GCPs,
for conducting, monitoring, recording and reporting the results of clinical trials to ensure that the data and results
are scientifically credible and accurate and that the trial subjects are adequately informed of the potential risks of
participating in clinical trials. Our reliance on third parties does not relieve us of these responsibilities and
requirements. These third parties may not be available when we need them or, if they are available, may not
comply with all regulatory and contractual requirements or may not otherwise perform their services in a timely
or acceptable manner, and we may need to enter into new arrangements with alternative third parties and our
preclinical studies or clinical trials may be extended, delayed or terminated. These independent third parties may
also have relationships with other commercial entities, some of which may compete with us. In addition, if such
third parties fail to perform their obligations in compliance with regulatory requirements and our protocols, our
preclinical studies or clinical trials may not meet regulatory requirements or may need to be repeated. As a result
of our dependence on third parties, we may face delays or failures outside of our direct control. These risks also
apply to the development activities of collaborators, and we do not control their research and development,
clinical trial or regulatory activities.

Our efforts will be seriously jeopardized if we are unable to retain and attract key and other employees.

Our success depends on the continued contributions of our principal management, development and
scientific personnel, and the ability to hire and retain key and other personnel. We face competition for such
personnel, and we believe that risks and uncertainties related to our business, including the timing and risk

49

associated with research, development and commercialization, the regulatory process, our available and
anticipated cash resources, pending and possible future litigation involving us, and the volatility of our stock
price, may impact our ability to hire and retain key and other personnel. The loss of services of any principal
member of our management or scientific staff or other personnel, particularly Jack Lief, our Chairman, President
and Chief Executive Officer, and Dominic P. Behan, Ph.D., D.Sc., our Executive Vice President and Chief
Scientific Officer, or a combination of different key employees, could adversely impact our operations and
ability to generate or raise additional capital. To our knowledge, neither Mr. Lief nor Dr. Behan plans to leave,
retire or otherwise disassociate with us in the near future.

We may incur substantial liabilities for any product liability claims or otherwise as a drug product
manufacturer.

We develop, test, manufacture and expect to commercialize drugs for use by humans. We face an inherent
risk of product liability exposure related to the testing of our drug candidates in clinical trials, and face an even
greater risk with the commercialization of BELVIQ as well as any other drug that may be approved for
marketing. In addition, under the marketing and supply agreement with Eisai, Arena GmbH and Eisai will, in
general, share equally in losses resulting from third-party product liability claims, with certain limited
exceptions.

Whether or not we are ultimately successful in any product liability or related litigation, such litigation
would consume substantial amounts of our financial and managerial resources, and might result in adverse
publicity, all of which would impair our business. In addition, damages awarded in a product liability action
could be substantial and could have a negative impact on our financial condition.

An individual may bring a liability claim against us if one of our drugs or drug candidates causes, or merely

appears to have caused, an injury. Regardless of merit or eventual outcome, liability claims may result in:

•

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•

•

•

•

•

decreased demand for our drug;

injury to our reputation;

increased difficulty to attract, or withdrawal of, clinical trial subjects;

costs of related litigation;

substantial monetary awards to subjects or other claimants;

loss of revenues; and

the inability to commercialize our drug candidates.

We will have limited product liability insurance that covers our clinical trials and products. We may not be
able to maintain or obtain insurance coverage at a reasonable cost, and we may not have insurance coverage that
will be adequate to satisfy any liability that may arise, which could have an adverse effect on our results of
operations and financial condition.

We expect that Arena GmbH will manufacture BELVIQ for commercialization and, from time to time, for

clinical trials or other studies. Arena GmbH also manufactures certain generic drug products for Siegfried. Arena
GmbH is subject to liability for non-performance, product recalls and breaches of the agreements with Siegfried
and our collaborators under the BELVIQ Agreements.

We have significant contractual obligations, which may adversely affect our cash flow, cash position and
stock price.

We have long-term leases on real properties and other contractual obligations. If we are unable to generate
cash from operations sufficient to meet financial obligations, we will need to obtain additional funds from other

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sources, which may include one or more financings. However, we may be unable to obtain sufficient additional
funds when we need them on favorable terms or at all. The sale of equity or convertible debt securities in the
future may be dilutive to our stockholders, and debt-financing arrangements may require us to enter into
covenants that would further restrict certain business activities or our ability to incur additional indebtedness, and
may contain other terms that are not favorable to our stockholders or us.

Also, if we are unable to generate cash from operations or obtain additional funds from other sources
sufficient to meet our contractual obligations, or we need to use existing cash to fund our contractual obligations,
we may have to delay or curtail some or all of our research, development and commercialization programs, or
sell or license some or all of our assets on terms that you or others may view as unfavorable. Our contractual
obligations could have significant additional negative consequences, including, without limitation:

•

•

•

increasing our vulnerability to general adverse economic conditions;

limiting our ability to obtain additional funds; and

placing us at a possible competitive disadvantage to less leveraged competitors and competitors that
have better access to capital resources.

We may be subject, directly or indirectly, to federal and state healthcare laws, including but not limited to
fraud and abuse and false claims laws. If we are unable to comply, or have not fully complied, with such
laws, we could face substantial penalties and prosecution.

In the United States, drug manufacturers and marketers are subject to various state and federal fraud and
abuse laws, including, without limitation, the Federal Anti-Kickback Statute and Federal False Claims Act. There
are similar laws in other countries. These laws may impact, among other things, the research, manufacturing,
sales, marketing and education programs for our drugs.

The Federal Anti-Kickback Statute prohibits persons and entities from knowingly and willingly soliciting,
offering, receiving or providing any remuneration, directly or indirectly, in exchange for or to induce either the
referral of an individual, or the purchase, lease, order or the furnishing or arranging for, a good, item, facility or
service, for which payment may be made, in whole or in part, under a federal healthcare program such as the
Medicare and Medicaid programs. Several courts have interpreted the statute’s intent requirement to mean that if
any one purpose of an arrangement involving remuneration is to induce referrals of federal healthcare covered
business, the statute has been violated. The Anti-Kickback Statute is broad and, despite a series of narrow statutory
exceptions and regulatory safe harbors, prohibits many arrangements and practices that are lawful in businesses
outside of the healthcare industry. Moreover, the PPACA, among other things, amended the intent requirement of
the Federal Anti-Kickback Statute and criminal healthcare fraud statutes. A person or entity no longer needs to have
actual knowledge of these statutes or specific intent to violate them. The PPACA also provides that 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. Many states have also adopted laws
similar to the Federal Anti-Kickback Statute, some of which apply to the referral of patients for healthcare items or
services reimbursed by any source, not only the Medicare and Medicaid programs.

The Federal False Claims Act prohibits, among other things, persons or entities from knowingly presenting,

or causing to be presented, a false claim to, or the knowing use of false statements to obtain payment from the
federal government. Suits filed under the False Claims Act can be brought by any individual on behalf of the
government, known as “qui tam” actions, and such individuals, commonly known as “whistleblowers,” may
share in any amounts paid by the entity to the government in fines or settlement. The filing of qui tam actions has
caused a number of pharmaceutical, medical device and other healthcare companies to have to defend a False
Claims Act action. When an entity is determined to have violated the False Claims Act, it may be required to pay
up to three times the actual damages sustained by the government, plus civil penalties for each separate false
claim, in addition to other penalties that may apply. Various states have also enacted laws modeled after the
Federal False Claims Act, some of which are broader in scope and may apply regardless of payer.

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The Federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, created federal
criminal statutes that prohibit among other actions, knowingly and willfully executing, or attempting to execute,
a scheme to defraud any healthcare benefit program, including private third-party payers, knowingly and
willfully embezzling or stealing from a healthcare benefit program, willfully obstructing a criminal investigation
of a healthcare offense, and knowingly and willfully falsifying, concealing or covering up 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. Additionally, the civil monetary penalties statute imposes penalties against
any person or entity that, among other things, is determined to have presented or caused to be presented a claim
to a federal health program that the person knows or should know is for an item or service that was not provided
as claimed or is false or fraudulent.

The Federal Physician Payment Sunshine Act, created under the PPACA, and its implementing regulations

requires certain manufacturers of drugs, devices, biologicals 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 the United States Department of Health and Human Services, or HHS, information related to
payments or other transfers of value made to physicians (defined to include doctors, dentists, optometrists,
podiatrists and chiropractors) and teaching hospitals, as well as ownership and investment interests held by
physicians and their immediate family members.

We may be subject to data privacy and security regulation by both the federal government and the states in
which we conduct our business. HIPAA, as amended by the Health Information Technology for Economic and
Clinical Health Act, or HITECH, and their respective implementing regulations, impose specified requirements
relating to the privacy, security and transmission of individually identifiable health information. Additionally,
other legislative changes have been proposed and adopted since the PPACA was enacted. For example, the Drug
Supply Chain Security Act imposes new obligations on manufacturers of pharmaceutical products, among others,
related to product tracking and tracing. Among the requirements of this new legislation, manufacturers will be
required to provide certain information regarding the drug product to individuals and entities to which product
ownership is transferred, label drug product with a product identifier, and keep certain records regarding the drug
product. The transfer of information to subsequent product owners by manufacturers will eventually be required
to be done electronically. Manufacturers will also be required to verify that purchasers of the manufacturers’
products are appropriately licensed. Further, under this new legislation, manufacturers will have drug product
investigation, quarantine, disposition, and notification responsibilities related to counterfeit, diverted, stolen, and
intentionally adulterated products, as well as products that are the subject of fraudulent transactions or which are
otherwise unfit for distribution such that they would be reasonably likely to result in serious health consequences
or death.

We are unable to predict whether we could be subject to actions under any of these fraud and abuse or other

laws, or the impact of such actions. If we are found to be in violation of any of the laws described above and
other applicable state and federal fraud and abuse laws, we may be subject to penalties, including civil, criminal
and/or administrative penalties, damages, fines, individual imprisonment, disgorgement, possible exclusion from
government healthcare reimbursement programs and the curtailment or restructuring of our operations, all of
which could have a material adverse effect on our business and results of operations.

We may not be able to effectively integrate or manage our international operations and such difficulty
could adversely affect our stock price, business operations, financial condition and results of operations.

The headquarters of our operations outside of the United States is in Switzerland. Activities conducted at
this location include manufacturing, quality control, quality assurance, development of manufacturing processes,
qualifying suppliers and otherwise managing aspects of the supply chain, regulatory compliance, distribution of
finished products, alliance management, and strategic planning and development. There are significant risks
associated with foreign operations, including, but not limited to, compliance with local laws and regulations, the
protection of our intellectual property, the ability to integrate our corporate culture with local customs and

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cultures, the distraction to our management, foreign currency exchange rates and the impact of shifts in the US
and local economies on those rates, and integration of our policies and procedures, including disclosure controls
and procedures and internal control over financial reporting, with our international operations.

We use biological materials, hazardous materials, chemicals and radioactive compounds.

Our research, development and manufacturing activities involve the use of potentially harmful biological

materials, as well as materials, chemicals and various radioactive compounds that could be hazardous to human
health and safety or the environment. These materials and various wastes resulting from their use are stored at
our facility pending ultimate use and disposal. We cannot completely eliminate the risk of contamination, which
could cause:

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•

•

interruption of our research, development or manufacturing efforts;

injury to our employees and others;

environmental damage resulting in costly clean up; and

liabilities under domestic or foreign laws and regulations governing the use, storage, handling and
disposal of these materials and specified waste products.

In such an event, we may be held liable for any resulting damages, and any such liability could exceed our

resources. Although we carry insurance in amounts and type that we consider commercially reasonable, we
cannot be certain that the coverage or coverage limits of our insurance policies will be adequate and we do not
have insurance coverage for losses relating to an interruption of our research and development efforts caused by
contamination.

Our business and operations might be adversely affected by business disruptions and security breaches,
including any cybersecurity incidents.

Our US operations, including laboratories, offices and a chemical development facility, are located in the

same business park in San Diego. We also have a drug product manufacturing facility in Zofingen, Switzerland,
and we expect that, at least for the near-term, this facility will be the sole location for the manufacturing of
BELVIQ finished drug product. We depend on our facilities and on collaborators, contractors and vendors for the
continued operation of our business, some of whom are located in Europe and Asia. Natural disasters or other
catastrophic events, including interruptions in the supply of natural resources, political and governmental
changes, disruption in transportation networks or delivery services, severe weather conditions, wildfires and
other fires, explosions, actions of animal rights activists, terrorist attacks, earthquakes and wars could disrupt our
operations or those of our collaborators, contractors and vendors.

We depend on the efficient and uninterrupted operation of our computer and communications systems,
which we use for, among other things, sensitive company data, including our intellectual property and proprietary
business information. We maintain our information technology, or IT, infrastructure for our San Diego campus,
and, at least for the near term, we have contracted with Siegfried to use their IT infrastructure for our
manufacturing facility in Switzerland. We are in the process of building our own IT infrastructure for such
manufacturing facility, but the timing and outcome of such process is uncertain.

While certain of our operations have business continuity and disaster recovery plans and other security
measures intended to prevent and minimize the impact of IT-related interruptions, our IT infrastructure and the
IT infrastructure of our current and any future collaborators, contractors and vendors are vulnerable to damage
from cyberattacks, computer viruses, unauthorized access, electrical failures and natural disasters or other
catastrophic events. Siegfried or we could experience failures in our information systems and computer servers,
which could result in an interruption of our normal business operations and require substantial expenditure of
financial and administrative resources to remedy. System failures, accidents or security breaches can cause

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interruptions in our operations and can result in a material disruption of our research and development programs,
manufacturing or commercialization activities and other business operations. The loss of data from completed or
future studies or clinical trials could result in delays in our research, development or regulatory approval efforts
and significantly increase our costs to recover or reproduce the data. Similarly, we rely on third parties to supply
materials for the manufacture of BELVIQ and our drug candidates, conduct studies and clinical trials of our drug
candidates and warehouse, market and distribute BELVIQ, and similar events relating to their computer systems
could also have a material adverse effect on our business. 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 liabilities and the development of any of our other drug candidates and
the commercialization of BELVIQ could be delayed or otherwise adversely affected.

Even though we believe we carry commercially reasonable business interruption and liability insurance, and
our contractors may carry liability insurance that protect us in certain events, we might suffer losses as a result of
business interruptions that exceed the coverage available under our and our contractors’ insurance policies or for
which we or our contractors do not have coverage. For example, we are not insured against a terrorist attack. Any
natural disaster or catastrophic event could have a significant negative impact on our operations and financial
results. Moreover, any such event could delay our research and development programs and adversely affect,
which may include stopping, our commercial production.

Our executive officers and directors may sell shares of their stock, and these sales could adversely affect
our stock price.

Sales of our stock by our executive officers and directors, or the perception that such sales may occur, could

adversely affect the market price of our stock. Our executive officers and directors may sell stock in the future,
either as part, or outside, of trading plans under SEC Rule 10b5-1.

Currency fluctuations may negatively affect our financial condition.

We primarily spend and generate cash in US dollars, and present our consolidated financial statements in

US dollars. However, a portion of our expected and potential payments and receipts under our agreements are in
foreign currencies, including Swiss francs. For example, payments and receipts under our agreements with
Siegfried are required to be paid in Swiss francs. A fluctuation of the exchange rates of foreign currencies versus
the US dollar may, thus, adversely affect our financial results, including cash balances, expenses and revenues.
We may in the future enter into hedging transactions to try to reduce our foreign currency exposure, but there is
no assurance that such transactions will occur or be successful.

Laws, rules and regulations relating to public companies may be costly and impact our ability to attract
and retain directors and executive officers.

Laws and regulations affecting public companies, including rules adopted by the SEC and by NASDAQ, as

well as the laws and regulations of foreign governments, may result in increased costs to us, particularly as we
continue to develop the required capabilities in the United States and abroad to commercialize our products.
These laws, rules and regulations could make it more difficult or costly for us to obtain certain types of
insurance, including directors’ and officers’ liability insurance, and we may be forced to accept reduced policy
limits and coverage or incur substantially higher costs to obtain the same or similar coverage. The impact of
these events could also make it more difficult for us to attract and retain qualified persons to serve on our board
of directors, on our board committees or as executive officers. We cannot estimate accurately the amount or
timing of additional costs we may incur to respond to these laws, rules and regulations.

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Risks Relating to Our Intellectual Property

Our success is dependent on intellectual property rights held by us and third parties and our interest in
these rights is complex and uncertain.

Our success will depend on our own and on current or future collaborators’ abilities to obtain, secure and

defend patents. In particular, the patents directed to BELVIQ and our drug candidates are important to
commercializing drugs. We have numerous US and foreign patent applications pending for our technologies.
There is no assurance that any of our patent applications will issue, or that any of the patents will be enforceable
or will cover a drug or other commercially significant technology or method, or that the patents will be held to be
valid for their expected terms.

The procedures for obtaining a patent in the United States and in most foreign countries are complex. These

procedures require an analysis of the scientific technology related to the invention and many sophisticated legal
issues. Obtaining patent rights outside the United States often requires the translation of highly technical
documents and an improper translation may lead to the loss of, or otherwise jeopardize, the patent protection of
our inventions. Ensuring adequate quality of translators and foreign patent attorneys is often very challenging.
Consequently, the process for having our pending patent applications issue as patents will be difficult, complex
and time consuming. Our patent position is very uncertain and we do not know when, or if, we will obtain
additional patents for our technologies, or if the scope of the patents obtained will be sufficient to protect our
drugs, or be considered sufficient by parties reviewing our patent positions pursuant to a potential marketing,
licensing or financing transaction.

In addition, other entities may challenge the validity or enforceability of our patents and patent applications

in litigation or administrative proceedings. Even the issuance of a patent is not conclusive as to its validity or
enforceability. We cannot make assurances as to how much protection, if any, will be given to our patents if we
attempt to enforce them or they are challenged. It is possible that a competitor or a generic pharmaceutical
provider may successfully challenge our patents and those challenges may result in reduction or elimination of
our patents’ coverage.

We also rely on confidentiality agreements and trade secrets to protect our technologies. However, such
information is difficult to protect. We require our employees to contractually agree not to improperly use our
confidential information or disclose it to others, but we may be unable to determine if our employees have
conformed or will conform to their legal obligations under these agreements. We also enter into confidentiality
agreements with prospective collaborators, collaborators, service providers and consultants, but we may not be
able to adequately protect our trade secrets or other proprietary information in the event of any unauthorized use
or disclosure or the lawful development by others of this information. Many of our employees and consultants
were, and many of them may currently be, parties to confidentiality agreements with other pharmaceutical and
biotechnology companies, and the use of our technologies could violate these agreements. In addition, third
parties may independently discover our trade secrets or proprietary information.

Some of our academic institution licensors, research collaborators and scientific advisors have rights to

publish data and information to which we have rights. We generally seek to prevent our collaborators from
disclosing scientific discoveries before we have the opportunity to file patent applications on such discoveries. In
some of our collaborations, we do not control our collaborators’ ability to disclose their own discoveries under
the collaboration and in some of our academic collaborations we are limited to relatively short periods to review
a proposed publication and file a patent application. If we cannot maintain the confidentiality of our technologies
and other confidential information in connection with our collaborations, our ability to receive patent protection
or protect our proprietary information will be impaired.

We believe that the United States is by far the largest single market for pharmaceuticals in the world.
Because of the critical nature of patent rights to our industry, changes in US patent laws could have a profound
effect on our future profits, if any. It is unknown which, if any, patent laws will change, how changes to the
patent laws will ultimately be enforced by the courts and the impact on our business. For example, in September

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2011 the America Invents Act was signed into US law, which changes include, among others, the awarding of a
patent to the first inventor to file a patent as opposed to the first inventor to make an invention and the creation of
new administrative procedures for challenging US patents. It may be several years before the impact of the
America Invents Act on patent law is understood, and we cannot predict with certainty whether or to what extent
the changes may impair our business.

A dispute regarding the infringement or misappropriation of our proprietary rights or the proprietary
rights of others could be costly and result in delays or termination of our future research, development,
manufacturing and sales activities.

Our commercial success depends upon our ability to develop and manufacture our drugs and drug
candidates, market and sell drugs, and conduct our research and development activities without infringing or
misappropriating the proprietary rights of others. There are many patents and patent applications filed, and that
may be filed, by others relating to drug discovery and development programs that could be determined to be
similar, identical or superior to ours or our licensors or collaborators. We may be exposed to future litigation by
others based on claims that our drugs, drug candidates, technologies or activities infringe the intellectual property
rights of others. Numerous US and foreign issued patents and pending patent applications owned by others exist
in the area of G protein-coupled receptors, or GPCRs, including some which purport to allow the patent holder to
control the use of all drugs that modulate a particular drug target or GPCR, regardless of whether the infringing
drug bears any structural resemblance to a chemical compound known to the patent holder at the time of patent
filing. Numerous US and foreign issued patents and pending patent applications owned by others also exist in the
therapeutic areas in, and for the therapeutic targets for, which we are developing drugs. There are also numerous
issued patents and patent applications to chemical compounds or synthetic processes that may be necessary or
useful to use in our research, development, manufacturing or commercialization activities. These could
materially affect our ability to develop our drug candidates or manufacture, import or sell drugs, and our
activities, or those of our licensors or collaborators, could be determined to infringe these patents. Because patent
applications can take many years to issue, there may be currently pending applications, unknown to us, which
may later result in issued patents that our drugs, drug candidates or technologies may infringe. There also may be
existing patents, of which we are not aware, that our drug candidates or technologies may infringe. Further, there
may be issued patents or pending patent applications in fields relevant to our business, of which we are or may
become aware, that we believe (i) are invalid or we do not infringe; (ii) relate to immaterial portions of our
overall drug discovery, development, manufacturing and commercialization efforts; or (iii) in the case of pending
patent applications, the resulting patent would not be granted or, if granted, would not likely be enforced in a
manner that would materially impact such efforts. We cannot assure you that others holding any of these patents
or patent applications will not assert infringement claims against us for damages or seek to enjoin our activities.
We also cannot assure you that, in the event of litigation, we will be able to successfully assert any belief we may
have as to non-infringement, invalidity or immateriality, or that any infringement claims will be resolved in our
favor.

In addition, others may infringe or misappropriate our proprietary rights, and we may have to institute costly

legal action to protect our intellectual property rights. We may not be able to afford the costs of enforcing or
defending our intellectual property rights against others.

There could be significant litigation and other administrative proceedings in our industry that affect us
regarding patent and other intellectual property rights. Any legal action or administrative action against us, or our
collaborators, claiming damages or seeking to enjoin commercial activities relating to our drug discovery,
development, manufacturing and commercialization activities could:

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•

require us, or our collaborators, to obtain a license to continue to use, manufacture or market the
affected drugs, methods or processes, which may not be available on commercially reasonable terms, if
at all;

prevent us from importing, making, using, selling or offering to sell the subject matter claimed in
patents held by others and subject us to potential liability for damages;

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•

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consume a substantial portion of our managerial, scientific and financial resources; or

be costly, regardless of the outcome.

Furthermore, because of the substantial amount of pre-trial document and witness discovery required in
connection with intellectual property litigation, there is a risk that some of our confidential information could be
compromised by disclosure during this type of litigation. In addition, during the course of this kind of litigation,
there could be public announcements of the results of hearings, motions or other interim proceedings or
developments. If securities analysts or investors perceive these results to be negative, it could have a substantial
adverse effect on the trading price of our common stock.

We have been contacted from time to time by third parties regarding their intellectual property rights, sometimes

asserting that we may need a license to use their technologies. For example, a third party has communicated that it
believes its issued US patents includes patent claims that cover BELVIQ or its use. We do not believe such patent
claims are valid or, even if they were held valid, that they cover BELVIQ or its use. If we fail to obtain any required
licenses or make any necessary changes to our technologies, we may become involved in expensive and time-
consuming litigation or we may be unable to develop or commercialize some or all of our drugs or drug candidates.

We cannot protect our intellectual property rights throughout the world.

Filing, prosecuting, defending and enforcing patents on all of our drug discovery technologies and all of our

potential drug candidates throughout the world would be prohibitively expensive. Competitors may use our
technologies to develop their own drugs in jurisdictions where we have not obtained patent protection. These
drugs may compete with our drugs, if any, and may not be covered by any of our patent claims or other
intellectual property rights. The laws of some foreign countries do not protect intellectual property rights to the
same extent as the laws of the United States, and many companies have encountered significant problems in
protecting and defending such rights in foreign jurisdictions. Many countries, including certain countries in
Europe, have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third
parties (for example, the patent owner has failed to “work” the invention in that country or the third party has
patented improvements). In addition, many countries limit the enforceability of patents against government
agencies or government contractors. In these countries, the patent owner may have limited remedies, which could
materially diminish the value of the patent. Compulsory licensing of life-saving drugs is also becoming
increasingly popular in developing countries either through direct legislation or international initiatives. Such
compulsory licenses could be extended to include some of our drug candidates, which could limit our potential
revenue opportunities. Moreover, the legal systems of certain countries, particularly certain developing countries,
do not favor the aggressive enforcement of patents and other intellectual property protection, particularly those
relating to biotechnology and/or pharmaceuticals, which makes it difficult for us to stop the infringement of our
patents. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial cost and divert
our efforts and attention from other aspects of our business.

Risks Relating to Our Securities

Our stock price will likely be volatile, and your investment in our stock could decline in value.

Our stock price has fluctuated historically. From January 1, 2012, to February 24, 2014, the market price of

our stock was as low as $1.51 per share and as high as $13.50 per share.

Very few drug candidates being tested will ultimately receive regulatory approval, and companies in our

industry sometimes experience significant volatility in their stock price. Our stock price may fluctuate
significantly depending on a variety of factors, including:

•

•

regulatory actions or decisions or legislation affecting BELVIQ, including decisions of regulatory
authorities relating to BELVIQ, or other drugs or drug candidates, including those of our competitors;

the commercial availability and success or failure of BELVIQ (including perceptions of prescription
trends or other information) or any of our drug candidates;

57

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

the entrance into, or failure to enter into, a new collaboration or the modification or termination of an
existing collaboration or other material transaction;

the timing and receipt by us of milestone and other payments or failing to achieve and receive the
same;

fluctuation in prescriptions, sales or financial results (including with respect to revenue recognition) or
inaccurate sales or cash forecasting;

accounting restatements and changes;

supply chain or manufacturing issues;

discussions or recommendations affecting our drugs or drug candidates by FDA advisory committees
or other reviewers of preclinical or clinical data or other information related to BELVIQ, drug
candidates or other drugs;

results or decisions affecting the development or commercialization of BELVIQ or any of our drug
candidates, including the results of studies, trials and other analyses;

the development and implementation of our continuing development and research plans, including
outcome studies and other research and development for BELVIQ (including related development
programs);

the timing of the discovery of drug leads and the development of our drug candidates;

changes in our research and development budget or the research and development budgets of our
existing or potential collaborators;

the introduction, development or withdrawal of drug candidates or drugs by others that target the same
diseases and conditions that we or our collaborators target or the introduction of new drug discovery
techniques;

the success, failure or setbacks of our or a perceived competitor’s drugs or drug candidates;

expenses related to, and the results of, litigation, other disputes and other proceedings;

financing strategy or decisions;

developments in intellectual property rights or related announcements; and

capital market conditions.

We are not able to control many of these factors. If our financial or scientific results in a particular period do

not meet stockholders’ or analysts’ expectations, our stock price may decline and such decline could be
significant.

There are a substantial number of shares of our common stock that may become eligible for future sale in
the public market, and the sale of our common stock could cause the market price of our common stock to
fall.

As of February 24, 2014, we had outstanding a seven-year warrant issued in August 2008 to purchase
1,965,418 shares of our common stock at an exercise price of $4.34 per share. Such warrant was adjusted as a
result of certain equity sales following its issuance to decrease the exercise price and increase the number of
shares issuable upon exercise of the warrant. Certain future equity issuances below the pre-defined warrant
adjustment price may result in additional adjustments to such warrant to the extent then outstanding.

Along with our outstanding warrant, as of February 24, 2014, there were (i) options to purchase 14,305,116 shares

of our common stock outstanding under our equity incentive plans at a weighted-average exercise price of $4.99 per
share, (ii) 434,846 restricted stock unit awards outstanding under our equity incentive plans, (iii) performance restricted

58

stock unit awards outstanding under our 2012 Long-Term Incentive Plan, targeted at 780,000 shares (however, the
actual number of shares that may be awarded ranges from 0% to 200% of such amount), (iv) 25,770,147 additional
shares of common stock remaining issuable under our 2013 Long-Term Incentive Plan, (v) 900,659 shares of common
stock remaining issuable under our 2009 Employee Stock Purchase Plan, as amended, and (vi) 79,169 shares of
common stock remaining issuable under our Deferred Compensation Plan.

Once issued, the shares described above will be available for immediate resale in the public market. The
market price of our common stock could decline as a result of such resales due to the increased number of shares
available for sale in the market. As of February 24, 2014, there were 219,259,995 shares of our common stock
outstanding.

Any future equity or debt issuances by us may have dilutive or adverse effects on our existing
stockholders.

We have been opportunistic in our efforts to obtain cash, and we expect to continue to evaluate various
funding alternatives from time to time. We have primarily financed our operations, and we may continue to
finance our operations, by issuing and selling our common stock or securities convertible into or exercisable for
shares of our common stock. We may issue additional shares of common stock or convertible securities that
could dilute your ownership in our company and may include terms that give new investors rights that are
superior to yours. Moreover, any issuances by us of equity securities may be at or below the prevailing market
price of our common stock and in any event may have a dilutive impact on your ownership interest, which could
cause the market price of our common stock to decline. In addition, we may also raise additional funds through
the incurrence of debt, and the holders of any debt we may issue would have rights superior to your rights in the
event we are not successful and are forced to seek the protection of bankruptcy laws.

