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XOMA Royalty Corp.

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FY2012 Annual Report · XOMA Royalty Corp.
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XOMA COrpOrAtiOn

2910 Seventh Street

Berkeley, CA 94710

(510) 204-7200 

Annual Report 2012
Annual Report 2012
Annual Report 2012

creating valuecapturing valuecreating valuecapturing valuecreating valuecapturing valueDire C tO rs

eX e Cuti V e  Offi Cers

AnnuAL Meeting

patrick J. scannon, M.D., ph.D.

at 2910 Seventh Street, Berkeley, CA

Corporate Information

W. Denman Van ness 1,2,3

Chairman of the Board

Hidden Hill Advisors

William K. Bowes, Jr. 3

Founding Partner

U.S. Venture Partners

peter Barton Hutt 3

Senior Counsel

Covington & Burling LLP

John Varian 

Chief Executive Officer

Executive Vice President and  

Chief Scientific Officer

paul D. rubin, M.D.

Senior Vice President,  

Research and Development and  

Chief Medical Officer

Joseph M. Limber 2

fred Kurland

President and Chief Executive Officer

Vice President, Finance,  

Prometheus Laboratories Inc.

Chief Financial Officer and Secretary

XO MA COrpO rAtiOn

2910 Seventh Street

Berkeley, CA 94710

Tel: (510) 204-7200

www.xoma.com

inDep enDent AuDitOrs

ernst & Young LLp

San Francisco, CA

trAnsfer Age nt  AnD 

reg istrAr

Wells fargo shareowner 

services

P.O. Box 64874

St. Paul, MN 55164

www.shareowneronline.com

Tel: (800) 468-9716 or  

(651) 450-4064

Kelvin M. neu, M.D.

Managing Director

Baker Brothers

patrick J. scannon, M.D., ph.D.

Executive Vice President and  

Chief Scientific Officer

XOMA Corporation

John Varian 

Chief Executive Officer

XOMA Corporation

timothy p. Walbert 1,3

Chairman, President and

Chief Executive Officer

Horizon Pharma, Inc.

Jack L. Wyszomierski 1,2

Former Executive Vice

President and Chief Financial Officer

VWR International, LLC

1  Audit Committee

2  Compensation Committee

3  Nominating & Governance Committee

The annual meeting of shareholders 

will be held at 9:00 a.m. PDT on  

May 23, 2013, at the Company’s offices 

sOurCes  Of 

infO rMAti On

XOMA’s website, with news releases, 

financial and other information, is 

accessible on the Internet at:  

www.xoma.com

seC fO rM 10 -K

A copy of XOMA’s annual report filed 

with the Securities and Exchange 

Commission on Form 10-K was made 

available to all shareholders of record 

and is available on XOMA’s website. To 

request a copy contact:

Investor Relations

XOMA Corporation

2910 Seventh Street

Berkeley, CA 94710

Tel: (510) 204-7200

investorrelations@xoma.com

tr ADeMArK

ACeOn® is a registered  

trademark of Biofarma

XOMA is an affirmative action,  

equal-opportunity employer.

Dear Shareholder:

When  I  wrote  to  you  last  year,  we  communicated 
the very important decisions we had made to transform 
XOMA. Our theme centered on value creation. In January 
2012, we announced our decision to streamline XOMA’s 
operations  to  eliminate  non-value  creating  activities  that 
might divert cash away from more impactful efforts. We 
outsourced  Phase  3  and  commercial  manufacturing, 
eliminated non-differentiating research activities and took 
steps  to  reduce  G&A  by  20%.  We  predicted  the  steps 
we took would reduce annual internal fixed costs by $14 
million, which would be freed to invest in value-creating 
activities.  Through  a  team-wide  effort,  our  internal  fixed 
costs in 2012 were actually $17 million lower than 2011, 
with G&A expense lower by 30%.

The  other  key  decision  we  made  was  to  directly 
invest  these  significant  internal  expense  savings  in  the 
clinical development of our IL-1 beta modulating antibody, 
gevokizumab.  We  believe  investing  in  this  asset  has 
the  greatest  potential  to  create  value  for  XOMA  and  its 
shareholders.  The  implementation  of  these  decisions  by 
the XOMA team throughout 2012 positions us to benefit 
from our refocusing. 

Under  the  leadership  of  Paul  Rubin,  MD,  the 
XOMA  Clinical  and  Regulatory  team,  together  with 
our  development  and  commercialization  partner  Les 
Laboratoires  Servier  (“Servier”),  launched  the  global 
Phase 3 EYEGUARD™ program to evaluate gevokizumab 
for the treatment of non-infectious uveitis (“NIU”) affecting 
the  posterior  segment  of  the  eye.  The  three  studies  in 
the  EYEGUARD  program  are  EYEGUARD-A  in  acute 
NIU  patients,  EYEGUARD-B  in  Behçet’s  uveitis  patients, 
and  EYEGUARD-C  in  controlled  NIU  patients.  XOMA 
is  responsible  for  managing  both  EYEGUARD-A  and 
EYEGUARD-C, while Servier is responsible for managing 
the EYEGUARD-B study and acting on our behalf with the 
non-U.S. clinical sites in all three studies. We are working 
diligently with the clinical trial sites to meet our enrollment 
targets, and we anticipate reporting the top-line data from 
EYEGUARD-A, B and C at the end of 2013 and into 2014.

The  second  important  step  we  took  to  increase 
the  value  of  gevokizumab  was  the  launch  of  a  proof-of-
concept  (“POC”)  program  in  three  distinctly  different 
indications.  These  studies  are  designed  to  provide  the 

data that allows us to choose our next Phase 3 indication 
for  gevokizumab.  The  interim  analysis  from  our  first 
POC  study  in  moderate  to  severe  inflammatory  acne 
vulgaris  showed  gevokizumab  has  a  direct  impact  on 
reducing inflammatory lesions, as well as improving the 
Investigators’ Global Assessment (“IGA”) of inflammatory 
acne.  This  study  provided  the  first  direct  scientific 
evidence that IL-1 beta may be involved in inflammatory 
acne.  We  believe  there  is  strong  evidence  gevokizumab 
may be successful in a Phase 3 acne study, yet we will not 
select our next indication until we generate data from our 
remaining two POC studies. The second POC study, which 
began in June 2012, will determine gevokizumab’s ability 
to  treat  erosive  inflammatory  osteoarthritis  of  the  hand 
(“EOA”).  We  anticipate  having  the  top-line  results  from 
this study in the summer of 2013. EOA is caused by the 
breakdown of the body’s natural balance between cartilage 
formation  and  degradation  with  patients  experiencing 
significant pain, stiffness, and ultimately loss of function. 
Our  third  POC  study  is  in  a  second  ocular  indication, 
active  non-infectious  anterior  scleritis.  Patients  with 
scleritis experience an inflammation of the sclera, which 
is  the  fibrous  white  membrane  surrounding  the  eyeball 
excluding  the  cornea.  Scleritis  is  associated  with  severe 
pain,  and  it  can  lead  to  ocular  complications  including 
keratitis,  uveitis,  and  glaucoma.  If  left  untreated,  it  may 
cause vision loss. We are working with the National Eye 
Institute,  a  part  of  the  National  Institutes  of  Health,  and 
anticipate we will have data from this study in the fourth 
quarter of 2013.

In addition to these programs, the relationships we 
are building with the medical community generate further 
ideas  on  how  to  potentially  create  additional  value  from 
gevokizumab.  We  are  exploring  two  very  rare  medical 
conditions,  neutrophilic  dermatoses  and  Schnitzler 
syndrome,  that  may  respond  to  gevokizumab.  We  are 
doing  the  necessary  work  to  determine  the  regulatory 
requirements for each indication, and we intend to solicit 
input from the U.S. Food and Drug Administration soon. 
There is no lack of opportunity to study gevokizumab in 
diseases  that  have  IL-1  beta  involvement;  our  challenge 
will be to select the right indications that we can pursue 
cost effectively and in a timely manner.  

Our  focus  on  creating  value  for  XOMA  and  its 
shareholders is now ingrained in our daily activities, and 
we look forward to the results of our efforts as the year 
progresses. 

In the middle of 2012, we began to focus squarely 
on the next building block in our evolution: the strategic 
decision to better capture value from our assets. In order 
to achieve our objectives, we need to capture the value 
that  we’ve  created  for  XOMA  and  our  shareholders. 
XOMA has had a long and successful history of creating 
value  through  its  scientific  discoveries,  advances  in 
antibody  development  and  manufacturing  innovation. 
There are extensive sections in our Form 10-K describing 
the progress other pharmaceutical companies are making 
with compounds we discovered or helped develop. But, 
depending  on  others  to  succeed  does  not  ensure  a 
company’s  long-term  success.  Historically,  advanced 
development and commercialization of XOMA’s scientific 
discoveries has been performed by larger companies. 

In order to control our own fate and capture more 
value for XOMA, we made the strategic decision that we 
will establish a U.S. commercial presence with targeted 
sales  forces  focused  on  specialized  physician  groups. 
Our collaboration with Servier is central to allowing us to 
implement this decision. Under our agreement we have 
full commercial rights to gevokizumab in the U.S. for each 
of the indications being tested by XOMA.

In  March  2013,  we  announced  Tom  Klein  joined 
the  company  as  our  Chief  Commercial  Officer,  a  newly 
created  executive  position.  Tom  will  use  his  extensive 
experience to lead our efforts to prepare for our anticipated 
gevokizumab launch in the U.S., as well as future XOMA 
products.  XMet D, an insulin receptor deactivator, is an 
example of this and has the potential to treat several rare 
diseases.  As this program fits our specialist focus, we 
intend  to  retain  full  U.S.  ownership  and  develop  it  for 
XOMA’s product portfolio. 

XOMA’s discovery engine also produces potential 
products  that  do  not  fit  within  our  planned  commercial 
focus  in  the  U.S.  In  these  cases,  we  will  seek  strategic 
alliances to advance development and to commercialize 
those  products  on  a  world-wide  basis.  In  addition  to 
XMet  D,  using  our  leading-edge  allosteric  modulation 
approach,  the  XOMA  discovery  team  discovered  two 
other antibodies impacting the insulin receptor: XMet A, 
an  insulin  receptor  activator,  and  XMet  S,  an  insulin 

receptor  sensitizer.  These  antibodies  have  received  a 
great deal of attention from the pharmaceutical industry, 
as they could have a revolutionary effect on how diabetes 
patients  are  treated.  Diabetes  mellitus  is  beyond  our 
focus on the specialist physician, and XMet A and XMet S 
will require a skilled partner. To ensure XOMA retains a 
significant  percentage  of  the  economic  value  of  these 
novel  assets,  we  will  continue  preclinical  development 
activities  internally.  We  believe  each  preclinical  step  we 
achieve from our own investment adds significant value 
to these programs, which will translate into an economic 
structure that benefits XOMA and its shareholders in the 
future. 

With our fully honed focus on attaining our vision 
of becoming a commercial organization in the U.S. with 
a continuing strong scientific discovery effort to generate 
future  commercial  products,  there  is  a  renewed  energy 
amongst the team here at XOMA. Our new direction on 
creating and capturing value allowed us to attract $79.2 
million  in  equity  capital  during  2012,  reflecting  the 
renewed  interest  institutional  investors  have  in  XOMA. 
We anticipate this fundraising will take us through 2014, 
beyond the time we expect to report Phase 3 data from 
the global gevokizumab NIU program. 

2012  was  the  year  we  implemented  our  new 
strategy and launched several crucial studies. 2013 will 
be the year of execution for our team. In 2013, we will 
have the data from our gevokizumab POC program and 
select the next indication to pursue in Phase 3. 2013 is the 
year in which we expect to receive the first NIU Phase 3 
data. 2013 is the year in which we will continue advancing 
all three assets in our XMet platform. Every single person 
on the XOMA team is committed to achieving our goals in 
2013, and as shareholders ourselves, we look forward as 
you do to seeing 2013 unfold.

We thank you for your continued support of XOMA. 

We are working hard to create a bright future together.

Sincerely,

John Varian

F O R M   1 0 -K

[THIS PAGE INTENTIONALLY LEFT BLANK]

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, 2012
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 No. 0-14710

XOMA Corporation

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction
of incorporation or organization)

2910 Seventh Street, Berkeley,
California 94710
(Address of principal executive offices,
including zip code)

52-2154066
(I.R.S. Employer Identification No.)

(510) 204-7200
(Telephone number)

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

Title of each class

Common Stock, $0.0075 par value
Preferred Stock Purchase Rights

Name of each exchange on which registered

The NASDAQ Stock Market, LLC

Securities registered pursuant to Section 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 ‘ No È

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ‘ No 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 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 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. ‘

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 definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the
Exchange Act. (Check one):

Large Accelerated Filer ‘ Accelerated Filer È Non-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 of

1934). Yes ‘ No È

The aggregate market value of voting common equity held by non-affiliates of the registrant is $202,720,779 as of June 30, 2012
Number of shares of Common Stock outstanding as of March 8, 2013: 82,852,846

DOCUMENTS INCORPORATED BY REFERENCE:
Portions of the Company’s Proxy Statement for the Company’s 2013 Annual General Meeting of Stockholders are incorporated by

reference into Part III of this Report.

XOMA Corporation

2012 FORM 10-K ANNUAL REPORT

TABLE OF CONTENTS

PART I

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

PART II

Item 5.

Item 6.
Item 7.
Item 7A.
Item 8.
Item 9.
Item 9A.
Item 9B.

PART III

Item 10.
Item 11.
Item 12.

Item 13.
Item 14.

PART IV

Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unresolved Staff Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Legal Proceedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mine Safety Disclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supplementary Item: Executive Officers of the Registrant

Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of
Equity Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selected Financial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Management’s Discussion and Analysis of Financial Condition and Results of Operations . . . .
Quantitative and Qualitative Disclosures about Market Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Financial Statements and Supplementary Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changes in and Disagreements With Accountants on Accounting and Financial Disclosure . . .
Controls and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Directors, Executive Officers, and Corporate Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Executive Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Ownership of Certain Beneficial Owners and Management and Related Stockholder
Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Certain Relationships and Related Transactions, and Director Independence . . . . . . . . . . . . . . .
Principal Accountant Fees and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Item 15.

Exhibits and Financial Statement Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SIGNATURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1
25
48
48
48
49
49

51
53
54
73
74
74
74
74

77
77

77
77
77

78

79

INDEX TO FINANCIAL STATEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1

INDEX TO EXHIBITS

PART I

Certain statements contained herein related to the anticipated size of clinical trials, the anticipated timing of
initiation of clinical trials, the expected availability of clinical trial results, the sufficiency of our cash resources,
the estimated costs of clinical trials and the amounts of certain revenues and certain costs in comparison to prior
years, or that otherwise relate to future periods, are forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, as amended
(the “Exchange Act”). The words “believe,” “may,” “estimate,” “continue,” “anticipate,” “intend,” “expect,”
“predict,” “potential” and similar expressions are intended to identify forward-looking statements. These
statements are based on assumptions that may not prove accurate. Actual results could differ materially from
those anticipated due to certain risks inherent in the biotechnology industry and for companies engaged in the
development of new products in a regulated market. Among other things: our product candidates are still being
developed, and we will require substantial funds to continue development which may not be available; we have
sustained losses in the past and we expect to sustain losses in the future; we are substantially dependent on
Servier for the development and commercialization of gevokizumab and for other aspects of our business; we
have received negative results from certain of our clinical trials, and we face uncertain results of other clinical
trials of our product candidates; if our therapeutic product candidates do not receive regulatory approval,
neither our third-party collaborators, our contract manufacturers nor we will be able to manufacture and market
them; we may not obtain orphan drug exclusivity or we may not receive the full benefit of orphan drug exclusivity
even if we obtain such exclusivity; even once approved, a product may be subject to additional testing or
significant marketing restrictions, its approval may be withdrawn or it may be voluntarily taken off the market;
we may not be successful in commercializing our products, which could also affect our development efforts; we
are subject to various state and federal healthcare related laws and regulations that may impact the
commercialization of ACEON or our product candidates and could subject us to significant fines and penalties;
and certain of our technologies are in-licensed from third parties, so our capabilities using them are restricted
and subject to additional risks. These and other risks, including those related to current economic and financial
market conditions, are contained principally in Item 1, Business; Item 1A, Risk Factors; Item 7, Management’s
Discussion and Analysis of Financial Condition and Results of Operations; and other sections of this Annual
Report on Form 10-K. Factors that could cause or contribute to these differences include those discussed in
Item 1A, Risk Factors, as well as those discussed elsewhere in this Annual Report on Form 10-K.

Forward-looking statements are inherently uncertain and you should not place undue reliance on these

statements, which speak only as of the date that they were made. These cautionary statements should be
considered in connection with any written or oral forward-looking statements that we may issue in the future. We
do not undertake any obligation to release publicly any revisions to these forward-looking statements after
completion of the filing of this Annual Report on Form 10-K to reflect later events or circumstances or to reflect
the occurrence of unanticipated events.

Item 1.

Business

Overview

XOMA Corporation (“XOMA”), a Delaware corporation, discovers and develops innovative antibody-based

therapeutics. Our lead drug candidate, gevokizumab (formerly XOMA 052), is a potent humanized monoclonal
antibody with unique allosteric modulating properties. Gevokizumab binds to the inflammatory cytokine
interleukin-1 beta (“IL-1 beta”), which we believe to be a primary trigger of pathologic inflammation in multiple
diseases. We have entered into a license and collaboration agreement with Les Laboratoires Servier (“Servier”)
to develop and commercialize gevokizumab in multiple indications. In collaboration with Servier we have
launched the global Phase 3 gevokizumab clinical development program for active and controlled non-infectious
uveitis (“NIU”) involving the intermediate and/or posterior segment of the eye, and Behçet’s uveitis. XOMA is
conducting both of the NIU studies, and Servier is sponsoring the Phase 3 study in Behçet’s uveitis. The study
sites are screening and enrolling patients in these separate studies.

1

Separately, we launched a Phase 2 proof-of-concept program for gevokizumab to evaluate additional

indications for further development, including a clinical trial in moderate-to-severe inflammatory acne, for which
we reported encouraging top line results in January 2013, a clinical trial in erosive osteoarthritis of the hand,
which was opened for enrollment in June 2012, and a clinical trial in scleritis that will be conducted by the
National Eye Institute (“NEI”), a part of the U.S. National Institutes of Health (“NIH”). We anticipate the NEI
will begin enrolling patients in this study during the first quarter of 2013. We expect Servier to institute its own
proof-of-concept program for gevokizumab in different indications from ours. In November 2012, Servier began
a Phase 2 study to determine gevokizumab’s potential to treat patients who have experienced a recent Acute
Coronary Syndrome.

Our proprietary preclinical pipeline includes classes of antibodies that activate, sensitize, or deactivate the

insulin receptor in vivo , that we have named XMet. This portfolio of antibodies represents potential new
therapeutic approaches to the treatment of diabetes and several diseases that involve insulin, which we believe
may be orphan drug opportunities.

We have developed these and other antibodies using some or all of our ADAPT™ antibody discovery and
development platform, our ModulX™ technologies for generating allosterically modulating antibodies, and our
OptimX™ technologies for optimizing biophysical properties of antibodies, including affinity, immunogenicity,
stability and manufacturability.

Our biodefense initiatives include XOMA 3AB, a biodefense anti-botulism product candidate comprised of

a combination of three antibodies. XOMA 3AB is directed against botulinum toxin serotype A and has been
developed through funding from the National Institute of Allergy and Infectious Diseases (“NIAID”), a part of
the NIH. All volunteers have been enrolled and dosed with XOMA 3AB in a Phase 1 clinical trial sponsored by
NIAID. In January 2012, we announced we will complete NIAID biodefense contracts currently in place but will
not actively pursue future contracts. Should the government choose to acquire XOMA 3AB or other biodefense
products in the future, we expect to be able to produce these antibodies through an outside manufacturer.

We also have developed antibody product candidates with premier pharmaceutical companies including
Novartis AG (“Novartis”) and Takeda Pharmaceutical Company Limited (“Takeda”). Two antibodies developed
with Novartis, LFA102 and HCD122 (lucatumumab), are in Phase 1 and/or Phase 2 clinical development by
Novartis for the potential treatment of breast or prostate cancer and hematological malignancies, respectively.

In January 2012, we announced we had acquired certain U.S. rights to a portfolio of antihypertensive
products from Servier. The portfolio includes ACEON (perindopril erbumine), a currently marketed angiotensin
converting enzyme (“ACE”) inhibitor, and three fixed-dose combination (“FDC”) product candidates where
perindopril is combined with another active ingredient(s). The last to expire proprietary form of perindopril in
each FDC product candidate provides patent protection until April 2023. We assumed commercialization
activities for ACEON in January 2012. In November 2012, we announced that the 837-patient Phase 3 trial for
the FDC of perindopril arginine and amlodipine besylate (“FDC1”) met its primary endpoint. Partial funding for
the trial was provided by Servier. We expect to pay the balance of study expenses, consisting primarily of costs
generated by our contract research organization, from the profits generated by our ACEON sales. We are
working to identify a third-party organization that could sublicense this FDC and move it forward toward
commercialization in the U.S. market.

In January 2012, we implemented a streamlining and restructuring plan designed to sharpen our focus on
value-creating opportunities, particularly gevokizumab and our antibody discovery and development capabilities.
The plan included a personnel reduction of 84 positions, or 34% of our staff. These staff reductions resulted
primarily from our decisions to utilize a contract manufacturing organization for Phase 3 and commercial
antibody production and to eliminate internal research functions that are non-differentiating or that can be
obtained cost-effectively by contract service providers. In August 2012, Servier and we announced XOMA had
entered into an agreement with Boehringer Ingelheim to transfer our technology and processes for the validation

2

of our technology and processes in preparation for the commercial manufacture of gevokizumab. It is our
intention that Boehringer Ingelheim will produce gevokizumab at its facility in Biberach, Germany for XOMA’s
commercial use.

Product Development Strategy

We are advancing a pipeline of antibody product candidates using our proven expertise, technologies and
capabilities from antibody discovery through product development. For products that we have the potential to
market on our own in the U.S. with a targeted sales force, we will develop the compound in a lead indication and
expand the asset’s value by conducting proof-of-concept studies in additional indications. We will seek a partner
for all non-U.S. development and commercial activities. For product candidates that require a large sales force or
an exceptionally large clinical development program, we will seek to out-license the candidates on economic
terms that reflect the potential commercial value of the asset. The principal elements of our strategy are to:

•

Focus on advancing gevokizumab, our lead product candidate. Using our proprietary antibody
technologies and allosteric modulating capabilities and expertise, we discovered gevokizumab, an
antibody that modulates IL-1 beta, a cytokine that triggers inflammatory pathways in the body. We
believe gevokizumab, by targeting IL-1 beta, has the potential to address the underlying inflammatory
causes of a wide range of unmet medical needs.

In December 2010, we entered into an agreement with Servier to jointly develop and commercialize
gevokizumab in multiple indications, which provided for a non-refundable upfront payment of $15.0
million that we received in January 2011. In connection with this agreement, Servier is funding the first
$30.0 million of gevokizumab global clinical development expenses and the first $20.0 million of
gevokizumab chemistry and manufacturing controls (“CMC”) expenses for all development expenses
for NIU and Behçet’s uveitis. All such expenses will be shared by both companies on a 50/50 basis
after these initial amounts are incurred. We have incurred the first $20.0 million in CMC expenses in
2012 and expect to have incurred the first $30.0 million in clinical development expenses at some time
during 2013.

Servier and we have initiated an expanded gevokizumab clinical development plan. The plan includes
two global Phase 3 trials in active and controlled NIU involving the intermediate and/or posterior
segments of the eye and a Phase 3 trial outside the U.S. in a subset of NIU patients who suffer from
Behçet’s uveitis. All three Phase 3 trials have been initiated: the active NIU trial in June 2012, named
EYEGUARD™-A; the Behçet’s uveitis trial in September 2012, named EYEGUARD™-B; and the
controlled NIU trial in October 2012, named EYEGUARD™-C. In addition to establishing efficacy,
these trials have been designed to meet the FDA safety requirement for ophthalmic indications: at least
300 patients must be treated for at least six months and 100 patients for one year at the to-be-marketed
dose. We anticipate we will have preliminary top-line results from EYEGUARD™-A at year-end
2013; EYEGUARD™-B during the first half of 2014; and EYEGUARD™-C during the first quarter of
2014.

We also initiated a Phase 2 proof-of-concept clinical program to identify additional conditions that may
respond to treatment with gevokizumab. The program is evaluating gevokizumab in three separate
diseases that have demonstrated IL-1 beta involvement. The first study in moderate to severe
inflammatory acne began enrolling patients in December 2011. In January 2013, we announced the
top-line results from the study, which demonstrated gevokizumab has a dose-dependent benefit on
moderate to severe acne lesions. This study also identified a non-effective dose, and the information we
have generated with this study should allow us to conduct a robust Phase 3 study should we choose
moderate to severe acne as our next Phase 3 indication. In June 2012, we announced that the second
clinical study in the gevokizumab proof-of-concept program in patients with erosive osteoarthritis of
the hand was opened for enrollment. We anticipate we will have results from this study in the third
quarter of 2013. In December 2012, we announced the third clinical study in this program, which will

3

•

•

study gevokizumab in patients with active non-infectious anterior scleritis. This study will be
conducted by the NEI. We anticipate the NEI will initiate patient enrollment in this study in the first
quarter of 2013, and we anticipate we will have data from this study in late 2013.

Separately, in November 2012, we announced Servier had initiated the first Servier-sponsored Phase 2
proof-of-concept study in patients who had experienced a recent Acute Coronary Syndrome.

In 2013 we plan to meet with the U.S. Food and Drug Administration (“FDA”) to discuss the
possibility for XOMA and Servier to enter into Phase 3 clinical studies in one or both of two potential
additional indications, Neutrophilic Dermatoses and Schnitzler syndrome. We believe these two
indications are rare diseases, which we consider to be diseases affecting less than one in 50,000
persons. Therefore, we intend to pursue orphan drug designations for one or both of these indications.
We believe each represents an attractive market because each may be eligible for accelerated approval
pathways with the FDA, increasing the potential for shorter development timelines and faster paths to
commercialization.

Advance our proprietary preclinical pipeline candidates and generate revenues from our proprietary
technologies. We continue to develop our proprietary preclinical pipeline, primarily focusing on the
development of allosteric modulating monoclonal antibodies. Our most advanced program, which
targets the insulin receptor, has generated three new classes of fully human monoclonal antibodies.
These allosteric modulating antibodies activate (XMetA) or sensitize (XMetS) or antagonize/deactivate
(XMetD) the insulin receptor in vivo . XMetA and XMetS represent the potential for distinct, new
therapeutic approaches for the treatment of diabetes. Separate preclinical studies of XMetA and XMetS
have demonstrated reduced fasting blood glucose levels and improved glucose tolerance in mouse
models of diabetes. To increase the value of these assets, we have chosen to continue developing both
antibodies internally, which should allow us to negotiate a more substantial return to XOMA on any
sales that XMetA and XMetS may generate. Ultimately, we expect to seek a partner for development
and commercialization of these assets at a future date. In the case of XMetD, we plan to develop this
compound internally, as it has potential as a treatment for as many as three rare life-threatening or
severely debilitating diseases: insulinomas, congenital hyperinsulinism and hyperinsulinemic
hypoglycemia in post-gastric bypass surgery patients.

Historically, we have established technology collaborations with several companies to provide access
to XOMA’s proprietary antibody discovery and optimization technologies. In addition, we have
licensed our bacterial cell expression (“BCE”) technology to more than 60 companies in exchange for
license, milestone and other fees, royalties and complementary technologies. A number of licensed
product candidates developed through these technology collaborations are in clinical development. We
believe we can continue to generate licensing revenue from our proprietary technologies in the future.

Complete current biodefense contracts. To date, we have been awarded four contracts, totaling
approximately $120 million, from NIAID to support development of XOMA 3AB and several product
candidates for the treatment of botulism poisoning. In addition, our biodefense programs included two
subcontracts from SRI International totaling $4.3 million, funded through NIAID, for the development
of antibodies to neutralize H1N1 and H5N1 influenza viruses and the virus that causes severe acute
respiratory syndrome (“SARS”).

NIAID is conducting a Phase 1 trial of XOMA 3AB, a novel formulation of three antibodies designed
to prevent and treat botulism poisoning. This double-blind, dose-escalation study in approximately 24
healthy volunteers is designed to assess the safety and tolerability and determine the pharmacokinetic
profile of XOMA 3AB. All volunteers in this trial have been enrolled and dosed with XOMA 3AB.

In January 2012, we announced we will complete NIAID biodefense contracts currently in place but
will not actively pursue future contracts. Should the government choose to acquire XOMA 3AB or
other biodefense products in the future, we expect to be able to produce these antibodies through an
outside manufacturer.

4

Commercialization Strategy

We are committed to establishing XOMA as a commercial organization in the U.S. to capture appropriate

value from our product discovery and development programs. We expect to establish our

U.S. commercial presence by utilizing small targeted sales teams that are focused exclusively on marketing
our products to specialized physician groups. For indications that require large numbers of sales representatives,
particularly for indications that are treated in the primary care setting, we will seek strategic partnerships with
companies that have the expertise in marketing products to this diverse audience.

We announced we acquired U.S. rights and had assumed commercialization activities for the branded
antihypertensive product ACEON (perindopril erbumine), an FDA-approved ACE inhibitor, from Servier and its
previous U.S. licensee in January 2012. In addition to ACEON, upon exercise by us of an option with respect to
each product, the acquisition includes a portfolio of additional FDC product candidates where perindopril is
combined with another active ingredient(s), such as a calcium channel blocker.

ACEON is subject to competition from multiple approved generic perindopril erbumine products, and our

commercialization activities are limited to distribution and post marketing regulatory responsibilities as the
current holder of the ACEON New Drug Application (“NDA”). We have contracted with third parties to
manufacture and distribute ACEON.

Proprietary Products

As part of our strategy, we are focusing our technology and resources on advancing our emerging

proprietary pipeline. Below is a summary of our proprietary products:

•

•

Gevokizumab is a potent monoclonal antibody with unique allosteric modulating properties and has
the potential to treat patients with a wide variety of inflammatory diseases and other diseases.
Gevokizumab binds strongly to IL-1 beta, a pro-inflammatory cytokine involved in NIU and Behçet’s
uveitis, moderate-to-severe inflammatory acne, erosive osteoarthritis of the hand, active non-infectious
anterior scleritis, cardiovascular disease, Neutrophilic Dermatoses, Schnitzler syndrome, and other
diseases. By binding to IL-1 beta, gevokizumab modulates the activation of the IL-1 receptor, thereby
preventing the cellular signaling events that produce inflammation. Gevokizumab is a humanized IgG2
antibody. Based on its binding properties, specificity for IL-1 beta and its half-life (the time it takes for
the amount administered to be reduced by one-half) in the body, gevokizumab may provide convenient
dosing of once per month or less frequently.

In December 2010, we entered into an agreement with Servier to jointly develop and commercialize
gevokizumab in multiple indications.

XOMA Metabolic Activating, Sensitizing and Antagonizing/Deactivating Antibodies (“XMet”).
Insulin receptor-activating antibodies, such as XMetA, are designed to provide long-acting insulin-like
activity to diabetic patients who cannot make sufficient insulin, potentially reducing the number of
insulin injections needed to control their blood glucose levels. Insulin receptor-sensitizing antibodies,
such as XMetS, are designed to reduce insulin resistance and could enable diabetic patients to use their
own insulin more effectively to control blood glucose levels. Insulin receptor-antagonizing/
deactivating antibodies, such as XMetD, are designed to treat several diseases that result from the
continuous overproduction of or inappropriate reaction to insulin. There are three orphan indications
that may benefit from XMetD that are of greatest interest to us: insulinomas, congenital
hyperinsulinism, and hyperinsulinemic hypoglycemia post-gastric bypass surgery.

Studies presented on XMetA have demonstrated it reduced fasting blood glucose levels and improved
glucose tolerance in a mouse model of diabetes. After six weeks of treatment, mice treated with
XMetA had a statistically significant reduction in HbA1c levels, a standard measure of average blood
glucose levels over time, compared to the control mice. In addition, there was a statistically significant
reduction in elevated non-HDL cholesterol levels.

5

We studied XMetS in a mouse model of obesity-induced insulin resistance. In mice treated with
XMetS, we saw enhanced insulin sensitivity and statistically significant improvements in fasting blood
glucose levels and glucose tolerance as compared to the control mice. In addition, there was a
statistically significant reduction in elevated non-HDL cholesterol levels.

XOMA 3AB is a multi-antibody product designed to neutralize the most potent of the botulinum
toxins, Type A, which causes paralysis and is a bioterrorism threat. Our anti-botulism program also
includes additional product candidates and is the first of its kind to combine multiple human antibodies
in each product candidate to target a broad spectrum of the most toxic botulinum toxins, including the
three most toxic serotypes, Types A, B and E. The antibodies are designed to bind to each toxin and
enhance the clearance of the toxin from the body. The use of multiple antibodies increases the
likelihood of clearing the harmful toxins by providing specific protection against each toxin type. In
contrast to existing agents that treat botulism, XOMA uses advanced human monoclonal antibody
technologies in an effort to achieve superior safety, potency and efficacy and avoid life-threatening
immune reactions associated with animal-derived products. All volunteers have been enrolled and
dosed with XOMA 3AB in a Phase 1 clinical trial sponsored by NIAID.

XOMA 629 is a topical anti-bacterial formulation of a peptide derived from bactericidal/permeability-
increasing protein (“BPI”), an integral part of the protective human immune system. In 2012, XOMA
entered into a license agreement with Margaux Biologics, Inc. (“Margaux”), under which XOMA
transferred its rights, title, and interest in BPI. As consideration for the transferred assets and licenses,
Margaux issued to XOMA shares of its common stock, representing an amount of capital stock equal to
7% of the outstanding capital stock of Margaux. Under the terms of this agreement, we may receive
milestone payments aggregating up to $5.6 million and low to mid single-digit royalties on future sales
of products subject to this license.

Preclinical Product Pipeline: We are pursuing additional opportunities to further broaden our
preclinical product pipeline, including internal discovery programs.

•

•

•

Partnership Products

Historically, we have provided research and development collaboration services for world-class

organizations, such as Novartis and Takeda, in pursuit of new antibody products. In more recent years, we have
evolved our business focus from a service provider model to a proprietary product development model. However,
we will continue to capitalize on partnered product arrangements as opportunities arise. Below is a list of such
partnerships:

•

•

Therapeutic Antibodies with Takeda: Since 2006, Takeda has been a collaboration partner for
therapeutic monoclonal antibody discovery and development against multiple targets selected by them.
In February 2009, we expanded our existing collaboration to provide Takeda with access to multiple
antibody technologies, including a suite of research and development technologies and integrated
information and data management systems. We may receive potential milestones and royalties on sales
of antibody products in the future.

Therapeutic Antibodies with Novartis: In November 2008, we restructured our product development
collaboration with Novartis, which was entered into in 2004 with Novartis (then Chiron Corporation).
Under the restructured agreement, Novartis received control over the two ongoing programs. We may,
in the future, receive milestones and/or double-digit royalty rates for the programs and options to
develop or receive royalties from four additional programs.

6

Technologies and Technology Licenses

We have a unique set of antibody discovery, optimization and development technologies, including:

•

ADAPT™ (Antibody Discovery Advanced Platform Technologies): proprietary phage display libraries
integrated with yeast and mammalian display to enable antibody discovery;

• ModulX™: technology that enables positive and negative modulation of biological pathways using

allosterically modulating antibodies; and

•

OptimX™: technologies used for optimizing biophysical properties of antibodies, including affinity,
immunogenicity, stability and manufacturability.

Technology Licenses

Below is a summary of certain proprietary technologies owned by us and available for licensing to other

companies:

•

Antibody discovery technologies: We use human antibody phage display libraries, integrated with
yeast and mammalian display (“ADAPT™ Integrated Display”), in our discovery of therapeutic
candidates, and we offer access to this platform, including novel phage libraries developed internally,
as part of our collaboration business. We believe access to ADAPT™ Integrated Display offers a
number of benefits to us and our collaboration partners because it enables us to combine the diversity
of phage libraries with accelerated discovery due to rapid IgG reformatting and FACS-based screening
using yeast and mammalian display. This increases the probability of technical and business success in
finding rare and unique functional antibodies directed to targets of interest.

• ModulX™ technology: ModulX™ technology allows modulation of biological pathways using

monoclonal antibodies and offers insights into regulation of signaling pathways, homeostatic control,
and disease biology. Using ModulX™, XOMA is generating product candidates with novel
mechanisms of action that specifically alter the kinetics of interaction between molecular constituents
(e.g. receptor-ligand). ModulX™ technology enables expanded target and therapeutic options and
offers a unique approach in the treatment of disease.

•

OptimX™ technologies:

Human Engineering™ (“HE™”): HE™ is a proprietary humanization technology that allows
modification of non-human monoclonal antibodies to reduce or eliminate detectable
immunogenicity and make them suitable for medical purposes in humans. The technology uses a
unique method developed by us, based on analysis of the conserved structure-function
relationships among antibodies. The method defines which residues in a non-human variable
region are candidates to be modified. The result is an HE™ antibody with preserved antigen
binding, structure and function that has eliminated or greatly reduced immunogenicity. HE™
technology was used in development of gevokizumab and is used in the development of certain
other antibody products.

Targeted Affinity Enhancement™ (“TAE™”): TAE™ is a proprietary technology involving
the assessment and guided substitution of amino acids in antibody variable regions, enabling
efficient optimization of antibody binding affinity and selectivity modulation. TAE™ generates a
comprehensive map of the effects of amino acid mutations in the CDR region likely to impact
binding. The technology is utilized by XOMA scientists and has been licensed to a number of our
collaborators.

•

Bacterial Cell Expression: The production or expression of antibodies using bacteria is an enabling
technology for the discovery and selection, as well as the development and manufacture, of
recombinant protein pharmaceuticals, including diagnostic and therapeutic antibodies for commercial

7

purposes. Genetically engineered bacteria are used in the recombinant expression of target proteins for
biopharmaceutical research and development, primarily due to the relative simplicity of gene
expression in bacteria, as well as many years of experience culturing species, including E. coli, in
laboratories and manufacturing facilities. Our scientists have developed bacterial expression
technologies to produce antibodies and other recombinant protein products.

We have granted more than 60 licenses to biotechnology and pharmaceutical companies to use our
patented and proprietary technologies relating to bacterial expression of recombinant pharmaceutical
products. Bacterial antibody expression is also a key technology used in multiple systems for high-
throughput screening of antibody domains. Expression of antibodies by phage display technology, for
example, depends upon the expression and secretion of antibody domains from bacteria as properly
folded, functional proteins.

Many licensees of our bacterial cell expression technology have developed, or are in the process of
developing, antibodies for which we may be entitled to future milestone payments and royalties on
product sales. Under the terms of our license agreement with Pfizer Inc. (“Pfizer”), signed in 2007, we
received an up-front cash payment of $30 million and from 2010 through 2012; we received milestone
payments relating to six undisclosed product candidates. We also may be eligible for additional
milestone payments aggregating up to $8.3 million relating to these six product candidates and low
single-digit royalties on future sales of all products subject to this license. In addition, we may receive
potential milestone payments aggregating up to $1.7 million for each additional qualifying product
candidate. Our right to milestone payments expires on the later of the expiration of the last-to-expire
licensed patent or the tenth anniversary of the effective date. Our right to royalties expires upon the
expiration of the last-to-expire licensed patent.

Current licensees include but are not limited to the following entities:

Active Biotech AB

Dompe, s.p.a.

Affimed Therapeutics AG

Dyax Corp.

MorphoSys AG

Novartis AG

Affitech AS

Eli Lilly and Company

Pfizer Inc.

Applied Molecular Evolution,
Inc. (now a subsidiary of Eli
Lilly and Company)

Genentech, Inc. (now a
member of the Roche
Group)

Bayer Healthcare AG

Invitrogen Corporation

Takeda Pharmaceutical
Company Ltd.

The Medical Research
Council UCB S.A.

BioInvent International AB

MedImmune Ltd.

Verenium Corporation

Centocor Ortho Biotech (now
a member of Johnson &
Johnson)

Crucell Holland B.V. (now a
member of Johnson &
Johnson)

Merck & Co., Inc.

Mitsubishi Tanabe Pharma
Corporation

Wyeth Pharmaceuticals
Division (now a member
of Pfizer Inc.)

ZymoGenetics, Inc. (now a
member of Bristol-Myers
Squibb Company)

These licenses sometimes are associated with broader agreements, which may include expanded license
rights, cell line development and process development.

8

Proprietary Product Summary:

The following table summarizes information related to the proprietary products we are developing currently:

Program

Description

Indication

Status

Developer

Gevokizumab

HE™ antibody to IL-
1 beta

XMetA,
XMetS
XMetD

XOMA 3AB

Multiple
preclinical
programs

Fully human
monoclonal
antibodies

Therapeutic
antibodies to
multiple
Type A botulinum
neurotoxins

Fully human
monoclonal
antibodies to
multiple disease
targets, including
TGF-beta and
FGFR-4.