The holders of our common stock and other securities may take actions that are contrary to your interests,
including selling their stock.

A small number of stockholders may hold or acquire a significant amount of our outstanding stock. From
time to time, there is a large short interest in our stock. These holders of such stock or positions may seek control
of us, support transactions that we or you do not believe are favorable, and have interests that are different from
yours. In addition, sales of a large number of shares of our stock by these large stockholders or other
stockholders within a short period of time could adversely affect our stock price.

We may also be involved in disagreements with the holders of our stock, warrants or other securities in the

future. Such disagreements may lead to proxy contests or litigation, which may be expensive and consume
management’s time, involve settlements, the terms of which may not be favorable to us, or result in other
negative consequences to our business.

Certain of our agreements, provisions in our charter documents, possible future agreements and Delaware
law could delay or prevent a change in management or a takeover attempt that you may consider to be in
your best interests.

There is a standstill provision in our marketing and supply agreement with Eisai, and we may enter into
agreements with similar provisions. In addition, we may in the future adopt a stockholders’ rights agreement,
which would cause substantial dilution to any person who attempts to acquire us in a manner or on terms not
approved by our board of directors. These provisions or agreements, as well as other provisions in our certificate
of incorporation and bylaws and under Delaware law, could delay or prevent the removal of directors and other
management and could make more difficult a merger, tender offer or proxy contest involving us that you may
consider to be in your best interests. For example, our charter provisions:

•

•

allow our board of directors to issue preferred stock without stockholder approval;

limit who can call a special meeting of stockholders;

59

•

•

eliminate stockholder action by written consent; and

establish advance notice requirements for nomination for election to the board of directors or for
proposing matters to be acted upon at stockholders’ meetings.

Item 1B. Unresolved Staff Comments.

None.

Item 2.

Properties.

As set forth in the table below, we own or lease approximately 356,000 square feet of research,

development, warehouse and office space located at various addresses in the same business park in San Diego,
California and approximately 85,000 square feet of laboratory, manufacturing, warehouse and office space
located in the same business park in Zofingen, Switzerland.

Location

Own/ Lease

Description

6114 Nancy Ridge Drive

Lease with option
to purchase

This chemical development facility consists of approximately
40,000 square feet (which includes approximately 18,000 of
internal square feet and approximately 22,000 square feet of
integrated external space), of which approximately 5,000 square
feet is office space. The remaining approximately 35,000 square
feet of space is dedicated to process research and scale-up
chemistry, the production of intermediates and other compounds
for research and development purposes, and the production of
active pharmaceutical ingredients to support our clinical trials.
We commenced cGMP operations in this facility in 2004.

6118 Nancy Ridge Drive

Lease with option
to purchase

This facility of approximately 30,000 square feet consists of
approximately 50% laboratory space and 50% office space.

6122-6124-6126 Nancy
Ridge Drive

Lease with option
to purchase

6138-6150 Nancy Ridge
Drive

Lease with option
to purchase

This facility of approximately 68,000 square feet consists of
approximately 28,500 square feet of laboratory space,
28,500 square feet of office space, 9,000 square feet of
unoccupied space and 2,000 square feet of warehouse space.

This facility of approximately 55,000 square feet consists of
approximately 33,000 square feet of laboratory space and
22,000 square feet of office space.

6154 Nancy Ridge Drive

Lease with option
to purchase

This facility of approximately 143,000 square feet consists of
approximately 131,000 square feet of office space and
12,000 square feet of warehouse space.

6162 Nancy Ridge Drive

Own

Zofingen, Switzerland

Own

Zofingen, Switzerland

Lease

This facility includes approximately 20,000 square feet of
warehouse and office space, all of which is presently
unoccupied.

The portion of this facility we own consists of approximately
67,000 square feet, including approximately 39,000 square feet
of manufacturing space, 21,000 square feet of warehouse space
and 7,000 square feet of office space.

We lease from Siegfried a total of approximately 18,000 square
feet, consisting of approximately 7,000 square feet of
warehouse space, 8,000 square feet of office space and
3,000 square feet of laboratory space, in various facilities.

60

We expect these facilities to be sufficient for our needs for at least the near term. We have significantly
more space in San Diego than we expect to need for the foreseeable future, and are exploring subleasing some of
our space and other options to reduce our expenses.

Item 3.

Legal Proceedings.

Beginning on September 20, 2010, a number of complaints were filed in the US District Court for the
Southern District of California against us and certain of our current and former employees and directors on
behalf of certain purchasers of our common stock. The complaints have been brought as purported stockholder
class actions, and, in general, include allegations that we and certain of our current and former employees and
directors violated federal securities laws by making materially false and misleading statements regarding our
BELVIQ program, thereby artificially inflating the price of our common stock. The plaintiffs are seeking
unspecified monetary damages and other relief. On November 19, 2010, eight prospective lead plaintiffs filed
motions to consolidate, appoint a lead plaintiff, and appoint lead counsel. The Court took the motions to
consolidate under submission on January 14, 2011. On August 8, 2011, the Court consolidated the actions and
appointed a lead plaintiff and lead counsel. On November 1, 2011, the lead plaintiff filed a consolidated amended
complaint. On December 30, 2011, we filed a motion to dismiss the consolidated amended complaint. On
March 28, 2013, the Court granted our motion to dismiss the consolidated amended complaint without prejudice.
On May 13, 2013, the lead plaintiff filed a new consolidated amended complaint. On June 14, 2013, we filed a
motion to dismiss the new consolidated amended complaint. On July 15, 2013, the lead plaintiff filed an
opposition to our motion to dismiss. On July 29, 2013, we filed our reply. On October 25, 2013, the Court heard
oral argument on the motion to dismiss. On November 5, 2013, the Court granted our motion to dismiss the new
consolidated amended complaint without prejudice as to all parties except for Robert E. Hoffman, who was
dismissed from the action with prejudice. On November 27, 2013, the lead plaintiff filed a motion for leave to
amend the now-dismissed new consolidated amended complaint. On December 20, 2013, we filed an opposition
to the motion for leave to amend. On December 27, 2013, the lead plaintiff filed his reply. On December 30,
2013, the Court took the motion under submission without a hearing.

In addition to the class actions, a complaint involving similar legal and factual issues has been brought by at

least one individual stockholder and is pending in federal court. On December 30, 2011, we filed a motion to
dismiss the individual stockholder’s complaint. On March 29, 2013, the Court granted our motion to dismiss, in
part without prejudice. On May 13, 2013, the individual stockholder filed a new amended complaint. On June 14,
2013, we filed a motion to dismiss the new amended complaint. On July 10, 2013, the individual stockholder
filed an opposition to our motion to dismiss. On July 29, 2013, we filed our reply. On October 22, 2013, the
Court took the motion under submission without a hearing.

Due to the stage of these proceedings, we are not able to predict or reasonably estimate the ultimate

outcome or possible losses relating to these claims.

Item 4. Mine Safety Disclosures.

Not applicable.

61

PART II

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

Equity Securities.

Market information

Our common stock is listed on the NASDAQ Global Select Market under the symbol “ARNA.” The
following table sets forth, for the periods indicated, the high and low sale prices for our common stock as
reported by the NASDAQ Global Select Market.

Year ended December 31, 2012

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First Quarter
Second Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fourth Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 3.47
$13.50
$12.07
$10.05

$1.51
$2.00
$6.95
$7.09

High

Low

Year ended December 31, 2013

First Quarter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Second Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fourth Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$11.00
$ 9.25
$ 7.87
$ 6.71

$7.39
$7.35
$5.06
$4.05

High

Low

Holders

As of February 24, 2014, there were approximately 110 stockholders of record of our common stock, one of

which is Cede & Co., a nominee for Depository Trust Company, or DTC. Shares of common stock that are held
by financial institutions as nominees for beneficial owners are deposited into participant accounts at DTC, and
are considered to be held of record by Cede & Co. as one stockholder.

Dividends

We have never paid cash dividends on our capital stock. We anticipate that we will retain earnings, if any, to

support operations and finance the growth and development of our business and, therefore, do not expect to pay
cash dividends in the foreseeable future.

Securities authorized for issuance under equity compensation plans

Information on securities authorized for issuance under our equity compensation plans is set forth in Item 12

of Part III of this Annual Report on Form 10-K.

62

Performance graph

The graph below compares the cumulative five-year total return on our common stock from December 31,

2008, through December 31, 2013, to the cumulative total return over such period for (i) the NASDAQ
Composite Index and (ii) the NASDAQ Biotechnology Index. The graph assumes the investment of $100 on
December 31, 2008, with the reinvestment of dividends, although dividends have not been declared on our
common stock, and is calculated according to the Securities and Exchange Commission’s methodology. We
caution that the stock price performance shown in the graph may not be indicative of future stock price
performance. The graph, including each of the graph lines, was provided by Research Data Group, Inc.

This information, including the graph below, is not deemed to be “soliciting material” or to be “filed” with

the Securities and Exchange Commission, or subject to the Securities and Exchange Commission’s proxy rules,
other than as provided in such rules, or to the liabilities of Section 18 of the Securities Exchange Act of 1934,
and shall not be deemed incorporated by reference into any prior or subsequent filing by us under the Securities
Act of 1933 or the Securities Exchange Act of 1934, except to the extent that we specifically incorporate it by
reference into any such filing.

COMPARISON OF FIVE-YEAR CUMULATIVE TOTAL RETURN

Among Arena Pharmaceuticals, Inc., the NASDAQ Composite Index and the NASDAQ Biotechnology Index

$350

$300

$250

$200

$150

$100

$50

$0

12/08

6/09

12/09

6/10

12/10

6/11

12/11

6/12

12/12

6/13

12/13

Arena Pharmaceuticals, Inc.

NASDAQ Composite

NASDAQ Biotechnology

63

Item 6.

Selected Financial Data.

The following Selected Financial Data should be read in conjunction with “Item 7. Management’s
Discussion and Analysis of Financial Condition and Results of Operations” and “Item 8. Financial Statements
and Supplementary Data” included below in this Annual Report on Form 10-K.

Years ended December 31,

2013

2012

2011

2010

2009

(In thousands, except share and per share data)

Revenues
Net product sales . . . . . . . . . . . . . . . . . . $
Eisai collaborative revenue . . . . . . . . . .
Manufacturing services . . . . . . . . . . . . .
Other collaborative revenue . . . . . . . . .

Total revenues . . . . . . . . . . . . . . . .

Operating Costs and Expenses
Cost of product sales . . . . . . . . . . . . . . .
Cost of manufacturing services . . . . . . .
Research and development
. . . . . . . . . .
General and administrative . . . . . . . . . .
Restructuring charges . . . . . . . . . . . . . .
Amortization of intangibles . . . . . . . . . .

Total operating costs and

5,702 $
72,416
2,690
586

81,394

1,803
4,377
66,468
31,681
0
0

0 $

0 $

0 $

23,617
3,817
153

27,587

0
3,671
54,112
26,226
0
691

6,770
5,338
611

12,719

0
8,100
58,706
24,248
3,467
997

1,923
7,057
7,633

0
0
6,579
3,808

16,613

10,387

0
7,414
75,459
27,936
0
2,159

0
6,536
110,159
25,247
3,324
3,508

expenses . . . . . . . . . . . . . . . . . .

104,329

84,700

95,518

112,968

148,774

Interest and other income (expense),

net

. . . . . . . . . . . . . . . . . . . . . . . . . . .

Net loss . . . . . . . . . . . . . . . . . . . . . . . . .
Deemed dividends related to beneficial
conversion feature of convertible
preferred stock . . . . . . . . . . . . . . . . . .

Net loss allocable to common

3,500

(19,435)

(28,364)

(85,477)

(26,425)

(28,179)

(14,817)

(109,224)

(124,534)

(153,204)

0

(2,824)

(2,260)

0

0

stockholders . . . . . . . . . . . . . . . . . . . . $

(19,435) $

(88,301) $

(111,484) $

(124,534) $ (153,204)

Net loss per share allocable to common

stockholders, basic and diluted . . . . . $

(0.09) $

(0.45) $

(0.80) $

(1.14) $

(1.82)

Shares used in calculating net loss per

share allocable to common
stockholders, basic and diluted . . . . .

218,104,323

196,523,708

139,170,725

109,573,177

84,341,362

Balance Sheet Data:
Cash and cash equivalents . . . . . . . . . . . $
Short-term investments, available-for-

2013

2012

2011

2010

2009

As of December 31,

(In thousands)

221,878

$

156,091

$

57,632

$ 150,669

$ 94,733

sale . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total assets . . . . . . . . . . . . . . . . . . . . . .
Total deferred revenues . . . . . . . . . . . . .
Total lease financing obligations . . . . .
Total derivative liabilities . . . . . . . . . . .
Total notes payable . . . . . . . . . . . . . . . .
Accumulated deficit
. . . . . . . . . . . . . . .
Total stockholders’ equity . . . . . . . . . . .

0
339,807
139,190
72,794
4,892
0
(1,207,733)
91,857

0
261,206
62,735
74,458
15,042
0
(1,188,298)
98,639

0
157,129
44,682
75,771
1,617
14,698
(1,079,751)
10,562

0
266,362
48,077
76,769
2,271
48,138
(970,527)
80,015

20,716
236,278
4,086
77,486
6,642
57,049
(845,993)
74,567

64

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

You should read the following discussion and analysis in conjunction with “Item 8. Financial Statements
and Supplementary Data” included below in this Annual Report on Form 10-K, or Annual Report. Operating
results are not necessarily indicative of results that may occur in future periods.

This discussion and analysis contains forward-looking statements that involve a number of risks,

uncertainties and assumptions. Actual events or results may differ materially from our expectations. Important
factors that could cause actual results to differ materially from those stated or implied by our forward-looking
statements include, but are not limited to, those set forth in “Item 1A. Risk Factors” in this Annual Report. All
forward-looking statements included in this Annual Report are based on information available to us as of the
time we file this Annual Report and, except as required by law, we undertake no obligation to update publicly or
revise any forward-looking statements.

BELVIQ® (pronounced “BEL-VEEK”) is the trade name for the finished drug product containing the active

pharmaceutical ingredient lorcaserin hydrochloride, or lorcaserin, that is marketed for chronic weight
management in the United States. Lorcaserin may in the future be marketed in the United States or in other
countries under a different trade name for chronic weight management. Lorcaserin may also be marketed under a
different trade name for a different indication, in a different formulation or in combination with another drug. In
this report, we use BELVIQ to refer to the finished drug product containing lorcaserin and/or, depending on the
context, the active pharmaceutical ingredient lorcaserin, and without regard to the current or potential indication,
formulation or combination.

OVERVIEW AND RECENT DEVELOPMENTS

We have incurred net losses of $1.2 billion from our inception in April 1997 through December 31, 2013,
and may incur substantial net losses in the future as we manufacture BELVIQ for commercial sale and studies,
advance our research and development programs and continue our efforts to discover additional drug candidates.

BELVIQ, our internally discovered drug for chronic weight management, is approved for marketing in the

United States and was made available by prescription in June 2013 to adults who are overweight with a
comorbidity or obese. Eisai is responsible for marketing and distributing BELVIQ in the United States under the
Second Amended and Restated Marketing and Supply Agreement, or Eisai Agreement, which is among our
wholly owned subsidiary, Arena Pharmaceuticals GmbH, or Arena GmbH, Eisai Inc., and Eisai Inc.’s parent
company, Eisai Co., Ltd., which we refer to collectively with Eisai Inc. as Eisai. Eisai recently doubled its
BELVIQ sales force to approximately 400 representatives, which will enable Eisai to reach approximately
65,000 physicians in the United States, while reimbursement coverage for BELVIQ has also increased since
BELVIQ’s launch.

Under the Eisai Agreement, Arena GmbH also granted Eisai exclusive commercialization rights for
BELVIQ in all of the other countries in the world, except for South Korea, Taiwan, Australia, New Zealand and
Israel. Arena GmbH also has marketing and supply agreements with Ildong Pharmaceutical Co., Ltd., or Ildong,
for BELVIQ in South Korea, which we refer to as the Ildong BELVIQ Agreement, and with CY Biotech
Company Limited, or CYB, in Taiwan, which we refer to as the CYB Agreement. We intend to enter into
additional collaborative agreements for the potential regulatory approval and commercialization of BELVIQ in
Australia, New Zealand and Israel.

The marketing of BELVIQ is subject to applicable regulatory approval. BELVIQ has been approved for

marketing in the United States, but currently not in any other country.

Our collaborators are responsible for regulatory activities related to obtaining marketing approval of
BELVIQ in the territories covered under the respective agreement. Eisai filed applications for regulatory
approval of BELVIQ in Mexico and Canada in March and June of 2013, respectively, and in Brazil in February
2014. In addition, Ildong submitted an application for regulatory approval of BELVIQ in South Korea in

65

November 2013. We previously filed applications for marketing approval of BELVIQ with the regulatory
authorities for the European Union and Switzerland, and these regulatory authorities notified us that we had not
yet satisfactorily addressed their concerns and that our applications would not be approved. We expect to
continue to work with Eisai in pursuing regulatory approvals for BELVIQ in Europe and other territories outside
the United States. In addition, CYB intends to file an application for regulatory approval of BELVIQ in Taiwan.

In November 2013, we received from Eisai an upfront payment of $60.0 million in connection with

expanding the territories under the Eisai Agreement. This upfront payment is in addition to the $50.0 million and
$5.0 million we received in connection with entering into the original marketing and supply agreement and the
first amended agreement, respectively. In addition to the upfront payments, through December 31, 2013, we have
received from Eisai a total of $66.0 million in milestones payments, and have recognized $5.7 million in net
product sales of BELVIQ. In 2014, we also expect to receive from Eisai additional payments for purchases of
BELVIQ product supply and a milestone payment of $0.5 million in connection with the recent filing of an
application for regulatory approval of BELVIQ in Brazil.

In addition to commercializing BELVIQ as a monotherapy for chronic weight management, we intend to

explore, with our collaborators or independently, BELVIQ’s therapeutic potential in combination with other
drugs, for other indications, and using different formulations. Under the Eisai Agreement, we and Eisai have
initially prioritized the development areas of smoking cessation, a once-daily formulation, and co-administration
with phentermine, as well as exploring BELVIQ’s effect on conversion to type 2 diabetes and improvements in
cardiovascular outcomes. We plan to initiate a Phase 2 clinical trial in the first half of 2014 to evaluate the
potential of lorcaserin as a drug candidate for smoking cessation, for which we and Eisai will share equally the
expenses. We have completed an initial study to evaluate the safety, tolerability and pharmacokinetic properties
of different formulations of lorcaserin 20 mg extended release tablets, and selected a once-daily formulation for
further development. We and Eisai will share equally the expenses related to the once-daily formulation. In
November 2013, Eisai initiated dosing in a pilot study of 12-week duration to preliminarily assess as the primary
outcome the short-term safety and tolerability of lorcaserin and phentermine when co-administered, for which
Eisai is responsible for 100% of the expenses.

In January 2014, Eisai initiated enrollment in the cardiovascular outcomes trial, or CVOT, required by the
US Food and Drug Administration, or FDA, as a postmarketing commitment. The CVOT is also referred to as
CAMELLIA (Cardiovascular And Metabolic Effects of Lorcaserin In Overweight And Obese Patients). We and
Eisai will be responsible for 10% and 90%, respectively, of the expenses for the FDA-required portion of such
trial. In addition, CAMELLIA will also evaluate whether lorcaserin reduces the incidence of conversion to type 2
diabetes in patients without type 2 diabetes at baseline and the incidence of MACE+ (MACE or hospitalization
for unstable angina or heart failure, or any coronary revascularization), both as compared to placebo. We and
Eisai will share equally the expenses for this non-FDA required portion of the trial up to $40.0 million each, and
Eisai will be responsible for 100% of such expenses thereafter. CAMELLIA is expected to run approximately
five years.

We also intend to utilize our discovery and development approach focused on G protein-coupled receptors,

or GPCRs, to advance other of our internally discovered drug candidates, which include the following clinical-
stage, orally available candidates:

• APD811, an agonist of the prostacyclin receptor intended for the treatment of pulmonary arterial
hypertension, has completed single- and multiple-ascending dose Phase 1 trials and is expected to
begin a Phase 2 trial in the first half of 2014.

• Temanogrel, an inverse agonist of the serotonin 2A receptor intended for the treatment of thrombotic

diseases, has completed single- and multiple-ascending dose Phase 1 trials. Under our Co-Development
and License Agreement with Ildong, which we refer to as the Ildong Temanogrel Agreement, we
expect Ildong to fund and complete an additional Phase 1 trial in healthy volunteers and potentially a
Phase 2a proof-of-concept trial in patients. We expect Ildong to initiate the Phase 1 trial in the first
quarter of 2014 to evaluate the safety of co-administration of temanogrel with aspirin and clopidogrel.

66

• APD334, an agonist of the sphingosine 1-phosphate subtype 1, or S1P1, receptor intended for the

treatment of a number of conditions related to autoimmune diseases, which has completed a Phase 1
single-ascending dose trial. We plan to initiate a Phase 1 multiple-ascending dose trial in 2014.

• APD371, an agonist of the cannabinoid-2 receptor intended for the treatment of pain, for which we

have initiated a Phase 1 single-ascending dose trial.

Developing marketed drugs is a long, uncertain and expensive process, and our ability to achieve our goals,
including furthering our collaborators’ commercialization of BELVIQ, and obtaining regulatory approval of, and
commercializing, BELVIQ in additional territories, conducting required postmarketing and other studies of
BELVIQ, and advancing our drug candidates, depends on numerous factors, many of which we do not control.
We will continue to seek to balance the high costs of research, development and manufacturing against the need
to maintain our operations long enough to achieve sustained profitability.

We will require substantial cash to achieve our goals. To date, we have generated limited revenues from
sales of BELVIQ, which is our first and only drug approved by any regulatory authority. We may continue to
incur substantial losses, and do not expect to generate consistent positive operating cash flows for at least the
short term. Accordingly, we will need to receive additional funds under our existing collaborative agreements,
under future collaborative agreements for BELVIQ or one or more of our drug candidates or programs, or by
raising additional funds through equity, debt or other financing transactions.

We have obtained cash and funded our operations to date primarily through the sale of common and
preferred stock, the issuance of debt and related financial instruments, payments from collaborators and sale
leaseback transactions. From our inception through December 31, 2013, we have generated $1.8 billion in cash
from these sources, of which $1.2 billion was through sales of equity, $425.0 million was through payments from
collaborators, $96.9 million was through the issuance of debt and related financial instruments to certain
Deerfield entities and $77.1 million was from sale and leaseback transactions. At December 31, 2013, we had
$221.9 million in cash and cash equivalents.

See the above “Business” section for a more complete discussion of our business.

RESULTS OF OPERATIONS

We are providing the following summary of our revenues, research and development expenses and general

and administrative expenses to supplement the more detailed discussion below. The dollar values in the
following tables are in millions.

Revenues

Source of revenue

Milestone payments from Eisai . . . . . . . . . . . . . . . . . . .
Net product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . .
Amortization of upfront payments from Eisai
Manufacturing services agreement with Siegfried . . . .
Reimbursements of development and patent expenses

from Eisai

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other collaborative agreements . . . . . . . . . . . . . . . . . . .

Years ended December 31,

2013

2012

2011

$66.0
5.7
4.0
2.7

$20.0
0.0
3.5
3.8

$ 0.0
0.0
3.4
5.3

2.4
0.6

0.1
0.2

3.3
0.7

Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$81.4

$27.6

$12.7

% change from
2012 to 2013

% change from
2011 to 2012

230.0%
—
15.2%
(29.5)%

1998.0%
281.6%

195.0%

100.0%
—
2.0%
(28.5)%

(96.6)%
(74.9)%

116.9%

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Research and development expenses

Type of expense

Salary and other personnel costs (excluding non-cash

share-based compensation) . . . . . . . . . . . . . . . . . . . . .
Facility and equipment costs . . . . . . . . . . . . . . . . . . . . . .
External clinical and preclinical study fees and internal

non-commercial manufacturing costs . . . . . . . . . . . . .
Research supply costs . . . . . . . . . . . . . . . . . . . . . . . . . . .
Non-cash share-based compensation . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Years ended December 31,

2013

2012

2011

% change from
2012 to 2013

% change from
2011 to 2012

$27.7
10.0

$23.7
11.0

$24.9
12.0

17.1%
(8.4)%

16.4
5.6
4.3
2.5

12.1
3.3
1.8
2.2

13.8
3.5
1.9
2.6

35.5%
68.5%
135.8%
9.6%

22.8%

(4.7)%
(9.0)%

(12.1)%
(5.0)%
(7.4)%
(13.6)%

(7.8)%

Total research and development expenses . . . . . . .

$66.5

$54.1

$58.7

General and administrative expenses

Type of expense

Years ended December 31, % change from
2011
2013
2012 to 2013

2012

% change from
2011 to 2012

Salary and other personnel costs (excluding non-cash

share-based compensation) . . . . . . . . . . . . . . . . . . . . .
Legal, accounting and other professional fees . . . . . . . . .
Facility and equipment costs . . . . . . . . . . . . . . . . . . . . . .
Non-cash share-based compensation . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other

$11.4
7.3
5.1
4.7
3.2

$ 9.8
6.7
4.4
3.2
2.1

$ 9.1
7.6
4.2
1.7
1.6

Total general and administrative expenses . . . . . . .

$31.7

$26.2

$24.2

16.8%
9.1%
13.9%
44.1%
55.8%

20.8%

8.1%
(12.3)%
4.2%
91.7%
27.2%

8.2%

YEAR ENDED DECEMBER 31, 2013, COMPARED TO YEAR ENDED DECEMBER 31, 2012

Revenues. We recognized revenues of $81.4 million for the year ended December 31, 2013, compared to
$27.6 million for the year ended December 31, 2012. This increase was primarily due to (i) $65.0 million of non-
refundable milestone payments from Eisai that we earned in connection with the final scheduling designation for
BELVIQ by the US Drug Enforcement Administration, or DEA, (ii) $5.7 million from net product sales of
BELVIQ, (iii) a $2.3 million increase in reimbursements from Eisai for development and patent expenses and
(iv) two non-refundable milestone payments of $0.5 million each that we earned in connection with Eisai filing
applications for regulatory approval of BELVIQ in Mexico and Canada. Of the $5.7 million of BELVIQ net
product sales recognized in the year ended December 31, 2013, $5.3 million represented 31.5% of Eisai’s net
product sales and $0.4 million related to redemptions of vouchers. The revenue recognized for the year ended
December 31, 2012, included a $20.0 million non-refundable milestone payment from Eisai that we earned in
connection with FDA approval of BELVIQ.

When collaborators pay us before revenues are earned, we record such payments as deferred revenues. As of

December 31, 2013, we had a total of $139.2 million in deferred revenues. Of such amount, $102.1 million is
attributable to upfront payments we received under our collaboration with Eisai, $30.3 million is attributable to
the BELVIQ product supply, $4.6 million is attributable to the upfront payment we received under the Ildong
BELVIQ Agreement and $2.2 million is attributable to the upfront payment we received under the CYB
Agreement.

Absent any new collaborations, we expect our 2014 revenues will primarily consist of (i) revenues from

sales of BELVIQ, (ii) amortization of the upfront payments we have received from Eisai and
(iii) reimbursements from Eisai for development expenses.

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Revenues from sales of BELVIQ and for milestones that may be achieved in the future are difficult to
predict, and our revenues will likely vary significantly from quarter to quarter and year to year. We expect that
this will particularly be the case in the short term as we transition from a research and development company to a
company with a marketed drug.

With respect to the United States, we expect that Eisai’s sales of BELVIQ will increase, but, due to the early
stage of commercialization, it is difficult to predict the amount or timing of such sales or the related revenues we
will generate. Future sales of BELVIQ will depend on, among other factors, the availability and use of BELVIQ,
the effectiveness of Eisai’s marketing program, competition and reimbursement coverage. Revenues we generate
from Eisai’s sales of BELVIQ depend on Eisai’s net product sales of BELVIQ, which are the gross invoiced
sales less certain deductions described in the Eisai Agreement. Deductions from gross sales to net product sales
may vary from period to period, particularly in the near term, depending on the amount and extent of such
deductions, which include deductions for vouchers, savings cards or other promotions for free or discounted
product. Eisai has reported that a majority of all BELVIQ prescriptions utilized vouchers or savings cards.

In addition to revenues from Eisai’s commercialization of BELVIQ in the United States, we expect that any

significant revenues in the short term will depend on whether and when (i) BELVIQ receives regulatory
approval, and is commercialized, outside of the United States, (ii) we enter into any additional agreements to
commercialize BELVIQ and (iii) we enter into any agreements to collaborate on or license any of our drug
candidates or programs.

Cost of product sales. Cost of product sales consists primarily of direct and indirect costs related to
manufacturing BELVIQ, including, among other costs, salaries, share-based compensation and other personnel
costs, machinery depreciation costs and amortization expense related to our manufacturing facility production
licenses. Upon receiving approval of BELVIQ by the FDA in June 2012 (which approval was subject to the
DEA’s final scheduling designation), we began to capitalize inventory costs for BELVIQ, which is subsequently
recognized as cost of product sales when the related inventory is sold. We recognized cost of product sales of
$1.8 million for the year ended December 31, 2013, and none for the year ended December 31, 2012, which was
prior to when BELVIQ was made available to patients.

Cost of manufacturing services. Cost of manufacturing services consists primarily of direct and indirect

costs associated with manufacturing drug products for Siegfried AG, or Siegfried, under our amended
manufacturing services agreement, including related salaries, other personnel costs, machinery depreciation costs
and amortization expense related to our manufacturing facility production licenses. Cost of manufacturing
services increased by $0.7 million to $4.4 million for the year ended December 31, 2013, from $3.7 million for
the year ended December 31, 2012, primarily due to our contract loss provision for these services, which is the
result of providing the services at sales prices that are less than our costs, as well as the reduced volume of
manufacturing services performed.

Research and development expenses. Research and development expenses, which account for the majority
of our expenses, consist primarily of salaries and other personnel costs, clinical trial costs (including payments to
contract research organizations, or CROs), preclinical study fees, manufacturing costs for non-commercial
products, costs for the development of our earlier-stage programs and technologies, research supply costs and
facility and equipment costs. We expense research and development costs as they are incurred when these
expenditures have no alternative future uses. We generally do not track our earlier-stage, internal research and
development expenses by project; rather, we track such expenses by the type of cost incurred.

Research and development expenses increased by $12.4 million to $66.5 million for the year ended

December 31, 2013, from $54.1 million for the year ended December 31, 2012. This was primarily due to
increases of (i) $4.3 million in external clinical and preclinical study fees and internal non-commercial
manufacturing costs, primarily related to manufacturing costs for non-commercial products and the BELVIQ

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cardiovascular outcomes trial, (ii) $4.0 million in salary and other personnel costs, primarily as a result of an
increase in headcount, (iii) $2.5 million in non-cash share-based compensation expense and (iv) $2.3 million in
research supply costs. We expect to continue to incur substantial research and development expenses in 2014,
which we expect will be substantially higher than 2013. Such expenses will include costs for FDA-required and
non-FDA required development work relating to BELVIQ, including studies for smoking cessation and using a
once-daily formulation, as well as our other research and development programs.

Included in the $16.4 million total external clinical and preclinical study fees and internal non-commercial
manufacturing costs for the year ended December 31, 2013, was $7.2 million of non-commercial manufacturing and
other development costs related to BELVIQ, $4.5 million related to BELVIQ, $1.9 million related to APD811,
$1.2 million related to APD334 and $1.1 million related to APD371. Included in the $12.1 million total external
clinical and preclinical study fees and internal non-commercial manufacturing costs for the year ended
December 31, 2012, was $4.4 million related to BELVIQ, $4.2 million of non-commercial manufacturing and other
development costs related to BELVIQ, $2.2 million related to APD811 and $1.0 million related to APD371.

Cumulatively through December 31, 2013, we have recognized external clinical and preclinical study fees and

internal non-commercial manufacturing costs of $267.3 million for BELVIQ, $43.7 million for nelotanserin (an
inverse agonist of the serotonin 2A receptor, which we previously studied in Phase 2 for the treatment of insomnia),
$33.0 million of non-commercial manufacturing and other development costs related to BELVIQ, $8.5 million for
APD811, $7.3 million for temanogrel, $3.0 million for APD334 and $2.2 million for APD371. As described above,
Ildong will be responsible for funding and conducting the next two planned clinical trials of temanogrel under the
Ildong Temanogrel Agreement.

While expenditures on current and future clinical development programs are expected to be substantial, they

are subject to many uncertainties, including whether we have adequate funds and develop our drug candidates
with one or more collaborators or independently. As a result of such uncertainties, we cannot predict with any
significant degree of certainty the duration and completion costs of our research and development projects or
whether, when and to what extent we will generate revenues from the commercialization and sale of BELVIQ or
any of our drug candidates. The duration and cost of clinical trials may vary significantly over the life of a
project as a result of unanticipated events arising during clinical development and a variety of factors, including:

•

•

•

•

•

•

•

•

the nature and number of trials and studies in a clinical program;

the potential therapeutic indication;

the number of patients who participate in the trials;

the number and location of sites included in the trials;

the rates of patient recruitment and enrollment;

the duration of patient treatment and follow-up;

the costs of manufacturing drug candidates; and

the costs, requirements, timing of, and the ability to secure regulatory approvals.

General and administrative expenses. General and administrative expenses increased by $5.5 million to

$31.7 million for the year ended December 31, 2013, from $26.2 million for the year ended December 31, 2012.
This was primarily due to increases of (i) $1.6 million in salary and other personnel costs, (ii) $1.5 million in
non-cash share-based compensation and (iii) $1.1 million in consultants and contractors. We expect that our 2014
general and administrative expenses will be higher than in 2013.

Amortization of intangibles. We recognized $0.7 million for amortization of intangibles related to our

manufacturing facility production licenses for the year ended December 31, 2012, and none for the year ended
December 31, 2013. In June 2012 when we received FDA approval for BELVIQ, we began to capitalize into
inventory amortization expense related to the manufacturing of BELVIQ. Such amortization will subsequently be
recognized as cost of product sales when the related inventory is sold.

70

Interest and other income (expense), net. Interest and other income (expense), net, increased to income of

$3.5 million for the year ended December 31, 2013, from an expense of $28.4 million for the year ended
December 31, 2012. This $31.9 million increase was primarily due to (i) a $10.2 million non-cash gain from
revaluation of our derivative liabilities for the year ended December 31, 2013, compared to a $13.4 million loss
for the year ended December 31, 2012, (ii) a $6.3 million non-cash loss on extinguishment of debt recognized for
the year ended December 31, 2012, and (iii) a $2.0 million decrease in interest expense due to the May 2012
payoff of our then-outstanding loan from certain Deerfield entities. Although our total interest expense decreased
due to the payoff of the Deerfield loan, we expect that it will continue to be substantial due to payments on our
lease financing obligations.

YEAR ENDED DECEMBER 31, 2012, COMPARED TO YEAR ENDED DECEMBER 31, 2011

Revenues. We recognized revenues of $27.6 million for the year ended December 31, 2012, compared to
$12.7 million for the year ended December 31, 2011. This increase was primarily due to the $20.0 million non-
refundable milestone payment we earned in connection with the FDA approval of BELVIQ, which was partially
offset by (i) a $3.3 million decrease in reimbursements we received from Eisai related to additional BELVIQ
development work and (ii) a $1.5 million decrease in manufacturing services revenue under our manufacturing
services agreement with Siegfried. The decrease in manufacturing services revenues was primarily the result of
decreased volume and, to a lesser extent, decreases in certain sales prices under the manufacturing services
agreement with Siegfried.

Cost of manufacturing services. We recognized cost of manufacturing services of $3.7 million and
$8.1 million for the years ended December 31, 2012, and 2011, respectively. This decrease was primarily related
to our contract loss provision for these services, as well as the reduced volume of manufacturing services
performed.

Research and development expenses. Research and development expenses decreased by $4.6 million to

$54.1 million for the year ended December 31, 2012, from $58.7 million for the year ended December 31, 2011.
This was primarily due to decreases of (i) $1.7 million in external clinical and preclinical study fees and internal
non-commercial manufacturing costs, (ii) $1.2 million in salary and personnel costs and (iii) $1.0 million in
facility and equipment costs, primarily depreciation expense. We previously recorded BELVIQ manufacturing
costs as research and development expenses.

Included in the $12.1 million total external clinical and preclinical study fees and internal non-commercial

manufacturing costs for the year ended December 31, 2012, was $4.4 million related to BELVIQ, $4.2 million of
non-commercial manufacturing and other development costs related to BELVIQ, $2.2 million related to APD811
and $1.0 million related to APD371. Included in the $13.8 million total external clinical and preclinical study
fees and internal non-commercial manufacturing costs for the year ended December 31, 2011, was $7.2 million
of non-commercial manufacturing and other development costs related to BELVIQ, $3.6 million related to
BELVIQ, $1.7 million related to APD811 and $0.7 million related to APD334.

General and administrative expenses. General and administrative expenses increased by $2.0 million to

$26.2 million for the year ended December 31, 2012, from $24.2 million for the year ended December 31, 2011.
This was primarily due to increases of (i) $1.5 million in non-cash share-based compensation and
(ii) $0.7 million in salary and other personnel costs. These increases were partially offset by a $1.1 million
decrease in patent fees.

Amortization of intangibles. We recognized $0.7 million for amortization of intangibles for the year ended

December 31, 2012, compared to $1.0 million for the year ended December 31, 2011. This decrease was
primarily due to reaching the end of the 10-year estimated useful life of our Melanophore screening technology
in the first quarter of 2011. The remaining amortization expense related to the manufacturing facility production
licenses we acquired in connection with our Swiss manufacturing facility.

71

Interest and other expense, net. Interest and other expense, net, increased by $2.0 million to $28.4 million

for the year ended December 31, 2012, from $26.4 million for the year ended December 31, 2011. This was
primarily due to a $13.4 million non-cash loss from revaluation of our derivative liabilities, primarily resulting
from the increase in the price of our common stock in 2012, which is an input into our Black-Scholes option
pricing model. This increased expense was partially offset by (i) a $5.2 million decrease in interest expense
primarily related to the May 2012 payoff of our former loan from certain Deerfield entities and (ii) a $4.2 million
decrease in the non-cash loss on extinguishment of debt.

Deemed dividend related to beneficial conversion feature of convertible preferred stock. We recorded

a deemed dividend of $2.8 million in the year ended December 31, 2012, upon the issuance of our formerly
outstanding Series D Convertible Preferred Stock and, in the year ended December 31, 2011, we recorded a
deemed dividend of $2.3 million upon the issuance of our formerly outstanding Series C Convertible Preferred
Stock. The fair value of the common stock into which both series of preferred stock was convertible on the
respective dates of issuance of the preferred stock exceeded the allocated proceeds on a relative fair value basis,
resulting in the beneficial conversion feature.

LIQUIDITY AND CAPITAL RESOURCES

We have accumulated a large deficit since inception that has primarily resulted from the significant research

and development expenditures we have made in seeking to identify and validate new drug targets and develop
compounds that could become marketed drugs. In June 2013, BELVIQ was made available to patients by
prescription in the United States by our collaborator, Eisai. It is difficult to predict the payments we will receive
from commercialization of BELVIQ in the United States or in any other territory in which BELVIQ may be
approved for marketing. We may incur substantial losses for at least the short term as a result of manufacturing
BELVIQ for commercial sale and studies, conducting required postmarketing and other studies of BELVIQ,
including other indications and formulations, and advancing our research and development programs.

Short term

As of December 31, 2013, we had $221.9 million in cash and cash equivalents. We believe our cash and

cash equivalents will be sufficient to fund our operations for at least the next 12 months. We expect that our
short-term operating expenses will be substantial as we continue to fund BELVIQ-related activities, and, at the
same time, advance certain of our research and development programs.

In addition to payments expected from Eisai for purchases of BELVIQ product supply, other potential
sources of liquidity in the short term include (i) payments from Eisai upon achievement of additional milestones,
(ii) entering into new collaborative, licensing or commercial agreements for BELVIQ in additional territories or
for one or more of our drug candidates or programs, (iii) milestone and other payments from collaborators other
than Eisai and (iv) the sale or lease of facilities or other assets we own.

Due to impairment charges, our investment in TaiGen Biotechnology Co., Ltd., or TaiGen, has had a cost

basis of zero since December 31, 2011. On January 17, 2014, TaiGen completed an initial public offering on the
GreTai Securities Listed Market, valuing our investment at a fair value of $49.1 million. In accordance with
generally accepted accounting principles, on January 17, 2014, we will record our investment in TaiGen at such
fair value, with the unrealized gain recorded as a component of accumulated other comprehensive income (loss)
in the stockholders’ equity section of our consolidated balance sheets. Our investment in TaiGen will continue to
be recorded at fair value based on the trading price of TaiGen’s common stock, with any unrealized gains or
losses being recorded in accumulated other comprehensive income (loss) until realized.

Eisai is commercializing BELVIQ in the United States, and, subject to applicable regulatory approval, we
expect Eisai to commercialize BELVIQ in additional territories under the Eisai Agreement. Eisai and we have

72

regulatory applications for approval of BELVIQ under review. We also expect that Eisai will file additional
regulatory applications for approval of BELVIQ in additional territories under the Eisai Agreement, but there is
no assurance of whether, where or when Eisai may file any additional applications. There is also no assurance of
whether, where or when BELVIQ will be approved for marketing outside of the United States, and, therefore, we
expect that all or most of the revenues for BELVIQ sales in the short term will be from Eisai’s commercialization
of BELVIQ in the United States.

We manufacture BELVIQ at our facility in Switzerland, and sell BELVIQ to Eisai for Eisai’s

commercialization in the United States and, subject to applicable regulatory approval, in the other territories
under the Eisai Agreement (other than Europe, China and Japan) for a purchase price starting at 31.5% and
30.75%, respectively (and starting at 27.5% in Europe, China and Japan), of Eisai’s aggregate annual net product
sales (which are the gross invoiced sales less certain deductions described in the Eisai Agreement), or the Product
Purchase Price, in the respective territory. The Product Purchase Price will increase on a tiered basis in the
United States and the other territories (other than Europe, China and Japan) to as high as 36.5% and 35.75%,
respectively, on the portion of Eisai’s annual aggregate net product sales exceeding $750.0 million in all
territories other than Europe, China and Japan. The Product Purchase Price will increase to 35% in Europe, China
and Japan on the portion of Eisai’s annual aggregate net product sales exceeding $500.0 million in such
territories. The Product Purchase Price is subject to reduction (for sales in a particular country), including in the
event of generic competition in the applicable country. The revenue we recognize for BELVIQ product revenue
related to redemption of vouchers is based on our cost of goods sold. Under the Eisai Agreement, we are eligible
to receive up to an aggregate of $176.5 million in additional regulatory and development milestone payments.
We do not expect to receive the majority (or potentially any) of such payments in the short term.

As part of the US approval of BELVIQ, the FDA is requiring the evaluation of the effect of long-term
treatment with BELVIQ on the incidence of major adverse cardiovascular events, or MACE, in overweight and
obese patients with cardiovascular disease or multiple cardiovascular risk factors, as well as the conduct of
postmarketing studies to assess the safety and efficacy of BELVIQ for weight management in obese pediatric
patients. With respect to such studies, which we expect will take several years to complete, Eisai and we will be
responsible for 90% and 10%, respectively, of the expenses for the FDA-required portion of the cardiovascular
outcomes trial, and we will share equally with Eisai the expenses of certain pediatric studies.

Eisai is responsible for regulatory activities related to the BELVIQ New Drug Application, or NDA, and for

the regulatory activities for obtaining marketing approval in any country in the additional territories under the
Eisai Agreement. If the regulatory authority for a country in the additional territories requires development work
before or following approval of BELVIQ in such country, we and Eisai will share expenses for such work. In
addition, Ildong and CYB are responsible for the regulatory approval and, ultimately, marketing and distribution
of BELVIQ in South Korea and Taiwan, respectively, including related development costs and other expenses.

We expect to incur additional expenses for the development of lorcaserin products that are in addition to
BELVIQ for weight management. We expect Eisai to share such expenses, but, nevertheless, that such expenses
will be significant. Under the Eisai Agreement, we and Eisai have initially prioritized the development areas of
smoking cessation, a once-daily formulation and co-administration with phentermine, as well as exploring,
including as part of CAMELLIA, BELVIQ’s effect on conversion to type 2 diabetes and improvements in
cardiovascular outcomes.

To date, we have obtained cash and funded our operations primarily through equity financings, payments

from collaborators, the issuance of debt and related financial instruments and sale leaseback transactions.
Although we expect that payments related to the commercialization of BELVIQ may be substantial in the short
term, we expect to continue to evaluate various funding alternatives on an ongoing basis. There is no guarantee
that additional funding will be available or that, if available, such funding will be adequate or available on terms
that we or our stockholders view as favorable.

73

Long term

We will need substantial cash to achieve our objectives of discovering, developing and commercializing

drugs, and this process typically takes many years and potentially several hundreds of millions of dollars for an
individual drug. We may not have adequate available cash, or assets that could be readily turned into cash, to
meet these objectives in the long term. We will need to obtain significant funds under our existing collaborations,
under new collaborative, licensing or other commercial agreements for BELVIQ or one or more of our drug
candidates and programs or patent portfolios, or from other potential sources of liquidity, which may include the
public and private financial markets.

We expect to continue to incur substantial costs for BELVIQ, including costs related to manufacturing and

required postmarketing and other studies. As described above under “short term,” we will be responsible for a
portion of the expenses for BELVIQ development work required by regulatory agencies. In addition, with respect
to any development work not required by the FDA that we may conduct relating to BELVIQ, we would expect to
incur additional expenses, which may be significant regardless of whether we share the expenses with Eisai.
Expenses for the portion of CAMELLIA not required by the FDA (most of which we do not expect will be
incurred for several years, if ever) will be shared equally by Eisai and us up to an aggregate of $40.0 million
each, and, thereafter, Eisai will be responsible for 100% of such expenses.

Subject to applicable regulatory approval, we expect Eisai to commercialize BELVIQ in additional

territories under the Eisai Agreement. Under such agreement, in addition to payments for purchases of BELVIQ,
we are eligible to receive up to an aggregate of $1.56 billion in one-time purchase price adjustment payments and
other payments. These payments include up to an aggregate of $1.19 billion that are based on Eisai’s annual net
product sales of BELVIQ in all of the territories under the Eisai Agreement on an aggregate basis, with the first
and last amounts payable with annual net product sales of $250.0 million and $2.5 billion, respectively. Of these
payments, Eisai will pay us a total of $330.0 million for annual net product sales of up to $1.0 billion. The $1.56
billion also includes $370.0 million in one-time purchase price adjustment payments we are eligible to receive
based on annual net product sales in the non-US territories, comprised of $185.0 million based on Eisai’s annual
net product sales in the non-US territories in North and South America and $185.0 million based on Eisai’s
annual net product sales in the territories outside of North and South America. The first and last amounts are
payable upon first achievement of annual net product sales of $100.0 million and $1.0 billion, respectively, with
respect to each of the following areas: (i) the non-US territories in North and South America and (ii) the
territories outside of North and South America. In addition, we are also eligible to receive certain payments by
Eisai if certain annual minimum sales requirements in Mexico, Canada and Brazil are not met during the first ten
years after initial commercial sale in such territories.

Under the Ildong BELVIQ Agreement and CYB Agreement, we are eligible to receive additional payments

upon regulatory approval, as well as payments from net product sales of BELVIQ. We will manufacture
BELVIQ at our facility in Switzerland, and sell BELVIQ to Ildong for marketing and distribution in South Korea
for a purchase price starting at 35% of Ildong’s annual net product sales (which are the gross invoiced sales less
certain deductions described in the Ildong BELVIQ Agreement). The purchase price will increase on a tiered
basis up to 45% on the portion of annual net product sales exceeding $15.0 million. If certain annual net product
sales amounts are not met, we can convert Ildong’s right to commercialize BELVIQ in South Korea to be non-
exclusive. Additionally, we will manufacture and sell BELVIQ to CYB for a purchase price starting at 45% of
CYB’s annual net product sales (which are the gross invoiced sales less certain deductions described in the CYB
Agreement). With respect to commercializing BELVIQ in countries that are not currently under collaboration
(Australia, New Zealand and Israel), we will need additional funds or a collaborative or other agreement with one
or more pharmaceutical companies.

In addition to potential payments from Eisai and other current collaborators, as well as funds from public

and private financial markets, potential sources of liquidity in the long term include (i) upfront, milestone,
royalty and other payments from any future collaborators or licensees and (ii) revenues from sales of any drugs
we commercialize on our own. The length of time that our current cash and cash equivalents and any available

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borrowings will sustain our operations will be based on, among other things, the rate of adoption and commercial
success of BELVIQ, regulatory decisions, prioritization decisions regarding funding for our programs, progress
in our clinical and earlier-stage programs, the time and costs related to current and future clinical trials and
nonclinical studies, our research, development, manufacturing and commercialization costs (including personnel
costs), our progress in any programs under collaborations, costs associated with intellectual property, our capital
expenditures, and costs associated with securing any in-licensing opportunities. Any significant shortfall in
funding may result in us reducing our development and/or research activities, which, in turn, would affect our
development pipeline and ability to obtain cash in the future. If we determine it is advisable to raise additional
funds, we do not know whether adequate funding will be available to us or, if available, that such funding will be
available on acceptable terms.

We evaluate from time to time potential acquisitions and in-licensing and other opportunities. Any such

transaction may impact our liquidity as well as affect our expenses if, for example, our operating expenses
increase as a result of such acquisition or license or we use our cash to finance the acquisition or license.

Sources and Uses of Our Cash

Net cash of $72.8 million was provided by operating activities in 2013, compared to net cash of

$44.0 million that was used in operating activities in 2012. This change was primarily the result of the $66.0
million of milestone payments we received from Eisai in 2013, and a $23.6 million change from a $13.4 million
loss from the revaluation of our derivative liabilities in 2012 to a $10.2 million gain in 2013. Net cash used in
operating activities in 2012 decreased by $34.2 million to $44.0 million. This was primarily due to a lower net
loss in 2012, as well as changes in our operating assets and liabilities. Net cash used in operating activities in
2011 increased by $26.0 million to $78.3 million. This was primarily due to changes in our operating assets and
liabilities.

Net cash used in investing activities increased by $6.5 million to $8.7 million in 2013. This increase was

primarily the result of purchases of equipment and improvements to our facilities, primarily for our
manufacturing facility in Switzerland. Net cash used in investing activities was $2.2 million in 2012 and $0.7
million in 2011, primarily for purchases of equipment and improvements to our facilities. We expect that our
2014 capital expenditures will increase over the 2013 amount due to deferments of capital spending in previous
years and purchases of equipment for our manufacturing facility in Switzerland.

Net cash of $1.6 million was provided by financing activities in 2013, primarily due to net proceeds of $3.3
million from stock option exercises and purchases under our employee stock purchase plan, which were partially
offset by $1.7 million for payments on our lease financing obligations. Net cash of $144.1 million was provided
by financing activities in 2012, primarily due to net proceeds of (i) $65.7 million from a public offering of
12,650,000 shares of our common stock at $5.50 per share, (ii) $32.5 million from the portion of Deerfield’s
formerly outstanding warrants to purchase a total of 23,000,000 shares of our common stock that were cash
exercised, (iii) $27.9 million, after prepayment of $5.0 million of loan principal, from the sale to Deerfield of
9,953,250 shares of our common stock and 9,953 shares of our preferred stock (subsequently converted in full
into 9,953,250 shares of our common stock) and (iv) $24.7 million from the sale of 14,414,370 shares of
common stock under an equity line of credit agreement we had with Azimuth Opportunity, L.P. These proceeds
were partially offset by principal repayments to Deerfield totaling $22.3 million. Net cash of $14.2 million was
used in financing activities in 2011, primarily due to principal repayments to Deerfield totaling $37.7 million and
$11.1 million paid to Siegfried in 2011. These repayments were partially offset by net proceeds of $35.3 million
from the sale of 12,150,000 shares of common stock and 12,150 shares of subsequently converted Series C
Preferred to Deerfield in March 2011.

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CONTRACTUAL OBLIGATIONS

The following table summarizes our contractual obligations as of December 31, 2013, in thousands:

Contractual Obligations

Payments due by period

Total

Less than 1
year

1-3
years

3-5
years

More than 5
years

Financing obligations . . . . . . . . . . . . . . . . . . . . . . . . . . .
Purchase obligations . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating leases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$119,994
2,575
12,947

$ 8,090
2,502
873

$18,298
73
1,704

$19,225
0
1,790

$74,381
0
8,580

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$135,516

$11,465

$20,075

$21,015

$82,961

In December 2003, we completed the sale and leaseback of one of our properties for total consideration of
$13.0 million, and, in May 2007, we completed the sale and leaseback of three of our properties and assigned an
option (subsequently exercised) to purchase a fourth property for total consideration of $50.1 million. Our
options to repurchase these properties in the future are considered continued involvement under the applicable
accounting guidance and, therefore, we have applied the financing method which requires that the book value of
the properties and related accumulated depreciation remain on our balance sheet with no sale recognized. Instead,
the sales price of the properties is recorded as a financing obligation and a portion of each lease payment is
recorded as interest expense. As of December 31, 2013, we expect interest expense over the term of these leases
to total $57.2 million. With the exception of the fourth property, which created an operating lease obligation and
is included under “operating leases” above, we have included the lease obligations related to these properties in
the above table as “financing obligations.”

Off-Balance Sheet Arrangements

Except for operating leases, we do not have, and did not have as of December 31, 2013, any off-balance

sheet arrangements that have or are reasonably likely to have a current or future material effect on our financial
condition, results of operations, liquidity, capital expenditures or capital resources.

COLLABORATIONS

Eisai

In November 2013, Arena GmbH and Eisai entered into the Eisai Agreement, which amended and restated

the previous agreement and expanded Eisai’s exclusive commercialization rights for BELVIQ to all of the
countries in the world, except for South Korea, Taiwan, Australia, New Zealand and Israel. Eisai’s
commercialization rights are subject to applicable regulatory approval. In addition to providing
commercialization rights, we provide services related to development and regulatory activities, and we
manufacture and sell BELVIQ to Eisai. Under the Eisai Agreement, we are entitled to receive upfront payments,
milestone payments based on the achievement of regulatory filings and approvals, one-time purchase price
adjustment payments and other payments, and payments from sales of BELVIQ.

Arena GmbH and Eisai Inc. entered into the original marketing and supply agreement in July 2010, under
which we granted Eisai Inc. exclusive commercialization rights for BELVIQ solely in the United States and its
territories and possessions. In May 2012, Arena GmbH and Eisai Inc. amended and restated such agreement by
entering into the first amended agreement, which expanded Eisai Inc.’s exclusive commercialization rights to
include most of North and South America.

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The following table summarizes the revenues we have recognized under our collaboration with Eisai for the

periods presented, in thousands:

December 31,

2013

2012

2011

From Inception
Through
December 31,
2013

Milestone payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Amortization of upfront payments . . . . . . . . . . . . . . . . . . . . . . . . . .
Reimbursement of research and development expenses . . . . . . . . .
Reimbursement of patent expenses . . . . . . . . . . . . . . . . . . . . . . . . . .

$66,000
5,702
4,035
2,020
361

$20,000
0
3,503
27
87

$

0
0
3,434
3,336
0

$ 86,000
5,702
12,895
5,383
448

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$78,118

$23,617

$6,770

$110,428

Upfront and Milestone Payments

In connection with entering into the Eisai Agreement, we received from Eisai an upfront payment of

$60.0 million. This payment is in addition to the $50.0 million and $5.0 million in upfront payments we received
from Eisai in connection with entering into the original agreement and the first amended agreement, respectively.
Revenues from these upfront payments have been deferred, as we determined that the exclusive rights did not
have standalone value without our ongoing development and regulatory activities. Accordingly, these payments
are recognized ratably as revenue over the periods in which we expect the services to be rendered, which are
approximately 15, 16 and 15 years for the Eisai Agreement, original agreement and first amended agreement,
respectively.

In addition to the upfront payments, we have received from Eisai a total of $86.0 million in milestones
payments, comprised of (i) $65.0 million in 2013 earned upon the final scheduling designation for BELVIQ by
the DEA, (ii) $20.0 million earned in 2012 for the inclusion in the approved prescribing information of the FDA
of the efficacy and safety data from the Phase 3 BLOOM-DM (Behavioral modification and Lorcaserin for
Overweight and Obesity Management in Diabetes Mellitus) clinical trial in patients with type 2 diabetes,
(iii) $0.5 million earned in 2013 upon Eisai filing for regulatory approval of BELVIQ in Mexico and (iv) $0.5
million earned in 2013 upon Eisai filing for regulatory approval of BELVIQ in Canada.

Under the Eisai Agreement, we are eligible to receive up to an aggregate of $176.5 million in additional

regulatory and development milestone payments.

Product Purchase Price and Purchase Price Adjustment Payments

We manufacture BELVIQ at our facility in Switzerland, and sell BELVIQ to Eisai for Eisai’s

commercialization in the United States and, subject to applicable regulatory approval, in the other territories
under the Eisai Agreement (other than Europe, China and Japan) for a purchase price starting at 31.5% and
30.75%, respectively (and starting at 27.5% in Europe, China and Japan), of Eisai’s aggregate annual net product
sales (which are the gross invoiced sales less certain deductions described in the Eisai Agreement), or the Product
Purchase Price, in the respective territory. The Product Purchase Price will increase on a tiered basis in the
United States and the other territories (other than Europe, China and Japan) to as high as 36.5% and 35.75%,
respectively, on the portion of Eisai’s annual aggregate net product sales exceeding $750.0 million in all
territories other than Europe, China and Japan. The Product Purchase Price will increase to 35% in Europe, China
and Japan on the portion of Eisai’s annual aggregate net product sales exceeding $500.0 million in such
territories. The Product Purchase Price is subject to reduction (for sales in a particular country), including in the
event of generic competition in the applicable country. The revenue we recognize for BELVIQ product revenue
related to redemption of vouchers is based on our cost of goods sold.

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In addition to payments for purchases of BELVIQ, we are eligible to receive up to an aggregate of $1.56
billion in one-time purchase price adjustment payments and other payments. These payments include up to an
aggregate of $1.19 billion that are based on Eisai’s annual net product sales of BELVIQ in all of the territories
under the Eisai Agreement on an aggregate basis, with the first and last amounts payable with annual net product
sales of $250.0 million and $2.5 billion, respectively. Of these payments, Eisai will pay us a total of
$330.0 million for annual net product sales of up to $1.0 billion. The $1.56 billion also includes $370.0 million in
one-time purchase price adjustment payments we are eligible to receive in the non-US territories, comprised of
$185.0 million based on Eisai’s annual net product sales in the non-US territories in North and South America
and $185.0 million based on Eisai’s annual net product sales in the territories outside of North and South
America. The first and last amounts are payable upon first achievement of annual net product sales of $100.0
million and $1.0 billion, respectively, with respect to each of the following areas: (i) the non-US territories in
North and South America and (ii) the territories outside of North and South America. In addition, we are also
eligible to receive certain payments by Eisai if certain annual minimum sales requirements in Mexico, Canada
and Brazil are not met during the first ten years after initial commercial sale in such territories.