XOMA (in
collaboration with
Servier)

Non-infectious
uveitis, Behçet’s
uveitis, moderate to
severe inflammatory
acne, erosive
osteoarthritis of the
hand, active non-
infectious anterior
scleritis, and cardio-
metabolic diseases

Ongoing Phase 3
studies for non-
infectious uveitis and
Behçet’s uveitis, and
ongoing Phase 2
studies for moderate
to severe
inflammatory acne,
erosive osteoarthritis
of the hand, active
non-infectious
anterior scleritis, and
cardiovascular
disease.

Diabetes, metabolic
disorders, and other
orphan indications

Preclinical

XOMA

Botulism poisoning

Phase 1

XOMA
(NIAID-funded)

Preclinical

XOMA

Autoimmune, cardio-
metabolic,
infectious,
inflammatory,
ophthalmological,
and oncological
diseases

Partnership Product Summary:

The following table summarizes information related to certain products that we currently are developing or

have developed in the past, for which we may earn royalties on product sales in the future:

Program

FDC1

HCD122 and
LFA102

Description

Indication

Status

Developer

Perindopril
arginine and
amlodipine
besylate

Fully human
antibody to CD40
and HE™ antibody
to prolactin
receptor

Hypertension

Phase 3
completed

XOMA (partially
funded by
Servier)

Phase 1 and 2;
Phase 1

Novartis (fully
funded)

Hematologic
tumors; certain
breast and
prostate cancers;
and other
undisclosed
diseases

9

Program

Description

Indication

Status

Developer

Therapeutic
antibodies

Therapeutic
antibodies

Fully human
monoclonal
antibodies to
undisclosed disease
targets

HE™ monoclonal
antibody to HGF

Undisclosed

Preclinical

Takeda (fully
funded)

Phase 2; Phase 1

AVEO (fully
funded)

Non-small cell
lung cancer;
solid tumors and
multiple
myeloma

Financial and Legal Arrangements of Product Collaborations, Licensing and Other Arrangements

Collaboration and Licensing Agreements

Servier — Gevokizumab

We have entered into a license and collaboration agreement with Servier to jointly develop and

commercialize gevokizumab in multiple indications, which provided a non-refundable upfront payment of $15
million, which we received in January 2011. Under the terms of the agreement, Servier has worldwide rights to
cardiovascular disease and diabetes indications and rights outside the U.S. and Japan to all other indications,
including NIU, Behçet’s uveitis and other inflammatory and oncology indications. XOMA retains development
and commercialization rights in the U.S. and Japan for all indications (including NIU, Behçet’s uveitis and other
inflammatory diseases and oncology indications) except cardiovascular disease and diabetes. XOMA has an
option to reacquire rights to cardiovascular disease and diabetes indications from Servier in these territories (the
“Cardiometabolic Indications Option”). Should we exercise the Cardiometabolic Indications Option, we will be
required to pay Servier an option fee and partially reimburse their incurred development expenses. Each party
has the right in certain circumstances to pursue development in indications not specified in the agreement, and in
such event, the other party will have the option to participate in such development in certain circumstances,
including reimbursement of a portion of the developing party’s expenses.

Under this agreement, Servier will fully fund activities to advance the global clinical development and
future commercialization of gevokizumab in cardiovascular-related diseases and diabetes. Also, Servier will fund
$50 million of gevokizumab global clinical development and CMC expenses and 50% of further expenses related
to the NIU and Behçet’s uveitis indications.

In addition, under the agreement, we are eligible to receive a combination of Euro- and U.S. Dollar
(“USD”)-denominated, development and sales milestones for multiple indications aggregating to a potential
maximum of approximately $470 million when converted using the December 31, 2012, Euro to USD exchange
rate (the “12/31/12 Exchange Rate of 1.3215”), if XOMA reacquires cardiovascular and/or diabetes rights in the
U.S. and Japan. If XOMA does not reacquire these rights, then the milestone payments aggregate to a potential
maximum of approximately $810 million converted using the 12/31/12 Exchange Rate of 1.3215. Servier’s
obligation to pay development and commercialization milestones will continue for so long as Servier is
developing or selling products under the agreement.

We are eligible to receive royalties on gevokizumab sales from sales outside of the U.S. and Japan, and from

global sales in cardio-metabolic indications, which are tiered based on sales levels and range from a mid-single
digit to up to a mid-teens percentage rate. Our right to royalties with respect to a particular product and country
will continue for so long as such product is sold in such country.

The collaboration is carried out and managed by committees mutually established by XOMA and Servier. In

general, in the event of any disputes, each party has decision-making authority over matters relating to its areas

10

of responsibility and territory, but neither party has unilateral decision-making rights if the decision would have a
material adverse impact on the other party’s rights in its territory. The agreement contains customary termination
rights relating to matters such as material breach by either party, safety issues and patents. Servier also has a
unilateral right to terminate the agreement on a country-by-country basis or in its entirety on six months’ notice.

We also entered into a loan agreement with Servier (the “Servier Loan Agreement”), which provided for an

advance of up to €15.0 million. The loan was fully funded in January 2011, with the proceeds converting to
approximately $19.5 million at the date of funding. The loan is secured by an interest in XOMA’s intellectual
property rights to all gevokizumab indications worldwide, excluding certain rights in the U.S. and Japan. Interest
is calculated at a floating rate based on a Euro Inter-Bank Offered Rate (“EURIBOR”) and is subject to a cap.
The interest rate is reset semi-annually in January and July of each year. The interest rate for the initial interest
period was 3.22%. The interest rate was reset to 3.83% for the six-month period from July 2011 through January
2012, 3.54% for the six-month period from January 2012 through July 2012, 2.80% for the six-month period
from July 2012 through January 2013 and 2.33% for the six-month period from January 2013 through July 2013.
Interest is payable semi-annually; however, the Servier Loan Agreement provides for a deferral of interest
payments over a period specified in the agreement. During the deferral period, accrued interest will be added to
the outstanding principal amount for the purpose of interest calculation for the next six-month interest period. On
the repayment commencement date, all unpaid and accrued interest shall be paid to Servier, and thereafter, all
accrued and unpaid interest shall be due and payable at the end of each six-month period. The loan matures in
2016; however, after a specified period prior to final maturity, the loan is to be repaid (i) at Servier’s option, by
applying up to a significant percentage of any milestone or royalty payments owed by Servier under our
collaboration agreement and (ii) using a significant percentage of any upfront, milestone or royalty payments we
receive from any third-party collaboration or development partner for rights to gevokizumab in the U.S. and/or
Japan. In addition, the loan becomes immediately due and payable upon certain customary events of default. At
December 31, 2012, the outstanding principal balance under this loan was $19.8 million using the 12/31/12
Exchange Rate of 1.3215. Refer to Management’s Discussion and Analysis of Financial Condition and Results of
Operations for further information regarding the Servier Loan Agreement.

NIAID

In March 2005, we were awarded a $15 million competitive bid contract from NIAID to develop three anti-

botulinum neurotoxin monoclonal antibodies. Under this contract, we created production cell lines using our
proprietary antibody expression systems, built Master and Manufacturer’s Working Cell Banks, developed
production processes and produced initial quantities of the three antibodies. The contract was performed over an
18-month period and was fully funded with Federal funds from NIAID under Contract No.
HHSN266200500004C (“NIAID 1”). Final acceptance of the project was received in October 2006.

In July 2006, we were awarded a $16.3 million NIAID contract under Contract No. HHSN266200600008C/

N01-Al-60008 (“NIAID 2”) to produce monoclonal antibodies for the treatment of botulism to protect United
States citizens against the harmful effects of botulinum neurotoxins used in bioterrorism. Under this contract, we
created and produced XOMA 3AB, an innovative injectable product comprised of three anti-type A botulinum
neurotoxin monoclonal antibodies. This work was complete in the third quarter of 2010.

In September 2008, we were awarded a third NIAID contract for $64.8 million under Contract No.

HHSN272200800028C (“NIAID 3”) to continue development of our anti-botulinum antibody product candidates,
including XOMA 3AB and additional product candidates directed against B and E toxin serotypes. As part of the
contract, we have developed, evaluated and produced the clinical supplies to support an IND filing with the FDA
for XOMA 3AB; independently, XOMA has funded preclinical studies required to support human clinical trials.
In May 2011, NIAID informed us it was initiating a Phase 1 trial of XOMA 3AB. All volunteers in this trial have
been enrolled and dosed with XOMA 3AB.

11

In October 2011, we announced we had been awarded a fourth NIAID contract for up to $28.0 million over
five years under Contract No. HHSN 272201100031C (“NIAID 4”) to develop broad-spectrum antitoxins for the
treatment of human botulism poisoning.

In January 2012, we announced we will complete NIAID biodefense contracts currently in place but will not

actively pursue future contracts. Should the government choose to acquire XOMA 3AB or other biodefense
products in the future, we expect to be able to provide these antibodies through an outside manufacturer.

Servier — U.S. Perindopril Franchise

On January 17, 2012, we announced we had acquired certain U.S. rights to a portfolio of antihypertensive

products from Servier. The portfolio includes ACEON (perindopril erbumine), a currently marketed angiotensin
converting enzyme (“ACE”) inhibitor, and three FDC product candidates where a form of proprietary perindopril
(perindopril arginine) is combined with another active ingredient(s). We assumed commercialization activities
for ACEON in January 2012. In November 2012, we announced an 837-patient Phase 3 study we conducted with
perindopril arginine and amlodipine besylate (“FDC1”) had demonstrated statistically superior reductions in
sitting systolic and diastolic blood pressure after six weeks of treatment than either compound alone. Partial
funding for the trial was provided by Servier; the balance of study expenses, consisting primarily of costs
generated by our contract research organization, is expected to be paid over time from the profits generated by
our ACEON sales. We are working to identify a third-party organization that can sublicense this FDC and move
it forward toward commercialization in the U.S. market.

In connection with this arrangement, we paid a $1.5 million license fee to Servier in the third quarter of

2010. We are required to pay a royalty on ACEON sales at a rate that is tiered based on sales levels and ranges
from a mid-single digit to a mid-teen percentage rate. If approved, we will pay a royalty on sales of the FDC
product candidates in the mid-teen percentage rate. The FDC royalty rate is subject to reduction in the event of
generic competition or if other intellectual property rights are required. We may be required to pay the following
milestones: development milestones aggregating $8.5 million (assuming we exercise our options on the
additional FDC product candidates) and sales milestones of up to an aggregate $15.1 million, in each case for all
of the FDC product candidates. We also may be required to make certain additional payments if the FDC product
candidates receive FDA approval but certain minimum sales levels are not reached. We generally will be
responsible for its development and commercialization expenses; however, Servier partially funded development
of FDC1.

By its terms, the arrangement, including our obligation to pay royalties and/or development and sales
milestones, will continue until the later of July 2018 or the expiration of the last-to-expire Servier patent licensed
to us under the arrangement, unless terminated earlier. The agreement contains customary termination rights
relating to matters, such as material breach by either party, insolvency of either party or safety issues. Each party
has the right to terminate the arrangement if the FDC1 does not receive FDA approval by December 31, 2014.
Servier also has the right to terminate the arrangement if certain aspects of our commercialization strategy are not
successful and Servier does not consent to an alternative strategy or, as to the FDC product candidates, if we
breach our obligations to certain of our service providers.

Takeda

In November 2006, we entered into a fully funded collaboration agreement with Takeda for therapeutic
monoclonal antibody discovery and development activities under which we agreed to discover and optimize
therapeutic antibodies against multiple targets selected by Takeda. Takeda agreed to make up-front, annual
maintenance and milestone payments to us, fund our research and development and manufacturing activities for
preclinical and early clinical studies and pay royalties on sales of products resulting from the collaboration.
Takeda is responsible for clinical trials and commercialization of drugs after an IND submission and is granted
the right to manufacture once a product enters into Phase 2 clinical trials. We have completed a technology
transfer and do not expect to perform any further research and development services under this program. From
2010 through 2012, we received milestone payments relating to one currently active program.

12

Under the terms of this agreement, we may receive milestone payments aggregating up to $19.0 million
relating to one undisclosed product candidate and low single-digit royalties on future sales of all products subject
to this license. In addition, in the event Takeda were to develop additional future qualifying product candidates
under the terms of our agreement, we would be eligible for milestone payments aggregating up to $20.75 million
for each such qualifying product candidate. Our right to milestone payments expires on the later of the receipt of
payment from Takeda of the last amount to be paid under the agreement or the cessation by Takeda of all
research and development activities with respect to all program antibodies, collaboration targets and/or
collaboration products. Our right to royalties expires on the later of 13.5 years from the first commercial sale of
each royalty-bearing discovery product or the expiration of the last-to-expire licensed patent.

In February 2009, we expanded our existing collaboration to provide Takeda with access to multiple
antibody technologies, including a suite of research and development technologies and integrated information
and data management systems. We may receive milestones of up to $3.25 million per discovery product
candidate and low single-digit royalties on future sales of all antibody products subject to this license. Our right
to milestone payments expires on the later of the receipt of payment from Takeda of the last amount to be paid
under the agreement or the cessation by Takeda of all research and development activities with respect to all
program antibodies, collaboration targets and/or collaboration products. Our right to royalties expires on the later
of 10 years from the first commercial sale of such royalty-bearing discovery product or the expiration of the last-
to-expire licensed patent.

Novartis

In November 2008, we restructured our product development collaboration with Novartis, which involved
six development programs, including the HCD122 program. Novartis is the sponsor of two Phase 2 trials using
HCD122 (lucatumumab), a fully human anti-CD40 antagonist antibody. The antibody has a dual mechanism of
action that involves inhibition of CD40-ligand mediated growth and survival while recruiting immune effector
cells to kill CD40-expressing tumor cells through a process known as antibody-dependent cellular cytotoxicity
(ADCC). CD40, a member of the tumor necrosis factor, or TNF, family of antigens, is a cell surface antigen
expressed in B-cell malignancies and involved in a broad variety of immune and inflammatory responses.
Novartis has initiated Phase 1 trials in the United States and Japan of LFA102, a HE™ antibody to prolactin
receptor, in patients with metastatic breast cancer or hormone refractory prostate cancer.

Under the restructured agreement, Novartis made a payment to us of $6.2 million in cash and reduced our
existing debt by $7.5 million; will fully fund all future research and development expenses; may pay potential
milestones of up to $14.0 million and royalty rates ranging from low-double digit to high-teen percentage rates
for two ongoing product programs, HCD122 and LFA102; and has provided us with options to develop or
receive royalties on four additional programs. In exchange, Novartis has control over the HCD122 and LFA102
programs, as well as the right to expand the development of these programs into additional indications outside of
oncology. As part of the agreement, Novartis paid us for all project costs incurred after July 1, 2008. Our right to
milestone payments expires at such time as no collaboration product or former collaboration product is being
developed or commercialized anywhere in the world and no royalty payments on these products are due. Our
right to royalty payments expires on the later of the expiration of any licensed patent covering each product or 20
years from the launch of each product.

In connection with the collaboration between XOMA and Novartis (then Chiron Corporation), a secured
note agreement was executed in May 2005. The note agreement is secured by our interest in the collaboration and
is due and payable in full in June 2015. At December 31, 2012, the outstanding principal balance under this note
agreement totaled $14.4 million, and pursuant to the terms of the arrangement as restructured in November 2008,
we will not make any additional borrowings on the Novartis note.

Arana

In September 2009, we entered into an antibody discovery collaboration with Arana Therapeutics Limited

(“Arana”), a wholly owned subsidiary of Teva Pharmaceutical Industries Ltd. The agreement with Arana

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involved multiple proprietary XOMA antibody research and development technologies, including a new antibody
phage display library and a suite of integrated information and data management systems. Arana paid us a fee of
$6.0 million, of which we received $4.0 million in the third quarter of 2009 and $2.0 million in the third quarter
of 2010. Also, we may be entitled to future milestone payments, aggregating up to $3.0 million per product, and
low single-digit royalties on product sales. Our right to milestone payments expires on the later of the receipt of
payment from Arana of the last amount to be paid under the agreement, the cessation by Arana of the use of all
research and development technologies or the cessation by Arana of the exercise of the patent rights granted to
them. Our right to royalties expires five years from the first commercial sale of each royalty-bearing product.

Kaketsuken

In October 2009, we entered into an antibody discovery collaboration with The Chemo-Sero-Therapeutic
Research Institute, a Japanese research foundation known as Kaketsuken, involving multiple proprietary XOMA
antibody research and development technologies, including a new antibody phage display library and a suite of
integrated information and data management systems. Kaketsuken paid us a fee of $8.0 million, of which we
received $6.0 million in the fourth quarter of 2009 and $2.0 million in the fourth quarter of 2010. Also, we may
be entitled to future milestone payments, aggregating up to $0.2 million per product, and low single-digit
royalties on product sales. Our right to milestone payments expires upon the receipt of payment from Kaketsuken
of the last amount to be paid pursuant to the agreement. Our right to royalties expires 15 years from the first
commercial sale of each royalty-bearing product.

AVEO Pharmaceuticals, Inc. (“AVEO”)

In April 2006, we entered into an agreement with AVEO to utilize our HE ™ technology to humanize AV-

299, AVEO’s novel anti-HGF antibody, under which AVEO paid us an up-front license fee and development
milestones. In addition, we will receive royalties on sales of products resulting from the agreement. Under this
agreement, we created four Human Engineered ™ versions of the original AV-299, all of which met design goals
and from which AVEO selected one as its lead development candidate. In September 2006, as a result of the
successful humanization of AV-299, we entered into a second agreement with AVEO to manufacture and supply
AV-299 in support of early clinical trials. Under the agreement, we created AV-299 production cell lines,
conducted process and assay development, and performed Good Manufacturing Practices (“cGMP”)
manufacturing activities. AVEO retains all development and commercialization rights to AV-299 and may be
required to pay annual maintenance fees to us, as well as additional development milestone payments
aggregating up to $6.3 million and low single-digit royalties on product sales in the future. Our right to milestone
payments expires upon full satisfaction of all financial obligations of AVEO pursuant to the agreement. Our right
to royalties expires on the later of 15 years from the first commercial sale of each royalty-bearing product or the
expiration of the last-to-expire licensed patent.

In April 2007, Merck/Schering-Plough entered into a research, development and license agreement with

AVEO concerning AV-299 and other anti-HGF molecules. In connection with the aforementioned license
agreement, AVEO assigned its entire right, title and interest in, to and under its manufacturing agreement with
XOMA to Merck/Schering-Plough. In the third quarter of 2010, AVEO regained its worldwide rights from
Merck/Schering-Plough to develop and commercialize AV-299 and other anti-HGF molecules. In June 2011,
AVEO announced patient enrollment has been completed in its ongoing Phase 2 trial evaluating AV-299
(ficlatuzumab) in combination with gefitinib as first-line therapy for patients with wild-type and mutant
epidermal growth factor receptor non-small cell lung cancer.

UCB

Celltech Therapeutics Ltd., now UCB Celltech, a branch of UCB, utilized our bacterial cell expression
technology under license in the development of CIMZIA ® for the treatment of moderate-to-severe Crohn’s
disease in adults who have not responded to conventional therapies and for the treatment of moderate-to-severe
rheumatoid arthritis in adults. The license provides for a low-single digit royalty on sales of CIMZIA ® in

14

countries where our bacterial cell expression technology is patented, which includes the U.S. and Canada, until
the expiration of the last-to-expire licensed patent. In August 2010, we sold our royalty interest in CIMZIA ® to
an undisclosed buyer for gross proceeds of $4.0 million. We no longer receive royalties on sales of CIMZIA ® .

Genentech

In April 1996, we entered into a collaboration agreement with Genentech, Inc., a wholly owned member of
the Roche Group (referred to herein as “Genentech”) for the development of RAPTIVA ® . In March 2003, we
entered into amended agreements that called for us to share in the development costs and called for Genentech to
finance our share of development costs via a convertible subordinated loan. Under the loan agreement, upon
FDA approval of the product, which occurred in October 2003, we elected to pay $29.6 million of the
development loan in convertible preference shares, which were convertible into approximately 0.3 million shares
of common stock at a price of $116.25 per share. In April 2011, the convertible preference shares were converted
by Genentech. The $29.6 million liquidation preference associated with the convertible preference shares was
eliminated as a result of this conversion.

Financing Agreements

Outstanding Warrants

In June of 2009, we issued warrants to certain institutional investors as part of a registered direct offering,

which represent the right to acquire an aggregate of up to 347,826 shares of common stock over a five-year
period beginning December 11, 2009, at an exercise price of $19.50 per share. As of December 31, 2012, all of
these warrants were outstanding.

In February 2010, we issued warrants to purchase 1,260,000 shares of XOMA’s common stock in
connection with an underwritten offering, which were exercisable beginning six months and one day after
issuance and have a five-year term and an exercise price of $10.50 per share. As of December 31, 2012, all of
these warrants were outstanding.

In December 2011, we issued warrants in connection with a debt financing, which entitle the holder to
purchase up to an aggregate of 263,158 unregistered shares of XOMA common stock at an exercise price equal
to $1.14 per share. The warrants are exercisable immediately and will expire on December 30, 2016. As of
December 31, 2012, all of these warrants were outstanding.

In March 2012, we issued warrants in connection with an underwritten public offering, which entitle the
holders to purchase up to an aggregate of 14,834,577 shares of XOMA common stock at an exercise price equal
to $1.76 per share. The warrants are exercisable immediately and will expire on March 6, 2017. As of
December 31, 2012, 14,265,970 of these warrants were outstanding.

In September 2012, we issued warrants in connection with an amendment to an existing debt financing,
which entitle the holder to purchase up to an aggregate of 39,346 unregistered shares of XOMA common stock at
an exercise price equal to $3.54 per share. The warrants are exercisable immediately and will expire on
September 27, 2017. As of December 31, 2012, all of these warrants were outstanding.

ATM Agreement

On February 4, 2011, we entered into an At Market Issuance Sales Agreement (the “2011 ATM

Agreement”), with McNicoll, Lewis & Vlak LLC (now known as MLV & Co. LLC, “MLV”), under which we
may sell shares of our common stock from time to time through MLV, as our agent for the offer and sale of the
shares, in an aggregate amount not to exceed the amount that can be sold under our registration statement on
Form S-3 (File No. 333-172197) filed with the SEC on February 11, 2011, and amended on March 10,
2011, June 3, 2011 and January 3, 2012, which was most recently declared effective by the SEC on January 17,
2012. MLV may sell the shares by any method permitted by law deemed to be an “at the market” offering as
defined in Rule 415 of the Securities Act, including without limitation sales made directly on The NASDAQ
Global Market, on any other existing trading market for our common stock or to or through a market maker.

15

MLV also may sell the shares in privately negotiated transactions, subject to our prior approval. We will pay
MLV a commission equal to 3% of the gross proceeds of the sales price of all shares sold through it as sales
agent under the 2011 ATM Agreement. From the inception of the 2011 ATM Agreement through December 31,
2012, we sold a total of 7,572,327 shares of common stock under this agreement for aggregate gross proceeds of
$14.6 million. No shares of common stock have been sold under this agreement since February 3, 2012. Total
offering expenses incurred related to sales under the 2011 ATM Agreement from inception to December 31,
2012, were $0.5 million.

General Electric Capital Corporation Term Loan

In December 2011, we entered into a loan agreement (the “GECC Loan Agreement”) with General Electric
Capital Corporation (“GECC”), under which GECC agreed to make a term loan in an aggregate principal amount
of $10 million (the “Term Loan”) to us, and upon execution of the GECC Loan Agreement, GECC funded the
Term Loan. As security for our obligations under the GECC Loan Agreement, we granted a security interest in
substantially all of our existing and after-acquired assets, excluding its intellectual property assets (such as those
relating to our gevokizumab and anti-botulism products). The Term Loan accrued interest at a fixed rate of
11.71% per annum and was to be repaid over a period of 42 consecutive equal monthly installments of principal
and accrued interest and was due and payable in full on June 15, 2015. We incurred debt issuance costs of
approximately $1.3 million in connection with the Term Loan and were required to pay a final payment fee equal
to $500,000 on the maturity date, or such earlier date as the Term Loan is paid in full. The debt issuance costs
and final payment fee were being amortized and accreted, respectively, to interest expense over the term of the
Term Loan using the effective interest method.

In connection with the GECC Loan Agreement, we issued to GECC unregistered warrants that entitle GECC

to purchase up to an aggregate of 263,158 unregistered shares of XOMA common stock at an exercise price
equal to $1.14 per share. These warrants are exercisable immediately and have a five-year term. We allocated the
aggregate proceeds of the GECC Term Loan between the warrants and the debt obligation based on their relative
fair values. The fair value of the warrants issued to GECC was determined using the Black-Scholes Model. The
warrants’ fair value of $0.2 million was recorded as a discount to the debt obligation and was being amortized
over the term of the loan using the effective interest method.

In September 2012, we entered into an amendment to the GECC Loan Agreement providing for an
additional term loan in the amount of $4.6 million, increasing the term loan obligation to $12.5 million (the
“Amended Term Loan”) and providing for an interest-only monthly repayment period following the effective
date of the amendment through March 1, 2013, at a stated interest rate of 10.9% per annum. Thereafter, we are
obligated to make monthly principal payments of $347,222, plus accrued interest, over a 27-month period
commencing on April 1, 2013, and through June 15, 2015, at which time the remaining outstanding principal
amount of $3.1 million, plus accrued interest, is due. We incurred debt issuance costs of approximately $0.2
million and are required to make a final payment fee in the amount of $875,000 on the date upon which the
outstanding principal amount is required to be repaid in full. This final payment fee replaced the original final
payment fee of $500,000. The debt issuance costs and final payment fee are being amortized and accreted,
respectively, to interest expense over the term of the Amended Term Loan using the effective interest method.

In connection with the amendment, on September 27, 2012 we issued to GECC unregistered stock purchase

warrants, which entitle GECC to purchase up to an aggregate of 39,346 shares of XOMA common stock at an
exercise price equal to $3.54 per share. These warrants are exercisable immediately and have a five-year term.
The warrants’ fair value of $0.1 million was recorded as a discount to the debt obligation and is being amortized
over the term of the loan using the effective interest method. The warrants are classified in permanent equity on
the condensed consolidated balance sheets.

The Amended Term Loan does not change the remaining terms of the GECC Loan Agreement. The GECC

Loan Agreement contains customary representations and warranties and customary affirmative and negative

16

covenants, including restrictions on the ability to incur indebtedness, grant liens, make investments, dispose of
assets, enter into transactions with affiliates and amend existing material agreements, in each case subject to
various exceptions. In addition, the GECC Loan Agreement contains customary events of default that entitle
GECC to cause any or all of the indebtedness under the GECC Loan Agreement to become immediately due and
payable. The events of default include any event of default under a material agreement or certain other
indebtedness.

We may prepay the Amended Term Loan voluntarily in full, but not in part, and any voluntary and certain
mandatory prepayments are subject to a prepayment premium of 3% in the first year after the effective date of
the amendment to the GECC Loan Agreement, 2% in the second year and 1% thereafter, with certain exceptions.
We will also be required to pay the $875,000 final payment fee in connection with any voluntary or mandatory
prepayment. On the effective date of the amendment to the GECC Loan Agreement, we paid an accrued final
payment fee in the amount of $0.2 million relating to the original final payment fee of $500,000.

At December 31, 2012, the outstanding principal balance under the Amended Term Loan was $12.5 million.

Underwritten Offerings

On March 9, 2012, we completed an underwritten public offering of 29,669,154 shares of our common
stock, and accompanying warrants to purchase one half of a share of common stock for each share purchased, at
a public offering price of $1.32 per share. Total gross proceeds from the offering were approximately $39.2
million, before deducting underwriting discounts and commissions and estimated offering expenses totaling
approximately $3.0 million. The warrants, which represent the right to acquire an aggregate of up to 14,834,577
shares of common stock, are exercisable immediately and have a five-year term and an exercise price of $1.76
per share. As of December 31, 2012, 14,265,970 of these warrants were outstanding.

On October 29, 2012, we completed an underwritten public offering of 13,333,333 shares of our common
stock, at a public offering price of $3.00 per share. In addition, we had granted the underwriters a 30-day option
to purchase up to an additional 1,999,999 shares of common stock on the same terms and conditions, solely to
cover over-allotments, which was not exercised within the 30-day option period. Total gross proceeds from the
offering were approximately $40.0 million, before deducting underwriting discounts and commissions and
estimated offering expenses totaling approximately $3.0 million.

Research and Development

Our research and development expenses currently include costs of personnel, supplies, facilities and
equipment, consultants, third-party costs and other expenses related to preclinical and clinical testing. In 2012,
our research and development expenses were $68.3 million, compared with $68.1 million in 2011 and $77.4
million in 2010.

Our research and development activities can be divided into those related to our internal projects and those

related to collaborative and contract arrangements, which are reimbursed by our customers. In 2012, research and
development expenses relating to internal projects were $30.5 million, compared with $24.4 million in 2011 and
$52.0 million in 2010. In 2012, research and development expenses related to collaborative and contract
arrangements were $37.8 million, compared with $43.7 million in 2011 and $25.4 million in 2010. Refer to
Management’s Discussion and Analysis of Financial Condition and Results of Operations-Research and
Development Expenses for further information regarding our research and development expenses.

Competition

The biotechnology and pharmaceutical industries are subject to continuous and substantial technological
change. Competition in antibody-based technologies is intense and is expected to increase as new technologies
emerge and established biotechnology firms and large chemical and pharmaceutical companies continue to

17

advance in the field. A number of these large pharmaceutical and chemical companies have enhanced their
capabilities by entering into arrangements with or acquiring biotechnology companies or entering into business
combinations with other large pharmaceutical companies. Many of these companies have significantly greater
financial resources, larger research and development and marketing staffs and larger production facilities than
ours. Moreover, certain of these companies have extensive experience in undertaking preclinical testing and
human clinical trials. These factors may enable other companies to develop products and processes competitive
with or superior to ours. In addition, a significant amount of research in biotechnology is being carried out in
universities and other non-profit research organizations. These entities are becoming increasingly interested in
the commercial value of their work and may become more aggressive in seeking patent protection and licensing
arrangements. Furthermore, many companies and universities tend not to announce or disclose important
discoveries or development programs until their patent position is secure or, for other reasons, later. As a result,
we may not be able to track development of competitive products, particularly at the early stages. There can be
no assurance that developments by others will not render our products or technologies obsolete or uncompetitive.

The ACE inhibitor market is highly genericized with most treatment options available generically. The

number one product within the ACE inhibitor category is lisinopril, formerly marketed by Astra-Zeneca
Pharmaceuticals LP under the brands ZESTRIL® or Prinivil®. ACE inhibitors represent the largest category of
anti-hypertensive medications and are considered a first-line treatment option by the majority of the medical
guidelines. There are multiple options in the FDC market combining ACE inhibitors with diuretics, but there are
few options combining an ACE inhibitor with a calcium channel blocker. Current options with a calcium channel
blocker are benazepril/amlodipine, formerly marketed by Novartis Pharmaceuticals as Lotrel®, and trandolapril/
verapamil, formerly marketed by Abbot Laboratories as Tarka®.

ACE inhibitors are a segment of the larger Renin Angiotensin Aldosterone System, or RAAS market. This
market is comprised of ACE inhibitors and angiotensin receptor blockers (ARB). Both classes act on the RAAS
in different ways to control blood pressure. The most successful of the ARBs is valsartan, trade name Diovan®,
which is marketed by Novartis. This compound, along with other ARBs, has been developed in multiple FDC
products: with a diuretic, a calcium channel blocker (amlodipine) and as a triple combining all three. Our
perindopril FDC franchise, if approved, will compete directly with FDCs containing an ACE inhibitor and
secondarily with FDCs containing an ARB.

Without limiting the foregoing, we are aware of the following competitors for the products and candidates

shown in the table below. This table is not intended to be representative of all existing competitors in the market:

Product/Candidate

Gevokizumab

ACEON
FDCs

XOMA 3AB

Government Regulation

Competitors

Abbott
Biovitrum AB
Eli Lilly and Company
Lux Biosciences, Inc.
MedImmune
Novartis AG
Regeneron Pharmaceuticals, Inc.
Santen Pharmaceutical Co., Ltd.
Generic manufacturers
Novartis AG
Takeda Pharmaceutical Company Ltd.
Daiichi Sankyo, Inc.
Cangene Corporation
Emergent BioSolutions, Inc.

The FDA and comparable regulatory agencies in state and local jurisdictions and in foreign countries
impose substantial requirements upon the clinical development, pre-market approval, manufacture, marketing
and distribution of biopharmaceutical products. These agencies and other regulatory agencies regulate research

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and development activities and the testing, approval, manufacture, quality control, safety, effectiveness, labeling,
storage, recordkeeping, advertising and promotion of products and product candidates. Failure to comply with
applicable FDA or other regulatory requirements may result in Warning Letters, civil or criminal penalties,
suspension or delays in clinical development, recall or seizure of products, partial or total suspension of
production or withdrawal of a product from the market. The development and approval process requires
substantial time, effort and financial resources, and we cannot be certain that any approvals for our product
candidates will be granted on a timely basis, if at all. We must obtain approval of our product candidates from the
FDA before we can begin marketing them in the United States. Similar approvals are also required in other
countries.

Product development and approval within this regulatory framework is uncertain, can take many years and
requires the expenditure of substantial resources. The nature and extent of the governmental review process for
our product candidates will vary, depending on the regulatory categorization of particular product candidates and
various other factors.

The necessary steps before a new biopharmaceutical product may be sold in the United States ordinarily

include:

•

•

•

•

•

•

preclinical in vitro and in vivo tests, which must comply with Good Laboratory Practices, or GLP;

submission to the FDA of an IND which must become effective before clinical trials may commence,
and which must be updated annually with a report on development;

completion of adequate and well controlled human clinical trials to establish the safety and efficacy of
the product candidate for its intended use;

submission to the FDA of a New Drug Application, or NDA, or a Biologics License Application, or
BLA, which must often be accompanied by payment of a substantial user fee;

FDA pre-approval inspection of manufacturing facilities for current Good Manufacturing Practices, or
GMP, compliance and FDA inspection of select clinical trial sites for Good Clinical Practice, or GCP,
compliance; and

FDA review and approval of the NDA or BLA and product prescribing information prior to any
commercial sale.

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

evaluate toxicity) for a particular product 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, within the 30 day time period, raises 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 GCP regulations and regulations for
informed consent and privacy of individually-identifiable information.

Clinical trials generally are conducted in three sequential phases that may overlap or in some instances, be

skipped. In phase I, the initial introduction of the product into humans, the product is tested to assess safety,
metabolism, pharmacokinetics and pharmacological actions associated with increasing doses. Phase II usually
involves trials in a limited patient population to evaluate the efficacy of the potential product for specific,

19

targeted indications, determine dosage tolerance and optimum dosage and further identify possible adverse
reactions and safety risks. Phase III and pivotal trials are undertaken to evaluate further clinical efficacy and
safety often in comparison to standard therapies within a broader patient population, generally at geographically
dispersed clinical sites. Phase IV, or post-marketing, trials may be required as a condition of commercial
approval by the FDA and may also be voluntarily initiated by us or our collaborators. Phase I, phase II or phase
III testing may not be completed successfully within any specific period of time, if at all, with respect to any of
our product candidates. Similarly, suggestions of safety, tolerability or efficacy in earlier stage trials do not
necessarily predict findings of safety and effectiveness in subsequent trials. Furthermore, the FDA, an IRB or we
may suspend a clinical trial at any time for various reasons, including a finding that the subjects or patients are
being exposed to an unacceptable health risk. Clinical trials are subject to central registration and results
reporting requirements, such as on www.clinicaltrials.gov.

The results of preclinical studies, pharmaceutical development and clinical trials, together with information
on a product’s chemistry, manufacturing, and controls, are submitted to the FDA in the form of an NDA or BLA,
for approval of the manufacture, marketing and commercial shipment of the pharmaceutical product. Data from
clinical trials are not always conclusive and the FDA may interpret data differently than we or our collaborators
interpret data. The FDA may also convene an Advisory Committee of external advisors to answer questions
regarding the approvability and labeling of an application. The FDA is not obligated to follow the Advisory
Committee’s recommendation. The submission of an NDA or BLA is required to be accompanied by a
substantial user fee, with few exceptions or waivers. The user fee is administered under the Prescription Drug
User Fee Act, or PDUFA, which sets goals for the timeliness of the FDA’s review. A standard review period is
twelve months from submission of the application, while priority review is eight months from submission of the
application. The testing and approval process is likely to require substantial time, effort and resources, and there
can be no assurance that any approval will be granted on a timely basis, if at all. The FDA may deny review of an
application by refusing to file the application or not approve an application by issuance of a complete response
letter if applicable regulatory criteria are not satisfied, require additional testing or information, or require risk
management programs and post-market testing and surveillance to monitor the safety or efficacy of the product.
Approval may occur with significant Risk Evaluation and Mitigation Strategies, or REMS, which limit the
clinical use in the prescribing information, distribution or promotion of a 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.

Orphan drugs are those intended for use in rare diseases or conditions. As a result of the high cost of

development and the low return on investment for rare diseases, governments provide regulatory and commercial
incentives for the development of drugs for small disease populations. In the U.S., the term ‘‘rare disease or
condition’’ means any disease or condition that affects fewer than 200,000 persons in the U.S. Applications for
United States orphan drug status are evaluated and granted by the Office of Orphan Products Development
(“OOPD”) of the FDA, and must be requested before submitting an NDA or BLA. In the U.S., orphan drugs are
subject to the standard regulatory process for marketing approval but are exempt from the payment of user fees
for licensure, may receive market exclusivity for a period of seven years and some tax benefits, and are eligible
for OOPD grants. If a product that has orphan designation subsequently receives the first FDA approval for the
disease or condition for which it has such designation, the product is entitled to orphan product exclusivity,
which means that the FDA may not approve any other applications to market the same drug or biological product
for the same indication, except in very limited circumstances, for seven years. Competitors, however, may
receive approval of different products for the indication for which the orphan product has exclusivity or obtain
approval for the same product but for a different indication for which the orphan product has exclusivity. Orphan
product exclusivity also could block the approval of one of our products for seven years if a competitor obtains
approval of the same drug or biological product as defined by the FDA or if our product candidate is determined
to be contained within the competitor’s product for the same indication or disease. If a drug or biological product
designated as an orphan product receives marketing approval for an indication broader than what is designated, it
may not be entitled to orphan product exclusivity.

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Products manufactured or distributed pursuant to FDA approvals are subject to continuing regulation by the

FDA, including manufacture, labeling, advertising, distribution, advertising, promotion, 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. Manufacturers and their subcontractors are required to register their establishments with
the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain
state agencies for compliance with ongoing regulatory requirements, including cGMPs, which impose certain
procedural and documentation requirements upon us and our third-party manufacturers. Following such
inspections, the FDA may issue notices on Form 483 and Warning Letters that could cause us to modify certain
activities. A Form 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 or guidance. Failure to adequately and
promptly correct the observations(s) can result in further regulatory enforcement action. In addition to Form 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 penalties. We cannot be certain that we or our present or future third-party
manufacturers or suppliers will be able to comply with the cGMP regulations and other ongoing FDA regulatory
requirements. If we or our present or future third-party manufacturers or suppliers are not able to comply with
these requirements, the FDA may halt our clinical trials, not approve our products, require us to recall a product
from distribution or withdraw approval of the BLA or NDA for that product. Failure to comply with ongoing
regulatory obligations can result in delay of approval or Warning Letters, product seizures, criminal penalties,
and withdrawal of approved products, among other enforcement remedies.

The FDA strictly regulates marketing, labeling, advertising and promotion of products that are placed on the

market. These regulations include standards and restrictions for direct-to-consumer advertising, industry-
sponsored scientific and educational activities, promotional activities involving the internet, and off-label
promotion. While physicians may prescribe for off label uses, manufacturers may only promote for the approved
indications and in accordance with the provisions of the approved label. The FDA has very broad enforcement
authority under the FDCA, and failure to abide by these regulations can result in penalties, including the issuance
of a warning letter directing entities to correct deviations from FDA standards, and state and federal civil and
criminal investigations and prosecutions.

Federal and state healthcare laws, including fraud and abuse and health information privacy and security

laws, are also applicable to our business. We could face substantial penalties and our business, results of
operations, financial condition and prospects could be adversely affected. The laws that may affect our ability to
operate include: the federal Anti-Kickback Statute, which prohibits soliciting, receiving, offering or paying
remuneration, directly or indirectly, to induce, or in return for, the purchase or recommendation of an item or
service reimbursable under a federal healthcare program, such as the Medicare and Medicaid programs; federal
civil and criminal false claims laws and civil monetary penalty laws, which prohibit, among other things,
individuals or entities from knowingly presenting, or causing to be presented, claims for payment from Medicare,
Medicaid, or other third-party payers that are false or fraudulent; and the federal Health Insurance Portability and
Accountability Act of 1996, or HIPAA, which created new federal criminal statutes that prohibit executing a
scheme to defraud any healthcare benefit program and making false statements relating to healthcare matters and
was amended by the Health Information Technology and Clinical Health Act, or HITECH, and its implementing
regulations, which imposes certain requirements relating to the privacy, security and transmission of individually
identifiable health information. State law equivalents of each of the above federal laws exist, many of which
differ from each other in significant ways and may not have the same effect, thus complicating compliance
efforts.