The amount that Eisai pays us for BELVIQ product supply is based on Eisai’s estimated price at the time the

order is shipped, which is Eisai’s estimate of the Product Purchase Price, and is subject to change on April 1 and
October 1 of each year. Eisai’s estimate of the Product Purchase Price was changed as of October 1, 2013. At the
end of Eisai’s fiscal year (March 31), the estimated price paid to us for product that Eisai sold to their distributors
is compared to the Product Purchase Price of such product, and the difference is either refunded back to Eisai (for
overpayments) or paid to us (for underpayments). On a monthly basis, Eisai provides us the total amount of net
product sales for the month, details of the total deductions from gross sales to net product sales and the sales in
units. We recognize our revenues monthly based on our percentage of Eisai’s monthly net product sales figures.
When the revenues we recognize differ from the estimated price that Eisai paid us for such product, the
difference is reclassified from deferred revenues to a receivable or payable account, as appropriate. We also
adjust the deferred revenues balance for the product supply held at Eisai based on the most current net product
sales figures provided to us, with the difference reclassified from deferred revenues to a receivable or payable
account.

Development Payments

In connection with the US approval of BELVIQ, the FDA is requiring (i) an evaluation of the effect of long-
term treatment with BELVIQ on the incidence of major adverse cardiovascular events, or MACE, in overweight
and obese patients with cardiovascular disease or multiple cardiovascular risk factors and (ii) the conduct of
postmarketing studies to assess the safety and efficacy of BELVIQ for weight management in obese pediatric
patients. In addition to the FDA-required studies, we and Eisai are prioritizing the development areas of smoking
cessation, a once-daily formulation, co-administration with phentermine, as well as exploring, including as part
of the CVOT, BELVIQ’s effect on conversion to type 2 diabetes and improvements in cardiovascular outcomes.

78

The below chart summarizes the general agreement regarding cost sharing between Eisai and us for
significant development activities under the Eisai Agreement. In addition, Eisai or we may from time to time
conduct approved development of BELVIQ at such party’s own expense. For example, Eisai is responsible for
the expenses of the pilot study of 12-week duration to preliminarily assess BELVIQ and phentermine when co-
administered.

Eisai Second Amended and Restated Marketing and Supply Agreement: Cost Sharing for Development

United States

Rest of
North and South America

Remaining Territories

BELVIQ for weight
management
- Pre-approval*

Not Applicable

General
Eisai: 90%; Arena: 10%

Up to total of $100.0 million -
Eisai: 50%; Arena: 50%

Certain stability work
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 100%

General
Eisai: 90%; Arena: 10%

Up to total of $50.0 million -
Eisai: 50%; Arena: 50%

Certain stability work
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 90%;
Arena: 10%

General - Eisai: 90%; Arena 10%

Non-FDA required portion of CVOT
Up to $80.0 million -
Eisai: 50%; Arena: 50%
Thereafter, Eisai: 100%

Certain pediatric studies
Eisai: 50%; Arena: 50%

Up to total of $250.0 million (as reduced by up to $80.0 million for non-FDA required portion of
CVOT) - Eisai: 50%; Arena: 50%

Up to a total of $100.0 million in the aggregate across all additional products -
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 90%; Arena: 10%

BELVIQ for weight
management
- Post-approval*

Products other than
BELVIQ for weight
management
- Pre-approval

Products other than
BELVIQ for weight
management
- Post-approval

*

Development required by a regulatory authority, with the exception of the non-FDA required portion of the CVOT.

Certain Other Terms

Eisai and we have agreed to limitations on the ability to commercialize outside of the Eisai Agreement any
weight management product or addiction disorder product in the territories under the agreement. The agreement
includes a stand-still provision limiting Eisai’s ability to acquire our securities and assets.

Eisai may terminate the Eisai Agreement with respect to any country in the territory following the later of

the expiration of all issued BELVIQ patents in such country and 12 years after the first commercial sale of
BELVIQ in such country. Arena GmbH and Eisai each has the right to terminate the Eisai Agreement early in
certain circumstances in its entirety or with respect to the applicable country or product, including (a) if the other
party is in material breach, (b) for commercialization concerns, and (c) for certain intellectual property
infringement. Eisai also has the right to terminate the Eisai Agreement early in its entirety or with respect to each
country in certain circumstances, including (i) termination in a country if sales of generic equivalents of BELVIQ
in such country exceed sales of BELVIQ in that country (based on volume), and (ii) if Eisai is acquired by a
company that has a product that competes with BELVIQ. In addition, Arena GmbH can terminate the Eisai
Agreement early in its entirety or with respect to each country in the non-US territories in North and South
America in certain circumstances, including termination in each country if Eisai does not satisfy certain
regulatory filing and commercialization diligence requirements in such country.

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Eisai will indemnify us for losses resulting from certain third-party claims, including for (a) Eisai’s negligence,

willful misconduct or violation of law, but excluding product liability claims, (b) Eisai’s breach of the Eisai
Agreement or related agreements, but excluding product liability claims, (c) certain uses or misuses of BELVIQ,
(d) certain governmental investigations of Eisai related to BELVIQ, and (e) infringement relating to Eisai’s use of
certain trademarks, tag lines and logos related to BELVIQ. Arena GmbH will indemnify Eisai for losses resulting
from certain third-party claims, including for (i) Arena GmbH’s negligence, willful misconduct, failure to comply
with law, breach of any agreement with a third party with respect to product development prior to the effective date
of the original agreement with Eisai, but excluding product liability claims, (ii) Arena GmbH’s negligence or willful
misconduct with respect to certain uses or misuses of BELVIQ outside of the agreement, (iii) certain uses or
misuses of BELVIQ after the term of the agreement, in any territory no longer under the agreement or with respect
to any product after the termination of the agreement with respect to such product, (iv) Arena GmbH’s negligence,
willful misconduct or violation of law, but excluding product liability claims, (v) Arena GmbH’s breach of the Eisai
Agreement or related agreements, but excluding product liability claims, (vi) certain infringement of intellectual
rights of a third party, and (vii) infringement relating to Eisai’s use of certain trademarks related to BELVIQ. We
are unable to predict the maximum potential amount of any indemnification claims. As of December 31, 2013, we
have not incurred any losses under these indemnification provisions.

Arena GmbH and Eisai will, in general, share equally in losses resulting from third-party product liability
claims, except where one party’s acts or omissions did not contribute to the events or circumstances leading to such
product liability claim and the other party’s actual willful misconduct, violation of law or breach of its obligations
under the Eisai Agreement or certain other agreements between Arena GmbH and Eisai were the sole and direct
cause of the product liability claim. We are unable to predict the range of loss from future product liability claims.

Ildong Pharmaceutical Co., Ltd.

BELVIQ

In November 2012, Arena GmbH entered into the Ildong BELVIQ Agreement. Under this agreement, we
granted Ildong exclusive rights to commercialize BELVIQ in South Korea for weight loss or weight management
in obese and overweight patients, subject to regulatory approval of BELVIQ by the South Korean Ministry of
Food and Drug Safety, or MFDS. We also provide certain services and will manufacture and sell BELVIQ to
Ildong. Under the Ildong BELVIQ Agreement, in addition to the upfront payment received, we are entitled to
receive a milestone payment based on regulatory approval as well as payments from sales of BELVIQ.

Under the agreement, we received from Ildong an upfront payment of $5.0 million, less withholding taxes, and

will receive an additional $3.0 million if and when BELVIQ is approved by the MFDS. We recorded this upfront
payment as deferred revenue and are recognizing it as revenue ratably over approximately 14 years, which is the
period in which we expect to provide services under the arrangement. For the years ended December 31, 2013, and
2012, we recognized revenues of $0.5 million and $0.1 million, respectively, under this agreement.

Ildong is responsible for the regulatory approval and, ultimately, commercialization of BELVIQ in South
Korea for weight loss or weight management in obese and overweight patients, including related development and
other costs and expenses. We will manufacture BELVIQ at our facility in Switzerland, and sell BELVIQ to Ildong
for a purchase price starting at 35% of Ildong’s annual net product sales (which are the gross invoiced sales less
certain deductions described in the Ildong BELVIQ Agreement). The purchase price will increase on a tiered basis
up to 45% on the portion of annual net product sales exceeding $15.0 million. If certain annual net product sales
amounts are not met, we can convert Ildong’s right to commercialize BELVIQ in South Korea to be non-exclusive.

Ildong has agreed not to conduct activities outside of our agreement related to the approval or

commercialization of any other pharmaceutical product for weight loss, weight management or obesity in South
Korea. We have agreed not to conduct activities outside of our agreement related to the commercialization in
South Korea of any pharmaceutical product containing BELVIQ intended for end use in weight loss or weight
management in obese and overweight patients.

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Ildong will indemnify us for losses resulting from certain third-party claims, including for (a) Ildong’s
negligence, willful misconduct or violation of law, (b) Ildong’s breach of the marketing and supply agreement or
related agreements, (c) certain uses or misuses of BELVIQ (including any product liability claim and other
claims relating to sales or development of BELVIQ in South Korea), (d) certain governmental investigations of
Ildong related to BELVIQ, and (e) infringement relating to Ildong’s use of trademarks related to BELVIQ. Arena
GmbH will indemnify Ildong for losses resulting from certain third-party claims, including for (i) Arena GmbH’s
negligence, willful misconduct or violation of law, and (ii) Arena GmbH’s breach of the marketing and supply
agreement or related agreements.

Unless terminated earlier, the agreement with Ildong will continue in effect until the later of the expiration of

all issued patents relating to BELVIQ in South Korea and 12 years after the first commercial sale of BELVIQ in
South Korea. Either party has the right to terminate the agreement early in certain circumstances, including (a) if the
other party is in material breach, (b) for certain commercialization concerns, and (c) for certain intellectual property
concerns. Ildong also has the right to terminate the agreement early in certain circumstances, including if we notify
Ildong that Ildong’s right to commercialize BELVIQ in South Korea will become non-exclusive.

Temanogrel

In November 2012, we entered into the Ildong Temanogrel Agreement for temanogrel, our internally
discovered inverse agonist of the serotonin 2A receptor. Under such agreement, we granted Ildong exclusive
rights to commercialize temanogrel in South Korea for myocardial infarction, acute coronary syndrome, stroke,
peripheral artery disease, and other cardiovascular diseases, subject to further development and regulatory
approval of temanogrel. Initially, Ildong will be responsible for funding and conducting, under the direction of a
joint steering committee, the next two planned clinical trials in this program: an additional Phase 1 trial in
healthy volunteers and a Phase 2a proof-of-concept trial in patients. To date, we have not recognized any revenue
under this agreement.

We will maintain ownership of temanogrel outside of South Korea, and have the rights to use data generated

by Ildong for the development and potential commercialization of temanogrel outside of South Korea by us or
other Arena licensees. In addition, Ildong has agreed to pay us a $2.0 million development milestone if the
planned additional Phase 1 and Phase 2a clinical trials conducted by Ildong support continued development and
we or another Arena licensee initiates a Phase 2b clinical trial of temanogrel. We are also eligible to receive a
royalty on net product sales of temanogrel in South Korea, and Ildong is eligible to receive a share of future
payments received by us related to licensing transactions and sales of temanogrel in other territories.

Ildong will indemnify us for losses resulting from certain third-party claims, including for (a) Ildong’s
negligence, willful misconduct or violation of law, (b) Ildong’s breach of the agreement, (c) certain uses or
misuses of temanogrel (including any product liability claim and other claims relating to sales or development of
temanogrel in South Korea), and (d) certain governmental investigations of Ildong related to temanogrel. We will
indemnify Ildong for losses resulting from certain third-party claims, including for (i) our negligence, willful
misconduct or violation of law, and (ii) our breach of the agreement.

Unless terminated earlier or extended, the agreement will continue in effect until the later of the expiration

of all issued patents relating to temanogrel in South Korea and 10 years after the first commercial sale of
temanogrel in South Korea. Either party has the right to terminate the agreement early in certain circumstances,
including (a) if the other party is in material breach, (b) for certain commercialization concerns, and (c) for
certain intellectual property concerns.

CY Biotech Company Limited

In July 2013, Arena GmbH entered into the CYB Agreement. Under this agreement, we granted CYB
exclusive rights to commercialize BELVIQ in Taiwan for weight loss or weight management in obese and
overweight patients, subject to regulatory approval of BELVIQ by the Taiwan Food and Drug Administration, or

81

TFDA. We also provide certain services and will manufacture and sell BELVIQ to CYB. In addition to the
upfront payment received, we will receive payments from sales of BELVIQ under the CYB Agreement, and are
eligible to receive purchase price adjustment payments based on CYB’s annual net product sales, as well as a
milestone payment upon approval of the first additional indication for BELVIQ by the TFDA. We received from
CYB an upfront payment of $2.0 million, net of withholding taxes, which was recorded as deferred revenue and
will be recognized as revenue ratably over approximately 14 years, which is the period in which we expect to
provide services under the arrangement. For the year ended December 31, 2013, we recognized revenues of $0.1
million under this agreement.

CYB is responsible for the regulatory approval and, ultimately, commercialization of BELVIQ in Taiwan
for weight loss or weight management in obese and overweight patients, including related development and other
costs and expenses. We will manufacture BELVIQ at our facility in Switzerland, and sell BELVIQ to CYB for a
purchase price starting at 45% of CYB’s annual net product sales (which are the gross invoiced sales less certain
deductions described in the CYB Agreement).

CYB has agreed not to conduct outside of our agreement activities related to the approval or

commercialization of any other pharmaceutical product for weight loss, weight management or obesity in
Taiwan. We have agreed not to outside of our agreement commercialize in Taiwan any pharmaceutical product
containing BELVIQ intended for end use in weight loss or weight management in obese and overweight patients.

CYB will indemnify us for losses resulting from certain third-party claims, including for (a) CYB’s
negligence, willful misconduct or violation of law, (b) CYB’s breach of the marketing and supply agreement or
related agreements, (c) certain uses or misuses of BELVIQ (including any product liability claim and other
claims relating to sales or development of BELVIQ in Taiwan), (d) certain governmental investigations of CYB
related to BELVIQ, and (e) infringement relating to CYB’s use of trademarks related to BELVIQ. Arena GmbH
will indemnify CYB for losses resulting from certain third-party claims, including for (i) Arena GmbH’s
negligence, willful misconduct or violation of law, and (ii) Arena GmbH’s breach of the marketing and supply
agreement or related agreements.

Unless terminated earlier, the agreement with CYB will continue in effect until the later of the expiration of

all issued patents relating to BELVIQ in Taiwan and 12 years after the first commercial sale of BELVIQ in
Taiwan. Either party has the right to terminate the agreement early in certain circumstances, including (a) if the
other party is in material breach, (b) for certain commercialization concerns, and (c) for certain intellectual
property concerns.

CRITICAL ACCOUNTING POLICIES AND MANAGEMENT ESTIMATES

The SEC defines critical accounting policies as those that are, in management’s view, important to the

portrayal of our financial condition and results of operations and demanding of management’s judgment. Our
discussion and analysis of financial condition and results of operations is based on our consolidated financial
statements, which have been prepared in accordance with US generally accepted accounting principles, or
GAAP. The preparation of these financial statements requires us to make estimates and judgments that affect the
reported amounts of assets, liabilities, revenues and expenses and related disclosures. We base our estimates on
historical experience and on various assumptions that we believe are reasonable under the circumstances, the
results of which form the basis for making judgments about the carrying values of assets and liabilities that are
not readily apparent from other sources. Actual results may differ significantly from those estimates.

While our significant accounting policies are described in more detail in Note 1 to our consolidated financial

statements, we believe the following accounting policies are critical in the preparation of our financial
statements:

Revenue recognition. Our revenues to date have been generated primarily through collaborative
agreements and, to a lesser extent, a manufacturing services agreement. Our collaborative agreements may

82

contain multiple elements including commercialization rights, services (joint steering committee and research
and development services) and manufactured products. Consideration we receive under these arrangements may
include upfront payments, research and development funding, cost reimbursements, milestone payments and
payments for net product sales. We recognize revenue when (i) persuasive evidence of an arrangement exists,
(ii) delivery has occurred and title has passed, (iii) the price is fixed or determinable and (iv) collectability is
reasonably assured. Any advance payments we receive in excess of amounts earned are classified as deferred
revenues on our consolidated balance sheets. We defer recognition of revenue at the time we sell BELVIQ to
Eisai because we presently do not have the ability to estimate product that may be returned to us. Instead, we
recognize revenues from net product sales when Eisai ships BELVIQ to their distributors.

We manufacture and sell BELVIQ to Eisai for Eisai’s marketing and distribution in the United States and,

subject to applicable regulatory approval, in most territories worldwide. The net product sales price Eisai pays us
for product supply for commercialization in the United States starts at 31.5% of their gross invoiced sales, less
certain deductions described in the Eisai Agreement. The amount we recognize for BELVIQ product revenue
related to redemption of vouchers is based on our cost of goods sold.

We adopted revised guidance on accounting for revenue arrangements involving multiple elements on
January 1, 2011, on a prospective basis, for agreements we entered into or materially modified after adoption.
This updated guidance (i) relates to whether multiple deliverables exist, how the deliverables in a revenue
arrangement should be separated and how the consideration should be allocated, (ii) requires companies to
allocate revenues in an arrangement using estimated selling prices of deliverables if a vendor does not have
vendor-specific objective evidence or third-party evidence of selling price and (iii) eliminates the use of the
residual method and requires companies to allocate revenues using the relative selling price method.

Since adoption of this guidance, we evaluate deliverables in a multiple-element arrangement to determine

whether each deliverable represents a separate unit of accounting. A deliverable constitutes a separate unit of
accounting when it has standalone value to the customer. If the delivered element does not have standalone value
without one of the undelivered elements in the arrangement, we combine such elements and account for them as
a single unit of accounting. We allocate the consideration to each unit of accounting at the inception of the
arrangement based on the relative selling price.

For agreements that we entered into prior to adoption of the revised multiple-element guidance, if fair value

exists for all elements in the arrangement, we allocate the consideration to the elements based on their relative
fair values. In cases where fair value exists for the undelivered elements but does not exist for the delivered
elements, we use the residual method to allocate the arrangement consideration. In cases where the delivered
element does not have standalone value without one of the undelivered elements in the arrangement, or fair value
does not exist for certain undelivered elements, we combine such delivered and undelivered elements and
account for them as a single unit of accounting.

Non-refundable upfront payments received under our collaborative agreements for commercialization rights

have been deferred as such rights have not been deemed to have standalone value without the ongoing services
required under the agreement. Such amounts are recognized as revenue on a straight-line basis over the period in
which we expect to perform the services. Amounts we receive as reimbursement for our research and
development expenditures are recognized as revenue as the services are performed.

Under the milestone method, we recognize revenue that is contingent upon the achievement of a substantive

milestone in its entirety in the period in which the milestone is achieved. A milestone is an event (i) that can be
achieved in whole or in part on either our performance or on the occurrence of a specific outcome resulting from
our performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the
event will be achieved and (iii) that would result in additional payments being due us. A milestone payment is
considered substantive when the consideration payable to us for each milestone (a) is consistent with our
performance necessary to achieve the milestone or the increase in value to the collaboration resulting from our

83

performance, (b) relates solely to our past performance and (c) is reasonable relative to all of the other
deliverables and payments under the arrangement. In making this assessment, we consider all facts and
circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and
other risks that must be overcome to achieve the respective milestone, the level of effort and investment required
to achieve the respective milestone and whether any portion of the milestone consideration is related to future
performance or deliverables. Other contingent-based payments received are recognized when earned.

We manufacture drug products under a manufacturing services agreement for a single customer, Siegfried.

Upon Siegfried’s acceptance of drug products manufactured by us, we recognize manufacturing services
revenues.

Clinical trial expenses. We accrue clinical trial expenses based on work performed. In determining the
amount to accrue, we rely on estimates of total costs incurred based on the enrollment of subjects, the completion
of trials and other events. We follow this method because we believe reasonably dependable estimates of the
costs applicable to various stages of a clinical trial can be made. However, the actual costs and timing of clinical
trials are highly uncertain, subject to risks and may change depending on a number of factors. Differences
between the actual clinical trial costs and the estimated clinical trial costs that we have accrued in any prior
period are recognized in the subsequent period in which the actual costs become known. Historically, these
differences have not been material; however, material differences could occur in the future.

Income taxes. Significant judgment is required by management to determine our provision for income

taxes, our deferred tax assets and liabilities, and the valuation allowance to record against our net deferred tax
assets, which are based on complex and evolving tax regulations throughout the world. Our tax calculation is
impacted by tax rates in the jurisdictions in which we are subject to tax and the relative amount of income earned
in each jurisdiction. Our deferred tax assets and liabilities are determined using the enacted tax rates expected to
be in effect for the years in which those tax assets are expected to be realized.

The effect of an uncertain income tax position is recognized at the largest amount that is “more-likely-than-
not” to be sustained under audit by the taxing authority. An uncertain income tax position will not be recognized
if it has less than a 50% likelihood of being sustained.

The realization of our deferred tax assets is dependent upon our ability to generate sufficient future taxable

income. We establish a valuation allowance when it is more-likely-than-not that the future realization of all or
some of the deferred tax assets will not be achieved. The evaluation of the need for a valuation allowance is
performed on a jurisdiction-by-jurisdiction basis, and includes a review of all available evidence, both positive
and negative. As of December 31, 2013, we concluded that it was more-likely-than-not that our deferred tax
assets would not be realized.

The above listing is not intended to be a comprehensive list of all of our accounting policies. In many cases,

the accounting treatment of a particular transaction is specifically dictated by GAAP. See our audited
consolidated financial statements and notes thereto included elsewhere in this Annual Report, which contain
additional accounting policies and other disclosures required by GAAP.

New Accounting Guidance

In February 2013, the Financial Accounting Standards Board, or FASB, issued Accounting Standards
Update, or ASU, No. 2013-04, “Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability
Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date.” Under ASU
No. 2013-04, companies are required to measure such obligations as the sum of the amount that the reporting
entity agreed to pay on the basis of its arrangements with co-obligors, as well as any additional amount the
reporting entity expects to pay on behalf of its co-obligors. ASU No. 2013-04 is effective for reporting periods
beginning after December 15, 2013. We do not expect the adoption of ASU No. 2013-04 to have a material
impact on our consolidated financial statements.

84

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Foreign Currency Exchange Risk

We have a wholly owned subsidiary in Switzerland, which exposes us to foreign currency exchange risk.
The functional currency of our subsidiary in Switzerland is the Swiss franc. Accordingly, all assets and liabilities
of our subsidiary are translated to US dollars based on the applicable exchange rate on the balance sheet date.
Revenue and expense components are translated to US dollars at weighted-average exchange rates in effect
during the period. Gains and losses resulting from foreign currency translation are reported as a separate
component of accumulated other comprehensive gain (loss) in the stockholders’ equity section of our
consolidated balance sheets. Foreign currency transaction gains and losses, which have not been material for us
to date, are included in our results of operations. We have not hedged exposures denominated in foreign
currencies, but may do so in the future.

Equity Price Risk

We received preferred stock in connection with our collaboration with TaiGen Biotechnology Co., Ltd.,
which has since converted into common stock. This investment had a cost basis of zero from December 31, 2011,
through December 31, 2013.

On January 17, 2014, TaiGen (under the name “TaiGen Biopharmaceuticals Holding Limited”) completed

an initial public offering and its common stock began to trade on the GreTai Securities Listed Market. Such
market is deemed to be comparable to a US over-the-counter market, and, as such, the fair value of our
investment in TaiGen became readily determinable under generally accepted accounting principles. As a result,
we began to record our investment in TaiGen on our financial statements based on the trading price of TaiGen’s
common stock. As of January 17, 2014, our investment in TaiGen was valued at approximately $49.1 million.
This investment will continue to be recorded at fair value based on the trading price of TaiGen’s common stock,
with any unrealized gains or losses being recorded in accumulated other comprehensive income (loss) in the
stockholders’ equity section of our consolidated balance sheets until realized.

Our investment in TaiGen is subject to market price volatility. Fluctuations in the market price of publicly
traded securities may result from perceived changes in the underlying economic characteristics of the issuer, the
relative price of alternative investments, general market conditions and other factors.

A 10% increase or decrease in the fair value of our investment in TaiGen would result in an increase or

decrease to the fair value of the investment of approximately $4.9 million, and a corresponding gain or loss in
accumulated other comprehensive income (loss). Because the market price for this investment is subject to
ongoing fluctuation, the amount we may eventually realize from a subsequent sale of the investment may differ
significantly from the reported amount. This hypothetical increase or decrease will likely be different from what
actually occurs in the future, and the impact may differ from that quantified herein.

85

Item 8.

Financial Statements and Supplementary Data.

ARENA PHARMACEUTICALS, INC.

INDEX TO FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting Firm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Balance Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Operations and Comprehensive Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Stockholders’ Equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Cash Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Notes to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

87
88
89
90
92
93

86

Report of Independent Registered Public Accounting Firm

The Board of Directors and Stockholders
Arena Pharmaceuticals, Inc.:

We have audited the accompanying consolidated balance sheets of Arena Pharmaceuticals, Inc. and

subsidiaries (the Company) as of December 31, 2013 and 2012, and the related consolidated statements of
operations and comprehensive loss, stockholders’ equity, and cash flows for each of the years in the three-year
period ended December 31, 2013. 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 conducted our audit in accordance with the standards of the Public Company Accounting Oversight
Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance
about whether the financial statements are free of material misstatement. An audit includes examining, on a test
basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by management, as well as evaluating
the overall financial statement presentation. We believe that our audits provide a reasonable basis for our
opinion.

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects,
the financial position of Arena Pharmaceuticals, Inc. and subsidiaries as of December 31, 2013 and 2012, and the
results of their operations and their cash flows for each of the years in the three-year period ended December 31,
2013, 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), Arena Pharmaceuticals, Inc.’s internal control over financial reporting as of December 31, 2013,
based on criteria established in Internal Control – Integrated Framework (1992) issued by the Committee of
Sponsoring Organizations of the Treadway Commission (COSO), and our report dated March 3, 2014, expressed
an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.

/s/ KPMG LLP

San Diego, California
March 3, 2014

87

ARENA PHARMACEUTICALS, INC.

Consolidated Balance Sheets
(In thousands, except share and per share data)

Assets
Current assets:

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Land, property and equipment, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intangibles, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other non-current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,

2013

2012

$

221,878
10,602
12,759
3,571

248,810
77,388
10,182
3,427

156,091
5,556
6,058
3,454

171,159
75,417
10,611
4,019

Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

339,807

$

261,206

Liabilities and Stockholders’ Equity
Current liabilities: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts payable and other accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . . .
Payable to Eisai
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of deferred revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of derivative liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of lease financing obligations . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred rent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenues, less current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Derivative liabilities, less current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lease financing obligations, less current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

7,317
19,305
4,205
37,861
0
2,056

70,744
247
101,329
4,892

70,738

7,123
0
3,087
15,453
2,587
1,664

29,914
122
47,282
12,455

72,794

Commitments and contingencies

Stockholders’ equity:

Preferred stock, $.0001 par value: 7,500,000 shares authorized and 0 shares

issued and outstanding at December 31, 2013, and 2012 . . . . . . . . . . . . . . . . .

0

0

Common stock, $.0001 par value: 367,500,000 shares authorized at

December 31, 2013, and 2012; 218,816,242 shares issued and outstanding at
December 31, 2013; 217,476,458 shares issued and outstanding at
December 31, 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additional paid-in capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated other comprehensive income . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated deficit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

22
1,293,840
5,728
(1,207,733)

22
1,281,426
5,489
(1,188,298)

Total stockholders’ equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

91,857

98,639

Total liabilities and stockholders’ equity . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

339,807

$

261,206

See accompanying notes to consolidated financial statements.

88

ARENA PHARMACEUTICALS, INC.

Consolidated Statements of Operations and Comprehensive Loss
(In thousands, except share and per share data)

Revenues:
Net product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Eisai collaborative revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manufacturing services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other collaborative revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Costs and Expenses:
Cost of product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cost of manufacturing services . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research and development
General and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restructuring charges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Amortization of intangibles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total operating costs and expenses . . . . . . . . . . . . . . . . . . . .

Loss from operations . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interest and Other Income (Expense):
Interest income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gain (Loss) from valuation of derivative liabilities . . . . . . . . . . .
Loss on extinguishment of debt
. . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total interest and other income (expense), net . . . . . . . . . . .

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deemed dividend related to beneficial conversion feature of

Years ended December 31,

2013

2012

2011

$

5,702
72,416
2,690
586

81,394

1,803
4,377
66,468
31,681
0
0

104,329

(22,935)

89
(7,091)
10,150
0
352

3,500

(19,435)

$

0
23,617
3,817
153

27,587

0
3,671
54,112
26,226
0
691

84,700

0
6,770
5,338
611

12,719

0
8,100
58,706
24,248
3,467
997

95,518

(57,113)

(82,799)

119
(9,120)
(13,425)
(6,338)
400

(28,364)

(85,477)

117
(14,309)
47
(10,514)
(1,766)

(26,425)

(109,224)

convertible preferred stock . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0

(2,824)

(2,260)

Net loss allocable to common stockholders . . . . . . . . . . . . . . . . .

$

(19,435) $

(88,301) $

(111,484)

Net loss per share allocable to common stockholders:

Basic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Diluted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

$

(0.09) $

(0.09) $

(0.45) $

(0.45) $

(0.80)

(0.80)

Shares used in calculating net loss per share allocable to

common stockholders:

Basic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

218,104,323

196,523,708

139,170,725

Diluted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

218,104,323

196,523,708

139,170,725

Comprehensive Loss:
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign currency translation gain (loss) . . . . . . . . . . . . . . . . . . . .

Comprehensive loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

$

(19,435) $
239

(85,477) $
746

(109,224)
(223)

(19,196) $

(84,731) $

(109,447)

See accompanying notes to consolidated financial statements.

89

ARENA PHARMACEUTICALS, INC.

Consolidated Statements of Stockholders’ Equity
(In thousands, except share data)

Convertible Preferred
Stock

Common Stock

Shares

Amount

Shares

Amount

Additional
Paid-In
Capital

Treasury
Stock

Accumulated
Other
Comprehensive
Income (Loss)

Accumulated
Deficit

Total
Stockholders’
Equity

$ 0

121,515,805

$ 12

$1,068,634 $(23,070)

$4,966

$ (970,527)

$ 80,015

272,014

12,150,000

stock to Deerfield . . . . . . . . .

12,150

1

(12,150)

(1)

12,150,000

1

1

1

314

15,412

15,412

2,260

(2,260)

5,105

3,748

315

15,413

15,413

2,260

(2,260)

5,105

3,748

5,000

(223)

(109,224)

(223)
(109,224)

0

146,092,819

15

1,108,625

(23,070)

4,743

(1,079,751)

10,562

1,071,661

4,657

Balance at December 31,

2010 . . . . . . . . . . . . . . . . . . . .

Issuance of common stock
under employee stock
purchase plan . . . . . . . . . . . . .

Issuance of common stock to

Deerfield . . . . . . . . . . . . . . . .

Issuance of Series C preferred

Issuance of common stock to

Deerfield upon conversion of
Series C preferred stock . . . .
Beneficial conversion feature of
Series C preferred stock . . . .

Deemed dividend related to

beneficial conversion feature
of Series C preferred stock . .

Exchange of Deerfield

warrants . . . . . . . . . . . . . . . . .

Share-based compensation

expense, net of forfeitures . . .

Restricted shares released from

deferred compensation
plan . . . . . . . . . . . . . . . . . . . .
Translation loss . . . . . . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . . .

Balance at December 31,

2011 . . . . . . . . . . . . . . . . . . . .
Issuance of common stock upon
exercise of options . . . . . . . . .

Issuance of common stock
under employee stock
purchase plan . . . . . . . . . . . . .

Issuance of common stock

under equity line of credit . . .

Issuance of common stock in
public offering, net of
offering costs of $3,875 . . . . .

Issuance of common stock to

Deerfield . . . . . . . . . . . . . . . .

Issuance of Series D preferred

341,108

14,414,370

12,650,000

9,953,250

1

1

1

1

3

470

24,726

65,699

14,560

14,561

39,199

3,803

2,824

(2,824)

stock to Deerfield . . . . . . . . .

9,953

(9,953)

9,953,250

23,000,000

Issuance of common stock to

Deerfield upon conversion of
Series D preferred stock . . . .
Issuance of common stock upon

exercise of Deerfield
warrants . . . . . . . . . . . . . . . . .

Exchange of Deerfield

warrants . . . . . . . . . . . . . . . . .
Beneficial conversion feature of
Series D preferred stock . . . .

Deemed dividend related to

beneficial conversion feature
of Series D preferred stock . .

90

4,657

470

24,727

65,700

14,561

14,561

1

39,202

3,803

2,824

(2,824)

Convertible Preferred
Stock

Common Stock

Shares

Amount

Shares

Amount

Additional
Paid-In
Capital

Treasury
Stock

Accumulated
Other
Comprehensive
Income (Loss)

Accumulated
Deficit

Total
Stockholders’
Equity

5,072

54

23,070

746

(23,070)

(85,477)

5,072

54

746
(85,477)

0

217,476,458

22

1,281,426

0

5,489

(1,188,298)

98,639

954,174

334,360

41,250

10,000

2,375

852

88

9,024

75

2,375

852

88

9,024

75
239
(19,435)

239

(19,435)

$0

218,816,242

$22

$1,293,840

$

0

$5,728

$(1,207,733)

$ 91,857

Share-based compensation

expense, net of forfeitures . . .

Share-based compensation

expense capitalized . . . . . . . .
Retirement of treasury stock . . .
Translation gain . . . . . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . . .

Balance at December 31,

2012 . . . . . . . . . . . . . . . . . . .
Issuance of common stock upon
exercise of options . . . . . . . .

Issuance of common stock
under employee stock
purchase plan . . . . . . . . . . . .
Issuance of common stock upon
vesting of restricted stock
unit awards . . . . . . . . . . . . . .
Issuance of common stock upon

exercise of Series B
warrant

. . . . . . . . . . . . . . . . .

Share-based compensation

expense, net of forfeitures . . .

Share-based compensation

expense capitalized . . . . . . . .
Translation gain . . . . . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . . .

Balance at December 31,

2013 . . . . . . . . . . . . . . . . . . .

See accompanying notes to consolidated financial statements.

91

ARENA PHARMACEUTICALS, INC.

Consolidated Statements of Cash Flows
(In thousands)

Operating Activities
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustments to reconcile net loss to net cash used in operating activities:

Years ended December 31,

2013

2012

2011

$ (19,435) $ (85,477) $(109,224)

Depreciation and amortization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Amortization of intangibles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Share-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Gain) Loss from valuation of derivative liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . .
Amortization of prepaid financing costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accretion of note payable to Deerfield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accretion of note payable to Siegfried . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Investment write-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss on extinguishment of debt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Gain) Loss on disposal or sale of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changes in assets and liabilities:

Accounts receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts payable, payable to Eisai and accrued liabilities . . . . . . . . . . . . . . . . .
Deferred revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred rent

7,733
469
9,024
(10,150)
136
0
0
0
0
49

(4,473)
(6,065)
(65)
19,572
75,880
125

9,055
691
5,072
13,425
292
1,225
0
0
6,338
(31)

(5,260)
(5,875)
(1,524)
276
17,849
(103)

10,127
997
3,748
(47)
438
4,146
345
1,963
10,514
18

2,878
0
539
(1,117)
(3,395)
(187)

Net cash provided by (used in) operating activities . . . . . . . . . . . . . . . . . . .

72,800

(44,047)

(78,257)

Investing Activities

Purchases of land, property and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from sale of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other non-current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net cash used in investing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Financing Activities

Principal payments on lease financing obligations . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principal payments on note payable to Deerfield . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Payments on note payable to Siegfried . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from issuance of common stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from issuance of preferred stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net cash provided by (used in) financing activities . . . . . . . . . . . . . . . . . . .
Effect of exchange rate changes on cash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(9,164)
60
439

(8,665)

(1,664)
0
0
3,315
0

1,651
1

Net increase (decrease) in cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cash and cash equivalents at beginning of year

65,787
156,091

(1,777)
31
(425)

(2,171)

(1,313)
(22,261)
0
151,218
16,462

144,106
571

98,459
57,632

(619)
33
(86)

(672)

(998)
(37,739)
(11,060)
17,977
17,662

(14,158)
50

(93,037)
150,669

Cash and cash equivalents at end of year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$221,878

$156,091

$ 57,632

Supplemental Disclosure Of Cash Flow Information:
Interest paid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 6,954

$ 7,670

$

9,492

Supplemental Disclosure Of Non-Cash Investing and Financing Information:
Conversion of preferred stock into common stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Deemed dividend related to beneficial conversion feature of convertible preferred

stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Retirement of treasury stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Purchases of land, property and equipment included in accounts payable and accrued

liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

$

$

$

See accompanying notes to consolidated financial statements.

92

0

0

0

$ 14,561

$ 15,413

$

2,824

$ 23,070

72

$

110

$

$

$

2,260

0

46

ARENA PHARMACEUTICALS, INC.

Notes to Consolidated Financial Statements

BELVIQ® (pronounced “BEL-VEEK”) is the trade name for the finished drug product containing the active

pharmaceutical ingredient lorcaserin hydrochloride, or lorcaserin, that is marketed for chronic weight
management in the United States. Lorcaserin may in the future be marketed in the United States or in other
countries under a different trade name for chronic weight management. Lorcaserin may also be marketed under
a different trade name for a different indication, in a different formulation or in combination with another drug.
In this report, we use BELVIQ to refer to the finished drug product containing lorcaserin and/or, depending on
the context, the active pharmaceutical ingredient lorcaserin, and without regard to the current or potential
indication, formulation or combination.

(1) The Company and Summary of Significant Accounting Policies

The Company

Arena Pharmaceuticals, Inc., or Arena, was incorporated on April 14, 1997, and commenced operations in

July 1997. We are a biopharmaceutical company focused on discovering, developing and commercializing novel
drugs that target G protein-coupled receptors, or GPCRs, to address unmet medical needs. We operate in one
business segment. Our US operations are located in San Diego, California, and our operations outside of the
United States, including our commercial manufacturing facility, are located in Zofingen, Switzerland.

BELVIQ, our internally discovered drug for chronic weight management in adults who are overweight with

a comorbidity or obese, is our first and only drug approved for marketing by any regulatory agency. In June
2013, BELVIQ was made available to patients by prescription in the United States by Eisai. Our wholly owned
subsidiary, Arena Pharmaceuticals GmbH, or Arena GmbH, granted Eisai Inc. and Eisai Inc.’s parent company,
Eisai Co., Ltd. (collectively with Eisai Inc., Eisai) exclusive commercialization rights to market BELVIQ in the
all of the countries in the world, except for South Korea, Taiwan, Australia, New Zealand and Israel. Arena
GmbH also granted exclusive commercialization rights to market BELVIQ to Ildong Pharmaceutical Co., Ltd., or
Ildong, for South Korea and to CY Biotech Company Limited, or CYB, for Taiwan. We also intend to enter into
collaborations for the potential regulatory approval and commercialization of BELVIQ in Australia, New
Zealand and Israel.

The marketing of BELVIQ is subject to applicable regulatory approval. BELVIQ has been approved for

marketing in the United States, but currently not in any other country.

With our collaborators or independently, we intend to continue to explore BELVIQ’s therapeutic potential

for additional indications, using new formulations and in combination with other drugs. We also intend to
continue our research and development efforts to advance our earlier-stage drug candidates and to discover and
advance additional compounds.

BELVIQ and our earlier-stage drug candidates and compounds have resulted from our GPCR-focused drug

discovery and development approach, specialized expertise and technologies.

Basis of Presentation

The accompanying consolidated financial statements reflect all of our activities, including those of our

wholly owned subsidiaries. All material intercompany accounts and transactions have been eliminated in
consolidation.

New Accounting Guidance

In February 2013, the Financial Accounting Standards Board, or FASB, issued Accounting Standards
Update, or ASU, No. 2013-04, “Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability

93

Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date.” Under ASU
No. 2013-04, companies are required to measure such obligations as the sum of the amount that the reporting
entity agreed to pay on the basis of its arrangements with co-obligors, as well as any additional amount the
reporting entity expects to pay on behalf of its co-obligors. ASU No. 2013-04 is effective for reporting periods
beginning after December 15, 2013. We do not expect the adoption of ASU No. 2013-04 to have a material
impact on our consolidated financial statements.

Use of Estimates

The preparation of financial statements in conformity with US generally accepted accounting principles, or
GAAP, requires our management to make estimates and assumptions that affect the reported amounts (including
assets, liabilities, revenues and expenses) and related disclosures. The amounts reported could differ under
different estimates and assumptions.

Reclassifications

Certain prior year amounts have been reclassified to conform to the current year presentation.

Cash and Cash Equivalents

Cash and cash equivalents consist of cash and highly liquid investments with remaining maturities of three

months or less when purchased.

Inventory

Inventory is stated at the lower of cost or market. We determine cost, which includes amounts related to

materials, labor and overhead, using a first-in, first-out basis. We evaluate our inventory each period to identify
potential obsolete, excess or otherwise non-saleable items. If non-saleable items are observed and there are no
alternate uses for the inventory, we will record a write-down to net realizable value in the period that the decline
in value is first recognized.

Concentration of Credit Risk and Major Customers

Financial instruments, which potentially subject us to concentrations of credit risk, consist primarily of cash

and cash equivalents. We limit our exposure to credit loss by holding our cash primarily in US dollars or, from
time to time, placing our cash and investments in US government, agency or government-sponsored enterprise
obligations and in corporate debt instruments that are rated investment grade, in accordance with an investment
policy approved by our Board of Directors.

Eisai is our only significant customer for BELVIQ. Eisai is the exclusive distributor of BELVIQ in the
United States, which is the only jurisdiction for which BELVIQ has received regulatory approval for marketing.
We also produce drug products for Siegfried AG, or Siegfried, under a manufacturing services agreement, and all
of our manufacturing services revenues are attributable to Siegfried.

Percentages of our total revenues are as follows:

Eisai marketing and supply agreement (See Note 12) . . . . . . . . . .
Manufacturing services agreement with Siegfried . . . . . . . . . . . . .
Other collaborative agreements . . . . . . . . . . . . . . . . . . . . . . . . . . .

96.0% 85.6% 53.2%
3.3% 13.8% 41.9%
4.9%
0.6%
0.7%

Total percentage of revenues . . . . . . . . . . . . . . . . . . . . . . . . .

100.0% 100.0% 100.0%

Year Ended December 31,

2013

2012

2011

94

Percentages of our total accounts receivable are as follows:

At December 31,

2013

2012

2011

Eisai marketing and supply agreement (See Note 12) . . . . . . . . . .
Manufacturing services agreement with Siegfried . . . . . . . . . . . . .
Ildong marketing and supply agreement (See Note 12) . . . . . . . . .
Other collaborative agreements . . . . . . . . . . . . . . . . . . . . . . . . . . .

94.5%
4.3% 12.3%
1.0% 85.5%
0.2%
0.2%

2.0% 91.3%
8.0%
0.0%
0.7%

Total percentage of accounts receivable . . . . . . . . . . . . . . . .

100.0% 100.0% 100.0%

Property and Equipment

Property and equipment are stated at cost and depreciated over the estimated useful lives of the assets
(generally 3 to 15 years) using the straight-line method. Buildings are stated at cost and depreciated over an
estimated useful life of approximately 20 years using the straight-line method. Leasehold improvements are
stated at cost and amortized over the shorter of the estimated useful lives of the assets or the lease term. Capital
improvements are stated at cost and amortized over the estimated useful lives of the underlying assets.

Intangibles

Intangible assets consist of our manufacturing facility production licenses we acquired from Siegfried in

January 2008 and are amortized using the straight-line method over its estimated useful life of 20 years.

Long-lived Assets

If indicators of impairment exist, we assess the recoverability of the affected long-lived assets by
determining whether the carrying value of such assets can be recovered through undiscounted cash flows. If
impairment is indicated, we measure the impairment loss by comparing the fair value of the asset, estimated
using discounted cash flows expected to be generated from the asset, to the carrying value.

Deferred Rent

For financial reporting purposes, rent expense is recognized on a straight-line basis over the term of the
lease. The difference between rent expense and amounts paid under lease agreements is recorded as deferred rent
in the liability section of our consolidated balance sheets.

Derivative Liabilities

We account for our warrants and other derivative financial instruments as either equity or liabilities based

upon the characteristics and provisions of each instrument. Warrants classified as equity are recorded as
additional paid-in capital on our consolidated balance sheets and no further adjustments to their valuation are
made. Warrants classified as derivative liabilities and other derivative financial instruments that require separate
accounting as liabilities are recorded on our consolidated balance sheets at their fair value on the date of issuance
and are revalued on each balance sheet date until such instruments are exercised or expire, with changes in the
fair value between reporting periods recorded as other income or expense. We estimate the fair value of our
warrants classified as derivative liabilities using the Black-Scholes option pricing model.

Foreign Currency Translation

The functional currency of our wholly owned subsidiary in Switzerland, Arena GmbH, is the Swiss franc.

Accordingly, all assets and liabilities of this subsidiary are translated to US dollars based on the applicable
exchange rate on the balance sheet date. Revenue and expense components are translated to US dollars at

95

weighted-average exchange rates in effect during the period. Gains and losses resulting from foreign currency
translation are reported as a separate component of accumulated other comprehensive income or loss in the
stockholders’ equity section of our consolidated balance sheets. Foreign currency transaction gains and losses are
included in our results of operations and, to date, have not been material.

Share-based Compensation

Our share-based awards are measured at fair value and recognized over the requisite service or performance

period. The fair value of each stock option is estimated on the date of grant using the Black-Scholes option
pricing model, based on the market price of the underlying common stock, expected life, expected stock price
volatility and expected risk-free interest rate. Expected volatility is computed using a combination of historical
volatility for a period equal to the expected term and implied volatilities from traded options to buy our common
stock, with historical volatility being weighted at 75% due to the historically low volume of traded options on our
common stock. The expected life of options is determined based on historical experience of similar awards,
giving consideration to the contractual terms of the share-based awards, vesting schedules and post-vesting
terminations. The risk-free interest rates are based on the US Treasury yield curve, with a remaining term
approximately equal to the expected term used in the option pricing model. The fair value of each restricted stock
unit award is estimated based on the market price of the underlying common stock on the date of the grant. The
fair value of restricted stock unit awards that include market-based performance conditions is estimated on the
date of grant using a Monte Carlo simulation model, based on the market price of the underlying common stock,
expected performance measurement period, expected stock price volatility and expected risk-free interest rate.
We estimate forfeitures at the time of grant and revise our estimate in subsequent periods if actual forfeitures
differ from those estimates.

Revenue Recognition

Our revenues to date have been generated primarily through collaborative agreements and, to a lesser extent,

a manufacturing services agreement. Our collaborative agreements may contain multiple elements including
commercialization rights, services (joint steering committee and research and development services) and
manufactured products. Consideration we receive under these arrangements may include upfront payments,
research and development funding, cost reimbursements, milestone payments and payments for net product
sales. We recognize revenue when (i) persuasive evidence of an arrangement exists, (ii) delivery has occurred
and title has passed, (iii) the price is fixed or determinable and (iv) collectability is reasonably assured. Any
advance payments we receive in excess of amounts earned are classified as deferred revenues. We defer
recognition of revenue at the time we sell BELVIQ to Eisai because we presently do not have the ability to
estimate product that may be returned to us. Instead, we recognize revenues from net product sales when Eisai
ships BELVIQ to their distributors. See Note 12.

We adopted revised guidance on accounting for revenue arrangements involving multiple elements on
January 1, 2011, on a prospective basis, for agreements we entered into or materially modified after adoption.
This updated guidance (i) relates to whether multiple deliverables exist, how the deliverables in a revenue
arrangement should be separated and how the consideration should be allocated, (ii) requires companies to
allocate revenues in an arrangement using estimated selling prices of deliverables if a vendor does not have
vendor-specific objective evidence or third-party evidence of selling price and (iii) eliminates the use of the
residual method and requires companies to allocate revenues using the relative selling price method.

Since adoption of this guidance, we evaluate deliverables in a multiple-element arrangement to determine

whether each deliverable represents a separate unit of accounting. A deliverable constitutes a separate unit of
accounting when it has standalone value to the customer. If the delivered element does not have standalone value
without one of the undelivered elements in the arrangement, we combine such elements and account for them as
a single unit of accounting. We allocate the consideration to each unit of accounting at the inception of the
arrangement based on the relative selling price.

96

For agreements that we entered into prior to adoption of the revised multiple-element guidance, if fair value

exists for all elements in the arrangement, we allocate the consideration to the elements based on their relative
fair values. In cases where fair value exists for the undelivered elements but does not exist for the delivered
elements, we use the residual method to allocate the arrangement consideration. In cases where the delivered
element does not have standalone value without one of the undelivered elements in the arrangement, or fair value
does not exist for certain undelivered elements, we combine such delivered and undelivered elements and
account for them as a single unit of accounting.

Non-refundable upfront payments received under our collaborative agreements for commercialization rights

have been deferred as such rights have not been deemed to have standalone value without the ongoing services
required under the agreement. Such amounts are recognized as revenue on a straight-line basis over the period in
which we expect to perform the services. Amounts we receive as reimbursement for our research and
development expenditures are recognized as revenue as the services are performed.

Under the milestone method, we recognize revenue that is contingent upon the achievement of a substantive

milestone in its entirety in the period in which the milestone is achieved. A milestone is an event (i) that can be
achieved in whole or in part on either our performance or on the occurrence of a specific outcome resulting from
our performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the
event will be achieved and (iii) that would result in additional payments being due us. A milestone payment is
considered substantive when the consideration payable to us for each milestone (a) is consistent with our
performance necessary to achieve the milestone or the increase in value to the collaboration resulting from our
performance, (b) relates solely to our past performance and (c) is reasonable relative to all of the other
deliverables and payments under the arrangement. In making this assessment, we consider all facts and
circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and
other risks that must be overcome to achieve the respective milestone, the level of effort and investment required
to achieve the respective milestone and whether any portion of the milestone consideration is related to future
performance or deliverables. Other contingent-based payments received are recognized when earned.

We manufacture drug products under a manufacturing services agreement for a single customer, Siegfried.

Upon Siegfried’s acceptance of drug products manufactured by us, we recognize manufacturing services
revenues.

Research and Development Expenses

Research and development expenses, which consist primarily of salaries and other personnel costs, clinical
trial costs and preclinical study fees, manufacturing costs for non-commercial products, and the development of
earlier-stage programs and technologies, are expensed as incurred when these expenditures have no alternative
future uses.

We accrue clinical trial expenses based on work performed. Payments made to reimburse collaborators for
our share of their research and development activities are recorded as research and development expenses, and
are recognized as the work is performed.

Comprehensive Loss

We report components of comprehensive income (loss), consisting of foreign currency translation gain and
loss, in the period in which they are recognized. Comprehensive income (loss) is defined as the change in equity
during a period from transactions and other events and circumstances from non-owner sources.

Net Loss Per Share

We calculate basic and diluted net loss per share allocable to common stockholders using the weighted-

average number of shares of common stock outstanding during the period.

97

Since we are in a net loss position, we have excluded from our calculation of diluted net loss per share all

potentially dilutive (i) stock options, (ii) restricted stock unit awards, or RSUs, (iii) Total Stockholder Return, or
TSR, performance restricted stock unit, or PRSU, awards, (iv) unvested restricted stock in our deferred
compensation plan and (v) warrants, and our diluted net loss per share is the same as our basic net loss per share.
The table below presents the potentially dilutive securities that were excluded from our calculation of diluted net
loss per share allocable to common stockholders at December 31, 2013, 2012, and 2011, in thousands.

Stock options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warrants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RSUs and unvested restricted stock . . . . . . . . . . . . . . . . . . . . . . . . .

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,

2013

2012

2011

5,158
776
74

6,008

4,261
607
303

5,171

0
0
40

40

Because the market condition for the PRSUs was not satisfied at December 31, 2013, such securities are

excluded from the table above.

Income Taxes

We use the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are
recognized for the estimated future tax consequences attributable to differences between the financial statement
carrying amounts of existing assets and liabilities and their respective tax bases. Our deferred tax assets and
liabilities are determined using the enacted tax rates expected to be in effect for the years in which those tax
assets are expected to be realized.

The realization of our deferred tax assets is dependent upon our ability to generate sufficient future taxable
income. We establish a valuation allowance when it is more-likely-than-not the future realization of all or some
of the deferred tax assets will not be achieved. The evaluation of the need for a valuation allowance is performed
on a jurisdiction-by-jurisdiction basis, and includes a review of all available evidence, both positive and negative.

The impact of an uncertain income tax position is recognized at the largest amount that is more-likely-than-

not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be
recognized if it has less than a 50% likelihood of being sustained.

(2) Fair Value Disclosures

We measure our financial assets and liabilities at fair value, which is defined as the exit price, or the amount

that would be received from selling an asset or paid to transfer a liability in an orderly transaction between
market participants at the measurement date.

We use the following three-level valuation hierarchy that maximizes the use of observable inputs and

minimizes the use of unobservable inputs to value our financial assets and liabilities:

Level 1— Observable inputs such as unadjusted quoted prices in active markets for identical instruments.

Level 2— Quoted prices for similar instruments in active markets or inputs that are observable for the asset
or liability, either directly or indirectly.

Level 3— Significant unobservable inputs based on our assumptions.

98

The following tables present our valuation hierarchy for our financial assets and liabilities that are measured

at fair value on a recurring basis, in thousands:

Fair Value Measurements at December 31, 2013

Balance at
December 31,
2013

Quoted Prices in
Active Markets
(Level 1)

Significant Other
Observable
Inputs
(Level 2)

Significant
Unobservable Inputs
(Level 3)

Assets:
Money market funds and

cash equivalents1 . . . . . . .

$208,833

$208,833

$

0

Liabilities:
Warrants . . . . . . . . . . . . . . . .

$

4,892

$

0

$ 4,892

$0

$0

Fair Value Measurements at December 31, 2012

Balance at
December 31,
2012

Quoted Prices in
Active Markets
(Level 1)

Significant Other
Observable
Inputs
(Level 2)

Significant
Unobservable Inputs
(Level 3)

Assets:
Money market funds and

cash equivalents1 . . . . . . .

$143,747

$143,747

$

0

Liabilities:
Warrants . . . . . . . . . . . . . . . .

$ 15,042

$

0

$15,042

$0

$0

(1)

Included in cash and cash equivalents on our consolidated balance sheets.

Due to impairment charges, our investment in TaiGen Biotechnology Co., Ltd., or TaiGen, has had a cost

basis of zero since December 31, 2011. In September 2013, TaiGen’s common shares began to trade on the
GreTai Securities Emerging Market, which is a thinly traded, over-the-counter market for pre-IPO securities,
under the name “TaiGen Biopharmaceuticals Holding Limited.” As this market is not deemed to be comparable
to a US over-the-counter market, the prices of securities traded on this market do not reflect fair value pursuant to
the accounting guidance over marketable securities. Accordingly, through December 31, 2013, we continued to
account for our investment in TaiGen as a cost method investment with a cost basis of zero. On January 17, 2014,
TaiGen completed an initial public offering and its common stock began to trade on the GreTai Securities Listed
Market, which is deemed to be comparable to a US over-the-counter market such that the fair value of our
investment in TaiGen became readily determinable under the accounting guidance. We will record our
investment in TaiGen, valued at approximately $49.1 million on January 17, 2014, with the unrealized gain
recorded as a component of accumulated other comprehensive income (loss) in the stockholders’ equity section
of our consolidated balance sheets. Our investment in TaiGen will continue to be recorded at fair value based on
the trading price of TaiGen’s common stock, with any unrealized gains or losses being recorded in accumulated
other comprehensive income (loss) until realized.

99

(3) Inventory

In June 2012, we began to capitalize inventory costs for BELVIQ, which were recorded as research and

development expenses prior to regulatory approval. Inventory consisted of the following, in thousands:

December 31,

2013

2012

Raw materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Work in process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Finished goods at Arena GmbH . . . . . . . . . . . . . . . . . . . .
Finished goods at Eisai . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

657
4,104
0
7,998

$

423
4,184
0
1,451

Total inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$12,759

$ 6,058

(4) Land, Property and Equipment

Land, property and equipment consisted of the following, in thousands:

Land . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Building and capital improvements . . . . . . . . . . . . . . . . .
Leasehold improvements . . . . . . . . . . . . . . . . . . . . . . . . . .
Machinery and equipment . . . . . . . . . . . . . . . . . . . . . . . . .
Computers and software . . . . . . . . . . . . . . . . . . . . . . . . . .
Furniture and office equipment . . . . . . . . . . . . . . . . . . . . .

Less accumulated depreciation and amortization . . . . . . .

December 31,

2013

2012

$ 10,854
67,747
17,854
55,143
11,568
2,207

$ 10,854
67,436
19,253
49,840
9,719
2,230

165,373
(87,985)

159,332
(83,915)

Land, property and equipment, net . . . . . . . . . . . . . .

$ 77,388

$ 75,417

(5) Intangibles

Intangibles consisted of the following, in thousands:

Acquired manufacturing production licenses – gross . . . .
Acquired manufacturing production licenses –

December 31,

2013

2012

$14,545

$14,148

accumulated amortization . . . . . . . . . . . . . . . . . . . . . . .

(4,363)

(3,537)

Intangibles, net

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$10,182

$10,611

In June 2012 when we received US Food and Drug Administration, or FDA, approval for BELVIQ, we

began to capitalize into inventory amortization expense related to the manufacturing of BELVIQ. Such
amortization will subsequently be recognized as cost of product sales when the related inventory is sold. Using
the exchange rate in effect on December 31, 2013, we expect to record amortization of $0.7 million per year
through 2027 for our manufacturing facility production licenses.

100

(6) Accounts Payable and Other Accrued Liabilities

Accounts payable and other accrued liabilities consisted of the following, in thousands:

Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued clinical and preclinical study fees . . . . . . . . . . . . . . . .
Loss provision (See Note 7) . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,

2013

2012

$3,721
1,477
1,317
567
235

$3,884
2,006
566
482
185

Total accounts payable and other accrued liabilities . . . . .