International Regulation

In addition to regulations in the U.S., we are subject to a variety of foreign regulations governing clinical
trials and commercial sales and distribution of any future products. Whether or not we obtain FDA approval for a

21

product, we must obtain approval by the comparable regulatory authorities of foreign countries before we can
commence clinical trials or marketing of the product in those countries. The approval process varies from
country to country, and the time may be longer or shorter than that required for FDA approval. The requirements
governing the conduct of clinical trials, product licensing, pricing and reimbursement vary greatly from country
to country.

Third-Party Payor Coverage and Reimbursement

The commercial success of ACEON and our product candidates, if approved, will depend, in part, upon the

availability of coverage and reimbursement from third-party payors at the federal, state and private levels.
Government payor programs, including Medicare and Medicaid, private health care insurance companies and
managed care plans have attempted to control costs by limiting coverage and the amount of reimbursement for
particular procedures or drug treatments. The U.S. Congress and state legislatures from time to time propose and
adopt initiatives aimed at cost containment. Ongoing federal and state government initiatives directed at lowering
the total cost of health care will likely continue to focus on health care reform, the cost of prescription
pharmaceuticals and on the reform of the Medicare and Medicaid payment systems. While we cannot predict
whether any proposed cost-containment measures will be adopted or otherwise implemented in the future, the
announcement or adoption of these proposals could have a material adverse effect on our ability to obtain
adequate prices and operate profitably.

Patents and Trade Secrets

Patent and trade secret protection are important to our business and our future will depend in part on our
ability to obtain patents, maintain trade secret protection and operate without infringing on the proprietary rights
of others. As a result of our ongoing activities, we hold and have filed applications for a number of patents in the
U.S. and internationally to protect our products and important processes. We also have obtained or have the right
to obtain exclusive licenses to certain patents and applications filed by others. However, the patent position of
biotechnology companies generally is highly uncertain and consistent policy regarding the breadth of allowed
claims has not emerged from the actions of the U.S. Patent and Trademark Office (“Patent Office”) with respect
to biotechnology patents. Accordingly, no assurance can be given that our patents will afford protection against
competitors with similar technologies or others will not obtain patents claiming aspects similar to those covered
by our patent applications.

We have established a portfolio of patents in the U.S., Europe and certain other countries for our

gevokizumab program, the longest of which expires in 2027. U.S. Patent Nos. 7,531,166 and 7,582,742 cover
gevokizumab and other antibodies and antibody fragments with similar binding properties for IL-1 beta, as well
as nucleic acids, expression vectors and production cell lines for the manufacture of such antibodies and antibody
fragments. U.S. Patent Nos. 7,744,865, 7,744,866 and 7,943,121 relate to additional IL-1 beta binding antibodies
and binding fragments. U.S. Patent No. 7,695,718 relates to methods of treating Type 2 diabetes with high
affinity antibodies and antibody fragments that bind to IL-1 beta, including gevokizumab. U.S. Patent
No. 7,695,717 relates to methods of treating certain IL-1 related inflammatory diseases, including rheumatoid
arthritis and osteoarthritis, with gevokizumab and other antibodies and antibody fragments with similar binding
properties for IL-1 beta. U.S. Patent No. 7,829,093 relates to methods of treating diabetes mellitus (“Type 1”)
with gevokizumab or other IL-1 beta antibodies and fragments having similar binding properties. U.S. Patent
No. 7,829,094 relates to methods of treating certain cancers with gevokizumab or other IL-1 beta antibodies and
fragments having similar binding properties, with the cancer being selected from multiple myeloma, acute
myelogenous leukemia and chronic myelogenous leukemia. U.S. Patent No. 7,988,968 relates to methods of
treating certain IL-1 beta related coronary conditions, including myocardial infarction, with gevokizumab or
other IL-1 beta antibodies and fragments having similar binding properties. Also, patents have been granted by
the European Patent Office and certain other countries for gevokizumab, as well as nucleic acids, expression
vectors and production cell lines for the manufacture of gevokizumab.

22

We have exclusively in-licensed a portfolio of patents and applications covering anti-botulinum toxin

antibodies from the Regents of the University of California. These include U.S. Patent Nos. 7,700,738,
7,999,079, and 8,263,747 covering certain XOMA 3AB antibodies, the longest of which expire in 2026.

We have exclusively in-licensed the U.S. rights to a portfolio of patents and applications related to the
perindopril franchise from Les Laboratoires Servier. These include U.S. Patent No. 6,696,481, covering an
arginine salt of perindopril and its hydrates, which expires in 2023.

We have established a portfolio of patents related to our bacterial expression technology, including claims to

novel promoter sequences, secretion signal sequences, compositions, methods for expression and secretion of
recombinant proteins from bacteria, including immunoglobulin gene products, and improved methods and cells
for expression of recombinant protein products. U.S. Patent Nos. 5,576,195 and 5,846,818 are related to DNA
encoding a pectate lyase signal sequence, recombinant vectors, host cells and methods for production and
externalization of recombinant proteins. U.S. Patent Nos. 5,595,898, 5,698,435 and 5,618,920 relate to secretable
immunoglobulin chains, DNA encoding the chains and methods for their recombinant production. U.S. Patent
Nos. 5,693,493, 5,698,417 and 6,204,023 relate to methods for recombinant production/secretion of functional
immunoglobulin molecules. U.S. Patent Nos. 7,094,579, 7,396,661, 7,972,811 and 7,977,068 relate to particular
eukaryotic signal sequences and their use in methods for prokaryotic expression of polypeptides and for
preparing polypeptide display libraries. U.S. Patent No. 6,803,210 relates to improved bacterial host cells that are
deficient in one or more of the active transport systems for an inducer of an inducible promoter, such as
arabinose for an araB promoter, and methods for the use of such cells for the production of recombinant proteins.
Most of the more important European patents in this portfolio expired in July 2008 or earlier.

We also have established a portfolio of patents related to our mammalian expression technology, including

U.S. Patent Nos. 7,192,737, 7,993,915 and 7,794,976, which relate to methods of producing recombinant proteins
using particular vectors, including expression vectors comprising multiple copies of a transcription unit encoding
a polypeptide separated by at least one selective marker gene.

We have established a portfolio of patents related to our Human Engineering ™ technology, including U.S.

Patent No. 5,766,886, directed to methods of modifying antibody variable domains to reduce immunogenicity.
We believe our patented Human Engineering ™ technology provides an attractive alternative to other
humanization technologies.

If certain patents issued to others are upheld or if certain patent applications filed by others issue and are

upheld, we may require certain licenses from others in order to develop and commercialize certain potential
products incorporating our technology. There can be no assurance that such licenses, if required, will be available
on acceptable terms.

Where appropriate, we also rely on trade secrets to protect aspects of our technology. However, trade secrets

are difficult to protect. We protect our proprietary technology and processes, in part, by confidentiality
agreements with our employees, consultants and collaborators. These parties may breach these agreements, and
we may not have adequate remedies for any breach. Our trade secrets may otherwise become known or be
independently discovered by competitors. To the extent that we or our consultants or collaborators use
intellectual property owned by others, we may have disputes with our collaborators or consultants or other third
parties as to the rights in related or resulting know-how and inventions.

International Operations

We believe, because the pharmaceutical industry is global in nature, international activities will be a
significant part of our future business activities and, when and if we are able to generate income, a substantial
portion of that income may be derived from product sales and other activities outside the U.S. As our strategic
goal is to establish XOMA as a commercial organization in the U.S., we will rely upon other companies to

23

market our product outside of the U.S. for the foreseeable future. Our decision to retain the U.S. commercial
rights to our product candidates while licensing the rights to our product candidates outside the U.S., or to license
our product candidates globally to one or more partners, depends upon a number of factors, including the primary
indication and size of the potential patient population, the size of the clinical trials required to obtain marketing
approval in the U.S. and globally, and the size of the sales force required to sell the product.

A number of risks are inherent in international operations. Foreign regulatory agencies often establish
standards different from those in the U.S. An inability to obtain foreign regulatory approvals on a timely basis
could have an adverse effect on our international business, financial condition and results of operations.
International operations may be limited or disrupted by the imposition of government controls, export license
requirements, political or economic instability, trade restrictions, changes in tariffs, restrictions on repatriating
profits, taxation or difficulties in staffing and managing international operations. In addition, our business,
financial condition and results of operations may be adversely affected by fluctuations in currency exchange
rates. There can be no assurance that we will be able to successfully operate in any foreign market.

Financial information regarding the geographic areas in which we operate and segment information is
included in Note 12 to the December 31, 2012, Financial Statements: Concentration of Risk, Segment and
Geographic Information .

Concentration of Risk

In 2012, Servier and NIAID accounted for 47 percent and 33 percent, respectively, of our total revenue,
compared to 61 percent and 32 percent, respectively, in 2011. In 2010, NIAID, UCB, and Takeda accounted for
64 percent, 13 percent, and 11 percent, respectively, of total revenue. At December 31, 2012, Servier and NIAID
accounted for 58 percent and 35 percent of the accounts receivable balance, compared to 57 percent and 43
percent, respectively, at the same period in 2011, and 72 percent and 23 percent, respectively, at the same period
of 2010. None of these parties represent a related party to XOMA and the loss of one or more of these customers
could have a material effect on our business and financial condition.

Organization

We were incorporated in Delaware in 1981 and became a Bermuda-exempted company in December 1998.

Effective December 31, 2011, we changed our jurisdiction of incorporation from Bermuda to Delaware and
changed our name from XOMA Ltd. to XOMA Corporation. When referring to a time or period before
December 31, 1998, or when the context so requires, the terms “Company” and “XOMA” refer to XOMA
Corporation, a Delaware corporation, and when referring to a time or period after December 31, 1998, and before
December 31, 2011, such terms refer to XOMA Ltd., a Bermuda company.

Employees

As of March 8, 2013, we employed 166 full-time employees, none of whom are unionized, at our facilities,

principally in Berkeley, California. Our employees primarily are engaged in clinical, process development,
research and product development, and in executive, business development, finance and administrative positions.
We consider our employee relations to be excellent.

Available Information

For information on XOMA’s investment prospects and risks, please contact Investor Relations and

Corporate Communications at (510) 204-7200 or by sending an e-mail message to investorrelations@xoma.com.
Our principal executive offices are located at 2910 Seventh Street, Berkeley, California 94710, U.S.A. Our
telephone number is (510) 204-7200.

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The following information can be found on our website at http://www.xoma.com or can be obtained free of

charge by contacting our Investor Relations Department:

•

•

•

Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and
any amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange
Act will be available as soon as reasonably practicable after such material is electronically filed or
otherwise furnished to the SEC. All reports we file with the SEC also can be obtained free of charge
via EDGAR through the SEC’s website at http://www.sec.gov.

Our policies related to corporate governance, including our Code of Ethics applying to our directors,
officers and employees (including our principal executive officer and principal financial and
accounting officer) that we have adopted to meet the requirements set forth in the rules and regulations
of the SEC and its corporate governance principles, are available.

The charters of the Audit, Compensation and Nominating & Governance Committees of our Board of
Directors are available.

We intend to satisfy the applicable disclosure requirements regarding amendments to, or waivers from,

provisions of our Code of Ethics by posting such information on our website.

Item 1A. Risk Factors

The following risk factors and other information included in this annual report should be carefully
considered. The risks and uncertainties described below are not the only ones we face. Additional risks and
uncertainties not presently known to us also may impair our business operations. If any of the following risks
occur, our business, financial condition, operating results and cash flows could be materially adversely affected.

Because our product candidates are still being developed, we will require substantial funds to continue; we
cannot be certain that funds will be available, and if they are not available, we may have to take actions
that could adversely affect the price of our common stock and may not be able to continue operations.

We will need to commit substantial funds to continue development of our product candidates, and we may
not be able to obtain sufficient funds on acceptable terms, or at all. If we raise additional funds by issuing equity
securities, our stockholders will experience dilution. Any debt financing or additional equity that we raise may
contain terms that are not favorable to our stockholders or us. If we raise additional funds through collaboration
and licensing arrangements with third parties, we may be required to relinquish some rights to our technologies
or our product candidates, grant licenses on terms that are not favorable to us or enter into a collaboration
arrangement for a product candidate at an earlier stage of development or for a lesser amount than we might
otherwise choose.

Additional funds may not be available when we need them on terms that are acceptable to us, or at all. If

adequate funds are not available on a timely basis, we may:

•

•

•

terminate or delay clinical trials for one or more of our product candidates;

further reduce our headcount and capital or operating expenditures; or

curtail our spending on protecting our intellectual property.

We finance our operations primarily through our multiple revenue streams resulting from discovery and
development collaborations, biodefense contracts, the licensing of our antibody technologies, and sales of our
common stock. In August 2010, we sold our royalty interest in CIMZIA ® for gross proceeds of $4.0 million,
including royalty revenue from the second quarter of 2010. As a result, we no longer have a royalty interest in
CIMZIA. We received revenue from this royalty interest of $0.5 million in 2010 and $0.5 million in 2009.

25

Based on our cash, cash equivalents and short-term investments of $85.3 million at December 31, 2012,
anticipated spending levels, anticipated cash inflows from collaborations, biodefense contracts and licensing
transactions, funding availability including under our loan agreements, and the proceeds from the October 2012
public offering, we believe we have sufficient cash resources to meet our anticipated net cash needs into the
fourth quarter of 2014. Any significant revenue shortfalls, increases in planned spending on development
programs, more rapid progress of development programs than anticipated, or the initiation of new clinical trials,
as well as the unavailability of anticipated sources of funding, could shorten this period or otherwise have a
material adverse impact on our ability to finance our continued operations. If adequate funds are not available,
we will be required to delay, reduce the scope of, or eliminate one or more of our product development programs
and further reduce personnel-related costs. Progress or setbacks by potentially competing products also may
affect our ability to raise new funding on acceptable terms. As a result, we do not know when or whether:

•

•

•

•

operations will generate meaningful funds;

additional agreements for product development funding can be reached;

strategic alliances can be negotiated; or

adequate additional financing will be available for us to finance our own development on acceptable
terms, or at all.

Because all of our product candidates still are being developed, we have sustained losses in the past, and
we expect to sustain losses in the future.

We have experienced significant losses, and as of December 31, 2012, we had an accumulated deficit of

$957.1 million.

For the year ended December 31, 2012, we had a net loss of approximately $71.1 million, or $1.10 per share
of common stock (basic and diluted). For the year ended December 31, 2011, we had a net loss of approximately
$32.7 million, or $1.04 per share of common stock (basic and diluted).

Our ability to achieve profitability is dependent in large part on the success of our development programs,
obtaining regulatory approval for our product candidates and licensing certain of our preclinical compounds, all
of which are uncertain. Our ability to fund our ongoing operations is dependent on the foregoing factors and on
our ability to secure additional funds. Because our product candidates still are being developed, we do not know
whether we will ever achieve sustained profitability or whether cash flow from future operations will be
sufficient to meet our needs.

We are substantially dependent on Servier for the development and commercialization of gevokizumab
and for other aspects of our business, and if we are unable to maintain our relationship with Servier, or
Servier does not perform under our development and commercialization agreements with Servier, our
business would be harmed significantly.

We have a number of agreements with Servier that are material to the conduct of our business, including:

•

In December 2010, we entered into a license and collaboration agreement with Servier, to jointly develop
and commercialize gevokizumab in multiple indications. Under the terms of the agreement, Servier has
worldwide rights to cardiovascular disease and diabetes indications and rights outside the United States and
Japan to all other indications, including Behçet’s uveitis and other inflammatory and oncology indications.
In late 2011, we announced Servier agreed to include the NIU Phase 3 trials under the terms of the
collaboration agreement for Behçet’s uveitis. We retain development and commercialization rights for NIU
and other inflammatory disease and oncology indications in the United States and Japan and have an option
to reacquire rights to cardiovascular disease and diabetes indications from Servier in these territories.
Should we exercise this option, we will be required to pay an option fee to Servier and partially reimburse a
specified portion of Servier’s incurred development expenses. The agreement contains mutual customary
termination rights relating to matters, such as material breach by either party. Servier may terminate for

26

•

•

safety issues, and we may terminate the agreement, with respect to a particular country or the European
Patent Organization (“EPO”) member states, for any challenge to our patent rights in that country or any
EPO member state, respectively, by Servier. Servier also has a unilateral right to terminate the agreement
for the European Union (“EU”) or for non-EU countries, on a country-by-country basis, or in its entirety, in
each case with six months’ notice.

In December 2010, we entered into a loan agreement with Servier (the “Servier Loan Agreement”), which
provides for an advance of up to €15.0 million andwas funded fully in January 2011 with the proceeds
converting to approximately $19.5 million at the January 13, 2011, Euro-to-U.S.-dollar exchange rate of
1.3020. This loan is secured by an interest in our intellectual property rights to all gevokizumab indications
worldwide, excluding the United States and Japan. The loan has a final maturity date in 2016; however,
after a specified period prior to final maturity, the loan is required to be repaid (1) at Servier’s option, by
applying up to a significant percentage of any milestone or royalty payments owed by Servier under our
collaboration agreement and (2) using a significant percentage of any upfront, milestone or royalty
payments we receive from any third-party collaboration or development partner for rights to gevokizumab
in the United States and/or Japan. In addition, the loan becomes immediately due and payable upon certain
customary events of default. At December 31, 2012, the €15.0 millino outstanding principal balance under
this Servier Loan Agreement would have equaled approximately $19.8 million using the December 31, 2012
Euro-to-U.S.-dollar exchange rate of 1.3215.

Effective in January 2012, we entered into an amended and restated agreement with Servier for the United
States commercialization rights to ACEON and, upon exercise by us of an option with respect to each
product, a portfolio of additional FDC product candidates where perindopril is combined with another active
ingredient(s), such as a calcium channel blocker. To date we have exercised this option with respect to one
FDC product. This agreement, together with a related trademark license agreement, provides us with
exclusive U.S. rights to ACEON and FDC1, and options on additional FDCs. The arrangement also provides
that Servier will supply to us, and we will purchase exclusively from Servier, the active ingredients in
ACEON and the FDCs, in some cases for a limited period. The agreement contains customary termination
rights relating to matters, such as material breach by, or insolvency of, either party or, as to particular
licensed products, for safety issues arising with respect to such products. Each party also has the right to
terminate the arrangement if FDC1 does not receive FDA approval by December 31, 2014. Servier also has
the right to terminate the arrangement if certain aspects of our commercialization strategy are not successful
and Servier does not consent to an alternative strategy, or as to the FDCs, if we breach our obligations to
certain of our service providers. Further, Servier also may terminate the agreement if we fail to achieve
certain levels of sales of products and do not make a specified payment in such circumstances to maintain
our license, or under certain circumstances upon our change in control, if we fail to take certain actions or
make certain payments.

Because Servier is an independent third party, it may be subject to different risks than we are and has
significant discretion in, and different criteria for, determining the efforts and resources it will apply related to its
agreements with us. Even though we have a collaborative relationship with Servier, our relationship could
deteriorate or other circumstances may prevent our relationship with Servier from resulting in successful
development of marketable products. If we are not able to maintain our working relationship with Servier, or if
Servier does not perform under our agreements with Servier, our ability to develop and commercialize
gevokizumab and the FDCs would be materially and adversely affected, as would our ability to commercialize
ACEON.

We have received negative results from certain of our clinical trials, and we face uncertain results of other
clinical trials of our product candidates.

Drug development has inherent risk, and we are required to demonstrate through adequate and well-
controlled clinical trials that our product candidates are effective, with a favorable benefit-risk profile for use in
their target profiles before we can seek regulatory approvals for their commercial use. It is possible we may
never receive regulatory approval for any of our product candidates. Even if a product candidate receives

27

regulatory approval, the resulting product may not gain market acceptance among physicians, patients, healthcare
payors and the medical community. In March 2011, we announced our 421—patient Phase 2b trial of
gevokizumab in Type 2 diabetes did not achieve the primary endpoint of reduction in hemoglobin A1c
(“HbA1c”) after six monthly treatments with gevokizumab compared to placebo. In June 2011, we announced
top-line trial results from our six-month 74—patient Phase 2a trial of gevokizumab in Type 2 diabetes , and there
were no differences in glycemic control between the drug and placebo groups as measured by HbA1c levels.

Many of our product candidates, including gevokizumab, XMet, and XOMA 3AB, require significant

additional research and development, extensive preclinical studies and clinical trials and regulatory approval
prior to any commercial sales. This process is lengthy and expensive, often taking a number of years. As clinical
results frequently are susceptible to varying interpretations that may delay, limit or prevent regulatory approvals,
the length of time necessary to complete clinical trials and to submit an application for marketing approval for a
final decision by a regulatory authority varies significantly. As a result, it is uncertain whether:

•

•

our future filings will be delayed;

our preclinical and clinical studies will be successful;

• we will be successful in generating viable product candidates to targets;

• we will be able to provide necessary additional data;

•

results of future clinical trials will justify further development; or

• we ultimately will achieve regulatory approval for any of these product candidates.

The timing of the commencement, continuation and completion of clinical trials may be subject to

significant delays relating to various causes, including completion of preclinical testing and earlier-stage clinical
trials in a timely manner, engaging contract research organizations and other service providers, scheduling
conflicts with participating clinicians and clinical institutions, difficulties in identifying and enrolling patients
who meet trial eligibility criteria, and shortages of available drug supply. Patient enrollment is a function of
many factors, including the size of the patient population, the proximity of patients to clinical sites, the eligibility
criteria for the trial, the existence of competing clinical trials and the availability of alternative or new treatments.
Regardless of the initial size or relative complexity of a clinical trial, the costs of such trial may be higher than
expected due to increases in duration or size of the trial, changes in the protocol pursuant to which the trial is
being conducted, additional or special requirements of one or more of the healthcare centers where the trial is
being conducted, or changes in the regulatory requirements applicable to the trial or in the standards or guidelines
for approval of the product candidate being tested or for other unforeseen reasons. In addition, we conduct
clinical trials in foreign countries, which may subject us to further delays and expenses as a result of increased
drug shipment costs, additional regulatory requirements and the engagement of foreign clinical research
organizations, as well as expose us to risks associated with foreign currency transactions insofar as we might
desire to use U.S. Dollars to make contract payments denominated in the foreign currency where the trial is being
conducted.

All of our product candidates are prone to the risks of failure inherent in drug development. Preclinical
studies may not yield results that satisfactorily support the filing of an Investigational New Drug application
(“IND”) (or a foreign equivalent) with respect to our product candidates. Even if these applications would be or
have been filed with respect to our product candidates, the results of preclinical studies do not necessarily predict
the results of clinical trials. Similarly, early stage clinical trials in healthy volunteers do not predict the results of
later-stage clinical trials, including the safety and efficacy profiles of any particular product candidates. In
addition, there can be no assurance the design of our clinical trials is focused on appropriate indications, patient
populations, dosing regimens or other variables that will result in obtaining the desired efficacy data to support
regulatory approval to commercialize the drug. Preclinical and clinical data can be interpreted in different ways.
Accordingly, FDA officials or officials from foreign regulatory authorities could interpret the data differently
than we or our collaboration or development partners do, which could delay, limit or prevent regulatory approval.

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Administering any of our products or potential products may produce undesirable side effects, also known

as adverse effects. Toxicities and adverse effects that we have observed in preclinical studies for some
compounds in a particular research and development program may occur in preclinical studies or clinical trials of
other compounds from the same program. Such toxicities or adverse effects could delay or prevent the filing of
an IND (or a foreign equivalent) with respect to such products or potential products or cause us to cease clinical
trials with respect to any drug candidate. In clinical trials, administering any of our products or product
candidates to humans may produce adverse effects. These adverse effects could interrupt, delay or halt clinical
trials of our products and product candidates and could result in the FDA or other regulatory authorities denying
approval of our products or product candidates for any or all targeted indications. The FDA, other regulatory
authorities, our collaboration or development partners or we may suspend or terminate clinical trials at any time.
Even if one or more of our product candidates were approved for sale, the occurrence of even a limited number
of toxicities or adverse effects when used in large populations may cause the FDA to impose restrictions on, or
stop, the further marketing of such drugs. Indications of potential adverse effects or toxicities that may occur in
clinical trials and that we believe are not significant during the course of such clinical trials may actually turn out
later to constitute serious adverse effects or toxicities when a drug has been used in large populations or for
extended periods of time. Any failure or significant delay in completing preclinical studies or clinical trials for
our product candidates, or in receiving and maintaining regulatory approval for the sale of any drugs resulting
from our product candidates, may severely harm our reputation and business.

In June 2011, Novartis announced an advisory committee of the FDA had voted in favor of the overall

efficacy but not the overall safety of Ilaris® (canakinumab), a fully human monoclonal antibody that, like
gevokizumab, targets IL-1 beta, to treat gouty arthritis attacks in patients who cannot obtain adequate relief with
non-steroidal anti-inflammatory drugs or colchicine. Ilaris was initially approved in June 2009 for Cryopyrin-
Associated Periodic Syndromes, an orphan indication. Novartis also stated that in two pivotal Phase 3 studies of
canakinumab in gouty arthritis patients, a higher percentage of patients had adverse events with canakinumab
than with the standard treatment for gouty arthritis, and more serious adverse events were reported by patients
treated with canakinumab compared to patients receiving the standard treatment. In August 2011, Novartis
announced the FDA had issued a Complete Response Letter requesting additional information, including clinical
data to evaluate the benefit risk profile of canakinumab in refractory gouty arthritis patients. We have not yet
determined what impact, if any, these developments may have on the development of gevokizumab.

If our therapeutic product candidates do not receive regulatory approval, neither our third-party
collaborators, our contract manufacturers nor we will be able to manufacture and market them.

Our product candidates (including gevokizumab, FDC1, XMetA, XMetD, XMetS, and XOMA 3AB) cannot
be manufactured and marketed in the United States or any other countries without required regulatory approvals.
The United States government and governments of other countries extensively regulate many aspects of our
product candidates, including:

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clinical development and testing;

• manufacturing;

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•

•

labeling;

storage;

record keeping;

promotion and marketing; and

importing and exporting.

In the United States, the FDA regulates pharmaceutical products under the Federal Food, Drug, and
Cosmetic Act and other laws, including, in the case of biologics, the Public Health Service Act. At the present
time, we believe many of our product candidates (including gevokizumab , XMetA, XMetD, XMetS, and XOMA
3AB) will be regulated by the FDA as biologics and some of our product candidates (including FDC1) will be

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regulated by the FDA as drugs. Initiation of clinical trials requires approval by health authorities. Clinical trials
involve the administration of the investigational new drug to healthy volunteers or to patients under the
supervision of a qualified principal investigator. Clinical trials must be conducted in accordance with FDA and
International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for
Human Use Good Clinical Practices and the European Clinical Trials Directive under protocols that detail the
objectives of the study, the parameters to be used to monitor safety and the efficacy criteria to be evaluated.
Other national, foreign and local regulations also may apply. The developer of the drug must provide information
relating to the characterization and controls of the product before administration to the patients participating in
the clinical trials. This requires developing approved assays of the product to test before administration to the
patient and during the conduct of the trial. In addition, developers of pharmaceutical products must provide
periodic data regarding clinical trials to the FDA and other health authorities, and these health authorities may
issue a clinical hold upon a trial if they do not believe, or cannot confirm, that the trial can be conducted without
unreasonable risk to the trial participants. We cannot assure you that U.S. and foreign health authorities will not
issue a clinical hold with respect to any of our clinical trials in the future.

The results of the preclinical studies and clinical testing, together with chemistry, manufacturing and
controls information, are submitted to the FDA and other health authorities in the form of an NDA for a drug,
and in the form of a Biologic License Application (“BLA”) for a biological product, requesting approval to
commence commercial sales. In responding to an NDA or BLA, the FDA or foreign health authorities may grant
marketing approvals, request additional information or further research, or deny the application if it determines
the application does not satisfy its regulatory approval criteria. Regulatory approval of an NDA, BLA, or
supplement never is guaranteed, the approval process can take several years, is extremely expensive and can vary
substantially based upon the type, complexity, and novelty of the products involved, as well as the target
indications. FDA regulations and policies permit applicants to request accelerated or priority review pathways for
products intended to treat certain serious or life-threatening illnesses in certain circumstances. If granted by the
FDA, these review pathways can provide a shortened timeline to commercialize the product, although the
shortened review timeline is often accompanied with additional post-market requirements. Although we may
pursue the FDA’s accelerated or priority review programs, we cannot guarantee the FDA will permit us to utilize
these pathways or the FDA’s review of our application will not be delayed. Moreover, even if the FDA agrees to
an accelerated or priority review of any of our applications, we may not ultimately be able to obtain approval of
our application in a timely fashion or at all. The FDA and foreign health authorities have substantial discretion in
the drug and biologics approval processes. Despite the time and expense incurred, 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, clinical or manufacturing-related studies.

Changes in the regulatory approval policy during the development period, changes in, or the enactment of
additional regulations or statutes, or changes in regulatory review for each submitted product application may
cause delays in the approval or rejection of an application. State regulations may also affect our proposed
products.

The FDA and other regulatory agencies have substantial discretion in both the product approval process and

manufacturing facility approval process, and as a result of this discretion and uncertainties about outcomes of
testing, we cannot predict at what point, or whether, the FDA or other regulatory agencies will be satisfied with
our or our collaborators’ submissions or whether the FDA or other regulatory agencies will raise questions that
may be material and delay or preclude product approval or manufacturing facility approval. In light of this
discretion and the complexities of the scientific, medical and regulatory environment, our interpretation or
understanding of the FDA’s or other regulatory agencies’ requirements, guidelines or expectations may prove
incorrect, which also could delay further or increase the cost of the approval process. As we accumulate
additional clinical data, we will submit it to the FDA and other regulatory agencies, as appropriate, and such data
may have a material impact on the approval process.

30

Given that regulatory review is an interactive and continuous process, we maintain a policy of limiting
announcements and comments upon the specific details of regulatory review of our product candidates, subject to
our obligations under the securities laws, until definitive action is taken.

We rely on third parties to provide services in connection with our product candidate development and
manufacturing programs. The inadequate performance by or loss of any of these service providers could
affect our product candidate development.

Several third parties provide services in connection with our preclinical and clinical development programs,

including in vitro and in vivo studies, assay and reagent development, immunohistochemistry, toxicology,
pharmacokinetics, clinical trial support, manufacturing and other outsourced activities. If these service providers
do not adequately perform the services for which we have contracted or cease to continue operations and we are
not able to find a replacement provider quickly or we lose information or items associated with our product
candidates, our development programs may be delayed. In particular, we have a master services agreement with a
contract research organization that provides the majority of our clinical trial services with respect to our
collaboration with Servier in relation to the FDC products. Under this agreement, which was amended in October
2011, we are obligated to fund the clinical trial services provided by the contract research organization by
allocating a specified portion of the revenue received from sales of ACEON. If we do not receive sufficient
revenue from sales of ACEON to fund such services, and we do not otherwise pay the contract research
organization for these services, certain of our rights under the commercialization agreement with Servier may
terminate, unless Servier elects to make such payments on our behalf, in which case we will be required to
reimburse Servier for such payments within a specified timeframe. Certain rights under the commercialization
agreement with Servier also will terminate if we fail to reimburse Servier within such period.

We may not obtain orphan drug exclusivity, or we may not receive the full benefit of orphan drug
exclusivity even if we obtain such exclusivity.

The FDA has awarded orphan drug status to gevokizumab for the treatment of non-infectious, intermediate,
posterior or pan uveitis, and chronic non-infectious anterior uveitis and Behçet’s uveitis. Under the Orphan Drug
Act, the first company to receive FDA approval for gevokizumab for the designated orphan drug indication will
obtain seven years of marketing exclusivity, during which time the FDA may not approve another company’s
application for gevokizumab for the same orphan indication. Even though we have obtained orphan drug
designation for certain indications for gevokizumab and even if we obtain orphan drug designation for our future
product candidates or other indications, due to the uncertainties associated with developing pharmaceutical
products, we may not be the first to obtain marketing approval for any particular orphan indication, or we may
not obtain approval for an indication for which we have obtained orphan drug designation. Further, even if we
obtain orphan drug exclusivity for a product, that exclusivity may not protect the product effectively from
competition because different drugs can be approved for the same condition. Even after an orphan drug is
approved, the FDA can subsequently approve the same drug for the same condition if the FDA concludes that the
later drug is safer, more effective or makes a major contribution to patient care. Orphan drug designation neither
shortens the development time or regulatory review time of a drug, nor gives the drug any advantage in the
regulatory review or approval process.

Even after FDA approval, a product may be subject to additional testing or significant marketing
restrictions, its approval may be withdrawn or it may be removed voluntarily from the market.

Even if we receive regulatory approval for our product candidates, we will be subject to ongoing regulatory
oversight and review by the FDA and other regulatory entities. The FDA, the European Commission or another
regulatory agency may impose, as a condition of the approval, ongoing requirements for post-approval studies or
post-approval obligations, including additional research and development and clinical trials, and the FDA,
European Commission or other regulatory agency subsequently may withdraw approval based on these additional
trials. As the current holder of the ACEON® NDA, we are required to submit annual reports to the FDA and are
responsible for pharmacovigilance activities related to the product.

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Even for approved products, the FDA, European Commission or other regulatory agency may impose
significant restrictions on the indicated uses, conditions for use, labeling, advertising, promotion, marketing and/
or production of such product. In addition, the labeling, packaging, adverse event reporting, storage, advertising,
promotion and record-keeping for our products are subject to extensive regulatory requirements.

Furthermore, a marketing approval of a product may be withdrawn by the FDA, the European Commission

or another regulatory agency or such a product may be withdrawn voluntarily by the company marketing it
based, for example, on subsequently arising safety concerns. In February 2009, the European Medicines Agency
(“EMA”) announced it had recommended suspension of the marketing authorization of RAPTIVA® in the EU
and its Committee for Medicinal Products for Human Use (“CHMP”) had concluded the benefits of RAPTIVA
no longer outweigh its risks because of safety concerns, including the occurrence of progressive multifocal
leukoencephalopathy (“PML”) in patients taking the medicine. In the second quarter of 2009, Genentech
announced and carried out a phased voluntary withdrawal of RAPTIVA from the U.S. market, based on the
association of RAPTIVA with an increased risk of PML. We had participated in the development of RAPTIVA.

The FDA, European Commission and other agencies also may impose various civil or criminal sanctions for

failure to comply with regulatory requirements, including withdrawal of product approval.

We may issue additional equity securities and thereby materially and adversely affect the price of our
common stock.

We are authorized to issue, without stockholder approval, 1,000,000 shares of preferred stock, of which
none were issued and outstanding as of March 8, 2013, which may give other stockholders dividend, conversion,
voting, and liquidation rights, among other rights, which may be superior to the rights of holders of our common
stock. In April 2011, the 2,959 Series B convertible preference shares previously issued to Genentech were
converted by Genentech into 254,560 shares of common stock. In addition, we are authorized to issue, generally
without stockholder approval, up to 138,666,666 shares of common stock, of which 82,852,846 were issued and
outstanding as of March 8, 2013. If we issue additional equity securities, the price of our common stock may be
materially and adversely affected.

On February 4, 2011, we entered into an At Market Issuance Sales Agreement (the “2011 ATM

Agreement”) with McNicoll, Lewis & Vlak LLC (now known as MLV & Co. LLC, “MLV”), under which we
may sell shares of our common stock from time to time through the MLV, as our agent for the offer and sale of
the shares, in an aggregate amount not to exceed the amount that can be sold under our Registration Statement on
Form S-3 (File No. 333-172197) filed with the SEC on February 11, 2011, and amended on March 10,
2011, June 3, 2011, and January 3, 2012, which was most recently declared effective by the SEC on January 17,
2012. MLV may sell the shares by any method permitted by law deemed to be an “at the market” offering as
defined in Rule 415 of the Securities Act, including without limitation sales made directly on The NASDAQ
Global Market, on any other existing trading market for our common stock or to or through a market maker.
MLV also may sell the shares in privately negotiated transactions, subject to our prior approval. From the
inception of the 2011 ATM Agreement through March 8, 2013, we sold a total of 7,572,327 shares of common
stock under this agreement for aggregate gross proceeds of $14.6 million.

On March 9, 2012, we completed an underwritten public offering of 29,669,154 shares of our common
stock, and accompanying warrants to purchase one half of a share of common stock for each share purchased, at
a public offering price of $1.32 per share. Total gross proceeds from the offering were approximately $39.2
million, before deducting underwriting discounts and commissions and estimated offering expenses totaling
approximately $3.0 million. The warrants, which represent the right to acquire an aggregate of up to 14,834,577
shares of common stock, are exercisable immediately and have a five-year term and an exercise price of $1.76
per share. As of March 8, 2013, 14,265,970 of these warrants were outstanding.

On October 29, 2012, we completed an underwritten public offering of 13,333,333 shares of our common
stock, at a public offering price of $3.00 per share. In addition, we granted the underwriters a 30-day option to

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purchase up to an additional 1,999,999 shares of common stock on the same terms and conditions, solely to cover
over-allotments, which option was not exercised within the 30-day option period. Total gross proceeds from the
offering were approximately $40.0 million, before deducting underwriting discounts and commissions and
estimated offering expenses totaling approximately $3.0 million.

The financial terms of future collaborative or licensing arrangements could result in dilution of our share
value.

Funding from collaboration partners and others has in the past and may in the future involve issuance by us
of our shares. We cannot be certain how the purchase price of such shares, the relevant market price or premium,
if any, will be determined or when such determinations will be made. Any such issuance could result in dilution
in the value of our issued and outstanding shares.

Our share price may be volatile and there may not be an active trading market for our common stock.

There can be no assurance the market price of our common stock will not decline below its present market

price or there will be an active trading market for our common stock. The market prices of biotechnology
companies have been and are likely to continue to be highly volatile. Fluctuations in our operating results and
general market conditions for biotechnology stocks could have a significant impact on the volatility of our
common stock price. We have experienced significant volatility in the price of our common stock. From
January 1, 2012, through March 8, 2013, the share price of our common stock has ranged from a high of $4.13 to
a low of $1.12. Factors contributing to such volatility include, but are not limited to:

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

results of preclinical studies and clinical trials;

information relating to the safety or efficacy of products or product candidates;

developments regarding regulatory filings;

announcements of new collaborations;

failure to enter into collaborations;

developments in existing collaborations;

our funding requirements and the terms of our financing arrangements;

technological innovations or new indications for our therapeutic products and product candidates;

introduction of new products or technologies by us or our competitors;

sales and estimated or forecasted sales of products for which we receive royalties, if any;

government regulations;

developments in patent or other proprietary rights;

the number of shares issued and outstanding;

the number of shares trading on an average trading day;

announcements regarding other participants in the biotechnology and pharmaceutical industries; and

• market speculation regarding any of the foregoing.

If we are unable to continue to meet the requirements for continued listing on The NASDAQ Global
Market, then we may be de-listed. In March 2010, we received a Staff Determination letter from The NASDAQ
Stock Market LLC (“NASDAQ”) indicating we had not regained compliance with the minimum $1.00 per share
requirement for continued inclusion on The NASDAQ Global Market, pursuant to NASDAQ Listing Rule
5450(a)(1). On August 18, 2010, we effected a reverse split of our common stock to regain compliance.

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We may not be successful in commercializing our products, which could affect our development efforts.

We began commercializing our first product, ACEON, in January 2012, and we have limited experience in

the sales, marketing and distribution of pharmaceutical products. There can be no assurance we will be able to
maintain the arrangements we have with third-party suppliers, distributors and other service providers that are
necessary for us to perform these activities or our efforts will be successful. Maintaining or expanding these
arrangements, or developing our own capabilities, may divert attention and resources from or otherwise
negatively affect our development programs.

Our rights to commercialize ACEON are licensed from Servier, and we are obligated to use diligent efforts

to develop and commercialize the products covered by our agreement in accordance with the terms and
conditions of that agreement. Our ability to satisfy some of these obligations is dependent on factors that are
outside of our control. Our agreement with Servier may be terminated by Servier if we materially breach our
obligations and fail to cure such breach, for our insolvency, or terminated by either party with respect to any
individual licensed product in the event of certain safety issues are presented. Each party also has the right to
terminate the agreement if FDC1 does not receive FDA approval by December 31, 2014, and Servier may
terminate the agreement if we fail to achieve certain levels of annual net sales of products and do not make a
specified payment to maintain our license. Servier also has the right to terminate the agreement if we do not meet
specified commercialization objectives and Servier does not consent to an alternative strategy or, as to the FDCs,
if we breach our obligations to certain of our service providers. Servier also may terminate under certain
circumstances upon our change in control, if we fail to take certain actions or make certain payments. If our
agreement is terminated, we would have no further rights to develop and commercialize these products.

Furthermore, because we intend to use revenues generated by sales of ACEON in part to fund development

of FDC1, lower than expected revenues from such sales could adversely affect our ability to fund the costs of,
and progress, such development.

We are subject to various state and federal healthcare related laws and regulations that may impact the
commercialization of ACEON or our product candidates and could subject us to significant fines and
penalties.

Our operations may be directly or indirectly subject to various state and federal healthcare laws, including,
without limitation, the federal Anti-Kickback Statute, the federal False Claims Act and HIPAA/HITECH. These
laws may impact, among other things, the commercial operations for ACEON or any of our product candidates
that may be approved for commercial sale.

The federal Anti-Kickback Statute prohibits persons from knowingly and willfully soliciting, offering,
receiving or providing remuneration, directly or indirectly, in exchange for or to induce either the referral of an
individual, or the furnishing or arranging for a good or service, for which payment may be made 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 prohibits many arrangements and practices that are lawful in businesses outside of the healthcare industry.
Penalties for violations of the federal Anti-Kickback Statute include criminal penalties and civil sanctions such as
fines, penalties, imprisonment and possible exclusion from Medicare, Medicaid and other federal healthcare
programs. Many states also have 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 Physician Payments Sunshine Act also has several state equivalents, which require, and
under which the Federal government will require in 2013, disclosure of payments or other transfers of value we
make to physicians.

The federal False Claims Act prohibits persons from knowingly filing, or causing to be filed, a false claim
to, or the knowing use of false statements to obtain payment from the federal government. Suits filed under the

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False Claims Act, known as “qui tam” actions, can be brought by any individual on behalf of the government 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. Various states also have enacted laws
modeled after the federal False Claims Act.

The Federal Health Insurance Portability and Accountability Act of 1996 (“HIPAA”), created new federal
criminal statutes that prohibit executing a scheme to defraud any healthcare benefit program and making false
statements relating to healthcare matters and was amended by the Health Information Technology and Clinical
Health Act (“HITECH”), and its implementing regulations, which imposes certain requirements relating to the
privacy, security and transmission of individually identifiable health information. We take our obligation to
maintain our compliance with these various laws and regulations seriously. If we are found to be in violation of
any of the laws and regulations described above or other applicable state and federal healthcare fraud and abuse
laws, we may be subject to penalties, including civil and criminal penalties, damages, fines, 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.

Certain of our technologies are in-licensed from third parties, so our capabilities using them are restricted
and subject to additional risks.

We license technologies from third parties. These technologies include but are not limited to phage display

technologies licensed to us in connection with our bacterial cell expression technology licensing program.
However, our use of these technologies is limited by certain contractual provisions in the licenses relating to
them, and although we have obtained numerous licenses, intellectual property rights in the area of phage display
are particularly complex. If the owners of the patent rights underlying the technologies that we license do not
properly maintain or enforce those patents, our competitive position and business prospects could be harmed.
Our success will depend in part on the ability of our licensors to obtain, maintain and enforce our in-licensed
intellectual property. Our licensors may not be successful in prosecuting the patent applications to which we have
licenses, or our licensors may fail to maintain existing patents. They may determine not to pursue litigation
against other companies that are infringing these patents, or they may pursue such litigation less aggressively
than we would. Our licensors also may seek to terminate our license, which could cause us to lose the right to use
the licensed intellectual property and adversely affect our ability to commercialize our technologies, products or
services.

We do not know whether there will be, or will continue to be, a viable market for the products in which we
have an ownership or royalty interest.

Even if products in which we have an interest receive approval in the future, they may not be accepted in the

marketplace. In addition, we or our collaborators or licensees may experience difficulties in launching new
products, many of which are novel and based on technologies that are unfamiliar to the healthcare community.
We have no assurance healthcare providers and patients will accept such products, if developed. For example,
physicians and/or patients may not accept a product for a particular indication because it has been biologically
derived (and not discovered and developed by more traditional means) or if no biologically derived products are
currently in widespread use in that indication. Similarly, physicians may not accept a product if they believe
other products to be more effective or more cost effective or are more comfortable prescribing other products.

Safety concerns also may arise in the course of on-going clinical trials or patient treatment as a result of

adverse events or reactions. For example, in February 2009, the EMA announced it had recommended
suspension of the marketing authorization of RAPTIVA in the EU and EMD Serono Inc., the company that
marketed RAPTIVA in Canada (“EMD Serono”) announced that in consultation with Health Canada, the

35

Canadian health authority (“Health Canada”), it would suspend marketing of RAPTIVA in Canada. In March
2009, Merck Serono Australia Pty Ltd, the company that marketed RAPTIVA in Australia (“Merck Serono
Australia”), following a recommendation from the Therapeutic Goods Administration, the Australian health
authority (“TGA”), announced it was withdrawing RAPTIVA from the Australian market. In the second quarter
of 2009, Genentech announced and carried out a phased voluntary withdrawal of RAPTIVA from the U.S.
market, based on the association of RAPTIVA with an increased risk of PML, and sales of the product ceased.

Furthermore, government agencies, as well as private organizations involved in healthcare, from time to

time publish guidelines or recommendations to healthcare providers and patients. Such guidelines or
recommendations can be very influential and may adversely affect product usage directly (for example, by
recommending a decreased dosage of a product in conjunction with a concomitant therapy or a government entity
withdrawing its recommendation to screen blood donations for certain viruses) or indirectly (for example, by
recommending a competitive product over our product). Consequently, we do not know if physicians or patients
will adopt or use our products for their approved indications.

Even approved and marketed products are subject to risks relating to changes in the market for such

products. Introduction or increased availability of generic versions of products can alter the market acceptance of
branded products, such as ACEON. In addition, unforeseen safety issues may arise at any time, regardless of the
length of time a product has been on the market.

Our third-party collaborators, licensees, suppliers or contractors may not have adequate manufacturing
capacity sufficient to meet market demand.

Upon approval of any of our product candidates or in the event of increased demand for marketed products,

we do not know whether the capacity of the manufacturing facilities of our existing or future third-party
collaborators, licensees, suppliers or contractors will be available or can be increased to produce sufficient
quantities of our products to meet market demand. Also, if we or our third-party collaborators, licensees,
suppliers or contractors need additional manufacturing facilities to meet market demand, we cannot predict that
we will successfully obtain those facilities because we do not know whether they will be available on acceptable
terms. In addition, any manufacturing facilities acquired or used to meet market demand must meet the FDA’s
quality assurance guidelines.

In addition to our agreements with Servier, our agreements with other third parties, many of which are
significant to our business, expose us to numerous risks.

Our financial resources and our marketing experience and expertise are limited. Consequently, our ability to
develop products successfully depends, to a large extent, upon securing the financial resources and/or marketing
capabilities of third parties other than Servier. For example:

•

•

In March 2004, we announced we had agreed to collaborate with Chiron Corporation (now Novartis)
for the development and commercialization of antibody products for the treatment of cancer. In April
2005, we announced the initiation of clinical testing of the first product candidate out of the
collaboration, HCD122, an anti-CD40 antibody, in patients with advanced chronic lymphocytic
leukemia. In October 2005, we announced the initiation of the second clinical trial of HCD122 in
patients with multiple myeloma. In November 2008, we announced the restructuring of this product
development collaboration, which involved six development programs including the ongoing HCD122
and LFA102 programs. In exchange for cash and debt reduction on our existing loan facility with
Novartis, Novartis has control over the HCD122 and LFA102 programs, as well as the right to expand
the development of these programs into additional indications outside of oncology.

In March 2005, we entered into a contract with the National Institute of Allergy and Infectious
Diseases (“NIAID”) to produce three monoclonal antibodies designed to protect U.S. citizens against
the harmful effects of botulinum neurotoxin used in bioterrorism. In July 2006, we entered into an
additional contract with NIAID for the development of an appropriate formulation for human

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•

administration of these three antibodies in a single injection. In September 2008, we announced we had
been awarded an additional contract with NIAID to support our on-going development of drug
candidates toward clinical trials in the treatment of botulism poisoning. In October 2011, we
announced we had been awarded an additional contract with NIAID to develop broad-spectrum
antitoxins for the treatment of human botulism poisoning.

In December 2011, we entered into a loan agreement with GECC (the “GECC Loan Agreement”),
under which GECC agreed to make a term loan in an aggregate principal amount of $10 million to
XOMA (US) LLC, our wholly owned subsidiary, and upon execution of the GECC Loan Agreement,
GECC funded the term loan. The term loan is guaranteed by us and our two other principal
subsidiaries, XOMA Ireland Limited and XOMA Technology Ltd. As security for our obligations
under the GECC Loan Agreement, we, XOMA (US) LLC, XOMA Ireland Limited and XOMA
Technology Ltd. each granted a security interest pursuant to a guaranty, pledge and security agreement
in substantially all of our existing and after-acquired assets, excluding our intellectual property assets
(such as those relating to our gevokizumab and anti-botulism products). We were required to repay the
principal amount of the Term Loan over a period of 42 installments of principal and accrued interest,
but we amended the GECC Loan Agreement on September 27, 2012, as described below. The GECC
Loan Agreement contains customary representations and warranties and customary affirmative and
negative covenants, including restrictions on the ability to incur indebtedness, grant liens, make
investments, dispose of assets, enter into transactions with affiliates and amend existing material
agreements, in each case subject to various exceptions. In addition, the GECC Loan Agreement
contains customary events of default that entitle GECC to cause any or all of the indebtedness under
the GECC Loan Agreement to become immediately due and payable. The events of default include any
event of default under a material agreement or certain other indebtedness. We may prepay the term
loan in full voluntarily, but not in part, and any voluntary and certain mandatory prepayments are
subject to a prepayment premium of 3% in the first year of the loan, 2% in the second year and 1%
thereafter, with certain exceptions. We also will be required to pay the final payment fee in connection
with any voluntary or mandatory prepayment. Pursuant to the GECC Loan Agreement, we issued to
GECC unregistered stock purchase warrants, which entitle GECC to purchase up to an aggregate of
263,158 unregistered shares of XOMA common stock at an exercise price equal to $1.14 per share, are
exercisable immediately and expire on December 30, 2016.

• On September 27, 2012, we entered into an amendment to the GECC Loan Agreement providing for an
additional term loan in the amount of $4.6 million and an interest-only monthly repayment period with
respect to the aggregate loan obligation of $12.5 million outstanding following the effective date of the
amendment through March 1, 2013, at a stated interest rate of 10.9% per annum. Thereafter, we are
obligated to make monthly principal payments of $0.3 million, plus accrued interest, at a stated interest
rate of 10.9% per annum, over a 27-month period commencing on April 1, 2013, and through June 15,
2015, at which time the remaining outstanding principal amount of $3.1 million, plus accrued interest,
shall be due. A final payment fee in the amount of $0.9 million is payable on the date upon which the
outstanding principal amount is required to be repaid in full. Any mandatory or voluntary prepayment
of the $12.5 million will accelerate the due date of the final payment fee and trigger a prepayment
penalty equal to 3% of the outstanding principal amount being prepaid if prepaid on or before
September 27, 2013, 2% if prepaid on or before September 27, 2014, and 1% if prepaid after
September 27, 2014, but prior to the maturity date. In connection with the amendment, on
September 27, 2012, we issued GE a warrant to purchase up to 39,346 shares of our common stock,
which warrant is exercisable immediately, has a five-year term and has an exercise price of $3.54 per
share.

• We have licensed our bacterial cell expression technology, an enabling technology used to discover and
screen, as well as develop and manufacture, recombinant antibodies and other proteins for commercial
purposes, to over 60 companies. As of March 11, 2013, we were aware of two antibody products
manufactured using this technology that have received FDA approval, Genentech’s LUCENTIS®
(ranibizumab injection) for treatment of neovascular wet age-related macular degeneration and UCB’s

37

CIMZIA® (certolizumab pegol) for treatment of Crohn’s disease and rheumatoid arthritis. In the third
quarter of 2009, we sold our LUCENTIS royalty interest to Genentech. In the third quarter of 2010, we
sold our CIMZIA royalty interest.

• On July 24, 2012, Servier and we entered into an agreement with Boehringer Ingelheim to transfer

XOMA’s technology and processes for the manufacture of gevokizumab to Boehringer lngelheim for
Boehringer Ingelheim’s implementation and validation in preparation for the commercial manufacture
of gevokizumab. Upon the successful completion of the transfer and the establishment of biological
comparability, including validation of the XOMA processes as implemented by Boehringer Ingelheim,
we intend Boehringer Ingelheim will produce gevokizumab for XOMA’s commercial use at its facility
in Biberach, Germany. Servier and we retain all rights to the development and commercialization of
gevokizumab. Transferring of our technology to Boehringer Ingelheim exposes us to numerous risks,
including the possibility that Boehringer Ingelheim may not perform under the agreement as
anticipated, and that we will need to successfully conduct a comparability trial demonstrating to the
FDA’s satisfaction the similarity between XOMA-manufactured and Boehringer Ingelheim-
manufactured product.

Because our collaborators, licensees, suppliers and contractors are independent third parties, they may be

subject to different risks than we are and have significant discretion in, and different criteria for, determining the
efforts and resources they will apply related to their agreements with us. If these collaborators, licensees,
suppliers and contractors do not successfully perform the functions for which they are responsible, we may not
have the capabilities, resources or rights to do so on our own.

We do not know whether we, our collaborators or licensees will successfully develop and market any of the
products that are or may become the subject of any of our collaboration or licensing arrangements. In some cases
these arrangements provide for funding solely by our collaborators or licensees, and in other cases, all of the
funding for certain projects and a significant portion of the funding for other projects is to be provided by our
collaborator or licensee, and we provide the balance of the funding. Even when we have a collaborative
relationship, other circumstances may prevent it from resulting in successful development of marketable
products. In addition, third-party arrangements such as ours also increase uncertainties in the related decision-
making processes and resulting progress under the arrangements, as we and our collaborators or licensees may
reach different conclusions, or support different paths forward, based on the same information, particularly when
large amounts of technical data are involved. Furthermore, our contracts with NIAID contain numerous standard
terms and conditions provided for in the applicable Federal acquisition regulations and customary in many
government contracts, some of which could allow the U.S. government to exercise certain rights under the
technology developed under these contracts. Uncertainty exists as to whether we will be able to comply with
these terms and conditions in a timely manner, if at all. In addition, we are uncertain as to the extent of NIAID’s
demands and the flexibility that will be granted to us in meeting those demands.

Although we continue to evaluate additional strategic alliances and potential partnerships, we do not know

whether or when any such alliances or partnerships will be entered into.

Products and technologies of other companies may render some or all of our products and product
candidates noncompetitive or obsolete.

Developments by others may render our products, product candidates, or technologies obsolete or
uncompetitive. Technologies developed and utilized by the biotechnology and pharmaceutical industries are
changing continuously and substantially. Competition in antibody-based technologies is intense and is expected
to increase in the future as a number of established biotechnology firms and large chemical and pharmaceutical
companies advance in these fields. Many of these competitors may be able to develop products and processes
competitive with or superior to our own for many reasons, including that they may have:

•

•

significantly greater financial resources;

larger research and development and marketing staffs;

38

•

•

•

larger production facilities;

entered into arrangements with, or acquired, biotechnology companies to enhance their capabilities; or

extensive experience in preclinical testing and human clinical trials.

These factors may enable others to develop products and processes competitive with or superior to our own

or those of our collaborators. In addition, a significant amount of research in biotechnology is being carried out in
universities and other non-profit research organizations. These entities are becoming increasingly interested in
the commercial value of their work and may become more aggressive in seeking patent protection and licensing
arrangements. Furthermore, many companies and universities tend not to announce or disclose important
discoveries or development programs until their patent position is secure or, for other reasons, later; as a result,
we may not be able to track development of competitive products, particularly at the early stages. Positive or
negative developments in connection with a potentially competing product may have an adverse impact on our
ability to raise additional funding on acceptable terms. For example, if another product is perceived to have a
competitive advantage, or another product’s failure is perceived to increase the likelihood that our product will
fail, then investors may choose not to invest in us on terms we would accept or at all.

The examples below pertain to competitive events in the market that we review quarterly yet are not

intended to be representative of all existing competitive events.

Gevokizumab

We, in collaboration with Servier, are developing gevokizumab, a potent monoclonal antibody with unique

allosteric modulating properties that binds strongly to interleukin-1 beta (IL-1 beta), a pro-inflammatory
cytokine. In binding to IL-1 beta, gevokizumab inhibits the activation of the IL-1 receptor, thereby modulating
the cellular signaling events that produce inflammation . Other companies are developing other products based
on the same or similar therapeutic targets as gevokizumab, and these products may prove more effective than
gevokizumab. We are aware that:

• Novartis markets and is developing Ilaris (canakinumab, ACZ885), a fully human monoclonal antibody
that selectively binds to and neutralizes IL-1 beta. Since 2009, canakinumab has been approved in over
50 countries for the treatment of children and adults suffering from Cryopyrin-Associated Periodic
Syndrome (“CAPS”). Novartis has filed for regulatory approval of canakinumab in the United States
and Europe for the treatment of acute attacks in gouty arthritis. In August 2011, Novartis announced
that the FDA had issued a Complete Response Letter requesting additional information, including
clinical data to evaluate the benefit:risk profile of canakinumab in refractory gouty arthritis patients. In
September 2011, Novartis announced positive results of a pivotal Phase 3 trial of canakinumab in
patients with systemic juvenile idiopathic arthritis and it plans to seek regulatory approval for this
indication in 2012. Novartis also is pursuing other diseases in which IL-1 beta may play a prominent
role, such as systemic secondary prevention of cardiovascular events.

• Eli Lilly and Company (“Lilly”) is developing a monoclonal antibody to IL-1 beta in Phase 1 studies

for the treatment of cardiovascular disease. In June 2011, Lilly reported results from a Phase 2 study of
LY2189102 in 106 patients with Type 2 diabetes, showing a significant (p<0.05), early reduction in C
reactive protein (“CRP”), moderate reduction in HbA1c and anti-inflammatory effects. We do not
know whether LY2189102 remains in development.

•

In 2008, Swedish Orphan Biovitrum obtained from Amgen the global exclusive rights to Kineret®
(anakinra) for rheumatoid arthritis as currently indicated in its label. In November 2009, the agreement
regarding Swedish Orphan Biovitrum’s Kineret license was expanded to include certain orphan
indications. Kineret is an IL-1 receptor antagonist (IL-1ra) that has been evaluated in multiple IL-1-
mediated diseases, including indications we are considering for gevokizumab. In addition to other on-
going studies, a proof-of-concept clinical trial in the United Kingdom investigating Kineret in patients
with a certain type of myocardial infarction, or heart attack, has been completed. In August 2010,
Biovitrum announced the FDA had granted orphan drug designation to Kineret for the treatment of
CAPS.

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•

In February 2008, Regeneron Pharmaceuticals, Inc. (“Regeneron”), announced it had received
marketing approval from the FDA for ARCALYST® (rilonacept) Injection for Subcutaneous Use, an
interleukin-1 blocker or IL-1 Trap, for the treatment of CAPS, including Familial Cold Auto-
inflammatory Syndrome and Muckle-Wells Syndrome in adults and children 12 and older. In
September 2009, Regeneron announced rilonacept was approved in the EU for CAPS. In June 2010
and February 2011, Regeneron announced positive results of two Phase 3 clinical trials of rilonacept in
gout. In November 2011, Regeneron announced the FDA had accepted for review Regeneron’s
supplemental BLA for ARCALYST for the prevention and treatment of gout. A meeting of an FDA
advisory panel to review this supplemental BLA was held in May 2012 with a recommendation against
approval of the new use in gout. In July 2012, the FDA issued a Complete Response Letter that states
the FDA cannot approve the application in its current form and has requested additional clinical data,
as well as additional CMC information related to a proposed new dosage form. Regeneron is reviewing
the complete response letter from the FDA and will determine appropriate next steps.

• Amgen has been developing AMG 108, a fully human monoclonal antibody that targets inhibition of

the action of IL-1. In April 2008, Amgen discussed results from a Phase 2 study in rheumatoid arthritis.
AMG 108 showed statistically significant improvement in the signs and symptoms of rheumatoid
arthritis and was well tolerated. In January 2011, MedImmune, the worldwide biologics unit for
AstraZeneca PLC, announced Amgen granted it rights to develop AMG 108 worldwide except in
Japan.

•

In June 2009, Cytos Biotechnology AG announced the initiation of an ascending dose Phase 1/2a study
of CYT013-IL1bQb, a therapeutic vaccine targeting IL-1 beta, in Type 2 diabetes. In 2010, this study
was extended to include two additional groups of patients.

• The following companies have completed or are conducting or planning Phase 3 clinical trials of the
following products for the treatment of intermediate, posterior or pan-noninfectious uveitis: Abbott—
HUMIRA® (adalimumab); Lux Biosciences, Inc.—LUVENIQ® (voclosporin); Novartis—Myfortic®
(mycophenalate sodium) and Santen Pharmaceutical Co., Ltd.—Sirolimus® (rapamycin).

Perindopril

We currently are selling ACEON, an angiotensin converting enzyme (“ACE”) inhibitor, and developing
FDC1, a fixed-dose combination of perindopril arginine and amlodipine besylate, a calcium channel blocker.

The ACE inhibitor market is highly genericized with all options being available generically. We are aware:

• The leading product (based on annual sales) in the United States within the ACE inhibitor category is
lisinopril, formerly marketed by Astra-Zeneca Pharmaceuticals LP under the brand ZESTRIL® and by
Merck & Co. under the brand Prinivil ® .

• There are multiple options in the FDC market combining ACE inhibitors with diuretics, and two

options combining an ACE inhibitor with a calcium channel blocker. Current options with a calcium
channel blocker are benazepril/amlodipine, formerly marketed by Novartis Pharmaceuticals as Lotrel®,
and trandolapril/verapamil, formerly marketed by Abbot Laboratories as Tarka ® .

ACE inhibitors are a segment of the larger Renin Angiotensin Aldosterone System (“RAAS”) market. This

market is comprised of ACE inhibitors and angiotensin receptor blockers (“ARB”). Both classes act on the
RAAS in different ways to control blood pressure. We are aware the most successful of the ARB (in terms of
annual sales) is valsartan, trade name Diovan®, which is marketed by Novartis. This compound, along with other
ARBs, has been developed in multiple FDC products: with a diuretic, a calcium channel blocker (amlodipine)
and as a triple combination of all three.

Our perindopril franchise will compete directly with FDCs containing an ACE inhibitor and secondarily

with fixed-dose combinations containing an ARB or calcium channel blocker.

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XOMA 3AB

We also are developing XOMA 3AB, a combination, or cocktail, of antibodies designed to neutralize the
most potent of botulinum toxins. Other companies are developing other products targeting botulism poisoning,
and these products may prove more effective than XOMA 3AB. We are aware:

• Cangene Corporation has a contract with the U.S. Department of Health & Human Services, expected
to be worth $423.0 million, to manufacture and supply an equine heptavalent botulism anti-toxin; and

• Emergent BioSolutions, Inc., is currently in development of a botulism immunoglobulin candidate that

may compete with our anti-botulinum neurotoxin monoclonal antibodies.

Manufacturing risks and inefficiencies may affect adversely our ability to manufacture products for
ourselves or others.

To the extent we continue to provide manufacturing services for our own benefit or to third parties, we are
subject to manufacturing risks. Additionally, unanticipated fluctuations in customer requirements have led and
may continue to lead to manufacturing inefficiencies, which if significant could lead to an impairment on our
long-lived assets or restructuring activities. We must utilize our manufacturing operations in compliance with
regulatory requirements, in sufficient quantities and on a timely basis, while maintaining acceptable product
quality and manufacturing costs. Additional resources and changes in our manufacturing processes may be
required for each new product, product modification or customer or to meet changing regulatory or third-party
requirements, and this work may not be completed successfully or efficiently.

Manufacturing and quality problems may arise in the future to the extent we continue to perform these

manufacturing activities for our own benefit or for third parties. Consequently, our development goals or
milestones may not be achieved in a timely manner or at a commercially reasonable cost, or at all. In addition, to
the extent we continue to make investments to improve our manufacturing operations, our efforts may not yield
the improvements that we expect.

Failure of our products to meet current Good Manufacturing Practices standards may subject us to delays
in regulatory approval and penalties for noncompliance.

Our contract manufacturers are required to produce ACEON and our clinical product candidates under
current Good Manufacturing Practices (“cGMP”) to meet acceptable standards for use in our clinical trials and
for commercial sale, as applicable. If such standards change, the ability of contract manufacturers to produce our
product candidates and ACEON on the schedule we require for our clinical trials or to meet commercial
requirements may be affected. In addition, contract manufacturers may not perform their obligations under their
agreements with us or may discontinue their business before the time required by us to successfully produce
clinical and commercial supplies of our product candidates and ACEON.

We and our contract manufacturers are subject to pre-approval inspections and periodic unannounced
inspections by the FDA and corresponding state and foreign authorities to ensure strict compliance with cGMP
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. Any difficulties or delays in our
contractors’ manufacturing and supply of our product candidates and ACEON or any failure of our contractors to
maintain compliance with the applicable regulations and standards could increase our costs, cause us to lose
revenue, make us postpone or cancel clinical trials, prevent or delay regulatory approval by the FDA and
corresponding state and foreign authorities, prevent the import and/or export of our product candidates and
ACEON, or cause any of our product candidates that may be approved for commercial sale and ACEON to be
recalled or withdrawn.

41

Because many of the companies with which we do business also are in the biotechnology sector, the
volatility of that sector can affect us indirectly as well as directly.

As a biotechnology company that collaborates with other biotechnology companies, the same factors that
affect us directly also can adversely impact us indirectly by affecting the ability of our collaborators, partners and
others with which we do business to meet their obligations to us and reduce our ability to realize the value of the
consideration provided to us by these other companies.

For example, in connection with our licensing transactions relating to our bacterial cell expression

technology, we have in the past and may in the future agree to accept equity securities of the licensee in payment
of license fees. The future value of these or any other shares we receive is subject both to market risks affecting
our ability to realize the value of these shares and more generally to the business and other risks to which the
issuer of these shares may be subject.

As we do more business internationally, we will be subject to additional political, economic and regulatory
uncertainties.

We may not be able to operate successfully in any foreign market. We believe that because the

pharmaceutical industry is global in nature, international activities will be a significant part of our future business
activities and when and if we are able to generate income, a substantial portion of that income will be derived
from product sales and other activities outside the United States. Foreign regulatory agencies often establish
standards different from those in the United States, and an inability to obtain foreign regulatory approvals on a
timely basis could put us at a competitive disadvantage or make it uneconomical to proceed with a product or
product candidate’s development. International operations and sales may be limited or disrupted by:

•

•

•

•

•

•

•

imposition of government controls;

export license requirements;

political or economic instability;

trade restrictions;

changes in tariffs;

restrictions on repatriating profits;

exchange rate fluctuations;

• withholding and other taxation; and

•

difficulties in staffing and managing international operations.

We are subject to foreign currency exchange rate risks.

We are subject to foreign currency exchange rate risks because substantially all of our revenues and

operating expenses are paid in U.S. Dollars, but we pay interest and principal obligations with respect to our loan
from Servier in Euros. To the extent the U.S. Dollar declines in value against the Euro, the effective cost of
servicing our Euro-denominated debt will be higher. Changes in the exchange rate result in foreign currency
gains or losses. Although we have managed some of our exposure to changes in foreign currency exchange rates
by entering into foreign exchange option contracts, there can be no assurance foreign currency fluctuations will
not have a material adverse effect on our business, financial condition, liquidity or results of operations. In
addition, our foreign exchange option contracts are re-valued at each financial reporting period, which also may
result in gains or losses from time to time.

If we and our partners are unable to protect our intellectual property, in particular our patent protection
for our principal products, product candidates and processes, and prevent its use by third parties, our
ability to compete in the market will be harmed, and we may not realize our profit potential.

42

We rely on patent protection, as well as a combination of copyright, trade secret, and trademark laws to

protect our proprietary technology and prevent others from duplicating our products or product candidates.
However, these means may afford only limited protection and may not:

•

•

•

prevent our competitors from duplicating our products;

prevent our competitors from gaining access to our proprietary information and technology; or

permit us to gain or maintain a competitive advantage.

Because of the length of time and the expense associated with bringing new products to the marketplace, we
and our collaboration and development partners hold and are in the process of applying for a number of patents in
the United States and abroad to protect our product candidates and important processes and also have obtained or
have the right to obtain exclusive licenses to certain patents and applications filed by others. However, the mere
issuance of a patent is not conclusive as to its validity or its enforceability. The U.S. Federal Courts or equivalent
national courts or patent offices elsewhere may invalidate our patents or find them unenforceable. In addition, the
laws of foreign countries may not protect our intellectual property rights effectively or to the same extent as the
laws of the United States. If our intellectual property rights are not protected adequately, we may not be able to
commercialize our technologies, products, or services, and our competitors could commercialize our
technologies, which could result in a decrease in our sales and market share that would harm our business and
operating results. Specifically, the patent position of biotechnology companies generally is highly uncertain and
involves complex legal and factual questions. The legal standards governing the validity of biotechnology patents
are in transition, and current defenses as to issued biotechnology patents may not be adequate in the future.
Accordingly, there is uncertainty as to:

• whether any pending or future patent applications held by us will result in an issued patent, or that if
patents are issued to us, that such patents will provide meaningful protection against competitors or
competitive technologies;

• whether competitors will be able to design around our patents or develop and obtain patent protection
for technologies, designs or methods that are more effective than those covered by our patents and
patent applications; or

•

the extent to which our product candidates could infringe on the intellectual property rights of others,
which may lead to costly litigation, result in the payment of substantial damages or royalties, and/or
prevent us from using technology that is essential to our business.

We have established a portfolio of patents, both United States and foreign, related to our bacterial cell
expression technology, including claims to novel promoter sequences, secretion signal sequences, compositions
and methods for expression and secretion of recombinant proteins from bacteria, including immunoglobulin gene
products. Most of the more important European patents in our bacterial cell expression patent portfolio expired in
July 2008 or earlier.

If certain patents issued to others are upheld or if certain patent applications filed by others issue and are

upheld, we may require licenses from others to develop and commercialize certain potential products
incorporating our technology or we may become involved in litigation to determine the proprietary rights of
others. These licenses, if required, may not be available on acceptable terms, and any such litigation may be
costly and may have other adverse effects on our business, such as inhibiting our ability to compete in the
marketplace and absorbing significant management time.

Due to the uncertainties regarding biotechnology patents, we also have relied and will continue to rely upon

trade secrets, know-how and continuing technological advancement to develop and maintain our competitive
position. All of our employees have signed confidentiality agreements under which they have agreed not to use
or disclose any of our proprietary information. Research and development contracts and relationships between us
and our scientific consultants and potential customers provide access to aspects of our know-how that are
protected generally under confidentiality agreements. These confidentiality agreements may be breached or may

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not be enforced by a court. To the extent proprietary information is divulged to competitors or to the public
generally, such disclosure may affect our ability to develop or commercialize our products adversely by giving
others a competitive advantage or by undermining our patent position.

Litigation regarding intellectual property can be costly and expose us to risks of counterclaims against us.

We may be required to engage in litigation or other proceedings to protect our intellectual property. The cost

to us of this litigation, even if resolved in our favor, could be substantial. Such litigation also could divert
management’s attention and resources. In addition, if this litigation is resolved against us, our patents may be
declared invalid, and we could be held liable for significant damages. In addition, we may be subject to a claim
that we are infringing another party’s patent. If such claim is resolved against us, we or our collaborators may be
enjoined from developing, manufacturing, selling or importing products, processes or services unless we obtain a
license from the other party.

Such license may not be available on reasonable terms, thus preventing us from using these products,

processes or services and adversely affecting our revenue.

We may be unable to price our products effectively or obtain adequate reimbursement for sales of our
products, which would prevent our products from becoming profitable.

If we or our third-party collaborators or licensees succeed in bringing our product candidates to the market,
they may not be considered cost effective, and reimbursement to the patient may not be available or may not be
sufficient to allow us to sell our products on a competitive basis. In both the United States and elsewhere, sales of
medical products and treatments are dependent, in part, on the availability of reimbursement to the patient from
third-party payors, such as government and private insurance plans. Third-party payors are increasingly
challenging the prices charged for pharmaceutical products and services. Our business is affected by the efforts
of government and third-party payors to contain or reduce the cost of healthcare through various means. In the
United States, there have been and will continue to be a number of federal and state proposals to implement
government controls on pricing.

In addition, the emphasis on managed care in the United States has increased and will continue to increase
the pressure on the pricing of pharmaceutical products. We cannot predict whether any legislative or regulatory
proposals will be adopted or the effect these proposals or managed care efforts may have on our business.

Healthcare reform measures and other statutory or regulatory changes could adversely affect our
business.

In both the United States and certain foreign jurisdictions, there have been a number of legislative and
regulatory proposals to change the healthcare system in ways that could impact our business . In March 2010, the
U.S. Congress enacted and President Obama signed into law the Patient Protection and Affordable Care Act, as
amended by the Health Care and Education Affordability Reconciliation Act (collectively, “PPACA”), which
includes a number of healthcare reform provisions. The reforms imposed by the law are expected to impact the
pharmaceutical industry significantly, most likely in the area of pharmaceutical product pricing. While the law
may increase the number of patients who have insurance coverage for our products or product candidates, its cost
containment measures also could adversely affect reimbursement for our existing or potential products; however,
the full effects of this law cannot be known until these provisions are implemented and the relevant Federal and
state agencies issue applicable regulations or guidance.

The pharmaceutical and biotechnology industries are subject to extensive regulation, and from time to time

legislative bodies and governmental agencies consider changes to such regulations that could have significant
impact on industry participants. For example, in light of certain highly publicized safety issues regarding certain
drugs that had received marketing approval, the U.S. Congress has considered various proposals regarding drug
safety, including some that would require additional safety studies and monitoring and could make drug

44

development more costly. We are unable to predict what additional legislation or regulation, if any, relating to
safety or other aspects of drug development may be enacted in the future or what effect such legislation or
regulation would have on our business.

Beginning in 2013, the PPACA also imposes new reporting and disclosure requirements on pharmaceutical
manufacturers for payments to healthcare providers and ownership of their stock by healthcare providers. Failure
to submit required information may result in civil monetary penalties of up to an aggregate of $150,000 per year
(or up to an aggregate of $1 million per year for “knowing failures”), for all payments, transfers of value or
ownership or investment interests not reported in an annual submission. On December 14, 2011, CMS released
its proposed rule implementing these provisions, providing further clarification to ambiguous or unclear statutory
language and providing instructions for manufacturers to comply with such requirements. CMS has not issued a
final rule to date.

The business and financial condition of pharmaceutical and biotechnology companies also are affected by

the efforts of governments, third-party payors and others to contain or reduce the costs of healthcare to
consumers. In the United States and various foreign jurisdictions there have been, and we expect there will
continue to be, a number of legislative and regulatory proposals aimed at changing the healthcare system, such as
proposals relating to the reimportation of drugs into the United States from other countries (where they are then
sold at a lower price) and government control of prescription drug pricing. We expect current health care reform
measures, such as PPACA, and those that may be adopted in the future could result in a decrease in the share
price of our common stock, limit our ability to raise capital or to obtain strategic collaborations or licenses or
successfully commercialize our products.

We are exposed to an increased risk of product liability claims, and a series of related cases is currently
pending against us.

The testing, marketing and sales of medical products entails an inherent risk of allegations of product
liability. We have been party to a number of product liability claims filed against Genentech Inc., and even
though Genentech has agreed to indemnify us in connection with these matters, there can be no assurance these
or other products liability lawsuits will not result in liability to us or that our insurance or contractual
arrangements will provide us with adequate protection against such liabilities. In the event of one or more large,
unforeseen awards of damages against us, our product liability insurance may not provide adequate coverage. A
significant product liability claim for which we were not covered by insurance or indemnified by a third party
would have to be paid from cash or other assets, which could have an adverse effect on our business and the
value of our common stock. To the extent we have sufficient insurance coverage, such a claim would result in
higher subsequent insurance rates. In addition, product liability claims can have various other ramifications,
including loss of future sales opportunities, increased costs associated with replacing products, a negative impact
on our goodwill and reputation, and divert our management’s attention from our business, each of which could
also adversely affect our business and operating results.

The loss of key personnel, including our Chief Executive Officer, could delay or prevent achieving our
objectives.

Our research, product development and business efforts could be affected adversely by the loss of one or
more key members of our scientific or management staff, particularly our executive officers: John Varian, our
Chief Executive Officer; Patrick J. Scannon, M.D., Ph.D., our Executive Vice President and Chief Scientific
Officer; Fred Kurland, our Vice President, Finance, Chief Financial Officer and Secretary; and Paul D. Rubin,
M.D., our Senior Vice President, Research and Development and Chief Medical Officer. We currently do not
have key person insurance on any of our employees.

Our ability to use our net operating loss carry-forwards and other tax attributes will be substantially
limited by Section 382 of the U.S. Internal Revenue Code.

Section 382 of the U.S. Internal Revenue Code of 1986, as amended, generally limits the ability of a
corporation that undergoes an “ownership change” to utilize its net operating loss carry-forwards (“NOLs”) and

45

certain other tax attributes against any taxable income in taxable periods after the ownership change. The amount
of taxable income in each taxable year after the ownership change that may be offset by pre-change NOLs and
certain other pre-change tax attributes is generally equal to the product of (a) the fair market value of the
corporation’s outstanding shares (or, in the case of a foreign corporation, the fair market value of items treated as
connected with the conduct of a trade or business in the United States) immediately prior to the ownership
change and (b) the long-term tax exempt rate (i.e., a rate of interest established by the U.S. Internal Revenue
Service (“IRS”) that fluctuates from month to month). In general, an “ownership change” occurs whenever the
percentage of the shares of a corporation owned, directly or indirectly, by “5-percent shareholders” (within the
meaning of Section 382 of the Internal Revenue Code) increases by more than 50 percentage points over the
lowest percentage of the shares of such corporation owned, directly or indirectly, by such “5-percent
shareholders” at any time over the preceding three years.

Based on an analysis under Section 382 of the Internal Revenue Code (which subjects the amount of pre-

change NOLs and certain other pre-change tax attributes that can be utilized to an annual limitation), the
Company experienced ownership changes in 2009 and 2012 which substantially limit the future use of our pre-
change NOLs and certain other pre-change tax attributes per year. As of December 31, 2012, the Company has
excluded the NOLs and R&D credits that will expire as a result of the annual limitations (See Note 8: Income
Taxes in the Notes to the financial statements). To the extent that the Company does not utilize its carry-forwards
within the applicable statutory carry-forward periods, either because of Section 382 limitations or the lack of
sufficient taxable income, the carry-forwards will also expire unused.

We may not realize the expected benefits of our initiatives to reduce costs across our operations, and we
may incur significant charges or write-downs as part of these efforts.

We have pursued and may continue to pursue a number of initiatives to reduce costs of our operations. In

January 2012, we implemented a workforce reduction of approximately 34% to improve our cost structure. This
workforce reduction resulted primarily from our decisions to utilize a contract manufacturing organization for
Phase 3 and commercial antibody production and to eliminate internal research functions that are non-
differentiating or that can be obtained cost effectively by contract service providers. During the year ended
December 31, 2012, as a result of our streamlining of operations, we incurred restructuring and related severance
costs totaling approximately $5.1 million, of which $2.2 million were cash charges.

We may not realize some or all of the expected benefits of our current and future initiatives to reduce costs.
In addition to restructuring or other charges, we may experience disruptions in our operations as a result of these
initiatives.

Because we are a relatively small biopharmaceutical company with limited resources, we may not be able
to attract and retain qualified personnel.

Our success in developing marketable products and achieving a competitive position will depend, in part, on

our ability to attract and retain qualified scientific and management personnel, particularly in areas requiring
specific technical, scientific or medical expertise. We had approximately 166 employees as of March 8, 2013.
We may require additional experienced executive, accounting, research and development, legal, administrative
and other personnel from time to time in the future. There is intense competition for the services of these
personnel, especially in California. Moreover, we expect that the high cost of living in the San Francisco Bay
Area, where our headquarters and manufacturing facilities are located, may impair our ability to attract and retain
employees in the future. If we do not succeed in attracting new personnel and retaining and motivating existing
personnel, our operations may suffer and we may be unable to implement our current initiatives or grow
effectively.

Global credit and financial market conditions may reduce our ability to access and maintain capital for
our operations.

Traditionally, we have funded a large portion of our research and development expenditures through raising

capital in the equity markets. Recent events, including failures and bankruptcies among large commercial and

46

investment banks, have led to considerable declines and uncertainties in these and other capital markets and have
led to new regulatory and other restrictions that may have broad effect on the nature of these markets. These
circumstances could severely restrict the ability to raise new capital by companies such as us in the future.