$7,317

$7,123

(7) Agreements with Siegfried

In January 2008, we acquired from Siegfried certain drug product facility assets, including manufacturing

facility production licenses, fixtures, equipment, other personal property and real estate assets in Zofingen,
Switzerland, under an asset purchase agreement. These assets are being used to manufacture BELVIQ as well as
certain drug products for Siegfried. The purchase price under the asset purchase agreement consisted of cash
consideration of CHF 31.8 million and common stock valued at $8.0 million. We paid CHF 21.8 million, or
$19.6 million, of the cash consideration in January 2008 and paid the remaining CHF 10.0 million, or $11.1
million, in 2011.

In connection with this transaction, we also entered into a long-term supply agreement for the active
pharmaceutical ingredient of BELVIQ, a manufacturing services agreement and a technical services agreement
with Siegfried. The sales prices under the manufacturing services agreement, as amended in 2011, 2012 and
2013, are below our cost to provide such services. Accordingly, we record loss provisions, classified in costs of
manufacturing services, reflecting our best estimate of the losses to be incurred during the remainder of the
agreement. Losses are determined to be the amount by which the estimated direct and indirect costs of the
services rendered exceed the estimated total manufacturing services revenues that will be generated under the
manufacturing services agreement. The remaining loss provision of $0.6 million as of December 31, 2013, is
recorded in accounts payable and other accrued liabilities on our consolidated balance sheets. See Note 6.

During the years ended December 31, 2013, 2012, and 2011, we recognized expenses of $2.8 million, $2.6

million and $3.0 million, respectively, for services incurred under the technical services agreement. The technical
services agreement provides us with administrative and other services to operate the facility.

(8) Transactions with Deerfield

In July 2009, pursuant to a Facility Agreement we entered into in June 2009, or the Facility Agreement, with

Deerfield Private Design Fund, L.P., Deerfield Private Design International, L.P., Deerfield Partners, L.P.,
Deerfield International Limited, Deerfield Special Situations Fund, L.P., and Deerfield Special Situations Fund
International Limited, or collectively Deerfield, Deerfield provided us with a $100.0 million secured loan. We
received net proceeds of $95.6 million from this loan and had the right, at any time, to prepay any or all of the
outstanding principal at par. In connection with the funding of this loan, we issued Deerfield warrants to purchase
an aggregate of 28,000,000 shares of our common stock, which were exercisable until June 17, 2013, at an
exercise price of $5.42 per share. As described below, the Deerfield loan has been repaid in full and none of
Deerfield’s former warrants remain outstanding.

As of the July 2009 funding of the loan, we separately valued the following four components under the

Facility Agreement: (i) the formerly outstanding $100.0 million loan was valued at $47.9 million on a relative
fair value basis and recorded as a liability, (ii) the formerly outstanding warrants to purchase 28,000,000 shares

101

of our common stock were valued at $39.1 million on a relative fair value basis and recorded as additional paid-
in capital, (iii) Deerfield’s former right to loan us up to an additional $20.0 million under the Facility Agreement,
which we refer to as the Deerfield Additional Loan Election, was valued at $9.5 million and classified as a
liability and (iv) Deerfield’s former ability to accelerate principal payments under the loan under certain
circumstances was valued at $0.5 million and classified as a liability.

As part of our various transactions with Deerfield subsequent to the funding of the loan, we amended the

terms of the Facility Agreement, repaid portions of the loan and exchanged all of the original warrants for a
lesser number of warrants at lower exercise prices. We exchanged certain of the warrants as part of equity
financings with Deerfield in June 2010, March 2011, and January 2012. Other than the exercise period, the
exercise price and certain provisions related to cashless exercise and early termination of the warrants, all of the
warrants issued in exchange contained substantially the same terms as the original warrants. In May 2012, we
repaid the remaining portion of our note payable to Deerfield.

In addition to various transactions with Deerfield that included warrant exchanges, the following Deerfield

transactions occurred in the years ended December 31, 2012 and 2011 as follows:

•

•

•

In January 2011, we prepaid $20.0 million of the then-outstanding principal balance on the loan. In
connection with this prepayment, we retired a proportional share of the debt discount and issuance
costs directly related to the repaid debt and recognized a non-cash loss on extinguishment of debt of
$2.5 million in 2011.

In March 2011, Deerfield purchased 12,150,000 shares of our common stock at $1.46 per share and
12,150 shares of our Series C Convertible Preferred Stock, or Series C Preferred, at $1,460.00 per
share. In April 2011, Deerfield converted all of the Series C Preferred into a total of 12,150,000 shares
of common stock. The fair value of the common stock into which the Series C Preferred was
convertible on the date of issuance exceeded the proceeds allocated to the Series C Preferred on a
relative fair value basis by $2.3 million, resulting in a beneficial conversion feature that we recognized
as a decrease to additional paid-in capital and a deemed dividend to the Series C Preferred stockholders
in 2011. Net proceeds to us from this transaction, after prepayment of $17.7 million of the then-
outstanding principal balance on the loan, were $17.6 million. In conjunction with this transaction, we
agreed to exchange warrants to purchase 14,368,590 shares of our common stock at an exercise price
of $3.45 per share for new warrants to purchase a like number of shares of our common stock at an
exercise price of $1.68 per share. On a relative fair value basis, we determined that the incremental
value of these new warrants was $5.1 million, which was recorded as a component of the stock
issuance and warrant exchange. With respect to the $17.7 million prepayment, we retired a proportional
share of the debt discount and issuance costs directly related to the repaid debt and recognized a non-
cash loss on extinguishment of debt of $8.0 million, which, along with the January 2011 amount above,
totaled $10.5 million in 2011.

In January 2012, Deerfield purchased 9,953,250 shares of our common stock at $1.65775 per share and
approximately 9,953 shares of our Series D Convertible Preferred Stock, or Series D Preferred, at
$1,657.75 per share. In February 2012, Deerfield converted all of the Series D Preferred into a total of
9,953,250 shares of common stock. The fair value of the common stock into which the Series D
Preferred was convertible on the date of issuance of the Series D Preferred exceeded the proceeds
allocated to the Series D Preferred on a relative fair value basis by $2.8 million, resulting in a
beneficial conversion feature that we recognized as a decrease to additional paid-in capital and a
deemed dividend to the Series D Preferred stockholders in 2012. Net proceeds to us from this
transaction, after prepayment of $5.0 million of the then-outstanding principal balance on the loan,
were $27.9 million. In conjunction with this transaction, we issued Deerfield warrants to purchase
8,631,410 shares of our common stock at an exercise price of $1.745 per share in exchange for the
cancellation of outstanding warrants to purchase 11,800,000 shares of our common stock at an exercise
price of $5.42 per share and outstanding warrants to purchase 1,831,410 shares of our common stock at
an exercise price of $3.45 per share. On a relative fair value basis, we determined that the incremental

102

value of these new warrants was $3.8 million, which was recorded as a component of the stock
issuance and warrant exchange. With respect to the $5.0 million prepayment, we retired a proportional
share of the debt discount and issuance costs directly related to the repaid debt and recognized a non-
cash loss on extinguishment of debt of $1.7 million in 2012.

In April and May 2012, Deerfield exercised certain of its warrants to purchase a total of 4,000,000
shares of our common stock, and elected to pay the exercise price by canceling $6.7 million of the
then-outstanding principal balance on its loan. In May 2012, we prepaid the remaining outstanding
principal balance and unpaid interest on the Deerfield loan, and the Facility Agreement was terminated.
In connection with these transactions, we retired the related debt discount and issuance costs and
recognized a non-cash loss on extinguishment of debt of $4.7 million, which, along with the
January 2012 amount above, totaled $6.4 million in 2012.

From June to August 2012, we received net proceeds totaling $32.5 million from the cash exercise of
Deerfield’s remaining warrants to purchase a total of 19,000,000 shares of our common stock.

•

•

The following table summarizes the principal repayments made on the Deerfield loan from its inception

through the date it was repaid in full, in thousands:

Original loan principal
. . . . . . . . . . . . . . . . . . . . . . . . . . .
July 2009 repayment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
August 2010 repayment
. . . . . . . . . . . . . . . . . . . . . . . . . .
January 2011 repayment . . . . . . . . . . . . . . . . . . . . . . . . . .
March 2011 repayment . . . . . . . . . . . . . . . . . . . . . . . . . . .
January 2012 repayment . . . . . . . . . . . . . . . . . . . . . . . . . .
April and May 2012 cancellations as part of

warrant exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .

May 2012 repayment

Loan Principal

$100,000
(10,000)
(30,000)
(20,000)
(17,739)
(5,000)

(6,720)
(10,541)

Outstanding principal balance at December 31,

2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

0

Total interest expense of $1.9 million and $6.6 million, including accretion of the debt discount attributable
to the warrants and the other derivative financial instruments and amortization of capitalized issuance costs, was
recognized in connection with this loan in the years ended December 31, 2012, and 2011, respectively.

(9) Derivative Liabilities

In June 2006 and August 2008, we issued seven-year warrants, which we refer to as the Series B Warrants,
to purchase 829,856 and 1,106,344 shares of our common stock, respectively, at an exercise price of $15.49 and
$7.71 per share, respectively. As a result of the warrants’ anti-dilution provision and certain subsequent equity
issuances at prices below the adjustment price of $6.72 defined in the Series B Warrants, the number of shares
issuable upon exercise of the warrants increased and the exercise price decreased. In June 2013, a portion of the
June 2006 Series B Warrant was exercised to purchase 10,000 shares of our common stock, resulting in net
proceeds to us of $0.1 million, and the remaining portion of the June 2006 Series B Warrant to purchase
1,457,405 shares of common stock expired pursuant to its terms in June 2013. As of December 31, 2013, the
number of shares issuable upon exercise of the outstanding August 2008 Series B Warrant was 1,965,418 at an
exercise price of $4.34 per share. The outstanding August 2008 Series B Warrant is recorded as a derivative
liability on our consolidated balance sheets.

103

Our derivative liabilities consisted of the following as of December 31, 2013, and 2012, in thousands:

Series B Warrants – current portion . . . . . . . . . . . . . . . . . . . .

$

Total current derivative liabilities . . . . . . . . . . . . . . . . . .

Series B Warrants, less current portion . . . . . . . . . . . . . . . . . .

Total long-term derivative liabilities . . . . . . . . . . . . . . . .

December 31

2013

2012

0

0

4,892

4,892

$ 2,587

2,587

12,455

12,455

Total derivative liabilities . . . . . . . . . . . . . . . . . . . . . . . .

$4,892

$15,042

Our outstanding warrants are revalued on each balance sheet date, with changes in the fair value between

reporting periods recorded as other income or expense. At December 31, 2013, and 2012, our outstanding
warrants were valued using the Black-Scholes option pricing model and the following assumptions:

December 31, 2013

December 31, 2012

August 2008
Series B
Warrant

June 2006
Series B
Warrant

August 2008
Series B
Warrant

Risk-free interest rate . . . . . . . . . . . . . . . . . . . .
Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . .
Expected volatility . . . . . . . . . . . . . . . . . . . . . .
Expected life (years) . . . . . . . . . . . . . . . . . . . . .

0.4%
0%
64%

1.62

0.1%
0%
66%

0.50

0.3%
0%
93%

2.62

The change in the fair value of our derivative liabilities between reporting periods is recorded in the interest

and other income (expense) section of our consolidated statements of operations and comprehensive loss. We
recognized the following gain (loss) in the years ended December 31, 2013, 2012, and 2011, in thousands:

Series B Warrants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Former Deerfield acceleration right . . . . . . . . . . . . . . . . . . .

$10,150
0

$(13,480)
55

$(328)
375

Total gain (loss) from valuation of derivative

liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$10,150

$(13,425)

$ 47

December 31,

2013

2012

2011

The Deerfield acceleration right, which we separately valued at $0.5 million as of the July 2009 issuance

date and previously recorded as a derivative liability, related to a formerly outstanding right to require us to
accelerate principal payments under our formerly outstanding loan from certain Deerfield entities. Until this right
was terminated in connection with the repayment of the Deerfield loan in May 2012 (see Note 8), such right was
revalued on each balance sheet date, with changes in the fair value between reporting periods recorded as other
income or expense.

(10) Commitments

We occupy four US properties under sale and leaseback agreements that allow us the option to repurchase
these properties at various dates between 2017 and 2027 and, in some cases, include renewal options. The terms
of these leases stipulate annual increases in monthly rental payments of 2.5%. We accounted for our sale and
leaseback transactions using the required financing method because our options to repurchase these properties in
the future are considered continued involvement. Under the financing method, the book value of the properties
and related accumulated depreciation remain on our balance sheet and no sale is recognized. Instead, the sales
price of the properties is recorded as a financing obligation, and a portion of each lease payment is recorded as

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interest expense. We recorded interest expense of $7.1 million, $7.2 million and $7.3 million in the years ended
December 31, 2013, 2012, and 2011, respectively, related to these leases. We expect interest expense related to
our facilities to total $57.2 million from December 31, 2013, through the terms of the leases. As of December 31,
2013, the total financing obligation for these facilities was $72.8 million. The aggregate residual value of the
facilities at the end of the lease terms is $10.0 million.

We lease an additional US property under an operating lease, which expires in May 2027 and stipulates

annual increases in monthly rental payments of 2.5%. We also lease space in various facilities in Zofingen,
Switzerland that can be terminated with 12 months written notice under an agreement that expires in 2032.

In accordance with the lease terms for certain of our US properties, we are required to maintain deposits for

the benefit of the landlord throughout the term of the leases. A total of $1.4 million and $1.5 million were
recorded in other non-current assets on our consolidated balance sheets as of December 31, 2013, and 2012,
respectively, related to such leases.

We recognize rent expense on a straight-line basis over the term of each lease. Rent expense of $1.1 million,

$1.7 million and $1.2 million was recognized in the years ended December 31, 2013, 2012, and 2011,
respectively.

Annual future obligations as of December 31, 2013, are as follows, in thousands:

Year ending December 31,

Financing
Obligations

Operating
Leases

2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2015 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2016 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2017 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thereafter

$

8,090
9,036
9,262
9,494
9,731
74,381

$

873
841
863
884
906
8,580

Total minimum lease payments . . . . . . . . . . . . . . . . .

119,994

$12,947

Less amounts representing interest . . . . . . . . . . . . . .
Add amounts representing residual value . . . . . . . . .

Lease financing obligations . . . . . . . . . . . . . . . . . . . .
Less current portion . . . . . . . . . . . . . . . . . . . . . . . . . .

(57,190)
9,990

72,794
(2,056)

$ 70,738

(11) Stockholders’ Equity

Equity Compensation Plans

On June 10, 2013, our stockholders approved our 2013 Long-Term Incentive Plan, or 2013 LTIP. Upon

such approval, our 2012 Long-Term Incentive Plan, or 2012 LTIP, was terminated. However, notwithstanding
such termination or the previous termination of our 2009 Long-Term Incentive Plan, 2006 Long-Term Incentive
Plan, as amended, 2002 Equity Compensation Plan, Amended and Restated 2000 Equity Compensation Plan, and
Amended and Restated 1998 Equity Compensation Plan (together with the 2012 LTIP, the “Prior Plans”), all
outstanding awards under the Prior Plans will continue to be governed under the terms of the Prior Plans. The
number of shares of common stock authorized for issuance under the 2013 LTIP may be increased by the number
of shares subject to any stock awards under the Prior Plans that are forfeited, expire or otherwise terminate
without the issuance of such shares and would otherwise be returned to the share reserve under the Prior Plans
but for their termination and as otherwise provided in the 2013 LTIP.

105

The 2013 LTIP provides for the grant of a total of 30 million shares of our common stock (subject to

adjustment for certain corporate events), as (i) decreased for grants made under the Prior Plans between
December 31, 2012, and the approval of the 2013 LTIP and (ii) increased by the number of shares subject to any
stock awards under the Prior Plans that, between December 31, 2012, and the approval of the 2013 LTIP, are
forfeited, expire or settled for cash and as otherwise provided in the 2013 LTIP.

Shares under the 2013 LTIP may be granted as incentive stock options, nonstatutory stock options, stock

appreciation rights, restricted stock awards, restricted stock unit awards and performance awards. Subject to
certain limited exceptions, stock options and stock appreciation rights granted under the 2013 LTIP reduce the
available number of shares by one share for every share issued while awards other than stock options and stock
appreciation rights granted under the 2013 LTIP reduce the available number of shares by 1.25 shares for every
share issued. In addition, shares that are released from awards granted under the Prior Plans or the 2013 LTIP
because the awards expire, are forfeited or are settled for cash will increase the number of shares available under
the 2013 LTIP by one share for each share released from a stock option or stock appreciation right and by 1.25
shares for each share released from awards other than stock options and stock appreciation rights.

Stock options granted under the 2013 LTIP generally vest 25% a year for four years and are exercisable for
up to seven years from the date of grant. The recipient of a restricted stock award has all rights of a stockholder
at the date of grant, subject to certain restrictions on transferability and a risk of forfeiture. Restricted stock unit
awards generally vest over one or four years from the date of grant. The minimum performance period under a
performance award is 12 months. Neither the exercise price of an option nor the grant price of a stock
appreciation right may be less than 100% of the fair market value of the common stock on the date such equity
award is granted, except in specified situations. The 2013 LTIP prohibits option and stock appreciation right
repricings (other than to reflect stock splits, spin-offs or certain other corporate events) without stockholder
approval.

In 2003, we set up a deferred compensation plan for our executive officers, whereby executive officers
elected to contribute their shares of restricted stock into the plan. There were 79,169 shares of restricted stock in
the plan at December 31, 2013, 2012 and 2011.

The following table summarizes our stock option activity under the Prior Plans and the 2013 LTIP, or
collectively, our Equity Compensation Plans, for the year ended December 31, 2013, in thousands (except per
share data):

Weighted-
Average
Exercise Price

Weighted-Average
Remaining
Contractual
Term (in years)

Aggregate
Intrinsic
Value

Outstanding at December 31, 2012 . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited/cancelled/expired . . . . . . . . . . . . .

Options

13,842
2,082
(954)
(289)

Outstanding at December 31, 2013 . . . . . . .

14,681

$4.44
7.58
2.49
5.98

$4.99

Vested and expected to vest at

December 31, 2013 . . . . . . . . . . . . . . . . . .

14,186

$4.97

Vested and exercisable at December 31,

2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7,244

$6.07

6.19

6.15

4.95

$31,782

$30,961

$11,999

The aggregate intrinsic value in the above table is calculated as the difference between the closing price of

our common stock at December 31, 2013, of $5.85 per share and the exercise price of stock options that had
strike prices below the closing price. The intrinsic value of all stock options exercised during the years ended
December 31, 2013, and 2012 was $4.6 million and $5.4 million, respectively, and there were no stock options

106

exercised in 2011. During the year ended December 31, 2013, cash of $2.4 million was received from stock
option exercises and cash of $0.9 million was received from stock purchases under the employee stock purchase
plans. There is no tax impact related to share-based compensation or stock option exercises because we are in a
net operating loss position with a full valuation allowance.

In June 2013, we granted to our non-employee directors 131,096 RSUs that vest in equal monthly
installments over one year from the date of grant, and will convert to the underlying common shares at the
earliest of (i) the three-year anniversary of the grant date, (ii) the director’s separation from service or (iii) a
change in control of Arena. In December 2013, we granted to our executive officers 180,000 RSUs that vest
25% per year over four years from the date of grant. The following table summarizes activity with respect to our
time-based RSUs under our Equity Compensation Plans for the year ended December 31, 2013, in thousands
(except per share data):

Unvested at January 1, 2013 . . . . . . . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited/cancelled . . . . . . . . . . . . . . . . . . . . . . . . . . .

Unvested at December 31, 2013 . . . . . . . . . . . . . . . .

Outstanding at December 31, 2013 . . . . . . . . . . . . . .

RSUs

165
311
(107)
0

369

435

Weighted-Average
Grant-Date Fair
Value

Aggregate
Intrinsic
Value

$8.87
6.91
8.83

$7.23

$8.31

$2,544

The total fair value of RSUs vested during the year ended December 31, 2013, was $0.9 million.

In March 2013, we granted PRSU awards to our executive officers. The PRSUs may be earned and
converted into outstanding shares of our common stock based on the TSR of our common stock relative to the
TSR over a three-year performance period beginning March 1, 2013, of the NASDAQ Biotech Index. In the
aggregate, the target number of shares of common stock that may be earned under the PRSUs is 780,000;
however, the actual number of shares that may be earned ranges from 0% to 200% of such amount based on our
TSR performance. As these awards contain a market condition, we used a Monte Carlo simulation model to
estimate their grant-date fair value, which totaled $5.9 million and will be recognized over the performance
period. The aggregate intrinsic value of the outstanding PRSUs as of December 31, 2013, was $4.6 million. All
of the PRSUs were outstanding and unvested at December 31, 2013.

Employee Stock Purchase Plans

In June 2012, our stockholders approved our 2009 Employee Stock Purchase Plan, as amended, or 2009
ESPP, which (i) increased the shares of our common stock authorized and available for future issuance under the
plan to a total of 1,500,000 as of June 15, 2012, (ii) modified the plan’s automatic transfer to a lower price
offering period to be based on the enrollment date of a new offering period instead of the exercise date of the
immediately preceding offering period, (iii) eliminated references to our former 2001 Employee Stock Purchase
Plan, as amended, and (iv) changed the termination date of the plan to the date our Board of Directors determines
to terminate the plan. Under applicable accounting guidance, the 2009 ESPP is considered a compensatory plan.
As of December 31, 2013, a total of 900,659 shares of common stock were available for issuance under the 2009
ESPP.

Under the 2009 ESPP, substantially all employees can choose to have up to 15% of their annual

compensation withheld to purchase up to 625 shares of common stock per purchase period, subject to certain
limitations. The shares of common stock may be purchased over an offering period with a maximum duration of

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24 months and at a price of not less than 85% of the lesser of the fair market value of the common stock on
(i) the first trading day of the applicable offering period or (ii) the last trading day of the applicable three-month
purchase period.

During the years ended December 31, 2013, 2012, and 2011, 334,360, 341,108 and 272,014 shares,

respectively, were purchased under our 2009 ESPP.

Share-based Compensation

We estimate the grant-date fair value of all of our share-based awards in determining our share-based
compensation expense. Our share-based awards include (i) stock options, (ii) options to purchase stock granted
under our employee stock purchase plan, (iii) restricted stock unit awards, or RSUs, and (iv) Total Stockholder
Return, or TSR, performance restricted stock unit, or PRSU, awards.

The table below sets forth the weighted-average assumptions and estimated fair value of stock options we

granted under our Equity Compensation Plans during the years ended December 31, 2013, 2012, and 2011:

Risk-free interest rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected volatility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected life (years) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Weighted-average estimated fair value per share of stock options
granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,

2013

2012

2011

1.3%
0%
80%

1.4%
0%
90%

2.2%
0%
86%

6.24

6.05

5.86

$5.25

$2.27

$1.06

The table below sets forth the assumptions and estimated fair value of the options to purchase stock granted
under our employee stock purchase plan for multiple offering periods during the years ended December 31, 2013,
2012, and 2011:

Risk-free interest rate . . . . . . . . . . . . . . . . .
Dividend yield . . . . . . . . . . . . . . . . . . . . . .
Expected volatility . . . . . . . . . . . . . . . . . . .
Expected life (years)
. . . . . . . . . . . . . . . . .
Range of fair value per share of options

granted under employee stock purchase
plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,

2013

2012

2011

0.0% - 0.5%
0%
79% -105%
0.25 - 2.0

0.0% - 0.7%
0%
85% - 106%
0.25 - 2.0

0.0% - 1.1%
0%
71% - 106%
0.25 - 2.0

$0.90 to $5.44

$0.56 to $5.44

$0.56 to $3.28

The table below sets forth the assumptions and estimated fair value of PRSU awards at the March 5, 2013,

date of grant:

Risk-free interest rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected volatility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remaining performance period (years)
. . . . . . . . . . . . . . . . . . .
Estimated fair value per share of PRSUs granted . . . . . . . . . . . .

0.4%
0%
89%
2.99
$ 7.50

108

We recognized share-based compensation expense as follows, in thousands, except per share data:

December 31,

2013

2012

2011

Cost of product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research and development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restructuring charges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

17
4,318
4,689
0

$

0
1,822
3,250
0

$

0
1,958
1,696
94

Total share-based compensation expense and impact on net loss allocable to

common stockholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$9,024

$5,072

$3,748

Impact on net loss per share allocable to common stockholders, basic and

diluted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 0.04

$ 0.03

$ 0.03

Share-based compensation capitalized into inventory . . . . . . . . . . . . . . . . . . . . . .

$

75

$

54

$

0

In June 2012, we began to capitalize into inventory share-based compensation related to awards granted to
employees involved with the manufacturing of BELVIQ. Such compensation will subsequently be recognized as
cost of product sales when the related inventory is sold.

The table below sets forth our total unrecognized estimated compensation expense at December 31, 2013,

by type of award and the weighted-average remaining requisite service period over which such expense is
expected to be recognized:

December 31, 2013

Unrecognized
Expense (in
thousands)

Remaining
Weighted-Average
Recognition
Period (in years)

Unvested stock options . . . . . . . . . . . . . . . . . . . .
RSUs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PRSUs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$16,055
2,695
4,236

2.35
3.00
2.16

Common Stock Reserved for Future Issuance

The following shares of our common stock are reserved for future issuance at December 31, 2013, in

thousands:

Outstanding warrants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equity Compensation Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2009 ESPP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred compensation plan . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1,965
43,056
901
79

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46,001

(12) Collaborations

Eisai

In November 2013, Arena GmbH and Eisai entered into the Second Amended and Restated Marketing and

Supply Agreement, or Eisai Agreement, which amended and restated the previous agreement and expanded
Eisai’s exclusive commercialization rights for BELVIQ to all of the countries in the world, except for South
Korea, Taiwan, Australia, New Zealand and Israel. Eisai’s commercialization rights are subject to applicable

109

regulatory approval. In addition to providing commercialization rights, we provide services related to
development and regulatory activities, and we manufacture and sell BELVIQ to Eisai. Under the Eisai
Agreement, we are entitled to receive upfront payments, milestone payments based on the achievement of
regulatory filings and approvals, one-time purchase price adjustment payments and other payments, and
payments from sales of BELVIQ.

Arena GmbH and Eisai Inc. entered into the original marketing and supply agreement in July 2010, under
which we granted Eisai Inc. exclusive commercialization rights for BELVIQ solely in the United States and its
territories and possessions. In May 2012, Arena GmbH and Eisai Inc. amended and restated such agreement by
entering into the first amended agreement, which expanded Eisai Inc.’s exclusive commercialization rights to
include most of North and South America.

The following table summarizes the revenues we have recognized under our collaboration with Eisai for the

periods presented, in thousands:

Milestone payments . . . . . . . . . . . . . . . . . . . .
Net product sales . . . . . . . . . . . . . . . . . . . . . .
Amortization of upfront payments . . . . . . . . .
Reimbursement of research and development
expenses . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reimbursement of patent expenses . . . . . . . .

December 31,

2013

2012

2011

$66,000
5,702
4,035

$20,000
0
3,503

$

0
0
3,434

2,020
361

27
87

3,336
0

From Inception
Through December 31,
2013

$ 86,000
5,702
12,895

5,383
448

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$78,118

$23,617

$6,770

$110,428

The following table summarizes the deferred revenues under our collaboration with Eisai as of

December 31, 2013, and 2012, in thousands:

December 31,

2013

2012

Upfront payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$102,104
30,299

$ 46,140
11,594

Total deferred revenues attributable to Eisai . . . . . . .
Less current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

132,403
(37,301)

57,734
(15,040)

Deferred revenues attributable to Eisai, less current

portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 95,102

$ 42,694

Upfront and Milestone Payments

In connection with entering into the Eisai Agreement, we received from Eisai an upfront payment of

$60.0 million. This payment is in addition to the $50.0 million and $5.0 million in upfront payments we received
from Eisai in connection with entering into the original agreement and the first amended agreement, respectively.
Revenues from these upfront payments have been deferred, as we determined that the exclusive rights did not
have standalone value without our ongoing development and regulatory activities. Accordingly, these payments
are recognized ratably as revenue over the periods in which we expect the services to be rendered, which are
approximately 15, 16 and 15 years for the Eisai Agreement, original agreement and first amended agreement,
respectively.

In addition to the upfront payments, we have received from Eisai a total of $86.0 million in milestones
payments, comprised of (i) $65.0 million in 2013 earned upon the final scheduling designation for BELVIQ by
the US Drug Enforcement Administration, or DEA, (ii) $20.0 million earned in 2012 for the inclusion in the

110

approved prescribing information of the FDA of the efficacy and safety data from the Phase 3 BLOOM-DM
(Behavioral modification and Lorcaserin for Overweight and Obesity Management in Diabetes Mellitus) clinical
trial in patients with type 2 diabetes, (iii) $0.5 million earned in 2013 upon Eisai filing for regulatory approval of
BELVIQ in Mexico and (iv) $0.5 million earned in 2013 upon Eisai filing for regulatory approval of BELVIQ in
Canada.

Under the Eisai Agreement, we are eligible to receive up to an aggregate of $176.5 million in additional

regulatory and development milestone payments.