Volatility in the financial markets also has created liquidity problems in investments previously thought to

bear a minimal risk. For example, money market fund investors, including us, have in the past been unable to
retrieve the full amount of funds, even in highly rated liquid money market accounts, upon maturity. Although as
of December 31, 2012, we have received the full amount of proceeds from money market fund investments, an
inability to retrieve funds from money market fund investments as they mature in the future could have a material
and adverse impact on our business, results of operations and cash flows.

Our cash and cash equivalents are maintained in highly liquid investments with remaining maturities of 90

days or less at the time of purchase. While we are not aware of any downgrades, material losses, or other
significant deterioration in the fair value of our cash equivalents since December 31, 2012, no assurance can be
given that further deterioration in conditions of the global credit and financial markets would not impact our
current portfolio of cash equivalents negatively or our ability to meet our financing objectives.

Our business and operations would suffer in the event of system failures.

Despite the implementation of security measures, our internal computer systems and those of our current

and any future collaborators, licensees, suppliers, contractors and consultants are vulnerable to damage from
cyber-attacks, computer viruses, unauthorized access, natural disasters, terrorism, war and telecommunication
and electrical failures. We could experience failures in our information systems and computer servers, which
could be the result of a cyber-attack and 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 interruptions in our operations and can result in a material disruption of our
development programs, commercialization activities and other business operations. The loss of clinical trial data
from completed or future clinical trials could result in delays in our regulatory approval efforts and significantly
increase our costs to recover or reproduce the data. Similarly, we rely on third parties to supply components for
and manufacture our product and product candidates, conduct clinical trials of our product candidates and
warehouse and distribute ACEON, 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 liability and the development of gevokizumab, FDC1 or any of our other product
candidates and the commercialization of ACEON could be delayed or otherwise adversely affected.

Calamities, power shortages or power interruptions at our Berkeley headquarters and manufacturing
facility could disrupt our business and adversely affect our operations.

Our principal operations are located in Northern California, including our corporate headquarters and

manufacturing facility in Berkeley, California. This location is in an area of seismic activity near active
earthquake faults. Any earthquake, terrorist attack, fire, power shortage or other calamity affecting our facilities
may disrupt our business and could have material adverse effect on our business and results of operations.

We have a significant stockholder, which may limit other stockholders’ ability to influence corporate
matters and may give rise to conflicts of interest.

Entities controlled by Felix J. Baker and Julian C. Baker beneficially own approximately 30.8% of our
outstanding common stock as of March 8, 2013, which includes warrants to purchase approximately 7.6 million
shares of XOMA’s common stock at an exercise price of $1.76 per share. On July 19, 2012, our Board of
Directors elected Kelvin Neu, M.D., to serve on our Board of Directors. Dr. Neu is a Managing Director at Baker
Bros. Advisors, LLC, an entity controlled by Felix J. Baker and Julian C. Baker. Accordingly, these entities may
exert significant influence over us and any action requiring the approval of the holders of our stock, including the
election of directors and approval of significant corporate transactions. Furthermore, conflicts of interest could

47

arise in the future between us, on the one hand, and these entities, on the other hand, concerning potential
competitive business activities, business opportunities, the issuance of additional securities and other matters.

Our organizational documents contain provisions that may prevent transactions that could be beneficial to
our stockholders and may insulate our management from removal.

Our charter and by-laws:

•

•

require certain procedures to be followed and time periods to be met for any stockholder to propose
matters to be considered at annual meetings of stockholders, including nominating directors for
election at those meetings; and

authorize our Board of Directors to issue up to 1,000,000 shares of preferred stock without stockholder
approval and to set the rights, preferences and other designations, including voting rights, of those
shares as the Board of Directors may determine.

In addition, we are subject to the provisions of Section 203 of the Delaware General Corporation Law (the

“DGCL”), that may prohibit large stockholders, in particular those owning 15% or more of our outstanding
common stock, from merging or combining with us.

These provisions of our organizational documents and the DGCL, alone or in combination with each other,

may discourage transactions involving actual or potential changes of control, including transactions that
otherwise could involve payment of a premium over prevailing market prices to holders of common stock, could
limit the ability of stockholders to approve transactions that they may deem to be in their best interests, and could
make it considerably more difficult for a potential acquirer to replace management.

Item 1B. Unresolved Staff Comments

None.

Item 2.

Properties

Our corporate headquarters and development and manufacturing facilities are located in Berkeley and

Emeryville, California. We currently lease five buildings, two of which have a sublease tenant under contract
through April 2013. We also lease space in a sixth building, for which we have a sublease tenant under contract
through May 2014. These buildings house our research and development laboratories, manufacturing facilities
and office space. A separate pilot scale manufacturing facility is owned by us. Our building leases expire in the
period from 2013 to 2014 and total minimum lease payments due from January 2013 until expiration of the
leases are $4.3 million. We have the option to renew our lease agreements for periods ranging from three to ten
years.

Item 3.

Legal Proceedings

On April 8, 2011, four complaints were filed in the United States District Court for the Eastern District of

Michigan. The cases are captioned: Muniz v. Genentech, et al., 5:11-cv-11489-JCO-RSW; Tifenthal v.
Genentech, et al., 2:11-cv-11488-DPH-LJM; Blair v. Genentech, et al., 2:11-cv-11463-SFC-MJH; and Marsh v.
Genentech, et al., 2:11-cv-11462-RHC-MKM. The complaints alleged claims against Genentech and us
(“Defendants”) for alleged strict liability failure to warn, negligence, breach of warranty, and fraud by
concealment based on injuries alleged to have occurred as a result of the plaintiffs’ treatment with RAPTIVA®.
The complaints sought unspecified compensatory and punitive damages. All four cases were transferred to the
United States District Court for the Western District of Michigan. On October 26, 2011, the Court granted the
Motions to Dismiss filed by Defendants in all four actions. On September 6, 2012, the 6th Circuit Court of
Appeals affirmed the judgment in favor of Defendants and, on October 12, 2012, denied a petition for en banc
rehearing. The deadline for seeking appellate review by the United States Supreme Court has expired.

48

On June 13, 2011, a complaint was filed in the Supreme Court for the State of New York, Onondaga
County. The case is captioned: McConnell v. Genentech, et al., 5:11-cv-1309-GLS-DEP. Defendants removed
the case to the United States District Court for the Northern District of New York on November 3, 2011. The
complaint asserted claims against the Defendants for alleged strict liability defective design and manufacture,
strict liability failure to warn, negligence, breach of warranty, and loss of consortium based on injuries alleged to
have occurred as a result of the plaintiff’s treatment with RAPTIVA®. The complaint sought unspecified
compensatory and punitive damages. On December 21, 2012, the case was dismissed with prejudice pursuant to a
settlement agreement.

Item 4. Mine Safety Disclosures

Not applicable.

Supplementary Item: Executive Officers of the Registrant

Our executive officers and their respective ages, as of December 31, 2012, and positions are as follows:

Name

John Varian

Age Title

53 Chief Executive Officer

Patrick J. Scannon, M.D., Ph.D.

65 Executive Vice President and Chief Scientific Officer

Paul D. Rubin, M.D.

59

Senior Vice President, Research and Development and
Chief Medical Officer

Fred Kurland

62 Vice President, Finance, Chief Financial Officer, and

Secretary

The Board of Directors elects all officers annually. There is no family relationship between or among any of

the officers or directors.

Business Experience

John Varian was appointed Chief Executive Officer of XOMA in January 2012 after serving as Interim
Chief Executive Officer since August 31, 2011. He has served as a XOMA director since December 2008. He
was Chief Operating Officer of Aryx Therapeutics from December 2003 through August 2011 and was its Chief
Financial Officer from April 2006 through March 2011. Previously, Mr. Varian was Chief Financial Officer of
Genset S.A., where he was a key member of the team negotiating the company’s sale to Serono S.A. in 2002.
From October 1998 to April 2000, Mr. Varian served as Senior Vice President, Finance and Administration of
Elan Pharmaceuticals, Inc., joining the company as part of its acquisition of Neurex Corporation. Prior to the
acquisition, he served as Neurex Corporation’s Chief Financial Officer from June 1997 until October 1998. From
1991 until 1997, Mr. Varian served as the Vice President Finance and Chief Financial Officer of Anergen Inc.
Mr. Varian was an Audit Principal / Senior Manager at Ernst & Young from 1987 until 1991 where he focused
on life sciences. He is a founding member of the Bay Area Bioscience Center and a former chairman of the
Association of Bioscience Financial Officers International Conference. Mr. Varian received a B.B.A. degree
from Western Michigan University.

Dr. Scannon is one of our founders and has served as a Director since our formation. Dr. Scannon became
Executive Vice President and Chief Scientific Officer in February 2011. Previously he was our Executive Vice
President and Chief Medical Officer beginning in March 2009 and served as Executive Vice President and Chief
Biotechnology Officer from May 2006 until March 2009, Chief Scientific and Medical Officer from March 1993
until May 2006, Vice Chairman, Scientific and Medical Affairs from April 1992 to March 1993 and our
President from our formation until April 1992. In 2007, Dr. Scannon was invited to join the newly formed
National Biodefense Science Board, reporting to the Secretary for the Department of Health and Human
Services. In 2007, he also became a member of the Board of Directors for Pain Therapeutics, Inc, a
biopharmaceutical company. He serves on the Defense Sciences Research Council for the Defense Advanced
Research Projects Agency (DARPA) and on the Threat Reduction Advisory Committee for the Department of

49

Defense. From 1979 until 1981, Dr. Scannon was a clinical research scientist at the Letterman Army Institute of
Research in San Francisco. A Board-certified internist, Dr. Scannon holds a Ph.D. in organic chemistry from the
University of California, Berkeley and an M.D. from the Medical College of Georgia.

Dr. Rubin is our Senior Vice President, Research and Development and Chief Medical Officer. Dr. Rubin

joined the Company in June 2011. Prior to joining XOMA, Dr. Rubin was Chief Medical Officer at Funxional
Therapeutics Ltd. He was Chief Executive Officer of Resolvyx Pharmaceuticals, Inc. from 2007 to 2009 and
President and Chief Executive Officer of Critical Therapeutics, Inc. from 2002 to 2007. From 1996 to 2002,
Dr. Rubin served as Senior Vice President, Development, and later as Executive Vice President, Research &
Development at Sepracor. He was responsible for the successful development of all of Sepracor’s internally
developed approved products including Xopenex®, Lunesta®, Xopenex HFA® and Brovana®. From 1993 to
1996, Dr. Rubin held senior level positions at Glaxo—Wellcome Pharmaceuticals, most recently as Vice
President of Worldwide Clinical Pharmacology and Early Clinical Development. During his tenure with Abbott
from 1987 to 1993, Dr. Rubin served as Vice President, Immunology and Endocrinology, where he successfully
advanced zilueton, the first 5-lipoxygenase inhibitor, from discovery to approval for the treatment of asthma.
Dr. Rubin received a BA from Occidental College and his M.D. from Rush Medical College. He completed his
training in internal medicine at the University of Wisconsin.

Mr. Kurland is our Vice President, Finance, Chief Financial Officer, and Secretary. He joined XOMA on

December 29, 2008. Mr. Kurland is responsible for directing the Company’s financial strategy, accounting,
financial planning and investor relations functions. He has more than 30 years of experience in biotechnology
and pharmaceutical companies including Aviron/MedImmune, Protein Design Labs and Syntex/Roche. Prior to
joining XOMA, Mr. Kurland served as Chief Financial Officer of Bayhill Therapeutics, Inc., Corcept
Therapeutics Incorporated and Genitope Corporation. From 1998 to 2002, Mr. Kurland served as Senior Vice
President and Chief Financial Officer of Aviron, acquired by MedImmune in 2001 and developer of FluMist.
From 1996 to 1998, he was Vice President and Chief Financial Officer of Protein Design Labs, Inc., an antibody
design company, and from 1995 to 1996, he served as Vice President and Chief Financial Officer of Applied
Immune Sciences, Inc. Mr. Kurland also held a number of financial management positions at Syntex
Corporation, a pharmaceutical company acquired by Roche, including Vice President and Controller between
1991 and 1995. He received his J.D. and M.B.A. degrees from the University of Chicago and his B.S. degree
from Lehigh University.

50

PART II

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

Equity Securities

Market for Registrant’s Common Equity

Our common stock trades on The NASDAQ Global Market under the symbol “ XOMA .” All references to

numbers of shares of common stock and per-share information in this Annual Report have been adjusted
retroactively to reflect the Company’s reverse stock split effective August of 2010. The following table sets forth
the quarterly range of high and low reported sale prices of our common stock on The NASDAQ Global Market
for the periods indicated:

2012
First Quarter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Second Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fourth Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2011
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First Quarter
Second Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fourth Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Price Range

High

Low

$2.93
$3.24
$4.13
$3.78

$7.71
$3.49
$2.45
$1.86

$1.12
$2.22
$2.91
$2.37

$2.77
$2.17
$1.38
$1.04

On March 8, 2013, there were 822 stockholders of record of our common stock, one of which was Cede &

Co., a nominee for Depository Trust Company (“DTC”). All of the shares of our common stock held by
brokerage firms, banks and other financial institutions as nominees for beneficial owners are deposited into
participant accounts at DTC and are therefore considered to be held of record by Cede & Co. as one stockholder.

Dividend Policy

We have not paid dividends on our common stock. We currently intend to retain any earnings for use in the

development and expansion of our business. We, therefore, do not anticipate paying cash dividends on our
common stock in the foreseeable future.

51

Performance Graph

The following graph compares the five-year cumulative total stockholder return for XOMA common stock
with the comparable cumulative return of certain indices. The graph assumes $100 invested on the same date in
each of the indices. Returns of the company are not indicative of future performance.

FIVE-YEAR PERFORMANCE GRAPH

s
r
a
l
l

o
D

.

.

S
U

225

200

175

150

125

100

75

50

25

0

2007

2008

2009

2010

2011

2012

XOMA Corporation

Nasdaq Composite Index

AMEX Biotechnology Index

As of December 31,

XOMA Corporation

Nasdaq
Composite Index

AMEX
Biotechnology Index

2007
2008
2009
2010
2011
2012

12/31/2007
12/31/2008
12/31/2009
12/31/2010
12/31/2011
12/31/2012

$100.00
18.29
20.65
10.09
2.26
4.72

Close Price
50.85
9.30
10.50
5.13
1.15
2.40

$100.00
59.46
85.55
100.02
98.22
113.85

2,652.28
1,577.03
2,269.15
2,652.87
2,605.15
3,019.51

$100.00
82.28
119.79
164.99
138.77
196.70

786.50
647.17
942.13
1,297.63
1,091.42
1,547.03

52

 
Item 6.

Selected Financial Data

The following table contains our selected financial information including consolidated statement of

operations and consolidated balance sheet data for the years 2008 through 2012. The selected financial
information has been derived from our audited consolidated financial statements. The selected financial
information should be read in conjunction with Item 8: Financial Statements and Supplementary Data and
Item 7: Management’s Discussion and Analysis of Financial Condition and Results of Operations included in
this Annual Report. The data set forth below is not necessarily indicative of the results of future operations.

Year Ended December 31,

2012

2011

2010

2009

2008

(In thousands, except per share amounts)

Consolidated Statement of Operations Data
Total revenues (1) . . . . . . . . . . . . . . . . . . . . . . . . .
Total operating costs and expenses . . . . . . . . . . . .
Restructuring costs . . . . . . . . . . . . . . . . . . . . . . . .

$ 33,782
85,332
5,074

$ 58,196
92,151
—

$ 33,641
100,663
82

$ 98,430
81,867
3,603

$ 67,987
106,721
—

(Loss) income from operations . . . . . . . . . . . . . . .
Other (expense) income, net (2) . . . . . . . . . . . . . .

Net (loss) income before taxes . . . . . . . . . . . . . . .
Income tax (benefit) expense, net (3) . . . . . . . . . .

(56,624)
(14,515)

(71,139)
(74)

(33,955)
1,227

(32,728)
15

(67,104)
(1,625)

(68,729)
27

12,960
(6,683)

6,277
5,727

(38,734)
(6,894)

(45,628)
(383)

Net (loss) income . . . . . . . . . . . . . . . . . . . . . . . . . .

$ (71,065) $ (32,743) $ (68,756) $

550

$ (45,245)

Basic and diluted net (loss) income per share of

common stock . . . . . . . . . . . . . . . . . . . . . . . . . .

$

(1.10) $

(1.04) $

(3.69) $

0.05

$

(5.11)

Balance Sheet Data
Cash and cash equivalents . . . . . . . . . . . . . . . . . . .
Short-term investments . . . . . . . . . . . . . . . . . . . . .
Restricted cash . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Working capital . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . .
Long-term liabilities (4)
. . . . . . . . . . . . . . . . . . . .
Redeemable convertible preferred stock, at par

value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated deficit . . . . . . . . . . . . . . . . . . . . . . . .
Total stockholders’ equity (net capital

2012

2011

2010

2009

2008

December 31,

$ 45,345
39,987
—
95,837
72,004
105,676
23,833
60,376

$ 48,344
—
—
62,695
42,064
78,036
20,631
42,394

(In thousands)

$ 37,304

$ 23,909

$

—
—
58,880
23,352
74,252
35,528
15,133

—
—
32,152
13,474
52,824
18,678
16,620

9,513
1,299
9,545
38,704
11,712
67,173
26,992
71,582

—

—

(957,118)

(886,053)

1
(853,310)

1
(784,554)

1
(785,104)

deficiency) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21,467

15,011

23,591

17,526

(31,401)

We have paid no dividends in the past five years.

(1) 2010 includes a non-recurring fee of $4.0 million related to the sale of our CIMZIA ® royalty interest to an
undisclosed buyer. 2009 includes a non-recurring fee of $25 million related to the sale of our LUCENTIS ®
royalty interest to Genentech, Inc., a member of the Roche Group (“Genentech”). 2008 includes a non-
recurring fee from Novartis AG (“Novartis”) of $13.7 million relating to a restructuring of the existing
collaboration agreement.

(2) 2012 includes a $9.5 million revaluation of contingent warrant liabilities issued in connection of an equity
financing in March 2012. 2010 includes a loss associated with the $4.5 million paid in the first quarter of
2010 to the holders of warrants issued in June 2009, upon modification of the terms.

53

(3) 2009 includes foreign income tax expense of $5.8 million recognized in connection with the expansion of

our existing collaboration with Takeda.

(4) 2012 includes $15.0 million of contingent warrant liabilities in connection with an equity financing in

March 2012. The balance in 2012 and 2011 includes a 15.0 million loan from Servier, which had a principal
balance equal to approximately $19.8 million and $19.4 million as of December 31, 2012 and 2011,
respectively, and a Term Loan from GECC, which had a principal balance equal to $12.5 million and $10.0
million as of December 31, 2012 and 2011, respectively. The balance as of December 31, 2008 includes
$50.4 million from our term loan with Goldman Sachs, which we repaid in 2009. In addition, the
outstanding principal on our Novartis note was reduced by $7.5 million due to the restructure of our
collaboration with Novartis.

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

Overview

We are a leader in the discovery and development of innovative antibody-based therapeutics. Our lead drug

candidate, gevokizumab (formerly XOMA 052), is a potent humanized monoclonal antibody with unique
allosteric modulating properties. Gevokizumab binds to the inflammatory cytokine interleukin-1 beta (“IL-1
beta”), which is believed to be a primary trigger of pathologic inflammation in multiple diseases. We have
entered into a license and collaboration agreement with Les Laboratoires Servier (“Servier”) to develop and
commercialize gevokizumab in multiple indications. In collaboration with Servier we have launched the global
Phase 3 gevokizumab clinical development program for active and controlled non-infectious uveitis (“NIU”)
involving the intermediate and/or posterior segment of the eye, and Behçet’s uveitis. XOMA is conducting both
of the NIU studies, and Servier is sponsoring the study in Behçet’s uveitis. The study sites are screening and
enrolling patients in these distinct studies.

Separately, we launched a Phase 2 proof-of-concept program for gevokizumab to evaluate additional

indications for further development, including a clinical trial in moderate-to-severe inflammatory acne, for which
we reported encouraging preliminary top-line results in January 2013, a clinical trial in erosive osteoarthritis of
the hand, which was opened for enrollment in June 2012, and a clinical trial in scleritis that will be conducted by
the National Eye Institute (“NEI”), a part of the U.S. National Institutes of Health (“NIH”). We anticipate the
NEI will begin screening patients in this study during the first quarter of 2013. Servier is expected to institute its
own proof-of-concept program for gevokizumab in different indications from ours. In November 2012, Servier
began a Phase 2 study to determine gevokizumab’s potential to treat patients who have experienced a recent
Acute Coronary Syndrome.

Our proprietary preclinical pipeline includes classes of antibodies that activate, sensitize, or deactivate the

insulin receptor in vivo , that we have named XMet. This portfolio of antibodies represents potential new
therapeutic approaches to the treatment of diabetes and several diseases that have insulin involvement, which we
believe may be orphan drug opportunities.

We have developed these and other antibodies using some or all of our ADAPT™ antibody discovery and
development platform, our ModulX™ technologies for generating allosterically modulating antibodies, and our
OptimX™ technologies for optimizing biophysical properties of antibodies, including affinity, immunogenicity,
stability and manufacturability.

Our biodefense initiatives include XOMA 3AB, a biodefense anti-botulism product candidate comprised of

a combination of three antibodies. XOMA 3AB is directed against botulinum toxin serotype A and has been
developed through funding from the National Institute of Allergy and Infectious Diseases (“NIAID”), a part of
the NIH. All volunteers have been enrolled and dosed with XOMA 3AB in a Phase 1 clinical trial sponsored by
NIAID. In January 2012, we announced we will complete NIAID biodefense contracts currently in place but will
not actively pursue future contracts. Should the government choose to acquire XOMA 3AB or other biodefense
products in the future, we expect to be able to produce these antibodies through an outside manufacturer.

54

We also have developed antibody product candidates with premier pharmaceutical companies including
Novartis AG (“Novartis”) and Takeda Pharmaceutical Company Limited (“Takeda”). Two antibodies developed
with Novartis, LFA102 and HCD122 (lucatumumab), are in Phase 1 and/or Phase 2 clinical development by
Novartis for the potential treatment of breast or prostate cancer and hematological malignancies, respectively.

In January 2012, we announced we had acquired certain U.S. rights to a portfolio of antihypertensive
products from Servier. The portfolio includes ACEON (perindopril erbumine), a currently marketed angiotensin
converting enzyme (“ACE”) inhibitor, and three fixed-dose combination (“FDC”) product candidates where
perindopril is combined with another active ingredient(s). The last to expire proprietary form of perindopril in
each FDC product candidate provides patent protection until April 2023. We assumed commercialization
activities for ACEON in January 2012. In November 2012, we announced the 837—patient Phase 3 trial for the
FDC of perindopril arginine and amlodipine besylate (“FDC1”) met its primary endpoint. Partial funding for the
trial was provided by Servier. We expect to pay the balance of study expenses, consisting primarily of costs
generated by our contract research organization, from the profits generated by our ACEON sales. We are
working to identify a third-party organization that could sublicense this FDC and move it forward toward
commercialization in the U.S. market.

Significant Developments in 2012

Gevokizumab

•

•

•

•

•

In June 2012, we initiated enrollment in a global Phase 3 study investigating the ability of
gevokizumab to reduce the signs and symptoms, including vitreous haze, in patients with NIU
involving the intermediate and/or posterior segment of the eye. The study is titled A randomizEd,
double-masked, placebo-controlled studY of the safety and Efficacy of GevokizUmAb in the
tReatment of subjects with active non-infectious intermeDiate, posterior or pan-uveitis
(EYEGUARD™-A). We intend to enroll patients with active non-infectious intermediate, posterior, or
pan-uveitis with a vitreous haze score equal to or greater than 2+ on the Standardization of Uveitis
Nomenclature / NEI scale in at least one eye. They will be randomized to receive either one of two
monthly doses of gevokizumab or placebo. The study’s primary endpoint is the proportion of patients
demonstrating a significant reduction in vitreous haze score on Day 56.

In June 2012, we initiated a Phase 2 proof-of-concept study to evaluate the efficacy and safety of
gevokizumab for the treatment of active inflammatory, EOA of the hand. Approximately 90 patients
will be randomized to receive gevokizumab or placebo. The study is designed and powered to detect a
significant improvement from baseline versus placebo in the mean Australian/Canadian Hand
Osteoarthritis Index pain score in the target hand at three months.

In August 2012, we and Servier entered into an agreement with Boehringer Ingelheim to transfer our
technology and process for the commercial manufacture of gevokizumab. Upon completion of the
transfer and the establishment of biological comparability, we expect Boehringer Ingelheim to produce
gevokizumab at its facility in Biberach, Germany, for our commercial use and use in Phase 3 clinical
trials. We and Servier retain all rights to the development and commercialization of gevokizumab.

In August 2012, we obtained FDA orphan drug status for gevokizumab in the treatment of non-
infectious intermediate, posterior, or pan-uveitis, or chronic non-infectious anterior uveitis.

In September 2012, we announced Servier had received authorization to initiate the Servier-sponsored
Behçet’s uveitis Phase 3 clinical trial in several European countries. The study is titled A randomizEd,
double-masked, placebo-controlled studY of the Efficacy of GevokizUmAb in the tReatment of
patients with Behçet’s Disease uveitis (EYEGUARD™-B). The objective of this study is to evaluate
the efficacy of gevokizumab as compared to placebo on top of current standard of care
(immunosuppressive therapy and oral corticosteroids) in reducing the risk of Behçet’s disease uveitis
exacerbations and to assess the safety of gevokizumab.

55

•

In October 2012, we announced we had opened enrollment in a Phase 3 clinical trial, titled A
randomizEd, double-masked, placebo-controlled study of the safetY and Efficacy of GevokizUmAb in
the tReatment of subjects with non-infectious intermeDiate, posterior or pan-uveitis currently
controlled with systemic treatment (EYEGUARD™-C), to determine gevokizumab’s potential to
reduce the risk of recurrent uveitic disease in patients with non-infectious intermediate, posterior, or
pan-uveitis. We intend to enroll patients with NIU who have experienced active uveitic disease but
whose disease currently is controlled with oral corticosteroids with or without immunosuppressive
medications. The study’s primary endpoint is the proportion of patients with an occurrence of uveitic
disease through Day 168. The study also will assess other important measures of improvement in their
uveitic disease including the reduction of steroid use.

•

In November 2012, we announced Servier had begun a Phase 2 study to determine gevokizumab’s
potential to treat patients who have experienced a recent Acute Coronary Syndrome.

Streamlining and Restructuring Charges

•

On January 5, 2012, we implemented a streamlining of operations, which resulted in a restructuring
designed to sharpen our focus on value-creating opportunities led by gevokizumab and our unique
antibody discovery and development capabilities. The restructuring plan included a reduction of our
personnel by 84 positions, or 34%, of which 52 were eliminated immediately, and the remainder
eliminated as of April 6, 2012. These staff reductions resulted primarily from our decisions to utilize a
contract manufacturing organization for Phase 3 and commercial antibody production and to eliminate
internal research functions that are non-differentiating or that can be obtained cost effectively by
contract service providers. As a result, we realized approximately a $17.0 million reduction in internal
expense reflecting streamlined operations to focus exclusively on value-creating activities. In
connection with the streamlining of operations, we incurred restructuring charges in 2012 of $2.0
million related to severance, other termination benefits and outplacement services, $2.5 million related
to the impairment and accelerated depreciation of various assets and leasehold improvements, and
$0.6 million related to moving and other facility charges.

Perindopril Franchise

•

•

On January 17, 2012, we announced we had acquired certain U.S. rights to a portfolio of
antihypertensive products from Servier. The portfolio includes ACEON, a currently marketed ACE
inhibitor, and three FDC product candidates where a proprietary form of perindopril (perindopril
arginine) is combined with other active ingredient(s). We assumed commercialization activities for
ACEON in January 2012 following the license transfer from Servier’s previous licensee and began
shipping XOMA-labeled ACEON to pharmaceutical wholesalers in the second quarter of 2012.

In February 2012, we initiated enrollment in a Phase 3 trial for FDC1. The trial enrolled approximately
837 patients with hypertension and completed in November 2012. The study results showed FDC1 met
its primary endpoint, demonstrating statistically superior reductions in sitting systolic and diastolic
blood pressure after six weeks of treatment than either compound alone. Partial funding for the trial
was provided by Servier; the balance of study expenses, consisting primarily of costs generated by our
contract research organization, we expect to pay over time from the profits generated by our ACEON
sales. We are working to identify a third-party organization that can sublicense this FDC and move it
forward toward commercialization in the U.S. market.

Management Change

•

On January 4, 2012, the Company’s Board of Directors appointed John Varian, a current Board
member and then interim Chief Executive Officer, as Chief Executive Officer. W. Denman Van Ness
continues to serve as Chairman of the Board.

56

•

•

In April 2012, the Company announced that it had integrated all research, preclinical and clinical
development activities under the leadership of Paul Rubin, MD. To reflect Dr. Rubin’s expanded role,
the Company promoted him to the role of Senior Vice President, Research and Development.
Dr. Rubin maintains his responsibilities as XOMA’s Chief Medical Officer.

Effective August 31, 2012, the Company’s Board of Directors accepted the retirement of Christopher J.
Margolin as Vice President, General Counsel and Secretary. Mr. Margolin’s retirement comes as a
result of our determination to restructure our legal services function and outsource much of that
function to outside legal counsel, in lieu of an internal general counsel. Our legal function is being
managed by Fred Kurland, our Vice President, Finance, Chief Financial Officer and Secretary, with the
assistance of outside legal counsel.

Financings

•

•

•

•

•

In the first quarter of 2012, we sold 2,285,375 shares of common stock through McNicoll, Lewis &
Vlak LLC (now known as MLV & Co. LLC, “MLV”), under our At Market Issuance Sales Agreement
dated February 4, 2011 (the “2011 ATM Agreement”), for aggregate gross proceeds of $3.3 million.

In March 2012, we completed an underwritten public offering of 29,669,154 shares of our common
stock, and accompanying warrants to purchase a total of 14,834,577 shares of our common stock, for
gross proceeds of $39.2 million.

In September 2012, we entered into an amendment to our existing loan agreement with General
Electric Capital Corporation (“GECC”) providing for an additional term loan of $4.6 million,
increasing the aggregate loan obligation to $12.5 million. The loan obligation accrues interest at a fixed
rate of 10.9% and the loan amendment provides for a six-month interest-only repayment period. The
loan obligation will be repaid over a 27-month period commencing on April 1, 2013. The loan
obligation matures on June 15, 2015, at which time the remaining principal amount of $3.1 million,
plus accrued interest and a final payment fee equal to 7% of the loan obligation will be due.

In connection with the September 2012 loan amendment, we issued to GECC unregistered stock
purchase warrants, which entitles GECC to purchase up to an aggregate of 39,346 unregistered shares
of XOMA common stock at an exercise price of $3.54 per share. These warrants are exercisable
immediately and have a five-year term.

In October 2012, we completed an underwritten public offering of 13,333,333 shares of our common
stock for gross proceeds of $40.0 million.

Critical Accounting Estimates

The accompanying discussion and analysis of our financial condition and results of operations are based

upon our consolidated financial statements and the related disclosures, which have been prepared in accordance
with accounting principles generally accepted in the United States. The preparation of these financial statements
requires us to make estimates, assumptions and judgments that affect the reported amounts in our consolidated
financial statements and accompanying notes. We base our estimates on historical experience and on various
other assumptions that we believe to be 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 from these estimates under different assumptions or conditions.

The consolidated financial statements include the accounts of XOMA and its wholly-owned subsidiaries.

All significant intercompany accounts and transactions have been eliminated.

We believe the following policies to be the most critical to an understanding of our financial condition and

results of operations because they require us to make estimates, assumptions and judgments about matters that
are inherently uncertain.

57

Revenue Recognition

License and Collaborative Fees

Revenue from non-refundable license, technology access or other payments under license and collaborative
agreements where we have a continuing obligation to perform is recognized as revenue over the expected period
of the continuing performance obligation. We estimate the performance period at the inception of the
arrangement and re-evaluate it each reporting period. This re-evaluation may shorten or lengthen the period over
which the remaining revenue is recognized. Changes to these estimates are recorded on a prospective basis.

Milestone payments under collaborative and other arrangements are recognized as revenue upon completion
of the milestone event, once confirmation is received from the third party and collectability is reasonably assured.
This represents the culmination of the earnings process because we have no future performance obligations
related to the payment. Milestone payments that require a continuing performance obligation on our part are
recognized over the expected period of the continuing performance obligation. Amounts received in advance are
recorded as deferred revenue until the related milestone is completed.

Contract Revenue

Contract revenue for research and development involves our providing research and development and
manufacturing services to collaborative partners, biodefense contractors or others. Revenue for certain contracts
is accounted for by a proportional performance, or output-based, method where performance is based on
estimated progress toward elements defined in the contract. The amount of contract revenue and related costs
recognized in each accounting period are based on estimates of the proportional performance during the period.
Adjustments to estimates based on actual performance are recognized on a prospective basis and do not result in
reversal of revenue should the estimate to complete be extended.

In addition, revenue related to certain research and development contracts is billed based on actual hours
incurred by XOMA related to the contract, multiplied by full-time equivalent (“FTE”) rates plus a mark-up. The
FTE rates are developed based on our best estimates of labor, materials and overhead costs. For certain contracts,
such as our government contracts, the FTE rates are agreed upon at the beginning of the contract and are subject
to review or audit by the contracting party at any time. Under our contracts with NIAID, a part of the NIH, we
bill using NIH provisional rates and thus are subject to future audits at the discretion of NIAID’s contracting
office. These audits can result in adjustments to previously reported revenue.

In 2011, the NIH conducted an audit of our actual data under two contracts for the period from January 1,

2007, through December 31, 2009, and developed final billing rates for this period. As a result, we retroactively
applied these NIH rates to the invoices from this period which resulted in an increase in revenue of $3.4 million
from the NIH, excluding $0.9 million billed to the NIH in 2010 resulting from our performance of a comparison
of 2009 calculated costs incurred and costs billed to the government under provisional rates. Final rates were
settled for one contract resulting in the recognition of revenue of $2.0 million in 2012. The remaining contract
will be settled through negotiations with the NIH. This revenue has been deferred and will be recognized upon
completion of negotiations with and approval by the NIH.

Upfront fees are recognized ratably over the expected benefit period under the arrangement. Given the
uncertainties of research and development collaborations, significant judgment is required to determine the
duration of the arrangement.

Stock-based Compensation

The valuation of stock-based compensation awards is determined at the date of grant using the Black-
Scholes option pricing model (the “Black-Scholes Model”). This model requires inputs such as the expected term
of the option, expected volatility and risk-free interest rate. Further, the forfeiture rate also impacts the amount of
aggregate compensation. These inputs are subjective and generally require significant analysis and judgment to

58

develop. To establish an estimate of expected term, we consider the vesting period and contractual period of the
award and our historical experience of stock option exercises, post-vesting cancellations and volatility. To
establish an estimate of forfeiture rate, we consider our historical experience of option forfeitures and
terminations. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues. We
review our valuation assumptions quarterly and, as a result, it is likely we will change our valuation assumptions
used to value stock-based awards granted in future periods. Stock-based compensation expense is recognized
ratably over the requisite service period.

Income Taxes

We account for uncertain tax positions in accordance with Accounting Standards Codification Topic 740,

Income Taxes (“ASC 740”). The application of income tax law and regulations is inherently complex.
Interpretations and guidance surrounding income tax laws and regulations change over time. As such, changes in
our subjective assumptions and judgments can materially affect amounts recognized in our financial statements.

ASC 740 provides for the recognition of deferred tax assets if realization of such assets is more likely than

not. Based upon the weight of available evidence, which includes our historical operating performance and carry-
back potential, we have determined that total deferred tax assets should be fully offset by a valuation allowance.

Warrants

We have issued warrants to purchase shares of our common stock in connection with financing activities.

We account for some of these warrants as a liability at fair value and others as equity at fair value. The fair value
of the outstanding warrants is estimated using the Black-Scholes Model. The Black-Scholes Model requires
inputs such as the expected term of the warrants, share price volatility and risk-free interest rate. These inputs are
subjective and generally require significant analysis and judgment to develop. For the estimate of the expected
term, we use the full remaining contractual term of the warrant. We base our estimate of expected volatility on
our historical volatility. The assumptions associated with contingent warrant liabilities are reviewed each
reporting period and changes in the estimated fair value of these contingent warrant liabilities are recognized in
other income (expense).

Results of Operations

Revenue

Total revenue in 2012 was $33.8 million, compared with $58.2 million in 2011 and $33.6 million in 2010 as

shown in the table below (in thousands):

Year ended December 31,

2011-2012
Increase

2010-2011
Increase

2012

2011

2010

(Decrease)

(Decrease)

License and collaborative fees . . . . . . . . . . . . . . . . . . . . . . .
Contract and other revenue . . . . . . . . . . . . . . . . . . . . . . . . .
Net product sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Royalties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 5,727
26,852
1,044
159

$17,991
40,037
—
168

$ 2,182
27,174
—
4,285

$(12,264) $15,809
12,863
(13,185)
—
1,044
(4,117)
(9)

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

$33,782

$58,196

$33,641

$(24,414) $24,555

License and Collaborative Fees

License and collaborative fee revenue includes fees and milestone payments related to the out-licensing of
our products and technologies. License and collaborative fee revenue in 2012 was $5.7 million, compared with
$18.0 million in 2011 and $2.2 million in 2010. The primary components of license and collaboration fee

59

revenue in 2012 were $3.3 million in upfront fees and annual maintenance fees relating to various out-licensing
arrangements, $1.4 million in revenue recognized related to the loan agreement with Servier, and $1.0 million
recognized for six milestone payments.

The primary components of license and collaboration fee revenue in 2011 were $16.2 million in revenue
recognized related to the collaboration and loan agreements with Servier to jointly develop and commercialize
gevokizumab in multiple indications. In addition, we recognized two milestone payments for an aggregate
amount of $1.0 million and $0.8 million in up-front fees and annual maintenance fees relating to various out-
licensing arrangements.

The primary components of license and collaboration fee revenue in 2010 were four milestone payments

recognized for an aggregate amount of $1.2 million, including one milestone from AVEO Pharmaceuticals, Inc.
(“AVEO”) for $0.8 million resulting from AVEO’s initiation of a Phase 2 clinical trial to evaluate its AV-299
antibody. In addition, we recognized $1.0 million in up-front fees and annual maintenance fees relating to
various out-licensing arrangements.

The generation of future revenue related to license fees and collaborative arrangements is dependent on our
ability to attract new licensees to our antibody and proprietary technologies and new collaboration partners. We
expect a slight decrease in license and collaboration fee revenue in 2013 compared to 2012 levels.

Contract and Other Revenue

Contract and other revenue includes agreements where we provide contracted research and development

services to our contract and collaboration partners, primarily Servier and NIAID. The following table shows the
activity in contract and other revenue for the years ended December 31, 2012, 2011, and 2010 (in thousands):

Year ended December 31,

2012

2011

2010

2011-2012
Increase
(Decrease)

2010-2011
Increase
(Decrease)

Servier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NIAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Takeda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$14,529
11,191
1,094
38

$19,348
18,781
1,217
691

$ — $ (4,819) $19,348
(2,633)
21,414
(2,351)
3,568
(1,501)
2,192

(7,590)
(123)
(653)

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

$26,852

$40,037

$27,174

$(13,185) $12,863

The 2012 decrease in contract revenue, as compared to 2011, was primarily due to decreased activity under

NIAID Contract No. HHSN272200800028C (“NIAID 3”). This decrease of $12.0 million in NIAID 3 revenue
was partially offset by the recognition of $2.0 million in revenue related to an adjustment to previously reported
revenue from NIAID resulting from an audit by NIAID’s contracting office. This revenue, which was previously
deferred, was recognized upon the completion of negotiations with and approval by the NIH in March 2012. Also
partially offsetting the decreases in NIAID revenue was a $2.4 million increase in activity under Contract No.
HHSN272201100031C (“NIAID 4”). The NIAID 4 contract was executed in October 2011. In addition, a
reduction in CMC activity under the collaboration with Servier contributed to the decrease in contract and other
revenue in 2012, as compared to 2011, partially offset by an increase in gevokizumab clinical development
activity under the collaboration with Servier and the recognition of partial funding received from Servier for the
FDC1 Phase 3 trial.

The 2011 increase in contract revenue, as compared to 2010, was primarily due to gevokizumab clinical

development and CMC activity under the collaboration with Servier. Partially offsetting this increase were
decreases in revenue from NIAID 3 due to decreased activity under the contract, our Takeda contracts as a result
of the cessation of certain Takeda programs in 2010, and our SRI International subcontract awards due to the
successful completion of the services we had agreed to perform in 2011.

60

Based on expected levels of revenue generating activity related to our Servier and NIAID contracts, we

expect contract and other revenue in 2013 to be comparable to 2012 levels. The following table shows the
activity in deferred revenue for the years ended December 31, 2012, 2011 and 2010 (in thousands):

Year ended December 31,

2012

2011

2010

Beginning deferred revenue . . . . . . . . . . . . . . .
Revenue deferred . . . . . . . . . . . . . . . . . . . . . . .
Revenue recognized . . . . . . . . . . . . . . . . . . . . .

$13,234
5,881
(9,391)

$ 18,130
12,673
(17,569)

$ 5,008
15,949
(2,827)

Ending deferred revenue . . . . . . . . . . . . . . . . . .

$ 9,724

$ 13,234

$18,130

We defer revenue until all requirements under our revenue recognition policy are met. In 2012 and 2011, we
deferred revenue from contracts including Servier, NIH and Takeda. In 2010, we deferred revenue from contracts
including Servier, NIH, Takeda, Merck/Schering-Plough and AVEO.

We expect a significant portion of the $9.7 million in deferred revenue to be recognized in 2013 with the

remainder to be earned during 2014 and 2015. Future amounts may be affected by additional consideration
received, if any, under existing or any future licensing or other collaborative arrangements as well as changes in
the estimated period of obligation or services to be provided under the arrangements.

Net Product Sales

We assumed product sales of ACEON in the first quarter of 2012. Net product sales, cost of sales, and

product gross margin for the year ended December 31, 2012 were as follows (in thousands):

Net product sales (1) . . . . . . . . . . . . . . . . . . . . . . . . . .
Cost of sales (2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product gross margin . . . . . . . . . . . . . . . . . . . . . . . . . .

$
$

1,044
143
86%

Year ended
December 31, 2012

(1) Product sales are recorded net of allowances and accruals for prompt pay discounts, volume rebates, and

product returns.

(2) Cost of sales includes raw materials, third-party manufacturing and distribution costs, and royalties payable

to Servier for ACEON sales.

Royalties

Revenue from royalties was $0.2 million in 2012 compared with $0.2 million in 2011 and $4.3 million in
2010. The decrease in royalties in 2011 was primarily due to the sale of our CIMZIA ® royalty interest for net
proceeds of $3.7 million in the third quarter of 2010. Royalties earned from sales of CIMZIA ® were $0.5 million
in 2010. We will not receive any further royalties on sales of CIMZIA ®.

Research and Development Expenses

Biopharmaceutical development includes a series of steps, including in vitro and in vivo preclinical testing,
and Phase 1, 2 and 3 clinical studies in humans. Each of these steps is typically more expensive than the previous
step, but actual timing and the cost to us depends on the product being tested, the nature of the potential disease
indication and the terms of any collaborative or development arrangements with other companies or entities.
After successful conclusion of all of these steps, regulatory filings for approval to market the products must be
completed, including approval of manufacturing processes and facilities for the product. Our research and
development expenses currently include costs of personnel, supplies, facilities and equipment, consultants, third-
party costs and other expenses related to preclinical and clinical testing.

61

Research and development expenses were $68.3 million in 2012, compared with $68.1 million in 2011 and

$77.4 million in 2010. Clinical trial costs increased in 2012, as compared to 2011, however, this increase was
offset by decreases in salaries and related personnel costs. The decrease in research and development expenses of
$9.3 million in 2011, as compared to 2010, was primarily due to decreased spending on clinical trials.

Salaries and related personnel costs are a significant component of research and development expenses. We

recorded $25.9 million in research and development salaries and employee-related expenses in 2012, compared
with $34.3 million in 2011 and $29.7 million in 2010. Included in these expenses for 2012 were $20.8 million for
salaries and benefits, $2.7 million for bonus expense and $2.4 million for stock-based compensation, which is a
non-cash expense. The decrease of $8.4 million in 2012, as compared to 2011, was primarily due to a decrease in
salaries and benefits of $6.9 million resulting from decreased headcount in manufacturing as result of the 2012
streamlining of operations, and a $1.3 million decrease in stock-based compensation.

Included in these expenses for 2011 were $27.7 million for salaries and benefits, $2.9 million for bonus
expense and $3.7 million for stock-based compensation, which is a non-cash expense, compared with $24.1
million, $3.3 million and $2.3 million, respectively, in 2010. The $4.6 million increase in salaries and employee-
related expenses in 2011, as compared to 2010, was primarily due to an increase in salaries and benefits of $3.6
million in connection with increased gevokizumab clinical development and CMC activity under the
collaboration with Servier, and a $1.4 million increase in stock-based compensation.

Our research and development activities can be divided into earlier-stage programs and later-stage
programs. Earlier-stage programs include molecular biology, process development, pilot-scale production and
preclinical testing. Also included in earlier-stage programs are costs related to excess manufacturing capacity,
which we expect will decrease in 2013 compared to 2012 due to our streamlining objective implemented in 2012
to utilize a contract manufacturing organization. Later-stage programs include clinical testing, regulatory affairs
and manufacturing clinical supplies. The costs associated with these programs approximate the following (in
thousands):

Earlier stage programs (1) . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
Later stage programs (1)

$33,170
35,154

$38,302
29,835

$44,251
33,162

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$68,324

$68,137

$77,413

Year ended December 31,

2012

2011

2010

(1) Certain research and development segment reclassifications have been made to previously reported amounts

to conform to the current year’s presentation.

Our research and development activities also can be divided into those related to our internal projects and

those projects related to collaborative and contract arrangements. The costs related to internal projects versus
collaborative and contract arrangements approximate the following (in thousands):

Internal projects (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Collaborative and contract arrangements (1) . . . . . . . . . . .

$30,531
37,793

$24,440
43,697

$52,031
25,382

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$68,324

$68,137

$77,413

Year ended December 31,

2012

2011

2010

(1) Certain research and development segment reclassifications have been made to previously reported amounts

to conform to the current year’s presentation.

In 2012, the program upon which we incurred the largest amount of expense (gevokizumab) accounted for

more than 40% but less than 50% of our total research and development expenses, a second development
program (NIAID) accounted for more than 20% but less than 30% of our total research and development

62

expenses, and a third development program (XMet) accounted for more than 10% but less than 20% of our total
research and development expenses. In 2011, each of the two programs upon which we incurred the largest
amount of expense (gevokizumab and NIAID) accounted for more than 30% but less than 40% of our total
research and development expenses. In 2010, the program upon which we incurred the largest amount of expense
(gevokizumab) accounted for more than 40% but less than 50% of our total research and development expenses,
and a second development program (NIAID) accounted for more than 30% but less than 40% of our total
research and development expenses. All remaining development programs accounted for less than 10% of our
total research and development expense in 2012, 2011, and 2010.

We expect our research and development spending in 2013 will increase primarily due to our ongoing
global Phase 3 clinical program for gevokizumab for the NIU indications, under our license and collaboration
agreement with Servier, and our ongoing Phase 2 proof-of-concept program.

Future research and development spending also may be impacted by potential new licensing or collaboration

arrangements, as well as the termination of existing agreements. Beyond this, the scope and magnitude of future
research and development expenses are difficult to predict at this time.

Selling, General and Administrative Expenses

Selling, general and administrative expenses include salaries and related personnel costs, facilities costs and
professional fees. In 2012, selling, general and administrative expenses were $16.9 million compared with $24.0
million in 2011 and $23.3 million in 2010. The $7.1 million decrease in selling, general and administrative
expenses in 2012 as compared with 2011 primarily was due to decreases in salaries and related personnel costs of
$3.7 million in large part due to the one-time $1.3 million severance expense and a $0.7 million stock-based
compensation charge incurred during the third quarter of 2011 in connection with the resignation of our former
Chairman, Chief Executive Officer and President, and a decrease in other stock-based compensation of $1.5
million. Also contributing to these changes were decreases in legal costs and consulting fees of $1.8 million and
$1.4 million, respectively.

The $0.7 million increase in selling, general and administrative expenses in 2011 as compared with 2010

primarily was due to an increase in salaries and related personnel costs of $2.8 million primarily due to the one-
time $1.3 million severance expense and a $0.7 million stock-based compensation charge incurred during the
third quarter of 2011 in connection with the resignation of our former Chairman, Chief Executive Officer and
President, and an increase in other stock-based compensation of $0.8 million. Partially offsetting this increase
were decreases in financing fees and legal costs of $1.0 million and $0.7 million, respectively.

We expect selling, general and administrative expenses in 2013 to be comparable to 2012 levels.

Streamlining and Restructuring Charges

In January 2012, we implemented a streamlining of operations, which resulted in a restructuring designed to

sharpen our focus on value-creating opportunities led by gevokizumab and its unique antibody discovery and
development capabilities. The restructuring plan included a reduction of XOMA’s personnel by 84 positions, or
34%, of which 52 were eliminated immediately and the remainder eliminated as of April 6, 2012. These staff
reductions resulted primarily from our decision to utilize a contract manufacturing organization for Phase 3 and
commercial antibody production, and to eliminate internal research functions that are non-differentiating or that
can be obtained cost effectively by contract service providers.

During the year ended December 31, 2012, in connection with this streamlining of operations, we recorded

charges of $2.0 million, related to severance, other termination benefits and outplacement services. We do not
expect to incur additional restructuring charges related to severance, other termination benefits and outplacement
services.

63

In 2012, we vacated and subleased facilities that housed our large-scale manufacturing operations and

associated quality functions. During the year ended December 31, 2012, we recorded charges of $0.6 million
related to moving and other facility costs in connection with the exit of these buildings. We do not expect to
incur any significant restructuring charges during 2013 in connection with lease payments for these buildings as
these payments will be offset by future sublease income.

In the first half 2012, we performed an impairment analysis of property and equipment and leasehold
improvements related to our manufacturing operations. Since the estimated undiscounted future cash inflows
from a certain group of assets were less than the carrying value, we determined these assets were impaired and
recorded a restructuring charge of $0.8 million. Further, we changed the useful life of certain property and
equipment and leasehold improvements impacted by our plans to vacate two leased buildings. As a result, we
recorded accelerated depreciation of $1.3 million as a restructuring charge. In the second half of 2012, we
entered into an agreement for the sublease of the aforementioned buildings and sale of the property and
equipment. We recorded an additional $0.4 million restructuring charge relating to the loss on sale of these
assets. We do not expect to incur additional restructuring charges during 2013 related to the property and
equipment and leasehold improvements.

Other Income (Expense)

Interest Expense

Interest expense and amortization of debt issuance costs and discounts are shown below for the years ended

December 31, 2012, 2011 and 2010 (in thousands):

Year ended December 31,

2012

2011

2010

2011-2012
Increase
(Decrease)

2010-2011
Increase
(Decrease)

Interest expense
Servier loan . . . . . . . . . . . . . . . . . . .
GECC term loan . . . . . . . . . . . . . . .
Novartis note . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . .

$ 2,097
1,850
397
43

$ 2,087
—
341
34

Total interest expense . . . . . .

$ 4,387

$ 2,462

$ —
—
354
31

$ 385

$

10
1,850
56
9

$ 2,087
—
(13)
3

$1 ,925

$ 2,077

The increase of $1.9 million in interest expense in 2012 as compared to 2011 primarily was due to interest
expense related to the loan with GECC, which was funded in December 2011 and amended in September 2012.

The increase of $2.1 million in interest expense in 2011 as compared to 2010 primarily was due to interest

expense related to the loan with Servier, which was funded in January 2011.

Interest expense for 2013 is expected to increase slightly compared to 2012 due to the September 2012
amendment to the loan agreement with GECC, which increased our outstanding loan to GECC from $7.8 million
to $12.5 million.

64

Other Expense

Other expense primarily consisted of unrealized and realized (losses) gains, and warrant modification
expense. The following table shows the activity in other expense for the years ended December 31, 2012, 2011
and 2010 (in thousands):

Year ended December 31,

2012

2011

2010

2011-2012
Increase
(Decrease)

2010-2011
Increase
(Decrease)

Other expense

Unrealized foreign exchange (loss) gain (1) . . . . . . . . . . . .
Realized foreign exchange gain (loss) (2) . . . . . . . . . . . . . .
Unrealized loss on foreign exchange options . . . . . . . . . . .
Warrant modification expense (3) . . . . . . . . . . . . . . . . . . . . . —
81
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(329)
6
(714)

(457)
554
(298)
—

24

6
(7)

—
(4,500)
979

128
(548)
(416)
—
57

(463)
561
(298)
4,500
(955)

Total other expense . . . . . . . . . . . . . . . . . . . . . . . . . . .

$(956) $(177) $(3,522)

$(779)

$3,345

(1) Unrealized foreign exchange loss for the years ended December 31, 2012 and 2011 primarily relates to the

re-measurement of the 15 million Servier loan.

(2) Realized foreign exchange gain for the year ended December 31, 2011 primarily relates to the conversion

into U.S. dollars of the €15 million cash proceeds received from Servier in January of 2011.

(3) Represents the 2010 loss associated with $4.5 million paid to the holders of warrants issued in June of 2009,

upon modification of the terms.

Revaluation of Contingent Warrant Liabilities

In March 2012, in connection with an underwritten offering, we issued five-year warrants to purchase

14,834,577 shares of XOMA’s common stock at an exercise price of $1.76 per share. These warrants contain
provisions that are contingent on the remote occurrence of a change in control, which would conditionally
obligate us to repurchase the warrants for cash in an amount equal to their fair value using the Black-Scholes
Option Pricing Model (the “Black-Scholes Model”) on the date of such change in control. We believe the
likelihood of a change in control prior to the expiration of the warrants is remote; however, due to these
provisions, we are required to account for the warrants issued in March 2012 as a liability at fair value. In
addition, the estimated liability related to the warrants is required to be revalued at each reporting period until the
earlier of the exercise of the warrants, at which time the liability will be reclassified to stockholders’ equity, or
expiration of the warrants. At issuance, the fair value of the warrant liability was estimated to be $6.4 million
using the Black-Scholes Model. We revalued the warrant liability at December 31, 2012, using the Black-Scholes
Model, and recorded a fair value increase of $9.5 million for the year ended December 31, 2012, as a loss in the
revaluation of contingent warrant liabilities line of our consolidated statements of comprehensive loss. We also
reclassified $0.9 million from contingent warrant liabilities to equity on our consolidated balance sheets due to
the exercise of warrants. As of December 31, 2012, 14,265,970 of these warrants were outstanding and had a fair
value of $15.0 million. This increase in liability is primarily due to the excess of the market value of our common
stock at December 31, 2012 compared to the warrant exercise price.

In February 2010, in connection with an underwritten offering, we issued five-year warrants to purchase
1,260,000 shares of XOMA’s common stock at an exercise price of $10.50 per share. These warrants contain
provisions that are contingent on the remote occurrence of a change in control, which would conditionally
obligate us to repurchase the warrants for cash in an amount equal to their fair value using the Black-Scholes
Model on the date of such change in control. We believe the likelihood of a change in control prior to the
expiration of the warrants is remote; however, due to these provisions, we are required to account for the
warrants issued in February 2010 as a liability at fair value. In addition, the estimated liability related to the
warrants is required to be revalued at each reporting period until the earlier of the exercise of the warrants, at
which time the liability will be reclassified to stockholders’ equity, or expiration of the warrants. At

65

December 31, 2011, the fair value of the warrant liability was estimated to be $0.3 million using the Black-
Scholes Model. At March 31, 2012, we changed our expected volatility assumption in the Black-Scholes Model
from an estimate of volatility based on historical stock price volatility observed on XOMA’s underlying stock to
a volatility estimate based on the volatility implied from warrants issued by XOMA in recent private placement
transactions. We revalued the warrant liability at December 31, 2012, using the Black-Scholes Model, and
recorded a fair value decrease of $0.3 million for the year ended December 31, 2012 as a gain in the revaluation
of contingent warrant liabilities line of our consolidated statements of comprehensive loss. As of December 31,
2012, all of these warrants were outstanding.

In June 2009, we issued warrants to certain institutional investors as part of a registered direct offering. The

warrants represent the right to acquire an aggregate of up to 347,826 shares of XOMA’s common stock over a
five year period beginning December 11, 2009 at an exercise price of $19.50 per share. These warrants contain
provisions that are contingent on the remote occurrence of a change in control, which would conditionally
obligate us to repurchase the warrants for cash in an amount equal to their fair value using the Black-Scholes
Model on the date of such change in control. We believe the likelihood of a change in control prior to the
expiration of the warrants is remote; however, due to these provisions, we are required to account for the
warrants issued in June 2009 as a liability at fair value. In addition, the estimated liability related to the warrants
is required to be revalued at each reporting period until the earlier of the exercise of the warrants, at which time
the liability will be reclassified to stockholders’ deficit) equity, or expiration of the warrants. At December 31,
2011, the fair value of the warrant liability was estimated to be $0.1 million using the Black-Scholes Model. At
March 31, 2012, we changed our expected volatility assumption in the Black-Scholes Model from an estimate of
volatility based on historical stock price volatility observed on XOMA’s underlying stock to a volatility estimate
based on the volatility implied from warrants issued by XOMA in recent private placement transactions. We
revalued the warrant liability at December 31, 2012, using the Black-Scholes Model, and recorded a fair value
decrease of $0.1 million for the year ended December 31, 2012 as a gain in the revaluation of contingent warrant
liabilities line of our consolidated statements of comprehensive loss. As of December 31, 2012, all of these
warrants were outstanding.

The following table provides a summary of the changes in fair value of contingent warrant liabilities for the

years ended December 31, 2012, 2011, and 2010 (in thousands):

Balance at December 31, 2010 . . . . . . . . . . . . . . . . . . . . . . . .
Net decrease in fair value of contingent warrant liabilities

upon revaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Balance at December 31, 2011 . . . . . . . . . . . . . . . . . . . . . . . .
Initial fair value of warrants issued in March 2012 . . . . . . . . .
Reclassification of contingent warrant liability to equity upon
exercise of warrants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net increase in fair value of contingent warrant liabilities

Warrant
Liabilities

$ 4,245

(3,866)
379
6,390

(940)

upon revaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9,172

Balance at December 31, 2012 . . . . . . . . . . . . . . . . . . . . . . . .

$15,001

Income Taxes

There was no material income tax expense for the years ended December 31, 2012, 2011, and 2010. The

income tax benefit in 2012 primarily relates to federal refundable credit true-up from prior years.

Accounting Standards Codification Topic 740, Income Taxes (“ASC 740”) provides for the recognition of

deferred tax assets if realization of such assets is more likely than not. Based upon the weight of available
evidence, which includes our historical operating performance and carry-back potential, we have determined that
total deferred tax assets should be fully offset by a valuation allowance.

66

We have recorded cumulative gross deferred tax assets of $234.1 million and $240.1 million at
December 31, 2012 and 2011, respectively, principally attributable to the timing of the deduction of certain
expenses associated with certain research and development expenses, net operating loss and other carry-forwards.
We also recorded corresponding valuation allowances of $234.1 million and $240.1 million at December 31,
2012 and 2011, respectively, to offset these deferred tax assets, as management cannot predict with reasonable
certainty that the deferred tax assets to which the valuation allowances relate will be realized.

As of December 31, 2012, we had federal net operating loss carry-forwards (“NOLs”) of approximately

$137.1 million, state net operating loss carry-forwards of approximately $134.9 million, and foreign net
operating loss carry-forwards of approximately 772.3 million to offset future taxable income. We had no federal
research and development tax credit carry-forwards as a result of the Section 382 annual limitation and state
research and development tax credit carry-forwards of approximately $16.4 million.

Based on an analysis under Section 382 of the Internal Revenue Code (which subjects the amount of pre-

change NOLs and certain other pre-change tax attributes that can be utilized to an annual limitation), we
experienced ownership changes in 2009 and 2012 which substantially limit the future use of our pre-change
NOLs and certain other pre-change tax attributes per year. We have excluded the NOLs and R&D credits that
will expire as a result of the annual limitations in the deferred tax assets as of December 31, 2012. To the extent
that we do not utilize our carry-forwards within the applicable statutory carry-forward periods, either because of
Section 382 limitations or the lack of sufficient taxable income, the carry-forwards will expire unused.

We do not expect the unrecognized tax benefits to change significantly over the next twelve months. We
will recognize interest and penalties accrued on any unrecognized tax benefits as a component of income tax
expense. As of December 31, 2012, we have not accrued interest or penalties related to uncertain tax positions.

Liquidity and Capital Resources

The following table summarizes our cash and cash equivalents, our working capital and our cash flow

activities as of the end of, and for each of, the periods presented (in thousands):

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Working Capital

$45,345
$72,004

$48,344
$42,064

December 31,

2012

2011

2011-2012
Change

$ (2,999)
$29,940

Year ended December 31,

2012

2011

2010

2011-2012
Change

2010-2011
Change

Net cash used in operating activities . . . . . . . . . . . . . . . .
Net cash used in investing activities . . . . . . . . . . . . . . . .
Net cash provided by financing activities . . . . . . . . . . . .
Effect of exchange rate changes on cash . . . . . . . . . . . . .

$(40,765) $(29,062) $(52,537) $(11,703) $ 23,475
(2,965)
(42,016)
(22,292)
79,782
(573)
—

(38,712)
35,803
573

(339)
66,271
—

(3,304)
43,979
(573)

Net increase in cash and cash equivalents . . . . . . . . . . . .

$ (2,999) $ 11,040

$ 13,395

$(14,039) $ (2,355)

Working Capital

The increase in working capital in 2012 as compared to 2011 primarily was due to an aggregate increase of

$37.0 million in cash, cash equivalents and short-term investments for the year ended December 31, 2012, as
compared to the same period in 2011. This increase was primarily due to the March 2012 and October 2012
underwritten public offerings for aggregate gross proceeds of $79.2 million and loan proceeds of $4.7 million
received in September 2012. These increases were partially offset by the 2011 receipt of loan proceeds for $20.1
million and a $15.0 million license fee received from Servier in 2011.

67

Cash Used in Operating Activities

Net cash used in operating activities was $40.8 million for the year ended December 31, 2012, compared

with $29.1 million for the same period in 2011. The increase in net cash used in operating activities was
primarily due to a $15.0 million license fee received in the first quarter of 2011 as consideration for the
collaboration with Servier. This cash receipt in 2011 was partially offset by a $2.0 million increase in cash
receipts in 2012 as a result of the timing under our collaboration agreement with Servier.

The $23.5 million decrease in net cash used in operating activities for the year ended December 31, 2011, as

compared to the same period in 2010, was primarily related to the receipt of the $15.0 million license fee
received in the first quarter of 2011 as consideration for the collaboration with Servier and a decrease in cash
paid on clinical trials.

We expect net cash used in operating activities in 2013 to increase compared to 2012 levels due to increased

spending on clinical trials.

Cash Used in Investing Activities

Net cash used in investing activities was $42.0 million for the year ended December 31, 2012, compared
with $3.3 million and $0.3 million for the same periods in 2011 and 2010, respectively. Cash used in investing
activities for the year ended December 31, 2012, consisted of purchases of short-term investments of $57.0
million and fixed asset purchases of $2.5 million, partially offset by $17.0 million in proceeds from maturities of
short-term investments and $0.5 million in proceeds from the sale of fixed assets. Cash used in investing
activities for the years ended December 31, 2011 and 2010, primarily consisted of fixed asset purchases.

Cash Provided by Financing Activities

Net cash provided by financing activities of $79.8 million for the year ended December 31, 2012, was

primarily related to net proceeds received from the issuance of common stock of $77.5 million, including net
proceeds of $37.0 million from the October 2012 underwritten public offering, net proceeds of $36.2 million
from the March 2012 underwritten public offering, net proceeds of $3.2 million received from the issuance of
common stock under the 2011 ATM Agreement, net proceeds of $1.0 million from the exercise of warrants
issued as part of the March 2012 underwritten public offering, and net proceeds of $0.2 million from the exercise
of outstanding options. Also contributing to net cash provided by financing activities was net loan proceeds of
$4.4 million received from GECC, partially offset by $2.1 million principal payments on our loan with GECC.

Net cash provided by financing activities of $44.0 million for the year ended December 31, 2011, was

primarily related to loan proceeds of $20.1 million received from Servier, issuance of shares of our common
stock for $15.1 million under the 2010 and 2011 ATM agreements, and loan proceeds of $10.0 million received
from GECC. The loan proceeds from GECC were partially offset by debt issuance costs of $1.3 million.

Net cash provided by financing activities of $66.3 million for the year ended December 31, 2010, was

primarily related to proceeds received from the issuance of shares of our common stock of $70.8 million,
including net proceeds of $19.2 million from an underwritten offering in February 2010, $13.9 million from our
common share purchase agreement with Azimuth in August 2010, and $37.7 million under the 2009 and 2010
ATM agreements, partially offset by $4.5 million paid to the holders of warrants issued in June 2009 upon
modification of the terms.

Equity Line of Credit

In July of 2010, we entered into a common share purchase agreement (the “2010 Purchase Agreement”)

with Azimuth pursuant to which we obtained a committed equity line of credit facility (the “2010 Facility”). In
August of 2010, we sold a total of 3,421,407 shares of our common stock under the 2010 Facility for aggregate

68

gross proceeds of $14.2 million, representing the maximum number of shares that could be sold under the 2010
Facility. As a result, the 2010 Facility is no longer in effect, and no additional shares can be issued thereunder.

Registered Direct Offerings

In June of 2009, we entered into a definitive agreement with certain institutional investors to sell 695,652
units, with each unit consisting of one share of our common stock and a warrant to purchase 0.50 of a share of
our common stock, for gross proceeds of approximately $12.0 million, before deducting placement agent fees
and estimated offering expenses of $0.8 million, in a second registered direct offering. In February of 2010, the
holders of these warrants agreed to amend the terms of their warrants to remove the Eliminated Adjustment
Provisions and we made a cash payment of $4.5 million to these warrant holders, which was recorded in other
income (expense). As of December 31, 2012, all of these warrants were outstanding.

ATM Agreements

In the third quarter of 2009, we entered into the 2009 ATM Agreement, under which we could sell up to
1.7 million shares of our common stock from time to time through Wm Smith, as our agent for the offer and sale
of the shares. From the inception of the 2009 ATM Agreement through October of 2010, the Company sold a
total of 1.7 million shares of our common stock through Wm Smith, constituting all of the shares available for
sale under the agreement, for aggregate gross proceeds of $12.2 million, including 1.4 million shares sold in
2010 for aggregate gross proceeds of $9.3 million. Total offering expenses related to these sales were $0.4
million.

In the third quarter of 2010, we entered into the 2010 ATM Agreement, with Wm Smith and MLV (the
“Agents”), under which we could sell shares of our common stock from time to time through the Agents, as our
agents for the offer and sale of the shares, in an aggregate amount not to exceed the amount that can be sold
under our registration statement on Form S-3 (File No. 333-148342) filed with the Securities and Exchange
Commission (the “SEC”) on December 26, 2007, and declared effective by the SEC on May 29, 2008. The
Agents could sell the shares by any method permitted by law deemed to be an “at the market” offering as defined
in Rule 415 of the Securities Act of 1933, as amended (the “Securities Act”), including without limitation sales
made directly on The NASDAQ Global Market, on any other existing trading market for our common stock or to
or through a market maker. The Agents could also sell the shares in privately negotiated transactions, subject to
our prior approval. From the inception of the 2010 ATM Agreement through May of 2011, we sold a total of
7,560,862 shares of our common stock under this agreement for aggregate gross proceeds of $34.0 million,
including 821,386 shares sold in 2011 for aggregate gross proceeds of $4.4 million. Total offering expenses
incurred related to sales under the 2010 ATM Agreement from inception to May of 2011 were $1.0 million,
including $0.1 million incurred in 2011. In May of 2011, 2010 ATM Agreement expired by its terms, and there
will be no further issuances under this facility.

On February 4, 2011, we entered into an At Market Issuance Sales Agreement (the “2011 ATM

Agreement”), with McNicoll, Lewis & Vlak LLC (now known as MLV & Co. LLC, “MLV”), under which we
may sell shares of our common stock from time to time through MLV, as our agent for the offer and sale of the
shares, in an aggregate amount not to exceed the amount that can be sold under our registration statement on
Form S-3 (File No. 333-172197) filed with the SEC on February 11, 2011, and amended on March 10,
2011, June 3, 2011, and January 3, 2012, which was most recently declared effective by the SEC on January 17,
2012. MLV may sell the shares by any method permitted by law deemed to be an “at the market” offering as
defined in Rule 415 of the Securities Act, including without limitation sales made directly on The NASDAQ
Global Market, on any other existing trading market for our common stock or to or through a market maker.
MLV also may sell the shares in privately negotiated transactions, subject to our prior approval. We will pay
MLV a commission equal to 3% of the gross proceeds of the sales price of all shares sold through it as sales
agent under the 2011 ATM Agreement. From the inception of the 2011 ATM Agreement through December 31,
2012, we sold a total of 7,572,327 shares of common stock under this agreement for aggregate gross proceeds of
$14.6 million. No shares of common stock have been sold under this agreement since February 3, 2012. Total

69

offering expenses incurred related to sales under the 2011 ATM Agreement from inception to December 31,
2012, were $0.5 million.

Underwritten Offerings

In February 2010, we completed an underwritten offering of 2.8 million units, with each unit consisting of

one shares of our common stock and a warrant to purchase 0.45 of a share of our common stock, for gross
proceeds of approximately $21.0 million, before deducting underwriting discounts and commissions and
estimated offering expenses of $1.7 million. The warrants, which represent the right to acquire an aggregate of up
to 1.26 million shares of our common stock, are exercisable beginning six months and one day after issuance and
have a five-year term and an exercise price of $10.50 per share. As of December 31, 2012, all of these warrants
were outstanding.

On March 9, 2012, we completed an underwritten public offering of 29,669,154 shares of our common
stock, and accompanying warrants to purchase one half of a share of common stock for each share purchased, at
a public offering price of $1.32 per share. Total gross proceeds from the offering were approximately $39.2
million, before deducting underwriting discounts and commissions and offering expenses totaling approximately
$3.0 million. The warrants, which represent the right to acquire an aggregate of up to 14,834,577 shares of
common stock, are exercisable immediately and have a five-year term and an exercise price of $1.76 per share.
As of December 31, 2012, 14,265,970 of these warrants were outstanding.

On October 29, 2012, we completed an underwritten public offering of 13,333,333 shares of our common

stock, at a public offering price of $3.00 per share. In addition, we have granted the underwriters a 30-day option
to purchase up to an additional 1,999,999 shares of common stock on the same terms and conditions, solely to
cover over-allotments, if any. Total gross proceeds from the offering were approximately $40.0 million, before
deducting underwriting discounts and commissions and offering expenses totaling approximately $3.0 million.

Servier Loan

In December 2010, we entered into a loan agreement with Servier (the “Servier Loan Agreement”), which
provided for an advance of up to €15.0 million. The loan was fully funded in January 2011, with the proceeds
converting to approximately $19.5 million at the date of funding. The loan is secured by an interest in XOMA’s
intellectual property rights to all gevokizumab indications worldwide, excluding certain rights in the U.S. and
Japan. Interest is calculated at a floating rate based on a Euro Inter-Bank Offered Rate (“EURIBOR”) and is
subject to a cap. The interest rate is reset semi-annually in January and July of each year. The interest rate for the
initial interest period was 3.22%. The interest rate was reset to 3.83% for the six-month period from July 2011
through January 2012, 3.54% for the six-month period from January 2012 through July 2012, 2.80% for the six-
month period from July 2012 through January 2013 and 2.33% for the six-month period from January 2013
through July 2013. Interest is payable semi-annually; however, the Servier Loan Agreement provides for a
deferral of interest payments over a period specified in the agreement. During the deferral period, accrued
interest will be added to the outstanding principal amount for the purpose of interest calculation for the next six-
month interest period. On the repayment commencement date, all unpaid and accrued interest shall be paid to
Servier, and thereafter, all accrued and unpaid interest shall be due and payable at the end of each six-month
period. The loan matures in 2016; however, after a specified period prior to final maturity, the loan is to be repaid
(i) at Servier’s option, by applying up to a significant percentage of any milestone or royalty payments owed by
Servier under our collaboration agreement and (ii) using a significant percentage of any upfront, milestone or
royalty payments we receive from any third-party collaboration or development partner for rights to
gevokizumab in the U.S. and/or Japan. In addition, the loan becomes immediately due and payable upon certain
customary events of default. At December 31, 2012, the outstanding principal balance under this loan was $19.8
million using the December 31, 2012 Euro to US Dollar exchange rate of 1.3215.

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GECC Term Loan

In December 2011, we entered into a loan agreement (the “GECC Loan Agreement”) with GECC, under

which GECC agreed to make a term loan in an aggregate principal amount of $10 million (the “Term Loan”) to
us, and upon execution of the GECC Loan Agreement, GECC funded the Term Loan. As security for our
obligations under the GECC Loan Agreement, we granted a security interest in substantially all of our existing
and after-acquired assets, excluding our intellectual property assets (such as those relating to our gevokizumab
and anti-botulism products). The Term Loan accrued interest at a fixed rate of 11.71% per annum and was to be
repaid over a period of 42 consecutive equal monthly installments of principal and accrued interest and was due
and payable in full on June 15, 2015. We incurred debt issuance costs of approximately $1.3 million in
connection with the Term Loan and were required to pay a final payment fee equal to $500,000 on the maturity
date, or such earlier date as the Term Loan is paid in full.

In connection with the GECC Loan Agreement, we issued to GECC unregistered warrants that entitle GECC

to purchase up to an aggregate of 263,158 unregistered shares of XOMA common stock at an exercise price
equal to $1.14 per share. These warrants are exercisable immediately and have a five-year term.

In September 2012, we entered into an amendment to the GECC Loan Agreement providing for an
additional term loan in the amount of $4.6 million, increasing the term loan obligation to $12.5 million (the
“Amended Term Loan”) and providing for an interest-only monthly repayment period following the effective
date of the amendment through March 1, 2013, at a stated interest rate of 10.9% per annum. Thereafter, we are
obligated to make monthly principal payments of $347,222, plus accrued interest, over a 27-month period
commencing on April 1, 2013, and through June 15, 2015, at which time the remaining outstanding principal
amount of $3.1 million, plus accrued interest, is due. We incurred debt issuance costs of approximately $0.2
million and are required to make a final payment fee in the amount of $875,000 on the date upon which the
outstanding principal amount is required to be repaid in full. This final payment fee replaced the original final
payment fee of $500,000.

In connection with the amendment, on September 27, 2012, we issued to GECC unregistered stock purchase

warrants, which entitle GECC to purchase up to an aggregate of 39,346 shares of XOMA common stock at an
exercise price equal to $3.54 per share. These warrants are exercisable immediately and have a five-year term.

At December 31, 2012, the outstanding principal balance under the Amended Term Loan was $12.5 million.

Proceeds received during the years 2012, 2011, and 2010 are being used to continue development of our

gevokizumab product candidate and for other working capital and general corporate purposes.

*

*

*

We have incurred significant operating losses and negative cash flows from operations since our inception.

At December 31, 2012, we had cash, cash equivalents, and short-term investments of $85.3 million. During 2013,
we expect to continue using our cash, cash equivalents and short-term investments to fund ongoing operations.
Additional licensing, antibody discovery and development collaboration agreements, government funding and
financing arrangements may positively impact our cash balances. Based on our cash reserves and anticipated
spending levels, revenue from collaborations including the gevokizumab license and collaboration agreement
with Servier, funding from the GECC Loan Agreement, our March 2012 public offering, our recent October 2012
public offering, biodefense contracts and licensing transactions and other sources of funding that we believe to be
available, we estimate that we have sufficient cash resources to meet our anticipated net cash needs into late
2014. Any significant revenue shortfalls, increases in planned spending on development programs or more rapid
progress of development programs than anticipated, as well as the unavailability of anticipated sources of
funding, could shorten this period. If adequate funds are not available, we will be required to delay, reduce the
scope of, or eliminate one or more of our product development programs and further reduce personnel-related
costs. Progress or setbacks by potentially competing products may also affect our ability to raise new funding on
acceptable terms.

71

Commitments and Contingencies

Schedule of Contractual Obligations

Payments by period due under contractual obligations at December 31, 2012, are as follows (in thousands):

Contractual Obligations

Operating leases (1) . . . . . . . . . . . . . . . . . . . . . . . . . .
Debt Obligations (2)

Total

Less than 1
year

1 to 3 years

3 to 5 years

More than 5
years

$ 3,457

$ 2,662

$

795

$ —

$ —

Principal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46,754
6,954

3,472
1,237

23,459
5,704

19,823
13

—
—

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 57,165

$ 7,371

$ 29,958

$ 19,836

$ —

(1) Operating leases are net of sublease income of $0.9 million.
(2) See Item 7A: Quantitative and Qualitative Disclosures about Market Risk and Note 7: Long-Term Debt and
Other Arrangements to the accompanying consolidated financial statements for further discussion of our
debt obligation.

In addition to the above, we have committed to make potential future “milestone” payments to third parties
as part of licensing and development programs. Payments under these agreements become due and payable only
upon the achievement of certain developmental, regulatory and/or commercial milestones. Because it is uncertain
if and when these milestones will be achieved, such contingencies, aggregating up to $96 million (assuming one
product per contract meets all milestones) have not been recorded on our consolidated balance sheet. We are also
obligated to pay royalties, ranging generally from 1.5% to 14% of the selling price of the licensed component and
up to 40% of any sublicense fees to various universities and other research institutions based on future sales or
licensing of products that incorporate certain products and technologies developed by those institutions. We are
unable to determine precisely when and if our payment obligations under the agreements will become due as
these obligations are based on future events, the achievement of which is subject to a significant number of risks
and uncertainties.

Although operations are influenced by general economic conditions, we do not believe that inflation had a

material impact on financial results for the periods presented. We believe that we are not dependent on materials
or other resources that would be significantly impacted by inflation or changing economic conditions in the
foreseeable future.

Recent Accounting Pronouncements

In May 2011, Accounting Standards Codification Topic 820, Fair Value Measurement was amended to

develop common requirements for measuring fair value and for disclosing information about fair value
measurements in accordance with U.S. generally accepted accounting principles and international financial
reporting standards. The Company adopted this guidance as of January 1, 2012, on a retrospective basis and this
adoption did not have a material effect on the Company’s consolidated financial statements.

In June 2011, Accounting Standards Codification Topic 220, Comprehensive Income was amended to
increase the prominence of items reported in other comprehensive income. Accordingly, a company can present
all nonowner changes in stockholders’ equity either in a single continuous statement of comprehensive income or
in two separate but consecutive statements. The Company adopted this guidance as of January 1, 2012, on a
retrospective basis and this adoption did not have a material effect on the Company’s consolidated financial
statements.

72

Off Balance Sheet Arrangements

None.

Item 7A. Quantitative and Qualitative Disclosures about Market Risk

Interest Rate Risk

Our exposure to market rate risk for changes in interest rates relates primarily to our investment portfolio
and our loan facilities. By policy, we make our investments in high quality debt securities, limit the amount of
credit exposure to any one non-U.S. Treasury issuer, and limit duration by restricting the term of the instrument.
We generally hold investments to maturity, with a weighted average portfolio period of less than twelve months.
However, if the need arose to liquidate such securities before maturity, we may experience losses on liquidation.

We hold interest-bearing instruments that are classified as cash, cash equivalents and short-term

investments. Fluctuations in interest rates can affect the principal values and yields of fixed income investments.
If interest rates in the general economy were to rise rapidly in a short period of time, our fixed income
investments could lose value.

The following table presents the amounts and related weighted average interest rates of our cash, cash
equivalents, and short-term investments at December 31, 2012 and 2011 (in thousands, except interest rate):

Maturity

Carrying
Amount
(in thousands)

Fair Value
(in thousands)

Weighted
Average
Interest Rate

December 31, 2012

Cash, cash equivalents, and short-term

investments . . . . . . . . . . . . . . . . . . . . . . . . . . Daily to 90 days

$ 85,332

$ 85,332

0.06%

December 31, 2011

Cash and cash equivalents . . . . . . . . . . . . . . . . Daily to 90 days

$ 48,344

$ 48,344

0.25%

As of December 31, 2012, we have an outstanding principal balance on our note with Novartis of $14.4

million, which is due in 2015. The interest rate on this note is charged at a rate of USD six-month LIBOR plus
2%, which was 2.51% at December 31, 2012. No further borrowing is available under this note.

As of December 31, 2012, we have an outstanding principal balance on our loan with Servier of €15.0
million, which converts to approximately $19.8 million at December 31, 2012. The interest rate on this loan is
charged at a floating rate based on a Euro Inter-Bank Offered Rate (“EURIBOR”) and subject to a cap. The
interest rate for the initial interest period was 3.22%. The interest rate was reset to 3.83% for the six-month
period from July 2011 through January 2012, 3.54% for the six-month period from January 2012 through July
2012, 2.80% for the six-month period from July 2012 through January 2013 and 2.33% for the six-month period
from January 2013 through July 2013. No further borrowing is available under this loan.

As of December 31, 2012, we have an outstanding principal balance on our loan with GECC of $12.5

million, which is to be repaid with monthly principal payments of $347,222, plus accrued interest, over a 27-
month period commencing on April 1, 2013, and through June 15, 2015, at which time the remaining outstanding
principal amount of $3.1 million, plus accrued interest, is due. The loan accrues interest at a fixed rate of 10.90%
per annum. No further borrowing is available under this loan.