Product Purchase Price and Purchase Price Adjustment Payments

We manufacture BELVIQ at our facility in Switzerland, and sell BELVIQ to Eisai for Eisai’s

commercialization in the United States and, subject to applicable regulatory approval, in the other territories
under the Eisai Agreement (other than Europe, China and Japan) for a purchase price starting at 31.5% and
30.75%, respectively (and starting at 27.5% in Europe, China and Japan), of Eisai’s aggregate annual net product
sales (which are the gross invoiced sales less certain deductions described in the Eisai Agreement), or the Product
Purchase Price, in the respective territory. The Product Purchase Price will increase on a tiered basis in the
United States and the other territories (other than Europe, China and Japan) to as high as 36.5% and 35.75%,
respectively, on the portion of Eisai’s annual aggregate net product sales exceeding $750.0 million in all
territories other than Europe, China and Japan. The Product Purchase Price will increase to 35% in Europe, China
and Japan on the portion of Eisai’s annual aggregate net product sales exceeding $500.0 million in such
territories. The Product Purchase Price is subject to reduction (for sales in a particular country), including in the
event of generic competition in the applicable country. The revenue we recognize for BELVIQ product revenue
related to redemption of vouchers is based on our cost of goods sold.

In addition to payments for purchases of BELVIQ, we are eligible to receive up to an aggregate of $1.56
billion in one-time purchase price adjustment payments and other payments. These payments include up to an
aggregate of $1.19 billion that are based on Eisai’s annual net product sales of BELVIQ in all of the territories
under the Eisai Agreement on an aggregate basis, with the first and last amounts payable with annual net product
sales of $250.0 million and $2.5 billion, respectively. Of these payments, Eisai will pay us a total of
$330.0 million for annual net product sales of up to $1.0 billion. The $1.56 billion also includes $370.0 million in
one-time purchase price adjustment payments we are eligible to receive based on annual net product sales in the
non-US territories, comprised of $185.0 million based on Eisai’s annual net product sales in the non-US
territories in North and South America and $185.0 million based on Eisai’s annual net product sales the
territories outside of North and South America. The first and last amounts are payable upon first achievement of
annual net product sales of $100.0 million and $1.0 billion, respectively, with respect to each of the following
areas: (i) the non-US territories in North and South America and (ii) the territories outside of North and South
America. In addition, we are also eligible to receive certain payments by Eisai if certain annual minimum sales
requirements in Mexico, Canada and Brazil are not met during the first ten years after initial commercial sale in
such territories.

The amount that Eisai pays us for BELVIQ product supply is based on Eisai’s estimated price at the time the

order is shipped, which is Eisai’s estimate of the Product Purchase Price, and is subject to change on April 1 and
October 1 of each year. Eisai’s estimate of the Product Purchase Price was changed as of October 1, 2013. At the
end of Eisai’s fiscal year (March 31), the estimated price paid to us for product that Eisai sold to their distributors
is compared to the Product Purchase Price of such product, and the difference is either refunded back to Eisai (for
overpayments) or paid to us (for underpayments). On a monthly basis, Eisai provides us the total amount of net
product sales for the month, details of the total deductions from gross to net product sales and the sales in units.
We recognize our revenues monthly based on our percentage of Eisai’s monthly net product sales figures. When
the revenues we recognize differ from the estimated price that Eisai paid us for such product, the difference is
reclassified from deferred revenues to a receivable or payable account, as appropriate. We also adjust the
deferred revenues balance for the product supply held at Eisai based on the most current net product sales figures
provided to us, with the difference reclassified from deferred revenues to a receivable or payable account.

111

We recognized total revenues from BELVIQ net product sales of $5.7 million in the year ended

December 31, 2013, of which $5.3 million related to sales at the Product Purchase Price and $0.4 million related
to redemptions of vouchers. The Product Purchase Price for the product Eisai has sold to date was lower than the
estimated price that Eisai paid us, primarily because the price that Eisai paid us did not include deductions for the
use of vouchers, savings cards and deductions for certain items related to product launch. These excess payments,
which reflect both the amounts Eisai has sold to date and the product supply remaining in Eisai’s inventory at
December 31, 2013, are included in the $19.3 million classified as Payable to Eisai on our consolidated balance
sheets.

Development Payments

In connection with the US approval of BELVIQ, the FDA is requiring (i) an evaluation as part of the
cardiovascular outcomes trial, or CVOT, of the effect of long-term treatment with BELVIQ on the incidence of
major adverse cardiovascular events, or MACE, in overweight and obese patients with cardiovascular disease or
multiple cardiovascular risk factors and (ii) the conduct of postmarketing studies to assess the safety and efficacy
of BELVIQ for weight management in obese pediatric patients. In addition to the FDA-required studies, we and
Eisai are prioritizing the development areas of smoking cessation, a once-daily formulation, co-administration
with phentermine, as well as exploring, including as part of the CVOT, BELVIQ’s effect on conversion to type 2
diabetes and improvements in cardiovascular outcomes.

112

The below chart summarizes the general agreement regarding cost sharing between Eisai and us for
significant development activities under the Eisai Agreement. In addition, Eisai or we may from time to time
conduct approved development of BELVIQ at such party’s own expense. For example, Eisai is responsible for
the expenses of the pilot study of 12-week duration to preliminarily assess BELVIQ and phentermine when co-
administered.

Eisai Second Amended and Restated Marketing and Supply Agreement: Cost Sharing for Development

United States

Rest of
North and South America

Remaining Territories

BELVIQ for weight
management
- Pre-approval*

Not Applicable

General
Eisai: 90%; Arena: 10%

Up to total of $100.0 million -
Eisai: 50%; Arena: 50%

Certain stability work
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 100%

General
Eisai: 90%; Arena: 10%

Up to total of $50.0 million -
Eisai: 50%; Arena: 50%

Certain stability work
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 90%;
Arena: 10%

General - Eisai: 90%; Arena 10%

Non-FDA required portion of CVOT
Up to $80.0 million -
Eisai: 50%; Arena: 50%
Thereafter, Eisai: 100%

Certain pediatric studies
Eisai: 50%; Arena: 50%

Up to total of $250.0 million (as reduced by up to $80.0 million for non-FDA required portion of
CVOT) - Eisai: 50%; Arena: 50%

Up to a total of $100.0 million in the aggregate across all additional products -
Eisai: 50%; Arena: 50%

Thereafter, Eisai: 90%; Arena: 10%

BELVIQ for weight
management
- Post-approval*

Products other than
BELVIQ for weight
management
- Pre-approval

Products other than
BELVIQ for weight
management
- Post-approval

*

Development required by a regulatory authority, with the exception of the non-FDA required portions of the CVOT.

Certain Other Terms

Eisai and we have agreed to limitations on the ability to commercialize outside of the Eisai Agreement any
weight management product or addiction disorder product in the territories under the agreement. The agreement
includes a stand-still provision limiting Eisai’s ability to acquire our securities and assets.

Eisai may terminate the Eisai Agreement with respect to any country in the territory following the later of

the expiration of all issued BELVIQ patents in such country and 12 years after the first commercial sale of
BELVIQ in such country. Arena GmbH and Eisai each has the right to terminate the Eisai Agreement early in
certain circumstances in its entirety or with respect to the applicable country or product, including (a) if the other
party is in material breach, (b) for commercialization concerns, and (c) for certain intellectual property
infringement. Eisai also has the right to terminate the Eisai Agreement early in its entirety or with respect to each
country in certain circumstances, including (i) termination in a country if sales of generic equivalents of BELVIQ
in such country exceed sales of BELVIQ in that country (based on volume), and (ii) if Eisai is acquired by a
company that has a product that competes with BELVIQ. In addition, Arena GmbH can terminate the Eisai
Agreement early in its entirety or with respect to each country in the non-US territories in North and South
America in certain circumstances, including termination in each country if Eisai does not satisfy certain
regulatory filing and commercialization diligence requirements in such country.

113

Eisai will indemnify us for losses resulting from certain third-party claims, including for (a) Eisai’s
negligence, willful misconduct or violation of law, but excluding product liability claims, (b) Eisai’s breach of
the Eisai Agreement or related agreements, but excluding product liability claims, (c) certain uses or misuses of
BELVIQ, (d) certain governmental investigations of Eisai related to BELVIQ, and (e) infringement relating to
Eisai’s use of certain trademarks, tag lines and logos related to BELVIQ. Arena GmbH will indemnify Eisai for
losses resulting from certain third-party claims, including for (i) Arena GmbH’s negligence, willful misconduct,
failure to comply with law, breach of any agreement with a third party with respect to product development prior
to the effective date of the original agreement with Eisai, but excluding product liability claims, (ii) Arena
GmbH’s negligence or willful misconduct with respect to certain uses or misuses of BELVIQ outside of the
agreement, (iii) certain uses or misuses of BELVIQ after the term of the agreement, in any territory no longer
under the agreement or with respect to any product after the termination of the agreement with respect to such
product, (iv) Arena GmbH’s negligence, willful misconduct or violation of law, but excluding product liability
claims, (v) Arena GmbH’s breach of the Eisai Agreement or related agreements, but excluding product liability
claims, (vi) certain infringement of intellectual rights of a third party, and (vii) infringement relating to Eisai’s
use of certain trademarks related to BELVIQ. We are unable to predict the maximum potential amount of any
indemnification claims. As of December 31, 2013, we have not incurred any losses under these indemnification
provisions.

Arena GmbH and Eisai will, in general, share equally in losses resulting from third-party product liability
claims, except where one party’s acts or omissions did not contribute to the events or circumstances leading to
such product liability claim and the other party’s actual willful misconduct, violation of law or breach of its
obligations under the Eisai Agreement or certain other agreements between Arena GmbH and Eisai were the sole
and direct cause of the product liability claim. We are unable to predict the range of loss from future product
liability claims.

Other Collaborations

In addition to the Eisai Agreement, Arena GmbH entered into the Marketing and Supply Agreement, or
Ildong BELVIQ Agreement, with Ildong for South Korea in November 2012, and into the Marketing and Supply
Agreement, or CYB Agreement, with CYB for Taiwan in July 2013. Under the Ildong BELVIQ Agreement, we
received from Ildong an upfront payment of $5.0 million, less withholding taxes, and will receive an additional
$3.0 million if and when BELVIQ is approved by the South Korean Ministry of Food and Drug Safety, as well as
payments from sales of BELVIQ and purchase price adjustment payments based on Ildong’s annual net product
sales (which are the gross invoiced sales less certain deductions described in the Ildong BELVIQ Agreement).
We recorded this upfront payment as deferred revenue and are recognizing it as revenue ratably over
approximately 14 years, which is the period in which we expect to provide services under the arrangement. At
December 31, 2013, our consolidated balance sheet included $0.4 million and $4.2 million for the current and
non-current portion, respectively, of the deferred revenue attributable to such upfront payment. For the years
ended December 31, 2013, and 2012, we recognized revenues of $0.5 million and $0.1 million, respectively,
under the Ildong BELVIQ Agreement.

Under the CYB Agreement, we received from CYB an upfront payment of $2.0 million, net of withholding

taxes. We recorded this upfront payment as deferred revenue and are recognizing it as revenue ratably over
approximately 14 years, which is the period in which we expect to provide services under the arrangement. At
December 31, 2013, our consolidated balance sheet included $0.2 million and $2.0 million for the current and
non-current portion, respectively, of the deferred revenue attributable to such upfront payment. For the year
ended December 31, 2013, we recognized revenues of $0.1 million under the CYB Agreement. Subject to
regulatory approval of BELVIQ by the Taiwan Food and Drug Administration, or TFDA, we will receive
payments from sales of BELVIQ, and are eligible to receive purchase price adjustment payments based on

114

CYB’s annual net product sales (which are the gross invoiced sales less certain deductions described in the CYB
Agreement), as well as a milestone payment upon approval of the first additional indication for BELVIQ by the
TFDA.

Arena GmbH also entered into the Co-Development and License Agreement with Ildong for temanogrel, our

internally discovered candidate intended for the treatment of thrombotic diseases. Under such agreement, we
granted Ildong exclusive rights to commercialize temanogrel in South Korea for myocardial infarction, acute
coronary syndrome, stroke, peripheral artery disease, and other cardiovascular diseases, subject to further
development and regulatory approval of temanogrel. Initially, Ildong will be responsible for funding and
conducting, under the direction of a joint steering committee, the next two planned clinical trials in this program:
an additional Phase 1 trial in healthy volunteers and a Phase 2a proof-of-concept trial in patients. To date, we
have not recognized any revenue under this agreement. We will maintain ownership of temanogrel outside of
South Korea, and have the rights to use data generated by Ildong for the development and potential
commercialization of temanogrel outside of South Korea by us or other Arena licensees. In addition, Ildong has
agreed to pay us a $2.0 million development milestone if the planned additional Phase 1 and Phase 2a clinical
trials conducted by Ildong support continued development and we or another Arena licensee initiates a Phase 2b
clinical trial of temanogrel. We are also eligible to receive a royalty on net product sales of temanogrel in South
Korea, and Ildong is eligible to receive a share of future payments received by us related to licensing transactions
and sales of temanogrel in other territories.

(13) Restructuring Charges

In March 2011, we completed a reduction of our US workforce and recorded a charge of $3.5 million in
2011, which is reflected as restructuring charges in the accompanying consolidated statements of operations and
comprehensive loss.

(14) Employee Benefit Plans

401(k) Plan

All of our US employees are eligible to participate in our defined contribution retirement plan that complies
with Section 401(k) of the Internal Revenue Code. We match 100% of each participant’s voluntary contributions,
subject to a maximum of 6% of the participant’s eligible compensation. Our matching portion, which totaled
$1.5 million, $1.1 million and $1.2 million in the years ended December 31, 2013, 2012, and 2011, respectively,
vests over a five-year period from the date of hire.

Pension Plan

Arena GmbH contributes to a multiemployer defined benefit pension plan, established under an affiliated
group of employers, for the purpose of providing mandatory occupational pension benefits for its employees. The
risks of participating in a multiemployer plan are different from a single-employer plan in that (i) assets
contributed to the multiemployer plan by one employer may be used to provide benefits to employees of other
participating employers, (ii) if a participating employer stops contributing to the plan, the unfunded obligations
of the plan may be borne by the remaining participating employers, (iii) if Arena GmbH elects to stop
participating in the multiemployer plan, Arena GmbH may be required to pay the plan an amount based on the
underfunded status of the plan, referred to as a withdrawal liability, and (iv) Arena GmbH has no involvement in
the management of the multiemployer plan’s investments. We currently have no intention of withdrawing from
the multiemployer plan.

Our contributions to the multiemployer plan were $0.7 million in the year ended December 31, 2013, and

$0.6 million in each of the years ended December 31, 2012, and 2011.

115

(15) Income Taxes

Our loss before benefit for income taxes is summarized by region as follows, in thousands:

United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 11,573
(31,008)

$(62,674)
(22,803)

$ (75,209)
(34,015)

Total loss before income taxes . . . . . . . . . . . . . . .

$(19,435)

$(85,477)

$(109,224)

December 31,

2013

2012

2011

We have not recorded a benefit for income taxes for the years ended December 31, 2013, 2012, and 2011

because we have a full valuation allowance.

Our effective income tax rate differs from the statutory Federal rate of 34% at December 31, 2013, 2012,

and 2011, due to the following, in thousands:

Benefit for income taxes at statutory Federal rate . . . . . . . . . . . . .
State income tax, net of Federal benefit . . . . . . . . . . . . . . . . . . . . .
Permanent differences and other . . . . . . . . . . . . . . . . . . . . . . . . . .
Gain (Loss) from valuation of derivative liabilities . . . . . . . . . . . .
Foreign losses at lower effective rates . . . . . . . . . . . . . . . . . . . . . .
Research and development credit . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustment to research and development credits and net

December 31,

2013

2012

2011

$ (6,608)
(901)
2,122
(3,922)
9,527
(2,594)

$(29,062)
(4,390)
(2,770)
5,244
6,744
(1,005)

$(37,136)
(3,857)
(1,124)
123
8,509
(1,955)

operating losses, or NOLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valuation allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(59,790)
62,166

4,831
20,408

7,086
28,354

Benefit for income taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

0

$

0

$

0

The components of our net deferred tax assets are as follows, in thousands:

Deferred tax assets:

Foreign NOL carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Federal and California NOL carryforwards . . . . . . . . . . . . . . . . . .
Federal and California research and development credit

carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Share-based compensation expense . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other, net

Total deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred tax liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valuation allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,

2013

2012

$

9,678
231,450

$

8,264
210,005

40,948
21,109
4,245
7,223
5,921

0
23,346
8,055
5,698
3,142

320,574
(1,853)

318,721
(318,721)

258,510
(1,957)

256,553
(256,553)

Net deferred tax liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

0

$

0

116

A valuation allowance is recorded against all of our deferred tax assets, as realization of such assets is not

more-likely-than-not. The realization of our deferred tax assets is dependent upon future taxable income. Our
ability to generate taxable income is analyzed regularly on a jurisdiction-by-jurisdiction basis. At such time as it
is more-likely-than-not that we will generate taxable income in a jurisdiction, we will reduce or remove the
valuation allowance. The valuation allowance increased by $62.2 million in 2013, compared to 2012.

At December 31, 2013, we had Federal NOL carryforwards of $586.4 million that will begin to expire in

2022 unless previously utilized. At the same date, we had California NOL carryforwards of $607.1 million,
which will begin to expire in 2014, and foreign NOL carryforwards of $121.0 million, which will begin to expire
in 2015. At December 31, 2013, approximately $8.4 million of the Federal and California NOL carryforwards
related to stock option exercise windfalls, which will result in an increase to additional paid-in capital, or APIC,
and a decrease in income taxes payable at the time such carryforwards are utilized. We also had Federal and
California research and development tax credit carryforwards, net of reserves, of $27.2 million and $20.8 million,
respectively. Federal research and development credit carryforwards will begin to expire in 2026 unless
previously utilized. The California research and development credit carryforwards carry forward indefinitely. No
deferred tax assets were recognized in our 2012 financial statements for Federal or California research and
development credits, as a formal study had not been performed to substantiate the validity of such credits. A
formal analysis of Federal and California research and development credits earned in prior years was conducted
in 2013, and we disclosed the credits as deferred tax assets as of December 31, 2013.

Sections 382 and 383 of the Internal Revenue Code, or IRC, limit the utilization of tax attribute

carryforwards that arise prior to certain cumulative changes in a corporation’s ownership. We have completed an
IRC Section 382/383 analysis through 2013 and identified ownership changes that limit our utilization of tax
attribute carryforwards. We have also adjusted our NOL carryforwards by jurisdiction based upon an additional
analysis. We reduced deferred tax assets associated with such tax attribute carryforwards to remove deferred tax
assets that will expire prior to utilization, as well as incorporating other adjustments based upon such additional
analysis. No deferred tax assets associated with California NOLs were recognized in our 2012 financial
statements as a California analysis of IRC Section 382 had not been completed. During 2013, we performed a
formal IRC Section 382 analysis and we disclosed California NOLs as deferred tax assets as of December 31,
2013.

In accordance with authoritative guidance, the impact of an uncertain income tax position on the income tax

return must be recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the
relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50%
likelihood of being sustained.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows, in

thousands:

December 31,

2013

2012

2011

Gross unrecognized tax benefits at the beginning of the year . . . . .
Additions from tax positions taken in the current year
. . . . . . . . . .
Additions from tax positions taken in prior years . . . . . . . . . . . . . .
Reductions from tax positions taken in prior years . . . . . . . . . . . . .
Tax settlements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

0
541
4,088
0
0

$0
0
0
0
0

$0
0
0
0
0

Gross unrecognized tax benefits at end of the year . . . . . . . . .

$4,629

$0

$0

Of our total unrecognized tax benefits, $3.4 million will impact our effective tax rate in the event the
valuation allowance is removed. We do not anticipate that there will be a substantial change in unrecognized tax
benefits within the next 12 months.

117

Our practice is to recognize interest and/or penalties related to income tax matters in income tax expense.

Because we have incurred net losses since our inception, we did not have any accrued interest or penalties
included in our consolidated balance sheets at December 31, 2013, or 2012, and did not recognize any interest
and/or penalties in our consolidated statements of operations and comprehensive loss during the years ended
December 31, 2013, 2012, or 2011.

During 2013, we elected the “with and without method – direct effects only”, prescribed in accordance with

authoritative guidance, with respect to recognition of stock option windfall tax benefits within APIC and will
utilize general NOLs to offset taxable income before utilization of NOLs attributable to windfall tax benefits.

We are subject to income taxation in the United States at the Federal and state levels. All tax years are
subject to examination by US and California tax authorities due to the carryforward of unutilized NOLs and tax
credits. We are also subject to foreign income taxes in the countries in which we operate. To our knowledge, we
are not currently under examination by any taxing authorities.

At December 31, 2013, no foreign subsidiaries have accumulated earnings and, as such, there are no

unrepatriated earnings.

Our Swiss subsidiary, Arena GmbH, has been granted a conditional incentive tax holiday by the Canton of
Aargau for its operations in Switzerland. Without a tax holiday or other tax incentives, the standard effective tax
rate of a company located in Aargau is approximately 19%. As a result of the tax holiday and other tax
incentives, we expect the effective tax rate for Arena GmbH to be approximately half of such rate. The tax
holiday came into effect on January 1, 2013, and will continue for a period of up to 10 years, not to extend
beyond December 31, 2022.

(16) Legal Proceedings

Beginning on September 20, 2010, a number of complaints were filed in the US District Court for the
Southern District of California against us and certain of our current and former employees and directors on
behalf of certain purchasers of our common stock. The complaints have been brought as purported stockholder
class actions, and, in general, include allegations that we and certain of our current and former employees and
directors violated federal securities laws by making materially false and misleading statements regarding our
BELVIQ program, thereby artificially inflating the price of our common stock. The plaintiffs are seeking
unspecified monetary damages and other relief. On November 19, 2010, eight prospective lead plaintiffs filed
motions to consolidate, appoint a lead plaintiff, and appoint lead counsel. The Court took the motions to
consolidate under submission on January 14, 2011. On August 8, 2011, the Court consolidated the actions and
appointed a lead plaintiff and lead counsel. On November 1, 2011, the lead plaintiff filed a consolidated amended
complaint. On December 30, 2011, we filed a motion to dismiss the consolidated amended complaint. On
March 28, 2013, the Court granted our motion to dismiss the consolidated amended complaint without prejudice.
On May 13, 2013, the lead plaintiff filed a new consolidated amended complaint. On June 14, 2013, we filed a
motion to dismiss the new consolidated amended complaint. On July 15, 2013, the lead plaintiff filed an
opposition to our motion to dismiss. On July 29, 2013, we filed our reply. On October 25, 2013, the Court heard
oral argument on the motion to dismiss. On November 5, 2013, the Court granted our motion to dismiss the new
consolidated amended complaint without prejudice as to all parties except for Robert E. Hoffman, who was
dismissed from the action with prejudice. On November 27, 2013, the lead plaintiff filed a motion for leave to
amend the now-dismissed new consolidated amended complaint. On December 20, 2013, we filed an opposition
to the motion for leave to amend. On December 27, 2013, the lead plaintiff filed his reply. On December 30,
2013, the Court took the motion under submission without a hearing.

In addition to the class actions, a complaint involving similar legal and factual issues has been brought by at

least one individual stockholder and is pending in federal court. On December 30, 2011, we filed a motion to
dismiss the individual stockholder’s complaint. On March 29, 2013, the Court granted our motion to dismiss, in
part without prejudice. On May 13, 2013, the individual stockholder filed a new amended complaint. On

118

June 14, 2013, we filed a motion to dismiss the new amended complaint. On July 10, 2013, the individual
stockholder filed an opposition to our motion to dismiss. On July 29, 2013, we filed our reply. On October 22,
2013, the Court took the motion under submission without a hearing.

Due to the stage of these proceedings, we are not able to predict or reasonably estimate the ultimate

outcome or possible losses relating to these claims.

(17) Quarterly Financial Data (Unaudited)

The following tables present quarterly data for the years ended December 31, 2013, and 2012, in thousands,

except per share data:

2013

Revenues . . . . . . . . . . . . . . . . . . . . . . .
Operating costs and expenses . . . . . . .
Net income (loss) allocable to

Quarter ended
December 31

Quarter ended
September 30

Quarter ended
June 30

Quarter ended
March 31

Year ended
December 31

$ 6,516
$ 28,487

$ 3,578
$ 23,444

$68,927
$29,021

$ 2,373
$ 23,377

$ 81,394
$104,329

common stockholders . . . . . . . . . . .

$(23,459)

$(17,200)

$40,100

$(18,876)

$ (19,435)

Net income (loss) per share allocable
to common stockholders, basic and
diluted . . . . . . . . . . . . . . . . . . . . . . .

2012

Revenues . . . . . . . . . . . . . . . . . . . . . . .
Operating costs and expenses . . . . . . .
Net loss allocable to common

$ (0.11)

$

(0.08)

$

0.18

$

(0.09)

$

(0.09)

Quarter ended
December 31

Quarter ended
September 30

Quarter ended
June 30

Quarter ended
March 31

Year ended
December 31

$ 1,936
$ 22,216

$ 1,485
$ 20,575

$ 21,977
$ 20,117

$ 2,189
$ 21,792

$ 27,587
$ 84,700

stockholders . . . . . . . . . . . . . . . . . . .

$(21,280)

$(15,521)

$(22,099)

$(29,401)

$(88,301)

Net loss per share allocable to

common stockholders, basic and
diluted . . . . . . . . . . . . . . . . . . . . . . .

$ (0.10)

$

(0.07)

$

(0.12)

$

(0.18)

$

(0.45)

119

Item 9.

Changes in and Disagreements With Accountants on Accounting and Financial Disclosure.

None.

Item 9A. Controls and Procedures.

Conclusion Regarding the Effectiveness of Disclosure Controls and Procedures

Under the supervision and with the participation of our management, including our principal executive
officer and principal financial officer, we conducted an evaluation of our disclosure controls and procedures, as
such term is defined under Rule 13a-15(e) promulgated under the Securities Exchange Act of 1934, as amended,
or the Exchange Act. Based on this evaluation, our principal executive officer and our principal financial officer
concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of the
end of the period covered by this Annual Report on Form 10-K.

Our management does not expect that our disclosure controls and procedures or our internal control over
financial reporting will prevent all potential errors and fraud. A control system, no matter how well conceived
and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are
met. Because of the inherent limitations in all control systems, no system of controls can provide absolute
assurance that all control issues and instances of fraud, if any, or misstatements due to error, if any, within the
company have been detected. While we believe that our disclosure controls and procedures and internal control
over financial reporting are and have been effective at the reasonable assurance level, we intend to continue to
examine and refine our disclosure controls and procedures and internal control over financial reporting and to
monitor ongoing developments in these areas.

Management’s Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining for us adequate internal control over
financial reporting, as such term is defined in Exchange Act Rule 13a-15(f). Under the supervision and with the
participation of our management, including our President and Chief Executive Officer and our Senior Vice
President, Finance and Chief Financial Officer, we conducted an evaluation of the effectiveness of our internal
control over financial reporting based on the framework in Internal Control—Integrated Framework (1992
framework) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on our
evaluation under this framework, our management concluded that our internal control over financial reporting
was effective as of December 31, 2013.

The registered public accounting firm that audited our financial statements as of and for the year ended
December 31, 2013, included in this Annual Report on Form 10-K has issued an attestation report on our internal
control over financial reporting, and such report is included below.

Changes in Internal Control Over Financial Reporting

In connection with the commercial launch of BELVIQ in 2013, we have enhanced our internal control over

financial reporting related to our inventory, cost of product sales and revenues from product sales.

Except as described above, there was no change in our internal control over financial reporting during the

fourth quarter of the period covered by this Annual Report on Form 10-K that has materially affected, or is
reasonably likely to materially affect, our internal control over financial reporting.

120

Report of Independent Registered Public Accounting Firm

The Board of Directors and Stockholders
Arena Pharmaceuticals, Inc.:

We have audited Arena Pharmaceuticals, Inc.’s internal control over financial reporting as of December 31,
2013, based on criteria established in Internal Control—Integrated Framework (1992) issued by the Committee
of Sponsoring Organizations of the Treadway Commission (COSO). Arena Pharmaceuticals, Inc.’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 Arena Pharmaceuticals,
Inc.’s internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight
Board (United States). 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 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.

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.

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.

In our opinion, Arena Pharmaceuticals, Inc. maintained, in all material respects, effective internal control
over financial reporting as of December 31, 2013, based on criteria established in Internal Control—Integrated
Framework (1992) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board

(United States), the consolidated balance sheets of Arena Pharmaceuticals, Inc. and subsidiaries as of
December 31, 2013 and 2012, and the related consolidated statements of operations and comprehensive loss,
stockholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2013, and
our report dated March 3, 2014 expressed an unqualified opinion on those consolidated financial statements.

San Diego, California
March 3, 2014

/s/ KPMG LLP

121

Item 9B. Other Information.

Not applicable.

122

PART III

Item 10. Directors, Executive Officers and Corporate Governance.

We have adopted a Code of Business Conduct and Ethics that applies to our directors and employees
(including our principal executive officer, principal financial officer, principal accounting officer and controller),
and have posted the text of the policy on our website (www.arenapharm.com) in connection with “Investor”
materials. In addition, we intend to promptly disclose on our website in the future (i) the date and nature of any
amendment (other than technical, administrative or other non-substantive amendments) to the policy that applies
to our principal executive officer, principal financial officer, principal accounting officer or controller, or persons
performing similar functions and relates to any element of the code of ethics definition enumerated in
Item 406(b) of Regulation S-K, and (ii) the nature of any waiver, including an implicit waiver, from a provision
of the policy that is granted to one of these specified individuals that relates to one or more of the elements of the
code of ethics definition enumerated in Item 406(b) of Regulation S-K, the name of such person who is granted
the waiver and the date of the waiver.