The variable interest rate related to our long-term debt instruments is based on LIBOR for our Novartis note
and EURIBOR for our Servier loan. We estimate that a hypothetical 100 basis point change in interest rates could
increase or decrease our interest expense by approximately $0.3 million on an annualized basis. Our loan with
GECC is not subject to interest rate risk as it accrues interest at a fixed rate.

73

Foreign Currency Risk

We hold debt, incur expenses, and may be owed milestones denominated in foreign currencies. The amount of
debt owed, expenses incurred, or milestones owed to us will be impacted by fluctuations in these foreign currencies.
When the U.S. Dollar weakens against foreign currencies, the U.S. Dollar value of the foreign-currency
denominated debt, expense, and milestones increases, and when the U.S. Dollar strengthens against these
currencies, the U.S. dollar value of the foreign-currency denominated debt, expense, and milestones decreases.
Consequently, changes in exchange rates will affect the amount we are required to repay on our €15.0 million loan
from Servier and may affect our results of operations. We estimate that a hypothetical 0.01 change the Euro to USD
exchange rate could increase or decrease our unrealized gains or losses by approximately $0.1 million.

Our loan from Servier was fully funded in January 2011, with the proceeds converting to approximately
$19.5 million using the January 13, 2011 Euro to U.S. dollar exchange rate of 1.3020. At December 31, 2012, the
€15.0 million outstanding pirncipal balance under the Servier Loan Agreement would have equaled
approximately $19.8 million using the December 31, 2012 Euro to USD exchange rate of 1.3215. In May 2011,
in order to manage our foreign currency exposure relating to our principal and interest payments on our loan
from Servier, we entered into two foreign exchange option contracts to buy €1.5 million and €15.0 million in
January 201a4nd January 2016, respectively. Upfront premiums paid on these foreign exchange option contracts
totaled $1.5 million and they had an aggregate fair value of $0.5 million at December 31, 2012. Our use of
derivative financial instruments represents risk management; we do not enter into derivative financial contracts
for trading purposes.

Item 8.

Financial Statements and Supplementary Data

The following consolidated financial statements of the registrant, related notes and report of independent

registered public accounting firm are set forth beginning on page F-1 of this report.

Report of Independent Registered Public Accounting Firm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-2

Consolidated Balance Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-3

Consolidated Statements of Comprehensive Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-4

Consolidated Statements of Stockholders’ Equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-5

Consolidated Statements of Cash Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6

Notes to the Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-7

Item 9.

Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Not applicable.

Item 9A. Controls and Procedures

Under the supervision and with the participation of our management, including our Chief Executive Officer

and our Vice President, Finance, Chief Financial Officer and Secretary, 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, as of the end of the period covered by this report. Our disclosure
controls and procedures are intended to ensure that the information we are required to disclose in the reports that
we file or submit under the Securities Exchange Act of 1934 is (i) recorded, processed, summarized and reported
within the time periods specified in the Securities and Exchange Commission’s rules and forms and (ii)
accumulated and communicated to our management, including the Chief Executive Officer and Vice President,
Finance, Chief Financial Officer and Secretary, as the principal executive and financial officers, respectively, to
allow timely decisions regarding required disclosures. Based on this evaluation, our Chief Executive Officer and
our Vice President, Finance, Chief Financial Officer and Secretary concluded that our disclosure controls and
procedures were effective as of the end of the period covered by this report.

74

There were no changes in our internal controls over financial reporting during 2012 that have materially

affected, or are reasonably likely to materially affect, our internal controls over financial accounting.

Management’s Report on Internal Control over Financial Reporting

Management, including our Chief Executive Officer and our Vice President, Finance, Chief Financial
Officer and Secretary, is responsible for establishing and maintaining adequate internal control over financial
reporting (as such term is defined in Exchange Act Rules 13a-159f). The Company’s internal control system was
designed to provide reasonable assurance to the Company’s management and board of directors regarding the
preparation and fair presentation of published financial statements in accordance with accounting principles
generally accepted in the United States.

Management assessed the effectiveness of our internal control over financial reporting as of December 31,

2012. In making this assessment, management used the criteria set forth by the Committee of Sponsoring
Organizations of the Treadway Commission (COSO) in Internal Control—Integrated Framework . Based on our
assessment we believe that, as of December 31, 2012, our internal control over financial reporting is effective
based on those criteria.

The Company’s internal control over financial reporting as of December 31, 2012, has been audited by

Ernst & Young, LLP, the independent registered public accounting firm who also audited the Company’s
consolidated financial statements. Ernst & Young’s attestation report on the Company’s internal control over
financial reporting follows.

Changes in Internal Control over Financial Reporting

Our management, including our Chief Executive Officer and our Vice President, Finance, Chief Financial
Officer and Secretary, has evaluated any changes in our internal control over financial reporting that occurred
during the quarter ended December 31, 2012, and has concluded that there was no change during such quarter
that has materially affected, or is reasonably likely to materially affect, our internal control over financial
reporting.

75

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors and Stockholders of XOMA Corporation:

We have audited XOMA Corporation’s internal control over financial reporting as of December 31, 2012,

based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring
Organizations of the Treadway Commission (the COSO criteria). XOMA Corporation’s management is
responsible for maintaining effective internal control over financial reporting, and for its assessment of the
effectiveness of internal control over financial reporting included in the accompanying Management’s Report on
Internal Control over Financial Reporting. Our responsibility is to express an opinion on the company’s internal
control over financial reporting based on our audit.

We 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, testing and evaluating the design and operating effectiveness of internal control based
on the assessed risk, and 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, XOMA Corporation maintained, in all material respects, effective internal control over

financial reporting as of December 31, 2012, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board

(United States), the consolidated balance sheets of XOMA Corporation as of December 31, 2012 and 2011 and
the related consolidated statements of comprehensive loss, stockholders’ equity and cash flows for each of the
three years in the period ended December 31, 2012, and our report dated March 12, 2013 expressed an
unqualified opinion thereon.

/s/ ERNST & YOUNG LLP
San Francisco, California
March 12, 2013

Item 9B. Other Information

None.

76

PART III

Item 10. Directors, Executive Officers, Corporate Governance

Certain information regarding our executive officers required by this Item is set forth as a Supplementary
Item at the end of Part I of this Form 10-K (pursuant to Instruction 3 to Item 401(b) of Regulation S-K). Other
information required by this Item will be included in the Company’s proxy statement for the 2013 Annual
General Meeting of Stockholders (“2013 Proxy Statement”), under the sections labeled “Item 1—Election of
Directors” and “Compliance with Section 16(a) of the Securities Exchange Act of 1934” , and is incorporated
herein by reference. The 2013 Proxy Statement will be filed with the SEC within 120 days after the end of the
fiscal year to which this report relates.

Code of Ethics

The Company’s Code of Ethics applies to all employees, officers and directors including the Chief
Executive Officer (principal executive officer) and the Vice President, Finance, Chief Financial Officer and
Secretary (principal financial and principal accounting officer) and is posted on the Company’s website at
www.xoma.com. We intend to satisfy the applicable disclosure requirements regarding amendments to, or
waivers from, provisions of our Code of Ethics by posting such information on our website.

Item 11. Executive Compensation

Information required by this Item will be included in the sections labeled “Compensation of Executive
Officers”, “Summary Compensation Table”, “Grants of Plan-Based Awards”, “Outstanding Equity Awards as
of December 31, 2012”, “Option Exercises and Shares Vested”, “Pension Benefits”, “Non-Qualified Deferred
Compensation” and “Compensation of Directors” appearing in our 2013 Proxy Statement, and is incorporated
herein by reference.

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

Matters

Information required by this Item will be included in the sections labeled “Stock Ownership” and “Equity

Compensation Plan Information” appearing in our 2013 Proxy Statement, and is incorporated herein by
reference.

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

Information required by this Item will be included in the section labeled “Transactions with Related

Persons” appearing in our 2013 Proxy Statement, and is incorporated herein by reference.

Item 14. Principal Accountant Fees and Services

Information required by this Item will be included in the section labeled “Item 2—Appointment of
Independent Registered Public Accounting Firm” appearing in our 2013 Proxy Statement, and is incorporated
herein by reference.

77

PART IV

Item 15. Exhibits and Financial Statement Schedules

(a) The following documents are included as part of this Annual Report on Form 10-K:

(1) Financial Statements:

All financial statements of the registrant referred to in Item 8 of this Report on Form 10-K.

(2) Financial Statement Schedules:

All financial statements schedules have been omitted because the required information is included
in the consolidated financial statements or the notes thereto or is not applicable or required.

(3) Exhibits:

The exhibits listed in the accompanying index to exhibits are filed or incorporated by reference as part of

this Annual Report on Form 10-K.

78

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant

has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized, on this 12 th
day of March 2013.

SIGNATURES

XOMA CORPORATION

By:

/S/

JOHN VARIAN
John Varian
Chief Executive Officer and Director

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below

constitutes and appoints John Varian and Fred Kurland, and each of them, as his or her true and lawful attorneys-
in-fact and agents, with full power of substitution and resubstitution for him or her and in his or her name, place,
and stead, in any and all capacities, to sign any and all amendments to this Annual Report on Form 10-K, and to
file the same, with exhibits thereto and other documents in connection therewith, with the SEC, granting unto
said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every
act and thing requisite and necessary to be done therewith, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, and any of them or
their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

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

the following persons on behalf of the registrant and in the capacities and on the dates indicated.

Signature

Title

Date

/S/

JOHN VARIAN
(John Varian)

/S/ FRED KURLAND

(Fred Kurland)

/S/ PATRICK J. SCANNON

(Patrick J. Scannon)

/S/ W. DENMAN VAN NESS
(W. Denman Van Ness)

Chief Executive Officer (Principal
Executive Officer) and Director

Vice President, Finance, Chief
Financial Officer and Secretary
(Principal Financial and Principal
Accounting Officer)

March 12, 2013

March 12, 2013

Executive Vice President and Chief
Scientific Officer and Director

March 12, 2013

Chairman of the Board of Directors

March 12, 2013

/S/ WILLIAM K. BOWES, JR.

Director

(William K. Bowes, Jr.)

/S/ PETER BARTON HUTT

Director

(Peter Barton Hutt)

/S/ TIMOTHY P. WALBERT

Director

(Timothy P. Walbert)

/S/

JACK L. WYSZOMIERSKI
(Jack L. Wyszomierski)

/S/ KELVIN M. NEU

(Kelvin M. Neu)

/S/

JOSEPH M. LIMBER
(Joseph M. Limber)

Director

Director

Director

79

March 12, 2013

March 12, 2013

March 12, 2013

March 12, 2013

March 12, 2013

March 12, 2013

[THIS PAGE INTENTIONALLY LEFT BLANK]

Index to Consolidated Financial Statements

Report of Independent Registered Public Accounting Firm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-2

Consolidated Balance Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-3

Consolidated Statements of Comprehensive Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-4

Consolidated Statements of Stockholders’ Equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-5

Consolidated Statements of Cash Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6

Notes to the Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-7

F-1

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors and Stockholders of XOMA Corporation:

We have audited the accompanying consolidated balance sheets of XOMA Corporation as of December 31,

2012 and 2011, and the related consolidated statements of comprehensive loss, stockholders’ equity, and cash
flows for each of the three years in the period ended December 31, 2012. These consolidated financial statements
are the responsibility of XOMA Corporation’s management. Our responsibility is to express an opinion on these
consolidated financial statements based on our audits.

We conducted our audits 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 XOMA Corporation at December 31, 2012 and 2011, and the results of its operations
and its cash flows for each of the three years in the period ended December 31, 2012, 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), XOMA Corporation’s internal control over financial reporting as of December 31, 2012, based
on criteria established in Internal Control-Integrated Framework issued by the Committee of Sponsoring
Organizations of the Treadway Commission and our report dated March 12, 2013 expressed an unqualified
opinion thereon.

/s/ ERNST & YOUNG LLP

San Francisco, California
March 12, 2013

F-2

XOMA Corporation
CONSOLIDATED BALANCE SHEETS
(in thousands, except share and per share amounts)

December 31,

2012

2011

Current assets:

ASSETS

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Short-term investments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trade and other receivables, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 45,345
39,987
8,249
2,256

$ 48,344
—
12,332
2,019

Total current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Property and equipment, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

95,837
8,143
1,696

62,695
12,709
2,632

Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 105,676

$ 78,036

LIABILITIES AND STOCKHOLDERS’ EQUITY

Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued and other liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest bearing obligation—current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenue—long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest bearing obligations—long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contingent warrant liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other liabilities—long-term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3,867
13,166
3,409
3,391

23,833
6,315
37,653
15,001
1,407

84,209

$

2,128
10,012
5,695
2,796

20,631
7,539
33,524
379
952

63,025

Commitments and contingencies (Note 11)
Stockholders’ equity:

Preferred stock, $0.05 par value, 1,000,000 shares authorized
Common stock, $0.0075 par value, 138,666,666 shares authorized, 82,447,274 and
35,107,007 shares outstanding at December 31, 2012 and 2011, respectively . . .
Additional paid-in capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated comprehensive income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated deficit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

615
977,962
8
(957,118)

263
900,801
—

(886,053)

Total stockholders’ equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21,467

15,011

Total liabilities and stockholders’ equity . . . . . . . . . . . . . . . . . . . . . .

$ 105,676

$ 78,036

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

F-3

XOMA Corporation
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
(in thousands, except per share amounts)

Year Ended December 31,

2012

2011

2010

Revenues:

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

33,782

58,196

33,641

Operating expenses:

Research and development
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selling, general and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restructuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cost of sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total operating expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

68,324
16,865
5,074
143

90,406

68,137
24,014
—
—

77,413
23,250
82
—

92,151

100,745

Loss from operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(56,624)

(33,955)

(67,104)

Other income (expense):

Interest expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revaluation of contingent warrant liabilities . . . . . . . . . . . . . . . . . . . . . . .

(4,387)
(956)
(9,172)

(2,462)
(177)
3,866

(385)
(3,523)
2,283

Net loss before taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Provision for income tax benefit (expense) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(71,139)
74

(32,728)
(15)

(68,729)
(27)

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$(71,065) $(32,743) $ (68,756)

Basic and diluted net loss per share of common stock . . . . . . . . . . . . . . . . . . . .

$

(1.10) $

(1.04) $

(3.69)

Shares used in computing basic and diluted net loss per share of common

stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

64,629

31,590

18,613

Comprehensive loss:

Net unrealized gains on available-for-sale securities . . . . . . . . . . . . . . . . .

8

—

—

Comprehensive loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$(71,057) $(32,743) $ (68,756)

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

F-4

XOMA Corporation
CONSOLIDATED STATEMENT OF STOCKHOLDERS’ EQUITY
(in thousands)

Balance, December 31, 2009 . . . .
Exercise of stock options,

Preferred Stock Common Stock

Paid-In Comprehensive Accumulated Stockholders’

Shares Amount Shares Amount Capital

Income

Deficit

Equity

Accumulated

Total

3

$ 1 13,536

$101

$801,978

$—

$(784,554)

$ 17,526

contributions to 401(k) and
incentive plans . . . . . . . . . . . . . —

Stock-based compensation

expense . . . . . . . . . . . . . . . . . . —

Sale of shares of common

stock . . . . . . . . . . . . . . . . . . . . . —
Exercise of warrants . . . . . . . . . . —
Comprehensive loss:

Net loss . . . . . . . . . . . . . . . . —

Comprehensive loss . . . . . . . —

—

—

94

1

945

—

—

4,913

— 14,469
392
—

—

—

—

—

109
3

—

—

66,232
2,618

—

—

Balance, December 31, 2010 . . . .
Exercise of stock options,

3

1 28,491

214

876,686

contributions to 401(k) and
incentive plans . . . . . . . . . . . . . —

Stock-based compensation

expense . . . . . . . . . . . . . . . . . . —

Sale of shares of common

—

—

253

2

1,099

—

—

7,759

stock . . . . . . . . . . . . . . . . . . . . . —

— 6,108

Conversion of Series B

convertible preferred stock . . .
Issuance of warrants . . . . . . . . . . —
Comprehensive loss:

(3)

Net loss . . . . . . . . . . . . . . . . —

Comprehensive loss . . . . . . . —

Balance, December 31, 2011 . . . . —
Exercise of stock options,

contributions to 401(k) and
incentive plans . . . . . . . . . . . . . —

Release of restricted stock

units . . . . . . . . . . . . . . . . . . . . . —

Stock-based compensation

expense . . . . . . . . . . . . . . . . . . —

Sale of shares of common

stock . . . . . . . . . . . . . . . . . . . . . —
Issuance of warrants . . . . . . . . . . —
Exercise of warrants . . . . . . . . . . —

45

2

—

—

—

15,043

(1)
215

—

—

(1)

—

—

—

255
—

—

—

— 35,107

263

900,801

— 1,089

8

1,323

—

—

397 —

—

—

—

4,284

— 45,288
—
—
566
—

340
—

4

—

75,960
(6,335)
1,929

—

Comprehensive loss . . . . . . . . . . . —

—

—

Balance, December 31, 2012 . . . . — $— 82,447

$615

$977,962

$

—

—

—
—

—

—

—

—

—

—

—
—

—

—

—

—

—

—

—
—
—

—

—

—
—

946

4,913

66,341
2,621

(68,756)

(68,756)

—

(68,756)

(853,310)

23,591

—

—

—

—
—

1,101

7,759

15,088

—
215

(32,743)

(32,743)

—

(32,743)

(886,053)

15,011

—

—

—

—
—
—

1,331

—

4,284

76,300
(6,335)
1,933

8

8

(71,065)

(71,057)

$(957,118)

$ 21,467

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

F-5

XOMA Corporation
CONSOLIDATED STATEMENTS OF CASH FLOWS
(in thousands)

Year Ended December 31,

2012

2011

2010

Cash flows from operating activities:

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustments to reconcile net loss to net cash used in operating activities:

$(71,065) $(32,743) $(68,756)

Depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common stock contribution to 401(k) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued interest on interest bearing obligations . . . . . . . . . . . . . . . . . . . . . . .
Revaluation of contingent warrant liabilities . . . . . . . . . . . . . . . . . . . . . . . . . .
Restructuring charge related to long-lived assets . . . . . . . . . . . . . . . . . . . . . .
Amortization of debt discount, final payment fee on debt, and debt issuance
costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unrealized loss on foreign currency exchange . . . . . . . . . . . . . . . . . . . . . . . .
Unrealized loss on foreign exchange options . . . . . . . . . . . . . . . . . . . . . . . . .
Warrant modification expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other non-cash adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changes in assets and liabilities:

4,124
1,134
4,284
1,186
9,172
2,460

1,958
295
714
—
18

5,357
1,046
7,759
1,023
(3,866)
—

1,360
513
298
—
107

5,721
905
4,913
353
(2,283)
—

—
—
—
4,500
19

Trade and other receivables, net
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts payable and accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4,064
(158)
4,485
(3,511)
75

8,532
(2,469)
(2,144)
(13,794)
(41)

(13,633)
199
2,650
13,122
(247)

Net cash used in operating activities . . . . . . . . . . . . . . . . . . . . . . . . . .

(40,765)

(29,062)

(52,537)

Cash flows from investing activities:

Purchase of investments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from maturities of investments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Purchase of property and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from sale of property and equipment . . . . . . . . . . . . . . . . . . . . . . . . . .

(56,970)
17,000
(2,509)
463

Net used in investing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(42,016)

Cash flows from financing activities:

Proceeds from issuance of common stock, net of issuance costs . . . . . . . . . . . .
Proceeds from issuance of long-term debt, net of issuance costs . . . . . . . . . . . .
Principal payments of debt
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Payment for modification of warrants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

77,491
4,434
(2,143)
—

Net cash provided by financing activities . . . . . . . . . . . . . . . . . . . . . .

79,782

Effect of exchange rate changes on cash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net increase in cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cash and cash equivalents at the beginning of the year . . . . . . . . . . . . . . . . . . . . . .

—
(2,999)
48,344

—
—
(3,304)
—

(3,304)

15,143
28,836
—
—

43,979

(573)
11,040
37,304

—
—
(339)
—

(339)

70,771
—
—
(4,500)

66,271

—
13,395
23,909

Cash and cash equivalents at the end of the year . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 45,345

$ 48,344

$ 37,304

Supplemental Cash Flow Information:

Cash paid during the year for:

Income taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ — $

15

$

16

Non-cash investing and financing activities:

Issuance of contingent warrant liabilities, net of extinguishments . . . . . . .
Interest added to principal balances on long-term debt . . . . . . . . . . . . . . . .

$ 5,450
$ 1,160

$ — $ 1,767
353
$

669

$

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

F-6

XOMA Corporation

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. Description of Business

XOMA Corporation (“XOMA” or the “Company”), a Delaware corporation combines a portfolio of late-

stage clinical programs and research activities to develop innovative therapeutic antibodies with its recently
launched commercial operations. The Company’s products are presently in various stages of development and
most are subject to regulatory approval before they can be commercially launched.

2. Basis of Presentation and Significant Accounting Policies

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its wholly-owned

subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the

United States requires management to make estimates and assumptions that affect the reported amounts of assets,
liabilities, revenue and expenses, and related disclosures. On an on-going basis, management evaluates its
estimates including, but not limited to, those related to contingent warrant liabilities, revenue recognition,
research and development expense, long-lived assets, derivative instruments and stock-based compensation. The
Company bases its estimates on historical experience and on various other market-specific and other relevant
assumptions that are believed to be 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 these estimates, such as the Company’s billing under
government contracts. Under the Company’s contracts with the National Institute of Allergy and Infectious
Diseases (“NIAID”), a part of the National Institutes of Health (“NIH”), the Company bills using NIH
provisional rates and thus are subject to future audits at the discretion of NIAID’s contracting office. These audits
can result in an adjustment to revenue previously reported.

At March 31, 2012, the Company changed its expected volatility assumption in the Black-Scholes Option
Pricing Model (“Black-Scholes Model”) used to calculate the fair value of its contingent warrant liabilities. The
Company changed its assumption from an estimate of volatility based on historical stock price volatility observed
on XOMA’s underlying stock to a volatility estimate based on the volatility implied from warrants issued by
XOMA in recent private placement transactions, which was determined to be a more precise indicator for the fair
value calculation of the Company’s warrants.

Reclassifications

Certain reclassifications of prior period amounts have been made to the financial statements and
accompanying notes to conform to the current period presentation. Prior period presentation of contingent
warrant liabilities has been reclassified from current liabilities to long-term liabilities based on the contingent
nature of these obligations. These contingent warrant liabilities represent a conditional obligation of the
Company to repurchase certain warrants for cash in the event of a change in control. In addition, gain or loss on
revaluation of the contingent warrant liabilities included in the other income (expense) line of the consolidated
statements of comprehensive loss in the prior period has been reclassified to the revaluation of contingent
warrant liabilities line of the consolidated statements of comprehensive loss. These reclassifications had no
impact on the Company’s previously reported net loss or cash flows.

F-7

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Long-lived Assets

The Company reviews the carrying values and depreciation estimates of its long-lived assets whenever

events or changes in circumstances indicate that the asset may not be recoverable. An impairment loss is
recognized when the estimated future net cash flows expected to result from the use of an asset is less than its
carrying amount. Long-lived assets include property and equipment and building and leasehold improvements.
During 2012, the Company recorded accelerated depreciation of $1.3 million and an impairment loss of $0.8
million on long-lived assets in connection with the Company’s 2012 streamlining plan. See Note 5: Streamlining
and Restructuring Charges for additional disclosure on the 2012 streamlining plan.

Newly Adopted Accounting Pronouncements

In May 2011, Accounting Standards Codification Topic 820, Fair Value Measurement was amended to

develop common requirements for measuring fair value and for disclosing information about fair value
measurements in accordance with U.S. generally accepted accounting principles and international financial
reporting standards. The Company adopted this guidance as of January 1, 2012 on a retrospective basis and this
adoption did not have a material effect on the Company’s consolidated financial statements.

In June 2011, Accounting Standards Codification Topic 220, Comprehensive Income was amended to
increase the prominence of items reported in other comprehensive income. Accordingly, a company can present
all nonowner changes in stockholders’ equity either in a single continuous statement of comprehensive income or
in two separate but consecutive statements. The Company adopted this guidance as of January 1, 2012 on a
retrospective basis and this adoption did not have a material effect on the Company’s consolidated financial
statements.

Revenue Recognition

Revenue is recognized when the four basic criteria of revenue recognition are met: (1) persuasive evidence

of an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the fee is fixed or
determinable; and (4) collectability is reasonably assured. The determination of criteria (2) is based on
management’s judgments regarding whether a continuing performance obligation exists. The determination of
criteria (3) and (4) are based on management’s judgments regarding the nature of the fee charged for products or
services delivered and the collectability of those fees. Allowances are established for estimated uncollectible
amounts, if any.

The Company recognizes revenue from its license and collaboration arrangements, contract services,

product sales and royalties. Revenue arrangements with multiple elements are divided into separate units of
accounting if certain criteria are met, including whether the delivered element has stand-alone value to the
customer and whether there is objective and reliable evidence of the fair value of the undelivered items. The
consideration received is allocated among the separate units based on their respective fair values and the
applicable revenue recognition criteria are applied to each of the separate units. Advance payments received in
excess of amounts earned are classified as deferred revenue until earned.

License and Collaborative Fees

Revenue from non-refundable license, technology access or other payments under license and collaborative

agreements where the Company has a continuing obligation to perform is recognized as revenue over the
expected period of the continuing performance obligation. The Company estimates the performance period at the
inception of the arrangement and reevaluates it each reporting period. This reevaluation may shorten or lengthen
the period over which the remaining revenue is recognized. Changes to these estimates are recorded on a
prospective basis.

F-8

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Milestone payments under collaborative and other arrangements are recognized as revenue upon completion
of the milestone event, once confirmation is received from the third party and collectability is reasonably assured.
This represents the culmination of the earnings process when the Company has no future performance obligations
related to the payment. Milestone payments that are not substantive or that require a continuing performance
obligation on the part of the Company are recognized over the expected period of the continuing performance
obligation. Amounts received in advance are recorded as deferred revenue until the related milestone is
completed.

Contract Revenue

Contract revenue for research and development involves the Company providing research and development

and manufacturing services to collaborative partners, biodefense contractors or others. Revenue for certain
contracts is accounted for by a proportional performance, or output-based, method where performance is based
on estimated progress toward elements defined in the contract. The amount of contract revenue and related costs
recognized in each accounting period are based on management’s estimates of the proportional performance
during the period. Adjustments to estimates based on actual performance are recognized on a prospective basis
and do not result in reversal of revenue should the estimate to complete be extended.

Up-front fees are recognized in the same manner as the final deliverable, which is generally ratably over the

period of the continuing performance obligation. Given the uncertainties of research and development
collaborations, significant judgment is required to determine the duration of the arrangement.

Net Product Sales

Revenue from net product sale are generally recorded in the periods these product sales are earned, in
advance of collection. The product sale revenue and receivables in these instances is based upon communication
with the distribution customers. Product sales are recorded net of allowances and accruals for prompt pay
discounts, volume rebates, and product returns.

Royalty Revenue

Royalty revenue and royalty receivables are generally recorded in the periods these royalties are earned, in
advance of collection. The royalty revenue and receivables in these instances is based upon communication with
collaborative partners or licensees, historical information and forecasted sales trends.

Research and Development Expenses

The Company expenses research and development costs as incurred. Research and development expenses
consist of direct costs such as salaries and related personnel costs, and material and supply costs, and research-
related allocated overhead costs, such as facilities costs. In addition, research and development expenses include
costs related to clinical trials. Expenses resulting from clinical trials are recorded when incurred based, in part on
estimates as to the status of the various trials. From time to time, research and development expenses may
include up-front fees and milestones paid to collaborative partners for the purchase of rights to in-process
research and development. Such amounts are expensed as incurred.

Cash and Cash Equivalents and Short-term Investments

The Company considers all highly liquid debt instruments with maturities of three months or less at the time

the Company acquires them to be cash equivalents.

F-9

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Short-term investments include debt securities classified as available-for-sale. Available-for-sale securities

are stated at fair value, with unrealized gains and losses, net of tax, if any, reported in other comprehensive
income (loss). The estimate of fair value is based on publicly available market information. Realized gains and
losses and declines in value judged to be other-than-temporary on available-for-sale securities are also included
in investment and other income. The Company reviews its instruments for other-than-temporary impairment
whenever the value of the instrument is less than the amortized cost. The cost of investments sold is based on the
specific identification method. Interest and dividends on securities classified as available-for-sale are included in
investment and other income.

Property and Equipment and Long-Lived Assets

Property and equipment is stated at cost less depreciation. Equipment depreciation is calculated using the
straight-line method over the estimated useful lives of the assets (three to seven years). Leasehold improvements,
buildings and building improvements are depreciated using the straight-line method over the shorter of the lease
terms or the useful lives (one to fifteen years).

The Company records impairment losses on long-lived assets used in operations when events and
circumstances indicate that the assets might be impaired and the undiscounted cash flows estimated to be
generated by those assets in the future are less than the carrying amounts of those assets.

Warrants

The Company has issued warrants to purchase shares of its common stock in connection with financing
activities. The Company accounts for some of these warrants as a liability at fair value and others as equity at fair
value. The fair value of the outstanding warrants is estimated using the Black-Scholes Model. The Black-Scholes
Model requires inputs such as the expected term of the warrants, share price volatility and risk-free interest rate.
These inputs are subjective and generally require significant analysis and judgment to develop. For the estimate
of the expected term, the Company uses the full remaining contractual term of the warrant. At March 31, 2012,
the Company changed its expected volatility assumption in the Black-Scholes Model from an estimate of
volatility based on historical stock price volatility observed on XOMA’s underlying stock to a volatility estimate
based on the volatility implied from warrants issued by XOMA in recent private placement transactions. A
market-based volatility rate was determined to be a more precise indicator for the fair value calculation of the
Company’s warrants. The assumptions associated with contingent warrant liabilities are reviewed each reporting
period and changes in the estimated fair value of these contingent warrant liabilities are recognized in other
income (expense).

Income Taxes

The Company accounts for uncertain tax positions in accordance with Accounting Standards Codification

Topic 740, Income Taxes (“ASC 740”). The application of income tax law and regulations are inherently
complex.

ASC 740 provides for the recognition of deferred tax assets if realization of such assets is more likely than

not. Based upon the weight of available evidence, which includes the Company’s historical operating
performance and carry-back potential, the Company has determined that total deferred tax assets should be fully
offset by a valuation allowance.

Net Loss per Share of Common Stock

Basic and diluted net loss per share of common stock is based on the weighted average number of shares of

common stock outstanding during the period.

F-10

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Potentially dilutive securities are excluded from the calculation of loss per share if their inclusion is anti-

dilutive. The following table shows the total outstanding securities considered anti-dilutive and therefore
excluded from the computation of diluted net loss per share (in thousands):

December 31,

2012

2011

2010

Options for common stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convertible preferred stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warrants for common stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5,603
—
13,830

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19,433

3,890
67
1,609

5,566

2,180
254
1,535

3,969

For the years ended December 31, 2012, 2011, and 2010, all outstanding common stock equivalents were

considered anti-dilutive and therefore the calculations of basic and diluted net loss per share are the same.

3. Consolidated Financial Statement Detail

Cash and Cash Equivalents

At December 31, 2012, cash equivalents consisted of demand deposits of $7.8 million and money market
funds of $37.5 million with maturities of less than 90 days at the date of purchase. At December 31, 2011, cash
equivalents consisted of demand deposits of $21.1 million and money market funds of $27.2 million with
maturities of less than 90 days at the date of purchase.

Short-term Investments

At December 31, 2012, short-term investments consisted of U.S. treasury securities of $40.0 million with
maturities of greater than 90 days and less than one year from the date of purchase. At December 31, 2011, the
Company did not have short-term investments.

Foreign Exchange Options

The Company holds debt and may incur revenue and expenses denominated in foreign currencies, which
exposes it to market risk associated with foreign currency exchange rate fluctuations between the U.S. dollar and
the Euro. The Company is required in the future to make principal and accrued interest payments in Euros on its
€15.0 million loan from Les Laboratoires Servier (“Servier”) (See Note 7: Long-Term Debt and Other
Arrangements). In order to manage its foreign currency exposure related to these payments, in May 2011, the
Company entered into two foreign exchange option contracts to buy €1.5 million and €15.0 million in January
2014 and January 2016, respectively. By having these option contracts in place, the Company’s foreign exchange
rate risk is reduced if the U.S. dollar weakens against the Euro. However, if the U.S. dollar strengthens against
the Euro, the Company is not required to exercise these options, but will not receive any refund on premiums
paid.

Upfront premiums paid on these foreign exchange option contracts totaled $1.5 million. The fair values of

these option contracts are revalued at each reporting period and are estimated based on pricing models using
readily observable inputs from actively quoted markets. The fair values of these option contracts are included in
other assets on the consolidated balance sheet and changes in fair value on these contracts are included in other
income (expense) on the consolidated statements of comprehensive loss.

The foreign exchange options were revalued at December 31, 2012 and had an aggregate fair value of $0.5
million. The Company recognized losses of $0.7 million and $0.3 million related to the revaluation for the years
ended December 31, 2012 and 2011, respectively.

F-11

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Receivables

Receivables consisted of the following at December 31, 2012 and 2011 (in thousands):

Trade receivables, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other receivables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$7,477
772

$11,820
512

Total

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

$8,249

$12,332

December 31,

2012

2011

Property and Equipment

Property and equipment consisted of the following at December 31, 2012 and 2011 (in thousands):

December 31,

2012

2011

Equipment and furniture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Buildings, leasehold and building improvements . . . . . . . . . . . . . . .
Construction-in-progress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Land . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 25,734
21,656
1,832
310

$ 33,483
21,490
973
310

Less: Accumulated depreciation and amortization . . . . . . . . . . . . . . .

49,532
(41,389)

56,256
(43,547)

Property and equipment, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 8,143

$ 12,709

Depreciation and amortization expense was $4.1 million, $5.4 million and $5.7 million for the years ended

December 31, 2012, 2011, and 2010, respectively.

Accrued Liabilities

Accrued liabilities consisted of the following at December 31, 2012 and 2011 (in thousands):

December 31,

2012

2011

Accrued clinical trial costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued management incentive compensation . . . . . . . . . . . . . . . . . . .
Accrued payroll and other benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued severance payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 4,702
3,978
2,461
490
1,535

$

140
4,096
3,007
1,207
1,562

Total

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

$13,166

$10,012

Deferred Revenue

In 2012, the Company deferred $5.9 million of revenue from contracts including Servier and NIH and
recognized $9.4 million in revenue. In 2011, the Company deferred $12.7 million of revenue from contracts
including Servier, NIH and Takeda Pharmaceutical Company Limited (“Takeda”) and recognized $17.6 million
in revenue.

F-12

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

4. Collaborative, Licensing and Other Arrangements

Collaborative and Other Agreements

Servier

In December 2010, the Company entered into a license and collaboration agreement with Servier, to jointly

develop and commercialize gevokizumab (formerly referred to as XOMA 052) in multiple indications, which
provided for a non-refundable upfront payment of $15.0 million that was received by the Company in January
2011. The upfront payment was recognized over the eight month period that the initial group of deliverables were
provided to Servier. The Company recognized $14.9 million in revenue relating to this upfront payment during
the year ended December 31, 2011. In addition, the Company received a loan of €15.0 million, which was fully
ufnded in January 2011, with the proceeds converting to $19.5 million at the date of funding. See Note 7: Long-
Term Debt and Other Arrangements. Also, the Company retains development and commercialization rights in
the U.S. and Japan for all indications except cardiovascular disease and diabetes, and an option to reacquire
rights to cardiovascular disease and diabetes indications from Servier in those territories. Servier will fully fund
activities to advance the global clinical development and future commercialization of gevokizumab in
cardiovascular related diseases and diabetes, as well as the first $50.0 million of future gevokizumab global
clinical development and chemistry and manufacturing controls expenses and 50% of further expenses for the
Behçet’s uveitis indication. For the years ended December 31, 2012 and 2011, the Company recorded revenue of
$14.5 million and $34.2 million, respectively, under this agreement, which included the revenue recognized in
2011 relating to the upfront payment.

Under the agreement, the Company is eligible to receive a combination of Euro and USD-denominated,
development and sales milestones for multiple indications aggregating to a potential maximum of approximately
$470 million converted using the December 31, 2012 Euro to US Dollar (“USD”) exchange rate (the “12/31/12
Exchange Rate of 1.3215”) if XOMA reacquires cardiovascular and/or diabetes rights in the U.S. and Japan. If
XOMA does not reacquire these rights, then the milestone payments aggregate to a potential maximum of
approximately $810 million converted using the 12/31/12 Exchange Rate of 1.3215. Servier’s obligation to pay
development and commercialization milestones will continue for so long as Servier is developing or selling
products under the agreement.

The Company is also eligible to receive royalties on gevokizumab sales, which are tiered based on sales

levels and range from a mid-single digit to up to a mid-teens percentage rate. The Company’s right to royalties
with respect to a particular product and country will continue for so long as such product is sold in such country.

NIAID

In July 2006, the Company was awarded a $16.3 million contract to produce monoclonal antibodies for the
treatment of botulism to protect United States citizens against the harmful effects of botulinum neurotoxins used
in bioterrorism. The contract work was performed on a cost plus fixed fee basis. The original contract was for a
three-year period, however the contract was extended into 2010. The Company recognizing revenue as the
services are performed on a proportional performance basis. This work was complete in the third quarter of 2010.
In 2011, the NIH conducted an audit of the Company’s actual data for period from January 1, 2007 through
December 31, 2009 and developed final billing rates for this period. As a result, the Company retroactively
applied these NIH rates to the invoices from this period resulting in an increase in revenue of $2.0 million from
the NIH. Final rates were settled in the first quarter of 2012 through negotiations with the NIH. Upon settlement,
the Company recognized the $2.0 million in revenue in 2012.

In September 2008, the Company announced that it had been awarded a $64.8 million multiple-year contract

funded with federal funds from NIAID, a part of the NIH (Contract No. HHSN272200800028C), to continue

F-13

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

development of anti-botulinum antibody product candidates. The contract work is being performed on a cost plus
fixed fee basis over a three-year period. The Company is recognizing revenue under the arrangement as the
services are performed on a proportional performance basis. In 2011, the NIH conducted an audit of the
Company’s actual data for period from January 1, 2007 through December 31, 2009 and developed final billing
rates for this period. As a result, the Company retroactively applied these NIH rates to the invoices from this
period resulting in an increase in revenue of $1.4 million from the NIH, excluding $0.9 million billed to the NIH
in 2010 resulting from the Company’s performance of a comparison of 2009 calculated costs incurred and costs
billed to the government under provisional rates. Final rates will be settled through negotiations with the NIH.
This revenue has been deferred and will be recognized upon completion of negotiations with and approval by the
NIH. In 2012, the Company recognized revenue of $6.6 million under this contract, compared with $18.6 million
in 2011 and $21.2 million in 2010.

In October 2011, the Company announced that NIAID had awarded the Company a new contract under
Contract No. HHSN272201100031C for up to $28.0 million over 5 years to develop broad-spectrum antitoxins
for the treatment of human botulism poisoning. The contract work is being performed on a cost plus fixed fee
basis over the life of the contract and the Company is recognizing revenue under the arrangement as the services
are performed on a proportional performance basis. In 2012, the Company recognized revenue of $2.5 million
under this contract, compared with $0.1 million in 2011.

Servier – U.S. Perindopril Franchise

On January 17, 2012, the Company announced it had acquired certain U.S. rights to a portfolio of
antihypertensive products from Servier. The portfolio includes ACEON® (perindopril erbumine), a currently
marketed angiotensin converting enzyme (“ACE”) inhibitor, and three FDC product candidates where a form of
proprietary perindopril (perindopril arginine) is combined with another active ingredient (s). The Company
assumed commercialization activities for ACEON in January 2012. In November 2012, the Company announced
that the 837-patient Phase 3 trial for the FDC of perindopril arginine and amlodipine besylate (“FDC1”) met its
primary endpoint. Partial funding for the trial was provided by Servier. The Company expects to pay the balance
of study expenses, consisting primarily of costs generated by its contract research organization, from the profits
generated by its ACEON sales.

In connection with the original agreement, the Company paid a $1.5 million license fee to Servier in the
third quarter of 2010. The Company also is required to pay a royalty on ACEON sales at a rate that is tiered
based on sales levels and ranges from a mid-single digit to a mid-teen percentage rate. If approved, the Company
also will pay a royalty on sales of the FDC product candidates in the mid-teen percentage rate. The FDC royalty
rate is subject to reduction in the event of generic competition or if other intellectual property rights are required.
The Company may be required to pay the following milestones: development milestones aggregating $8.5
million (assuming the Company exercises its options on the additional FDC product candidates) and sales
milestones of up to an aggregate $15.1 million, in each case for all of the FDC product candidates. The Company
also may be required to make certain additional payments if the FDC product candidates receive FDA approval
but certain minimum sales levels are not reached. The Company generally will be responsible for its
development and commercialization expenses, however, Servier partially funded development of FDC1.