The other information required by this item is incorporated herein by reference from the information under

the captions “Election of Directors,” “Compensation and Other Information Concerning Executive Officers,
Directors and Certain Stockholders” and “Section 16(a) Beneficial Ownership Reporting Compliance” contained
in our proxy statement for the annual meeting of stockholders to be held in June 2014, or the Proxy Statement.

Item 11. Executive Compensation.

The information required by this item is incorporated herein by reference from the information under the

captions “Compensation and Other Information Concerning Executive Officers, Directors and Certain
Stockholders” and “Compensation Committee Interlocks and Insider Participation” contained in the Proxy
Statement.

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

Matters.

The following table summarizes our compensation plans under which our equity securities are authorized

for issuance as of December 31, 2013:

Plan category

Equity compensation plans
approved by security
holders . . . . . . . . . . . . . . . . . . .

Equity compensation plans not

approved by security
holders . . . . . . . . . . . . . . . . . . .

Number of securities to be
issued upon exercise of
outstanding options, warrants
and rights

Weighted-average
exercise price of
outstanding options,
warrants and rights

Number of securities remaining
available for future issuance
under equity compensation plans
(excluding securities reflected in
column (a))

(a)

(b)

(c)

16,675,890*

$4.39

26,738,631**

0

0

Total

. . . . . . . . . . . . . . . . . . . . . .

16,675,890*

$4.39

26,738,631**

*

Includes 14,681,044 stock options with a per share weighted-average exercise price of $4.99. Also includes
(i) 434,846 restricted stock unit awards with no exercise price and (ii) 780,000 performance restricted stock
unit awards with no exercise price. In the aggregate, the target number of shares of common stock that may
be earned under the performance restricted stock unit awards is 780,000; however, the actual number of
shares that may be earned ranges from 0% to 200% of such amount, and this table reflects 200%.

123

**

Includes 900,659 shares of common stock available for future issuance under our 2009 Employee Stock
Purchase Plan, as amended. Stock options and stock appreciation rights granted under our 2013 Long-Term
Incentive Plan, or 2013 LTIP, reduce the available number of shares under our 2013 LTIP by 1 share for
every share issued while awards other than stock options and stock appreciation rights granted under our
2013 LTIP reduce the available number of shares by 1.25 shares for every share issued. In addition, shares
that are released from awards granted under any of our prior long-term incentive plans or the 2013 LTIP
because the awards expire, are forfeited or are settled for cash will increase the number of shares available
under our 2013 LTIP by 1 share for each share released from a stock option or stock appreciation right and
by 1.25 shares for each share released from a restricted stock award or restricted stock unit award. Each
share we withhold to satisfy any tax withholding obligation with respect to an award other than an option or
stock appreciation right under any of our prior long-term incentive plans or the 2013 LTIP will increase the
share reserve by 1.25 shares.

In 2003, we set up a deferred compensation plan for our executive officers, whereby they may elect to defer

their shares of restricted stock. At December 31, 2013, a total of 79,169 shares of restricted stock were in the
plan. All of the shares contributed to this plan were previously granted to such officers under an equity
compensation plan approved by our stockholders.

The other information required by this item is incorporated herein by reference from the information under

the caption “Security Ownership of Certain Beneficial Owners and Management” contained in the Proxy
Statement.

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

The information required by this item is incorporated herein by reference from the information under the
captions “Certain Relationships and Related Transactions” and “Election of Directors” contained in the Proxy
Statement.

Item 14. Principal Accountant Fees and Services.

The information required by this item is incorporated herein by reference from the information under the

captions “Independent Auditors’ Fees” and “Pre-approval Policies and Procedures” contained in the Proxy
Statement.

124

Item 15. Exhibits, Financial Statement Schedules.

(a)

1. FINANCIAL STATEMENTS.

PART IV

Reference is made to the Index to Financial Statements under Item 8, Part II hereof.

2. FINANCIAL STATEMENT SCHEDULES.

The Financial Statement Schedules have been omitted either because they are not required or because
the information has been included in the financial statements or the notes thereto included in this annual
report.

3. EXHIBITS

EXHIBIT
NO.

2.1*

3.1

3.2

3.3

3.4

3.5

4.4

10.1**

10.2**

DESCRIPTION

Agreement of Purchase and Sale, dated as of March 21, 2007, by and between Arena and BMR-
6114-6154 Nancy Ridge Drive LLP (as assignee of BioMed Realty, L.P.) (incorporated by
reference to Exhibit 2.1 to Arena’s report on Form 8-K filed with the Securities and Exchange
Commission on May 8, 2007, Commission File No. 000-31161)

Fifth Amended and Restated Certificate of Incorporation of Arena (incorporated by reference to
Exhibit 3.1 to Arena’s quarterly report on Form 10-Q for the quarter ended June 30, 2002, filed
with the Securities and Exchange Commission on August 14, 2002, Commission
File No. 000-31161)

Certificate of Amendment of the Fifth Amended and Restated Certificate of Incorporation of
Arena (incorporated by reference to Exhibit 4.2 to Arena’s registration statement on Form S-8 filed
with the Securities and Exchange Commission on June 28, 2006, Commission
File No. 333-135398)

Certificate of Amendment No. 2 of the Fifth Amended and Restated Certificate of Incorporation of
Arena, as amended (incorporated by reference to Exhibit 4.3 to Arena’s registration statement on
Form S-8 filed with the Securities and Exchange Commission on June 30, 2009, Commission
File No. 333-160329)

Certificate of Amendment No. 3 of the Fifth Amended and Restated Certificate of Incorporation of
Arena, as amended (incorporated by reference to Exhibit 3.4 to Arena’s registration statement on
Form S-8 filed with the Securities and Exchange Commission on June 20, 2012, Commission
File No. 333-182238)

Amended and Restated Bylaws of Arena (incorporated by reference to Exhibit 3.1 to Arena’s
current report on Form 8-K filed with the Securities and Exchange Commission on October 4,
2007, Commission File No. 000-31161)

Form of common stock certificate (incorporated by reference to Exhibit 4.2 to Arena’s registration
statement on Form S-1, as amended, filed with the Securities and Exchange Commission on
July 19, 2000, Commission File No. 333-35944)

Amended and Restated 2000 Equity Compensation Plan (incorporated by reference to Exhibit 10.2
to Arena’s annual report on Form 10-K for the year ended December 31, 2001, filed with the
Securities and Exchange Commission on March 15, 2002, Commission File No. 000-31161)

2002 Equity Compensation Plan (incorporated by reference to Exhibit A to Arena’s proxy
statement regarding Arena’s June 11, 2002, Annual Stockholders Meeting, filed with the Securities
and Exchange Commission on April 23, 2002, Commission File No. 000-31161)

125

EXHIBIT
NO.

DESCRIPTION

10.3

10.4

10.5

10.6**

10.7**

10.8**

10.9**

10.10**

10.11**

10.12**

10.13**

10.14**

10.15

Form of Warrant dated December 24, 2003 (incorporated by reference to Exhibit 10.3 to Arena’s
report on Form 8-K filed with the Securities and Exchange Securities and Exchange Commission
on December 30, 2003, Commission File No. 000-31161)

Purchase and Sale Agreement and Joint Escrow Instructions, dated December 22, 2003, between
Arena and ARE—Nancy Ridge No. 3, LLC (incorporated by reference to Exhibit 10.1 to Arena’s
report on Form 8-K filed with the Securities and Exchange Securities and Exchange Commission
on January 6, 2004, Commission File No. 000-31161)

Lease Agreement, dated December 30, 2003, between Arena and ARE—Nancy Ridge No. 3, LLC
(incorporated by reference to Exhibit 10.2 to Arena’s report on Form 8-K filed with the Securities
and Exchange Commission on January 6, 2004, Commission File No. 000-31161)

Arena’s Deferred Compensation Plan, effective November 11, 2003, between Arena and
participating executive officers (incorporated by reference to Exhibit 10.29 to Arena’s annual
report on Form 10-K for the year ended December 31, 2003, filed with the Securities and
Exchange Commission on March 1, 2004, Commission File No. 000-31161)

Form of stock option grant for non-employee directors under Arena’s 2002 Equity Incentive Plan
(incorporated by reference to Exhibit 10.1 to Arena’s report on Form 8-K filed with the Securities
and Exchange Commission on January 21, 2005, Commission File No. 000-31161)

2006 Long-Term Incentive Plan, as amended (incorporated by reference to Exhibit 10.1 to Arena’s
report on Form 8-K filed with the Securities and Exchange Commission on April 13, 2007,
Commission File No. 000-31161)

Form of Stock Option Grant Agreement under the Arena 2006 Long-Term Incentive Plan, as
amended (incorporated by reference to Exhibit 10.1 to Arena’s report on Form 8-K filed with the
Securities and Exchange Commission on August 1, 2006, Commission File No. 000-31161)

Form of Stock Option Grant Agreement—Director under the Arena 2006 Long-Term Incentive
Plan, as amended (incorporated by reference to Exhibit 10.2 to Arena’s report on Form 8-K filed
with the Securities and Exchange Commission on August 1, 2006, Commission
File No. 000-31161)

Form of Incentive Stock Option Grant Agreement under the Arena 2006 Long-Term Incentive
Plan, as amended (incorporated by reference to Exhibit 10.3 to Arena’s report on Form 8-K filed
with the Securities and Exchange Commission on August 1, 2006, Commission
File No. 000-31161)

Form of Indemnification Agreement between Arena and its directors (incorporated by reference to
Exhibit 10.1 to Arena’s report on Form 8-K filed with the Securities and Exchange Commission on
June 18, 2007, Commission File No. 000-31161)

Form of Indemnification Agreement between Arena and its executive officers (incorporated by
reference to Exhibit 10.2 to Arena’s report on Form 8-K filed with the Securities and Exchange
Commission on June 18, 2007, Commission File No. 000-31161)

Form of Indemnification Agreement between Arena and individuals serving as its directors and
executive officers (incorporated by reference to Exhibit 10.3 to Arena’s report on Form 8-K filed
with the Securities and Exchange Commission on June 18, 2007, Commission File No. 000-31161)

Lease agreement between BMR-6114-6154 Nancy Ridge Drive LLC and Arena for 6114 Nancy
Ridge Drive, San Diego, California (incorporated by reference to Exhibit 10.5 to Arena’s quarterly
report on Form 10-Q for the quarter ended June 30, 2007, filed with the Securities and Exchange
Commission on August 9, 2007, Commission File No. 000-31161)

126

EXHIBIT
NO.

10.16

10.17

10.18

10.19*

10.20

10.21**

10.22**

DESCRIPTION

Lease agreement between BMR-6114-6154 Nancy Ridge Drive LLC and Arena for 6118 Nancy
Ridge Drive, San Diego, California (incorporated by reference to Exhibit 10.6 to Arena’s quarterly
report on Form 10-Q for the quarter ended June 30, 2007, filed with the Securities and Exchange
Commission on August 9, 2007, Commission File No. 000-31161)

Lease agreement between BMR-6114-6154 Nancy Ridge Drive LLC and Arena for 6122, 6124
and 6126 Nancy Ridge Drive, San Diego, California (incorporated by reference to Exhibit 10.7 to
Arena’s quarterly report on Form 10-Q for the quarter ended June 30, 2007, filed with the
Securities and Exchange Commission on August 9, 2007, Commission File No. 000-31161)

Lease agreement between BMR-6114-6154 Nancy Ridge Drive LLC and Arena for 6154 Nancy
Ridge Drive, San Diego, California (incorporated by reference to Exhibit 10.8 to Arena’s quarterly
report on Form 10-Q for the quarter ended June 30, 2007, filed with the Securities and Exchange
Commission on August 9, 2007, Commission File No. 000-31161)

Asset Purchase Agreement, dated as of December 18, 2007, by and between Arena
Pharmaceuticals GmbH and Siegfried Ltd (incorporated by reference to Exhibit 10.38 to Arena’s
annual report on Form 10-K for the year ended December 31, 2007, filed with the Securities and
Exchange Commission on March 5, 2008, Commission File No. 000-31161)

Amendment No. 1 to the Asset Purchase Agreement, dated effective as of January 1, 2011, by and
between Arena Pharmaceuticals GmbH and Siegfried Ltd (incorporated by reference to
Exhibit 10.2 to Arena’s quarterly report on Form 10-Q for the quarter ended March 31, 2011, filed
with the Securities and Exchange Commission on May 10, 2011, Commission File No. 000-31161)

Amended and Restated Severance Benefit Plan, dated effective December 30, 2008, and providing
benefits for Messrs. Lief, Hoffman and Spector and Drs. Behan and Shanahan (incorporated by
reference to Exhibit 10.1 to Arena’s Form 8-K filed with the Securities and Exchange Commission
on December 31, 2008, Commission File No. 000-31161)

Amendment No. 1 to Amended and Restated Severance Benefit Plan, dated as of February 10,
2012 (incorporated by reference to Exhibit 10.1 to Arena’s Form 8-K filed with the Securities and
Exchange Commission on February 14, 2012, Commission File No. 000-31161)

10.23**

Amendment No. 2 to Amended and Restated Severance Benefit Plan, dated as of October 4, 2013

10.24**

10.25**

10.26**

10.27**

Form of Amended and Restated Termination Protection Agreement, dated December 30, 2008, by
and among Arena and Messrs. Lief and Spector and Dr. Behan (incorporated by reference to
Exhibit 10.2 to Arena’s Form 8-K filed with the Securities and Exchange Commission on
December 31, 2008, Commission File No. 000-31161)

Arena’s 2009 Long-Term Incentive Plan (incorporated by reference to Exhibit 99.1 to Arena’s
registration statement on Form S-8 filed with the Securities and Exchange Commission on June 30,
2009, Commission File No. 333-160329)

Form of Incentive Stock Option Grant Agreement for Employees under the Arena 2009 Long-
Term Incentive Plan (incorporated by reference to Exhibit 10.7 to Arena’s quarterly report on
Form 10-Q for the quarter ended June 30, 2009, filed with the Securities and Exchange
Commission on August 7, 2009, Commission File No. 000-31161)

Form of Stock Option Grant Agreement for Employees or Consultants under the Arena 2009
Long-Term Incentive Plan (incorporated by reference to Exhibit 10.8 to Arena’s quarterly report
on Form 10-Q for the quarter ended June 30, 2009, filed with the Securities and Exchange
Commission on August 7, 2009, Commission File No. 000-31161)

127

EXHIBIT
NO.

10.28**

10.29**

10.30**

10.31**

10.32**

10.33**

10.34**

10.35**

10.36**

10.37**

10.38**

10.39**

DESCRIPTION

Form of Stock Option Grant Agreement for Non-Employee Directors under the Arena 2009 Long-
Term Incentive Plan (incorporated by reference to Exhibit 10.9 to Arena’s quarterly report on
Form 10-Q for the quarter ended June 30, 2009, filed with the Securities and Exchange
Commission on August 7, 2009, Commission File No. 000-31161)

Arena’s 2009 Employee Stock Purchase Plan, as amended (incorporated by reference to
Exhibit 99.2 to Arena’s registration statement on Form S-8 filed with the Securities and Exchange
Commission on June 20, 2012, Commission File No. 333-182238)

Arena’s 2012 Long-Term Incentive Plan (incorporated by reference to Exhibit 99.1 to Arena’s
registration statement on Form S-8 filed with the Securities and Exchange Commission on June 20,
2012, Commission File No. 333-182238)

Form of Incentive Stock Option Grant Agreement for Employees for grants prior to December 13,
2012, under the Arena 2012 Long-Term Incentive Plan (incorporated by reference to Exhibit 10.3
to Arena’s report on Form 8-K filed with the Securities and Exchange Commission on June 20,
2012, Commission File No. 000-31161)

Form of Stock Option Grant Agreement for Employees or Consultants for grants prior to
December 13, 2012, under the Arena 2012 Long-Term Incentive Plan (incorporated by reference to
Exhibit 10.4 to Arena’s report on Form 8-K filed with the Securities and Exchange Commission on
June 20, 2012, Commission File No. 000-31161)

Form of Stock Option Grant Agreement for Non-Employee Directors under the Arena 2012 Long-
Term Incentive Plan (incorporated by reference to Exhibit 10.5 to Arena’s report on Form 8-K
filed with the Securities and Exchange Commission on June 20, 2012, Commission
File No. 000-31161)

Form of Restricted Stock Grant Agreement under the Arena 2012 Long-Term Incentive Plan
(incorporated by reference to Exhibit 10.6 to Arena’s report on Form 8-K filed with the Securities
and Exchange Commission on June 20, 2012, Commission File No. 000-31161)

Form of Incentive Stock Option Grant Agreement for Employees for grants beginning on
December 13, 2012, under the Arena 2012 Long-Term Incentive Plan (incorporated by reference to
Exhibit 10.45 to Arena’s annual report on Form 10-K for the year ended December 31, 2013, filed
with the Securities and Exchange Commission on March 1, 2013, Commission
File No. 000-31161)

Form of Stock Option Grant Agreement for Employees or Consultants for grants beginning on
December 13, 2012, under the Arena 2012 Long-Term Incentive Plan (incorporated by reference to
Exhibit 10.46 to Arena’s annual report on Form 10-K for the year ended December 31, 2013, filed
with the Securities and Exchange Commission on March 1, 2013, Commission
File No. 000-31161)

Form of Restricted Stock Unit Grant Agreement under the Arena 2012 Long-Term Incentive Plan
(incorporated by reference to Exhibit 10.47 to Arena’s annual report on Form 10-K for the year
ended December 31, 2013, filed with the Securities and Exchange Commission on March 1, 2013,
Commission File No. 000-31161)

Form of Performance Restricted Stock Unit Grant Agreement under the Arena 2012 Long-Term
Incentive Plan (incorporated by reference to Exhibit 10.2 to Arena’s quarterly report on Form 10-Q
for the quarter ended March 31, 2013, filed with the Securities and Exchange Commission on
May 9, 2013, Commission File No. 000-31161)

Arena’s 2013 Long-Term Incentive Plan (incorporated by reference to Exhibit 99.1 to Arena’s
registration statement on Form S-8 filed with the Securities and Exchange Commission on June 10,
2013, Commission File No. 333-189213)

128

EXHIBIT
NO.

10.40**

10.41**

10.42**

10.43**

10.44**

10.45**

DESCRIPTION

Form of Stock Option Grant Agreement for Employees or Consultants under the Arena 2013
Long-Term Incentive Plan (incorporated by reference to Exhibit 10.2 to Arena’s current report on
Form 8-K filed with the Securities and Exchange Commission on June 14, 2013, Commission
File No. 000-31161)

Form of Incentive Stock Option Grant Agreement for Employees under the Arena 2013 Long-
Term Incentive Plan (incorporated by reference to Exhibit 10.3 to Arena’s current report on
Form 8-K filed with the Securities and Exchange Commission on June 14, 2013, Commission
File No. 000-31161)

Form of Restricted Stock Unit Grant Agreement (other than for non-employee directors) under the
Arena 2013 Long-Term Incentive Plan (incorporated by reference to Exhibit 10.4 to Arena’s
current report on Form 8-K filed with the Securities and Exchange Commission on June 14, 2013,
Commission File No. 000-31161)

Form of Restricted Stock Unit Grant Agreement for Non-Employee Directors under the Arena
2013 Long-Term Incentive Plan (incorporated by reference to Exhibit 10.5 to Arena’s current
report on Form 8-K filed with the Securities and Exchange Commission on June 14, 2013,
Commission File No. 000-31161)

Annual Incentive Plan for Arena’s executive officers (incorporated by reference to Exhibit 10.1 to
Arena’s report on Form 8-K filed with the Securities and Exchange Commission on December 19,
2012, Commission File No. 000-31161)

Summary of compensation for non-employee directors (incorporated by reference to Exhibit 10.1
to Arena’s quarterly report on Form 10-Q for the quarter ended March 31, 2013, filed with the
Securities and Exchange Commission on May 9, 2013, Commission File No. 000-31161)

10.46+

Second Amended and Restated Marketing and Supply Agreement, dated November 7, 2013, by
and among Arena Pharmaceuticals GmbH, Eisai Inc. and Eisai Co., Ltd.

21.1

23.1

31.1

31.2

32.1

Subsidiaries of the registrant

Consent of Independent Registered Public Accounting Firm

Certification of Chief Executive Officer pursuant to Rule 13a-14(A) promulgated under the
Securities Exchange Act of 1934

Certification of Chief Financial Officer pursuant to Rule 13a-14(A) promulgated under the
Securities Exchange Act of 1934

Certification of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C.
Section 1350 and Rule 13a-14(B) promulgated under the Securities Exchange Act of 1934

101.INS

XBRL Instance Document

101.SCH

XBRL Taxonomy Extension Schema Document

101.CAL

XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF

XBRL Taxonomy Extension Definition Linkbase Document

101.LAB

XBRL Taxonomy Extension Label Linkbase Document

101.PRE

XBRL Taxonomy Extension Presentation Linkbase Document

+

Confidential treatment has been requested with respect to certain portions of this exhibit. Omitted portions
have been filed separately with the SEC.

129

*

Exhibits and schedules to this agreement have been omitted pursuant to the rules of the Securities and
Exchange Commission. We will submit copies of such exhibits and schedules to the Securities and
Exchange Commission upon request.

** Management contract or compensatory plan or arrangement.

(b) EXHIBITS

See Item 15(a)(3) above.

(c) FINANCIAL STATEMENT SCHEDULES

See Item 15(a)(2) above.

130

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant

has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

SIGNATURES

Arena Pharmaceuticals, Inc.,
a Delaware corporation

Date: March 3, 2014

By:

/s/

JACK LIEF
Jack Lief
President and Chief Executive Officer

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

the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By:

Signatures

/s/

JACK LIEF
Jack Lief

By:

/s/ ROBERT E. HOFFMAN

Robert E. Hoffman

Title

Date

Chairman, President and Chief Executive
Officer

March 3, 2014

Senior Vice President, Finance and Chief
Financial Officer (principal financial and
accounting officer)

March 3, 2014

By:

/s/ DOMINIC P. BEHAN

Director

March 3, 2014

Dominic P. Behan, Ph.D., D.Sc.

By:

/s/ DONALD D. BELCHER

Director

March 3, 2014

By:

By:

By:

Donald D. Belcher

/s/ SCOTT H. BICE

Scott H. Bice

/s/ HARRY F. HIXSON, JR.
Harry F. Hixson, Jr., Ph.D.

/s/ TINA S. NOVA
Tina S. Nova, Ph.D.

Director

Director

Director

March 3, 2014

March 3, 2014

March 3, 2014

By:

/s/ PHILLIP M. SCHNEIDER

Director

March 3, 2014

Phillip M. Schneider

By:

/s/ CHRISTINE A. WHITE
Christine A. White, M.D.

Director

March 3, 2014

By:

/s/ RANDALL E. WOODS

Director

March 3, 2014

Randall E. Woods

131

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[THIS PAGE INTENTIONALLY LEFT BLANK]

[THIS PAGE INTENTIONALLY LEFT BLANK]

Corporate Information

BOARD OF DIRECTORS
Jack Lief 
Chairman, President and Chief Executive Officer
Arena Pharmaceuticals, Inc.

Dominic P. Behan, Ph.D., D.Sc.  
Director, Executive Vice President and Chief Scientific Officer 
Arena Pharmaceuticals, Inc.

Donald D. Belcher 
Former Chairman and Chief Executive Officer 
Banta Corporation

Scott H. Bice
Robert C. Packard Professor 
University of Southern California Law School 

Harry F. Hixson, Jr., Ph.D. 
Chairman and Chief Executive Officer
Sequenom, Inc.

Tina S. Nova, Ph.D. 
Former President and Chief Executive Officer  
Genoptix, Inc.

Phillip M. Schneider
Former Senior Vice President and Chief Financial Officer
IDEC Pharmaceuticals Corporation

Christine A. White, M.D. 
Former Senior Vice President, Global Medical Affairs 
Biogen Idec Inc.

Randall E. Woods
President and Chief Executive Officer
Sophiris Bio Inc.

EXECUTIVE OFFICERS
Jack Lief 
President and Chief Executive Officer 

Craig M. Audet, Ph.D.
Senior Vice President, Operations and  
Head of Global Regulatory Affairs

Dominic P. Behan, Ph.D., D.Sc. 
Executive Vice President and Chief Scientific Officer

Robert E. Hoffman
Senior Vice President, Finance and Chief Financial Officer

William R. Shanahan, Jr., M.D., J.D. 
Senior Vice President and Chief Medical Officer 

Steven W. Spector, J.D. 
Executive Vice President, General Counsel and Secretary

CORPORATE HEADQUARTERS
Arena Pharmaceuticals, Inc.
6154 Nancy Ridge Drive
San Diego, California 92121
Telephone: 858.453.7200
Facsimile: 858.677.0065

ANNUAL MEETING 
The Annual Meeting of Stockholders will be held on Friday, June 13, 2014,  
at 9:00 a.m. Pacific Time, at 6154 Nancy Ridge Drive, San Diego, California 92121.  
For further information, contact Investor Relations at 858.453.7200.

INVESTOR RELATIONS
Stockholder inquiries should be directed to: 

Investor Relations 
Arena Pharmaceuticals, Inc. 
6154 Nancy Ridge Drive 
San Diego, California 92121 
Telephone: 858.453.7200 
Facsimile: 858.677.0065

Arena will provide stockholders without charge, upon written request, a copy of its 
Annual Report on Form 10-K, including the financial statements, schedules and list 
of exhibits. Arena will furnish stockholders a copy of any exhibit to such report upon 
written request and payment of its reasonable expenses in furnishing such exhibit. 
Requests should be sent to Investor Relations at Arena’s corporate headquarters. 

In addition, Arena’s Annual Report on Form 10-K, other filings with the Securities 
and Exchange Commission, and press releases, along with general information on 
Arena’s business and technology, are available through Arena’s home page on the 
Internet at the following address: www.arenapharm.com.

TRANSFER AGENT AND REGISTRAR
Computershare
P.O. Box 30170
College Station, TX 77842-3170
Telephone: 800.962.4284
Facsimile: 303.262.0700

STOCK LISTING
Arena’s common stock trades on the NASDAQ Global Select Market® under the 
symbol ARNA.

INDEPENDENT AUDITORS
KPMG LLP
4747 Executive Drive, Suite 600
San Diego, California 92121
Telephone: 858.750.7100
Facsimile: 858.750.7101

TRADEMARKS
Arena Pharmaceuticals®, Arena® and our corporate logo are registered trademarks 
of Arena Pharmaceuticals, Inc. CART ™ is a trademark of Arena Pharmaceuticals, Inc. 
BELVIQ® is a registered trademark of Arena Pharmaceuticals GmbH.

INFORMATION RELATING TO FORWARD-LOOKING STATEMENTS
Certain statements in this Annual Report are forward-looking statements involving a number of risks and uncertainties, including statements about our focus, plans, goals, strategy, 
expectations, technologies, internal and collaborative programs, ability to discover and develop compounds and commercialize drugs, and future activities and achievements. The 
forward-looking  statements  also  involve  other  statements  that  are  not  historical  facts,  including  statements  that  are  preceded  by  the  words  “may,”  “will,”  “intend,”  “believe,” 
“anticipate,” “expect,” “estimate,” “potential,” “continue,” “likely,” or “opportunity,” similar words or the negative of these words. For such statements, we claim the protection of 
the Private Securities Litigation Reform Act of 1995. Actual events or results may differ materially from our expectations. Factors that could cause actual results to differ materially 
from the forward-looking statements include, but are not limited to: risks related to commercializing drugs, including regulatory, manufacturing, supply and marketing issues and 
the availability and use of BELVIQ; cash and revenues generated from BELVIQ, including the impact of competition; our revenues will be based in part on estimates, judgment and 
accounting policies, and incorrect estimates or disagreement regarding estimates or accounting policies may result in changes to our guidance or previously reported results; the 
timing and outcome of regulatory review is uncertain, and BELVIQ may not be approved for marketing when expected or ever in combination with another drug, for another indication 
or using a different formulation or in any other territory for any indication; regulatory decisions in one territory may impact other regulatory decisions and our business prospects; 
reimbursement and pricing decisions; risks related to relying on collaborative arrangements; the timing and receipt of any payments from others; the entry into or modification or 
termination of collaborative arrangements; unexpected or unfavorable new data; nonclinical and clinical data is voluminous and detailed, and regulatory agencies may interpret or 
weigh the importance of data differently and reach different conclusions than us or others, request additional information, have additional recommendations or change their guidance 
or requirements before or after approval; data and other information related to any of our research and development may not meet regulatory requirements or otherwise be sufficient 
for (or we or a collaborator may not pursue) further research and development, regulatory review or approval or continued marketing; our ability to obtain and defend patents; the 
timing, success and cost of our research and development; results of clinical trials and other studies are subject to different interpretations and may not be predictive of future results; 
clinical trials and other studies may not proceed at the time or in the manner expected or at all; having adequate funds; and satisfactory resolution of litigation or other disagreements. 
Additional factors that could cause actual results to differ materially from those stated or implied by our forward-looking statements are disclosed in our filings with the Securities 
and Exchange Commission. The information in this Annual Report is as of April 7, 2014, and these forward-looking statements represent our judgment as of the earlier of when dated 
or released. We disclaim any intent or obligation to update these forward-looking statements, other than as may be required under applicable law.

EMBRACING THE 
CHALLENGE OF 
IMPROVING HEALTH BY 
BRINGING INNOVATIVE 
MEDICINES TARGETING 
G PROTEIN-COUPLED 
RECEPTORS TO PATIENTS

Arena Pharmaceuticals, Inc.  I  6154 Nancy Ridge Drive  I  San Diego, California 92121

www.arenapharm.com

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