By its terms, the arrangement, including XOMA’s obligation to pay royalties and/or development and sales
milestones, will continue until the later of July 2018 or the expiration of the last-to-expire Servier patent licensed
to us under the arrangement, unless terminated earlier. The agreement contains customary termination rights
relating to matters, such as material breach by either party, insolvency of either party or safety issues. Each party
has the right to terminate the arrangement if the FDC1 does not receive FDA approval by December 31, 2014.

F-14

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Servier also has the right to terminate the arrangement if certain aspects of the Company’s commercialization
strategy are not successful and Servier does not consent to an alternative strategy or, as to the FDC product
candidates, if the Company breaches its obligations to certain of its service providers.

Takeda

In November 2006, the Company entered into a fully funded collaboration agreement with Takeda for
therapeutic monoclonal antibody discovery and development. Under the agreement, Takeda will make up-front,
annual maintenance and milestone payments to the Company, fund its research and development and
manufacturing activities for preclinical and early clinical studies and pay royalties on sales of products resulting
from the collaboration. Takeda will be responsible for clinical trials and commercialization of drugs after an
Investigational New Drug Application (“IND”) submission and is granted the right to manufacture once the
product enters into Phase 2 clinical trials. During the collaboration, the Company will discover therapeutic
antibodies against targets selected by Takeda. The Company will recognize revenue on the up-front and annual
payments on a straight-line basis over the expected term of each target antibody discovery, on the research and
development and manufacturing services as they are performed on a time and materials basis, on the milestones
when they are achieved and on the royalties when the underlying sales occur. In 2012, the Company recognized
revenue of $1.2 million under this agreement, compared with $2.0 million in 2011 and $3.6 million in 2010.

Under the terms of this agreement, the Company may receive milestone payments aggregating up to $19.0

million relating to one undisclosed product candidate and low single-digit royalties on future sales of all products
subject to this license. In addition, in the event Takeda were to develop additional future qualifying product
candidates under the terms of the agreement, the Company would be eligible for milestone payments aggregating
up to $20.75 million for each such qualifying product candidate. The Company’s right to milestone payments
expires on the later of the receipt of payment from Takeda of the last amount to be paid under the agreement or
the cessation of all research and development activities with respect to all program antibodies, collaboration
targets and/or collaboration products. The Company’s right to royalties expires on the later of 13.5 years from the
first commercial sale of each royalty-bearing discovery product or the expiration of the last-to-expire licensed
patent.

In February 2009, the Company expanded its existing collaboration agreement with Takeda to provide

Takeda with access to multiple antibody technologies, including a suite of research and development
technologies and integrated information and data management systems. The Company may receive milestones of
up to $3.25 million per discovery product candidate and low single-digit royalties on future sales of all antibody
products subject to this license. The Company’s right to milestone payments expires on the later of the receipt of
payment from Takeda of the last amount to be paid under the agreement or the cessation of all research and
development activities with respect to all program antibodies, collaboration targets and/or collaboration products.
The Company’s right to royalties expires on the later of 10 years from the first commercial sale of such royalty-
bearing discovery product, or the expiration of the last-to-expire licensed patent.

Novartis

In November 2008, the Company restructured its product development collaboration with Novartis entered
into in 2004 for the development and commercialization of antibody products for the treatment of cancer. Under
the restructured agreement, the Company received $6.2 million in cash and $7.5 million in the form of debt
reduction on its existing loan facility with Novartis. In addition, the Company may, in the future, receive
potential milestones of up to $14.0 million and royalty rates ranging from low-double digit to high-teen
percentage rates for two ongoing product programs, HCD122 and LFA 102 and options to develop or receive
royalties on additional programs. In exchange, Novartis received control over the HCD122 and LFA 102

F-15

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

programs, as well as the right to expand the development of these programs into additional indications outside of
oncology. The Company’s right to royalty-style payments expires on the later of the expiration of any licensed
patent covering each product or 20 years from the launch of each product that is produced from a cell line
provided to Novartis by XOMA.

A loan facility of up to $50 million was available to the Company to fund up to 75% of its share of
development expenses incurred beginning in 2005. See Note 7: Long-Term Debt and Other Arrangements for
additional disclosure of the financing arrangement between the Company and Novartis.

Arana

In September 2009, the Company entered into an antibody discovery collaboration with Arana Therapeutics

Limited, a wholly-owned subsidiary of Teva Pharmaceutical Industries Ltd. (“Arana”), involving multiple
proprietary XOMA antibody research and development technologies, including a new antibody phage display
library and a suite of integrated information and data management systems. Arana agreed to pay the Company a
fee of $6.0 million, of which $4.0 million was received in the third quarter of 2009 and the remaining $2.0
million was received in the third quarter of 2010. The Company may be entitled to future milestone payments,
aggregating up to $3.0 million per product, and low single-digit royalties on product sales. The Company’s right
to milestone payments expires on the later of the receipt of payment from Arana of the last amount to be paid
under the agreement, the cessation by Arana of the use of all research and development technologies or the
cessation by Arana of the exercise of the patent rights granted to them. The Company’s right to royalties expires
five years from the first commercial sale of each royalty-bearing product.

Kaketsuken

In October 2009, the Company entered into an antibody discovery collaboration with The Chemo-Sero-

Therapeutic Research Institute, a Japanese research foundation known as Kaketsuken, involving multiple
proprietary XOMA antibody research and development technologies, including a new antibody phage display
library and a suite of integrated information and data management systems. Kaketsuken agreed to pay the
Company a fee of $8.0 million, of which $6.0 million was received in the fourth quarter of 2009 and the
remaining $2.0 million was received in the fourth quarter of 2010. The Company may be entitled to future
milestone payments, aggregating up to $0.2 million per product, and low single-digit royalties on product sales.
The Company’s right to milestone payments expires upon the receipt of payment from Kaketsuken of the last
amount to be paid pursuant to the agreement. The Company’s right to royalties expires 15 years from the first
commercial sale of each royalty-bearing discovery product.

AVEO Pharmaceuticals, Inc. (“AVEO”)

In April 2006, the Company entered into an agreement with AVEO to utilize XOMA’s HE ™ technology to

humanize AV-299 under which AVEO paid the Company an up-front license fee and development milestones.
Under this agreement the Company created four HE ™ versions of the original AV-299, all of which met design
goals and from which AVEO selected one as its lead development candidate.

In September 2006, as a result of the successful humanization of AV-299, the Company entered into a
second agreement with AVEO to manufacture and supply AV-299 in support of early clinical trials. Under the
agreement, the Company created AV-299 production cell lines, conducted process and assay development and
performed Good Manufacturing Practices (“cGMP”) manufacturing activities. AVEO retains all development
and commercialization rights to AV-299 and may be required to pay XOMA annual maintenance fees, additional
development milestone payments aggregating up to $6.3 million and low single-digit royalties on product sales in

F-16

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

the future. The Company’s right to milestone payments expires upon full satisfaction of all financial obligations
of AVEO pursuant to the agreement. The Company’s right to royalties expires on the later of 15 years from the
first commercial sale of each royalty-bearing product or the expiration of the last-to-expire licensed patent.

In April 2007, Merck/Schering-Plough entered into a research, development and license agreement with
AVEO concerning AV-299 and other anti-HGF molecules, under which AVEO assigned its entire right, title and
interest in, to and under its manufacturing agreement with XOMA to Merck/Schering-Plough. In the third quarter
of 2010, AVEO regained its worldwide rights from Merck/Schering-Plough to develop and commercialize AV-
299 and other anti-HGF molecules. In 2012, the Company recognized revenue of $0.1 million under this
agreement, compared with $0.1 million in 2011 and $0.9 million in 2010.

UCB

In December 1998, the Company licensed its bacterial cell expression technology to Celltech Therapeutics
Ltd., now UCB Celltech, a branch of UCB, which utilizes this technology in the production of CIMZIA ® for the
treatment of moderate-to-severe Crohn’s disease and moderate-to-severe rheumatoid arthritis. The license
provides for a low single-digit royalty on sales of CIMZIA ® in those countries where the bacterial cell
expression technology is patented, which includes the U.S. and Canada. In August 2010, the Company sold its
royalty interest in CIMZIA ® to OrbiMed Advisors, LLC for gross proceeds of $4.0 million. In connection with
this transaction, XOMA CDRA LLC, a wholly owned bankruptcy-remote entity, was established to hold the
rights, title, and interests under the license agreement with UCB. As a bankruptcy-remote entity, XOMA CDRA
LLC has a corporate existence, assets, properties, and creditors separate from the Company’s. Accordingly, in
calculating the value of its own assets, the Company has not ascribed any value to the assets owned by XOMA
CDRA LLC, and the assets of XOMA CDRA LLC will not be available to pay any creditors of the Company.
The Company did not recognize revenue under this agreement in 2012 or 2011. During 2010, including the sale
of its royalty interest in CIMZIA ® , the Company recognized $4.2 million in revenue. The Company no longer
receives royalties on sales of CIMZIA ® .

Genentech, Inc., a wholly-owned member of the Roche Group (referred to herein as “Genentech”)

In April 1996, the Company entered into a collaboration agreement with Genentech for the development of
RAPTIVA ® . In March 2003, it entered into amended agreements which called for the Company to share in the
development costs and to receive a 25% share of future U.S. operating profits and losses and a royalty on sales
outside the United States. The amended agreements also called for Genentech to finance the Company’s share of
development costs up until first FDA marketing approval via a convertible subordinated loan, and its share of
pre-launch marketing and sales costs via an additional commercial loan facility. Under the loan agreement, upon
FDA approval of the product, which occurred in October 2003, the Company elected to pay $29.6 million of the
development loan in convertible preference shares, which are convertible into approximately 0.3 million shares
of common stock at a price of $116.25 per share. In April 2011, the convertible preference shares were converted
by Genentech. The $29.6 million liquidation preference associated with the convertible preference shares was
eliminated as a result of this conversion.

Licensing Agreements

XOMA has granted more than 60 licenses to biotechnology and pharmaceutical companies to use the
Company’s patented and proprietary technologies relating to bacterial expression of recombinant pharmaceutical
products. In exchange, the Company receives license and other fees as well as access to certain of these
companies’ antibody display libraries, intellectual property and/or services that complement the Company’s
existing development capabilities and support the Company’s own antibody product development pipeline.

F-17

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Certain of these agreements also provide releases of the licensee companies and their collaborators from
claims under the XOMA patents arising from past activities using the companies’ respective technologies to the
extent they also used XOMA’s antibody expression technology. Licensees are generally also allowed to use
XOMA’s technology in combination with their own technology in future collaborations.

Pfizer

In August 2007, the Company entered into a license agreement with Pfizer Inc. (“Pfizer”) for non-exclusive,

worldwide rights for XOMA’s patented bacterial cell expression technology for research, development and
manufacturing of antibody products. Under the terms of the agreement, the Company received a license fee
payment of $30 million in 2007.

From 2010 through 2012, the Company received milestone payments relating to six undisclosed product
candidates. The Company may also be eligible for additional milestone payments aggregating up to $8.3 million
relating to these six product candidates and low single-digit royalties on future sales of all products subject to this
license. In addition, the Company may receive potential milestone payments aggregating up to $1.7 million for
each additional qualifying product candidate. The Company’s right to milestone payments expires on the later of
the expiration of the last-to-expire licensed patent or the tenth anniversary of the effective date. The Company’s
right to royalties expires upon the expiration of the last-to-expire licensed patent. The Company will recognize
revenue on milestones when they are achieved and on royalties when the underlying sales occur.

5.

Streamlining and Restructuring Charges

In January 2012, the Company implemented a streamlining of operations, which resulted in a restructuring
plan designed to sharpen its focus on value-creating opportunities led by gevokizumab and its unique antibody
discovery and development capabilities. The restructuring plan included a reduction of XOMA’s personnel by 84
positions, or 34%, of which 52 were eliminated immediately and the remainder eliminated as of April 6, 2012.
These staff reductions resulted primarily from the Company’s decisions to utilize a contract manufacturing
organization for Phase 3 and commercial antibody production, and to eliminate internal research functions that
are non-differentiating or that can be obtained cost effectively by contract service providers.

During 2012, in connection with this streamlining of operations, the Company recorded charges of $2.0

million, related to severance, other termination benefits and outplacement services. The Company does not
expect to incur additional restructuring charges related to severance, other termination benefits and outplacement
services.

In 2012, the Company vacated and subleased leased facilities, which housed its large scale manufacturing

operations and associated quality functions. During 2012, the Company recorded charges of $0.6 million related
to moving and other facility costs in connection with the exit of these buildings. The Company does not expect to
incur any significant restructuring charges during 2013 in connection with lease payments for these buildings as
these payments will be offset by future sublease income.

In the first half of 2012, the Company performed an impairment analysis of property and equipment and
leasehold improvements related to its manufacturing operations. Since the estimated undiscounted future cash
inflows from a certain group of assets were less than the carrying value, the Company determined that these
assets were impaired and recorded a restructuring charge of $0.8 million. Further, the Company changed the
useful life of certain property and equipment and leasehold improvements impacted by its plans to vacate two
leased buildings. As a result, the Company recorded accelerated depreciation of $1.3 million as a restructuring
charge. In the second half of 2012, the Company entered into an agreement for the sublease of the

F-18

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

aforementioned buildings and sale of the property and equipment. The Company recorded an additional $0.4
million restructuring charge relating to the loss on sale of these assets. The Company does not expect to incur
additional restructuring charges during 2013 related to the property and equipment and leasehold improvements.

The current and long-term portions of the outstanding restructuring liabilities are included in accrued and

other liabilities and other liabilities – long-term on the consolidated balance sheets and are based upon
restructuring charges recognized as of December 31, 2012 and 2011 in connection with the Company’s
restructuring plans. As of December 31, 2012 and 2011, the components of these liabilities are shown below (in
thousands):

Employee
Severance and
Other Benefits

Facility
Charges (1)

Asset Impairment
and Accelerated
Depreciation (2)

Balance at December 31, 2011 . . . . . . . . . .
Restructuring charges . . . . . . . . . . . . . . . . .
Cash payments . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from sale of assets . . . . . . . . . . . .
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . .

$ —
2,027
(2,027)
—
—

Balance at December 31, 2012 . . . . . . . . . .

$ —

$ 162
587
(689)
—
15

$ 75

$ —
2,460
—
461
(2,921)

$ —

Employee
Severance and
Other Benefits

Facility
Charges (1)

Asset Impairment
and Accelerated
Depreciation (2)

Balance at December 31, 2010 . . . . . . . . . .
Restructuring charges . . . . . . . . . . . . . . . . .
Cash payments . . . . . . . . . . . . . . . . . . . . . . .
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . .

Balance at December 31, 2011 . . . . . . . . . .

$ —
—
—
—

$ —

$ 243
—
(113)
32

$ 162

$ —
—
—
—

$ —

Total

$

162
5,074
(2,716)
461
(2,906)

$

75

Total

$

243
—
(113)
32

$

162

(1)

Includes moving and relocation costs, and lease payments, net of sublease payments.

(2) Restructuring charges include non-cash impairments and accelerated depreciation of property and

equipment and leasehold improvements; however, these amounts are excluded from the restructuring
accrual.

6.

Fair Value Measurements

Fair value is defined as the price 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. The Company applies ASC 820,
which establishes a framework for measuring fair value and a fair value hierarchy that prioritizes the inputs used
in valuation techniques. ASC 820 describes a fair value hierarchy based on three levels of inputs, of which the
first two are considered observable and the last unobservable, that may be used to measure fair value which are
the following:

Level 1 – Quoted prices in active markets for identical assets or liabilities.

Level 2 – Observable inputs other than quoted prices in active markets for similar assets or liabilities.

Level 3 – Unobservable inputs.

F-19

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

The following tables set forth the Company’s fair value hierarchy for its financial assets and liabilities
measured at fair value on a recurring basis as of December 31, 2012 and 2011 are classified as follows (in
thousands):

Fair Value Measurements at December 31, 2012 Using

Quoted Prices in
Active Markets
for Identical
Assets

(Level 1)

Significant
Other
Observable
Inputs

(Level 2)

Significant
Unobservable
Inputs

(Level 3)

Total

Assets:

Money market funds (1) . . . . . . . . . .
U.S. treasury securities . . . . . . . . . . .
Foreign exchange options . . . . . . . .

37,461
39,987
—

Total . . . . . . . . . . . . . . . . . . . . .

$77,448

—
—
488

$488

—
—
—

37,461
39,987
488

$ —

$77,936

Liabilities:

Contingent warrant liabilities . . . . . .

$ —

$—

$15,001

$15,001

Fair Value Measurements at December 31, 2011 Using

Quoted Prices in
Active Markets
for Identical
Assets

(Level 1)

Significant
Other
Observable
Inputs

(Level 2)

Significant
Unobservable
Inputs

(Level 3)

Total

Assets:

Money market funds (1) . . . . . . . . . .
Foreign exchange options . . . . . . . .

Total . . . . . . . . . . . . . . . . . . . . .

$27,222
—

$27,222

$ —
1,202

$1,202

$—
—

$—

$27,222
1,202

$28,424

Liabilities:

Contingent warrant liabilities . . . . . .

$ —

$ —

$379

$

379

(1)

Included in cash and cash equivalents

The fair value of the foreign exchange options at December 31, 2012 and 2011 was determined using
readily observable market inputs from actively quoted markets obtained from various third-party data providers.
These inputs, such as spot rate, forward rate and volatility have been derived from readily observable market
data, meeting the criteria for Level 2 in the fair value hierarchy.

The fair value of the warrant liabilities at December 31, 2012 and 2011 was determined using the Black-

Scholes Model, which requires inputs such as the expected term of the warrants, volatility and risk-free interest
rate. These inputs are subjective and generally require significant analysis and judgment to develop. At
March 31, 2012, the Company changed its expected volatility assumption in the Black-Scholes Model from an
estimate of volatility based on historical stock price volatility observed on XOMA’s underlying stock to a
volatility estimate based on the volatility implied from warrants issued by XOMA in recent private placement
transactions. A market-based volatility rate was determined to be a more precise indicator for the fair value
calculation of the Company’s warrants.

F-20

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

The fair value of the contingent warrant liabilities was estimated using the following range of assumptions

at December 31, 2012 and 2011:

December 31,
2012

December 31,
2011

Expected volatility . . . . . . . . . . . . . . . . . . . . . .

40% 102.1 - 103.2%

Risk-free interest rate . . . . . . . . . . . . . . . . . . . .

0.3% - 0.7%

0.4%

Expected term . . . . . . . . . . . . . . . . . . . . . . . . .

1.9 - 4.2 years

2.9 - 3.1 years

The following table provides a summary of changes in the fair value of the Company’s Level 3 financial

liabilities for the years ended December 31, 2012 and 2011 (in thousands):

Warrant
Liabilities

Balance at December 31, 2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 4,245
(3,866)
Net decrease in fair value of contingent warrant liabilities upon revaluation . . . . . . .
379
Balance at December 31, 2011 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6,390
Initial fair value of warrants issued in March 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . .
(940)
Reclassification of contingent warrant liability to equity upon exercise of warrants . . .
9,172
Net increase in fair value of contingent warrant liabilities upon revaluation . . . . . . .

Balance at December 31, 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $15,001

7. Long-Term Debt and Other Arrangements

Novartis Note

In May 2005, the Company executed a secured note agreement with Novartis (then Chiron Corporation),

which is due and payable in full in June 2015. Under the note agreement, the Company borrowed semi-annually
to fund up to 75% of the Company’s research and development and commercialization costs under its
collaboration arrangement with Novartis, not to exceed $50 million in aggregate principal amount. Interest on the
principal amount of the loan accrues at six-month LIBOR plus 2%, which was equal to 2.51% at December 31,
2012, and is payable semi-annually in June and December of each year. Additionally, the interest rate resets in
June and December of each year. At the Company’s election, the semi-annual interest payments can be added to
the outstanding principal amount, in lieu of a cash payment, as long as the aggregate principal amount does not
exceed $50 million. The Company has made this election for all interest payments thus far. Loans under the note
agreement are secured by the Company’s interest in its collaboration with Novartis, including any payments
owed to it thereunder.

At December 31, 2012 and 2011, the outstanding principal balance under this note agreement was $14.4

million and $14.0 million. Pursuant to the terms of the arrangement as restructured in November 2008, the
Company will not make any additional borrowings under the Novartis note. Accrued interest of $0.4 million,
$0.3 million and $0.4 million was added to the principal balance of the loan for the years ended December 31,
2012, 2011 and 2010, respectively.

Servier Loan

In December 2010, in connection with the license and collaboration agreement entered into with Servier, the

Company executed a loan agreement with Servier (the “Servier Loan Agreement”), which provided for an
advance of up to €15.0 million. Theloan was fully funded in January 2011, with the proceeds converting to

F-21

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

approximately $19.5 million. The loan is secured by an interest in XOMA’s intellectual property rights to all
gevokizumab indications worldwide, excluding certain rights in the U.S. and Japan. Interest is calculated at a
floating rate based on a Euro Inter-Bank Offered Rate (“EURIBOR”) and subject to a cap. The interest rate is
reset semi-annually in January and July of each year. The interest rate for the initial interest period was 3.22%.
The interest rate has been 3.83% for the six-month period from July 2011 through January 2012, 3.54% for the
six-month period from January 2012 through July 2012, 2.80% for the six-month period from July 2012 through
January 2013 and 2.33% for the six-month period from January 2013 through July 2013. Interest is payable semi-
annually; however, the Servier Loan Agreement provides for a deferral of interest payments over a period
specified in the agreement. During the deferral period, accrued interest will be added to the outstanding principal
amount for the purpose of interest calculation for the next six-month interest period. On the repayment
commencement date, all unpaid and accrued interest shall be paid to Servier and thereafter, all accrued and
unpaid interest shall be due and payable at the end of each six-month period. The loan matures in 2016; however,
after a specified period prior to final maturity, the loan is to be repaid (i) at Servier’s option, by applying up to a
significant percentage of any milestone or royalty payments owed by Servier under the Company’s collaboration
agreement and (ii) using a significant percentage of any upfront, milestone or royalty payments the Company
receives from any third party collaboration or development partner for rights to gevokizumab in the U.S. and/or
Japan. In addition, the loan becomes immediately due and payable upon certain customary events of default. At
December 31, 2012, the outstanding principal balance under this loan was $19.8 million using the 12/31/12
Exchange Rate of 1.3215. The Company recorded an unrealized foreign exchange loss of $0.4 million and an
unrealized foreign exchange gain of $0.1 million for the years ended December 31, 2012 and 2011, respectively,
related to the re-measurement of the loan.

The loan has a stated interest rate lower than the market rate based on comparable loans held by similar
companies, which represents additional value to the Company. The Company recorded this additional value as a
discount to the face value of the loan amount, at its fair value of $8.9 million. The fair value of this discount,
which was determined using a discounted cash flow model, represents the differential between the stated terms
and rates of the loan, and market rates. Based on the association of the loan with the collaboration arrangement,
the Company recorded the offset to this discount as deferred revenue.

The loan discount is amortized under the effective interest method over the expected five-year life of the

loan. The Company recorded non-cash interest expense of $1.4 million during both the years ended
December 31, 2012 and 2011, resulting from the amortization of the loan discount. At December 31, 2012, the
net carrying value of the loan was $14.2 million. The Company recorded an unrealized foreign exchange gain of
$0.1 million and an unrealized foreign exchange loss of $0.6 million for the years ended December 31, 2012 and
2011, respectively related to the re-measurement of the loan discount.

The Company believes that realization of the benefit and the associated deferred revenue is contingent on

the loan remaining outstanding over the five-year contractual term of the loan. If the Company were to stop
providing service under the collaboration arrangement and the arrangement is terminated, the maturity date of the
loan would be accelerated and a portion of measured benefit would not be realized. As the realization of the
benefit is contingent, in part, on the provision of future services, the Company is recognizing the deferred
revenue over the expected five-year life of the loan. The deferred revenue is amortized under the effective
interest method, and the Company recorded $1.4 million of related non-cash revenue during both the years ended
December 31, 2012 and 2011.

General Electric Capital Corporation Term Loan

In December 2011, the Company entered into a loan agreement (the “GECC Loan Agreement”) with
General Electric Capital Corporation (“GECC”), under which GECC agreed to make a term loan in an aggregate

F-22

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

principal amount of $10 million (the “Term Loan”) to the Company, and upon execution of the GECC Loan
Agreement, GECC funded the Term Loan. As security for its obligations under the GECC Loan Agreement, the
Company granted a security interest in substantially all of its existing and after-acquired assets, excluding its
intellectual property assets (such as those relating to its gevokizumab and anti-botulism products). The Term
Loan accrued interest at a fixed rate of 11.71% per annum and was to be repaid over a period of 42 consecutive
equal monthly installments of principal and accrued interest and was due and payable in full on June 15, 2015.
The Company incurred debt issuance costs of approximately $1.3 million in connection with the Term Loan and
was required to pay a final payment fee equal to $500,000 on the maturity date, or such earlier date as the Term
Loan is paid in full. The debt issuance costs and final payment fee were being amortized and accreted,
respectively, to interest expense over the term of the Term Loan using the effective interest method.

In connection with the GECC Loan Agreement, the Company issued to GECC unregistered warrants that

entitle GECC to purchase up to an aggregate of 263,158 unregistered shares of XOMA common stock at an
exercise price equal to $1.14 per share. These warrants are exercisable immediately and have a five-year term.
The Company allocated the aggregate proceeds of the GECC Term Loan between the warrants and the debt
obligation based on their relative fair values. The fair value of the warrants issued to GECC was determined
using the Black-Scholes Model. The warrants’ fair value of $0.2 million was recorded as a discount to the debt
obligation and was being amortized over the term of the loan using the effective interest method.

In September 2012, The Company entered into an amendment to the GECC Loan Agreement providing for

an additional term loan in the amount of $4.6 million, increasing the term loan obligation to $12.5 million (the
“Amended Term Loan”) and providing for an interest-only monthly repayment period following the effective
date of the amendment through March 1, 2013, at a stated interest rate of 10.9% per annum. Thereafter, the
Company is obligated to make monthly principal payments of $347,222, plus accrued interest, over a 27-month
period commencing on April 1, 2013, and through June 15, 2015, at which time the remaining outstanding
principal amount of $3.1 million, plus accrued interest, is due. The Company incurred debt issuance costs of
approximately $0.2 million and are required to make a final payment fee in the amount of $875,000 on the date
upon which the outstanding principal amount is required to be repaid in full. This final payment fee replaced the
original final payment fee of $500,000. The debt issuance costs and final payment fee are being amortized and
accreted, respectively, to interest expense over the term of the Amended Term Loan using the effective interest
method.

In connection with the amendment, on September 27, 2012 the Company issued to GECC unregistered stock

purchase warrants, which entitle GECC to purchase up to an aggregate of 39,346 shares of XOMA common
stock at an exercise price equal to $3.54 per share. These warrants are exercisable immediately and have a five-
year term. The warrants’ fair value of $0.1 million was recorded as a discount to the debt obligation and is being
amortized over the term of the loan using the effective interest method. The warrants are classified in permanent
equity on the condensed consolidated balance sheets.

The Amended Term Loan does not change the remaining terms of the GECC Loan Agreement. The GECC

Loan Agreement contains customary representations and warranties and customary affirmative and negative
covenants, including restrictions on the ability to incur indebtedness, grant liens, make investments, dispose of
assets, enter into transactions with affiliates and amend existing material agreements, in each case subject to
various exceptions. In addition, the GECC Loan Agreement contains customary events of default that entitle
GECC to cause any or all of the indebtedness under the GECC Loan Agreement to become immediately due and
payable. The events of default include any event of default under a material agreement or certain other
indebtedness.

F-23

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

The Company may prepay the Amended Term Loan voluntarily in full, but not in part, and any voluntary

and certain mandatory prepayments are subject to a prepayment premium of 3% in the first year after the
effective date of the loan amendment, 2% in the second year and 1% thereafter, with certain exceptions. The
Company will also be required to pay the $875,000 final payment fee in connection with any voluntary or
mandatory prepayment. On the effective date of the loan amendment, the Company paid an accrued final
payment fee in the amount of $0.2 million relating to the original final payment fee of $500,000.

At December 31, 2012, the outstanding principal balance under the Amended Term Loan was $12.5 million.

Aggregate future principal and final fee payments of the Company’s total interest bearing obligations—

long-term as of December 31, 2012 are as follows (in thousands):

Year Ending December 31,

2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2015 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2016 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Less current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total

3,472
4,167
20,167
19,823

47,629
(3,472)

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$44,157

Interest Expense

Interest expense and amortization of debt issuance costs and discounts, recorded as other expense in the
consolidated statements of comprehensive loss for the year ended December 31, 2012, 2011 and 2010 are shown
below (in thousands):

Year ended December 31,

2012

2011

2010

Interest expense
Servier loan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GECC term loan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Novartis note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$2,097
1,850
397
43

$2,087
—
341
34

Total interest expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$4,387

$2,462

$—
—
354
31

$385

8.

Income Taxes

The total (benefit) provision for income taxes consists of the following (in thousands):

Federal income tax (benefit) provision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total

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

Year ended December 31,

2012

$(74)

$(74)

2011

$15

$15

2010

$27

$27

The Company has significant losses in 2012, 2011 and 2010 and as such there was no material income tax
expense for the years ended December 31, 2012, 2011 and 2010. The income tax benefit in 2012 primarily relates
to federal refundable credit true-up from prior year.

F-24

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

The significant components of net deferred tax assets as of December 31, 2012 and 2011 were as follows (in

millions):

December 31,

2012

2011

Capitalized research and development expenses . . . . . . . . . . . . . . . . . . . . . . . . . .
Net operating loss carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research and development and other credit carryforwards . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 51.5
150.8
8.5
23.3

$ 68.7
135.7
21.6
14.1

Total deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valuation allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

234.1
(234.1)

240.1
(240.1)

Net deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ —

$ —

The net (decrease) increase in the valuation allowance was $(6.0) million, $25.8 million and $24.4 million

for the years ended December 31, 2012, 2011 and 2010, respectively.

As of December 31, 2012, the Company had federal net operating loss carry-forwards of approximately
$137.1 million, state net operating loss carry-forwards of approximately $134.9 million and foreign net operating
loss carry-forwards of approximately $772.3 million to offset future taxable income. The net operating loss
carry-forwards include $0.5 million which relates to stock option deductions that will be recognized through
additional paid in capital when utilized. As such, these deductions are not reflected in the Company’s deferred
tax assets. No federal net operating loss carry-forward expired in 2012, 2011 and 2010. California net operating
losses of $10.4 million, $9.5 million and $0.3 million expired in the years 2012, 2011 and 2010, respectively.
There is no expiration for the foreign net operating loss.

ASC 740 provides for the recognition of deferred tax assets if realization of such assets is more likely than

not. Based upon the weight of available evidence, which includes the Company’s historical operating
performance and carry-back potential, the Company has determined that total deferred tax assets should be fully
offset by a valuation allowance.

Based on an analysis under Section 382 of the Internal Revenue Code (which subjects the amount of pre-

change NOLs and certain other pre-change tax attributes that can be utilized to an annual limitation), the
Company experienced ownership changes in 2009 and 2012 which substantially limit the future use of its pre-
change NOLs and certain other pre-change tax attributes per year. The Company has excluded the NOLs and
R&D credits that will expire as a result of the annual limitations in the deferred tax assets as of December 31,
2012. To the extent that the Company does not utilize its carry-forwards within the applicable statutory carry-
forward periods, either because of Section 382 limitations or the lack of sufficient taxable income, the carry-
forwards will expire unused.

The Company files income tax returns in the U.S. federal jurisdiction, State of California, and Ireland. The

Internal Revenue Service has completed an audit of the Company’s 2009 and 2010 federal income tax returns
which resulted in no change. The Company’s federal income tax returns for tax years 2011 and beyond remain
subject to examination by the Internal Revenue Service. The Company’s California and Irish income tax returns
for tax years 2008 and beyond remain subject to examination by the Franchise Tax Board and Irish Revenue
Commissioner. In addition, all of the net operating losses and research and development credit carry-forwards
that may be used in future years are still subject to adjustment.

F-25

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

The following table summarizes the Company’s activity related to its unrecognized tax benefits (in

thousands):

Balance at January 1, 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Increase related to current year tax position . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Increase related to prior year tax position . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Balance at December 31, 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

December 31,
2012

$ —
49
4,054

$4,103

A total of $3.0 million of the unrecognized tax benefits would affect the Company’s effective tax rate. The

Company currently has a full valuation allowance against its U.S. net deferred tax assets which would impact the
timing of the effective tax rate benefit should any of these uncertain tax positions be favorably settled in the
future.

The Company does not expect the unrecognized tax benefits to change significantly over the next twelve

months. The Company will recognize interest and penalties accrued on any unrecognized tax benefits as a
component of income tax expense. As of December 31, 2012, the Company has not accrued interest or penalties
related to uncertain tax positions.

9. Compensation and Other Benefit Plans

The Company grants qualified and non-qualified stock options, restricted stock units (“RSUs”), common
stock and other stock-based awards under various plans to directors, officers, employees and other individuals.
Stock options are granted at exercise prices of not less than the fair market value of the Company’s common
stock on the date of grant. Generally, stock options granted to employees fully vest four years from the grant date
and expire ten years from the date of the grant or three months from the date of termination of employment
(longer in case of death or certain retirements). However, certain options granted to employees vest monthly or
immediately, certain options granted to directors vest monthly over one year or three years and certain options
may fully vest upon a change of control of the Company or may accelerate based on performance-driven
measures. Additionally, the Company has an Amended and Restated Employee Stock Purchase Plan (“ESPP”)
that allows employees to purchase Company shares at a purchase price equal to 95% of the closing price on the
exercise date.

Employee Stock Purchase Plan

Under the ESPP plan approved by the Company’s stockholders, the Company is authorized to issue up to

233,333 shares of common stock to employees through payroll deductions at a purchase price per share equal to
95% of the closing price of XOMA shares on the exercise date. An employee may elect to have payroll
deductions made under the ESPP for the purchase of shares in an amount not to exceed 15% of the employee’s
compensation.

In 2012, 2011, and 2010, employees purchased 17,054, 30,044 and 5,903 shares of common stock,

respectively, under the ESPP. Net payroll deductions under the ESPP totaled $46,000, $54,000 and $41,000 for
2012, 2011 and 2010, respectively.

Deferred Savings Plan

Under section 401(k) of the Internal Revenue Code of 1986, the Board of Directors adopted, effective
June 1, 1987, a tax-qualified deferred compensation plan for employees of the Company. Participants may make

F-26

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

contributions which defer up to 50% of their eligible compensation per payroll period, up to a maximum for 2012
of $17,000 (or $22,500 for employees over 50 years of age). The Company may, at its sole discretion, make
contributions each plan year, in cash or in shares of the Company’s common stock, in amounts which match up
to 50% of the salary deferred by the participants. The expense related to these contributions was $0.8 million,
$1.1 million and $1.0 million for the years ended December 31, 2012, 2011 and 2010, respectively, and 100%
was paid in common stock in each year.

Stock Option Plans

Historically, option grants intended as long-term incentive compensation have been made pursuant to the
Company’s 1981 Share Option Plan (the “Option Plan”) and Restricted Share Plan (the “Restricted Plan”). In
May of 2010, the Compensation Committee and the full Board adopted, and in July of 2010 the Company’s
stockholders approved, a new equity-based compensation plan, the 2010 Long Term Incentive and Share Award
Plan, which has since been amended and restated as the Amended and Restated 2010 Long Term Incentive and
Stock Award Plan (the “Long Term Incentive Plan”). The Long Term Incentive Plan is intended to consolidate
the Company’s long-term incentive compensation under a single plan, by replacing the Option Plan, the
Restricted Plan and the 1992 Directors Share Option Plan (the “Directors Plan”) going forward, and to provide a
more current set of terms pursuant to which to provide this type of compensation.

The Long Term Incentive Plan grants stock options, RSUs, and other stock-based awards to eligible
employees, consultants and directors. No further grants or awards will be made under the Option Plan, the
Restricted Share Plan or the Directors Plan. Shares underlying options previously issued under the Option Plan,
the Restricted Share Plan or the Directors Plan that are currently outstanding will, upon forfeiture, cancellation,
surrender or other termination, become available under the Long Term Incentive Plan. Stock-based awards
granted under the Long Term Incentive Plan may be exercised when vested and generally expire ten years from
the date of the grant or three to six months from the date of termination of employment (longer in case of death
or certain retirements). Vesting periods vary based on awards granted, however, certain stock-based awards may
vest immediately or may accelerate based on performance-driven measures.

Up to 15,753,331 shares are authorized for issuance under the stock option plans. As of December 31, 2012,

options and RSUs covering 8,649,331 shares of common stock were outstanding under the stock option plans.

Stock Options

In 2012, the Board of Directors of the Company approved grants under the Amended and Restated 2010
Long Term Incentive Plan for an aggregate of 2,351,445 stock options to certain employees and directors of the
Company. The options vest monthly over four years for employees and one year for directors.

In October 2011, the Board of Directors of the Company approved a grant under the Long Term Incentive

Plan for an aggregate of 1,097,926 stock options to certain employees of the Company. These stock options
include immediate vesting in an amount equal to each employee’s percentage of outstanding options that are
exercisable immediately prior to this grant. The remaining portion will vest monthly over two years.

On August 31, 2011, the Company announced that Steven B. Engle resigned as Chairman of the Board,
Chief Executive Officer and President of the Company. In the third quarter of 2011, the Company incurred a
stock-based compensation charge of approximately $0.7 million, due to a modification to Mr. Engle’s stock
options as a result of his resignation.

In December of 2010, the Board of Directors of the Company approved a company-wide grant of stock
options under the Long Term Incentive Plan and, in the first quarter of 2011, the options for 1,430,840 shares

F-27

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

became effective. 1,040,220 of these options were granted subject to stockholder approval of an increase in the
number of shares available under the Long Term Incentive Plan. On May 26, 2011, stockholder approval was
obtained at the Company’s annual general meeting of shareholders. A portion of the 2011 annual options granted
include immediate vesting terms with the remainder of the options vesting monthly over two years for employees
and one year for directors.

In March of 2010, the Board of Directors of the Company approved a company-wide grant of an aggregate
of 865,806 stock options. This grant included 856,006 options that were issued as part of the Company’s annual
incentive compensation review, of which 596,666 options were granted subject to stockholder approval of an
increase in the number of shares available under the Company’s existing stock option plans. On July 21, 2010
stockholder approval was obtained at the Company’s annual general meeting of shareholders. The options
granted as part of this annual incentive compensation review will vest monthly over four years.

Stock Option Plans Summary

A summary of the status of the Company’s stock option plans as of December 31, 2012, 2011 and 2010, and

changes during the years ended on those dates is presented below:

Options:

2012

2011

2010

Shares

Price*

Shares

Price*

Shares

Price*

Outstanding at beginning of year . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited, expired or cancelled . . . . . . . . . . . . . .

5,053,435
(90,252)
(526,245)

$12.55
1.68
15.84

2,331,450

—

(198,181)

$25.36
—
35.56

1,520,102
(19)
(166,897)

$38.40
8.40
37.26

Outstanding at end of year . . . . . . . . . . . . . . . . .

6,788,383

8.99

5,053,435

12.55

2,331,450

25.36

Exercisable at end of year

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

4,276,834

$12.42

3,366,807

$16.33

1,259,272

$36.51

* Weighted-average exercise price

At December 31, 2012, there were 6,484,641 stock options vested and expected to vest with a weighted-
average exercise price per share of $9.28. The weighted average remaining contractual term of outstanding stock
options at December 31, 2012 was 7.4 years and there was an aggregate intrinsic value of $1.5 million. The
weighted average remaining contractual term of exercisable stock options at December 31, 2012 was 6.5 years
and there was an aggregate intrinsic value of $0.8 million.

Restricted Stock Units

In 2012, the Board of Directors of the Company approved grants under the Amended and Restated 2010

Long Term Incentive Plan for an aggregate of 1,292,923 RSUs to certain employees and directors of the
Company. The RSUs vest annually over three years in equal increments.

In October 2011, the Board of Directors of the Company approved a company-wide grant under the Long

Term Incentive Plan for an aggregate of 1,177,082 RSUs. The RSUs vest annually over three years in equal
increments.

RSUs held by employees who qualify for retirement age (defined as employees that are a minimum of 55
years of age and the sum of their age plus years of full-time employment with the Company exceeds 70 years)
vest immediately.

F-28

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Unvested RSU activity for the year ended December 31, 2012 is summarized below:

Unvested balance at December 31, 2011 . . . . . . . . . . . . . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Number of
Shares

903,874
1,292,923
(590,862)
(212,055)

Unvested balance at December 31, 2012 . . . . . . . . . . . . . . . . . . . . . . . . .

1,393,880

Weighted-
Average Grant-
Date Fair Value

$1.69
2.83
2.27
1.69

$2.75

The total grant-date fair value of RSUs that vested during the year ended December 31, 2012 was $1.3

million.

Stock-based Compensation Expense

The Company recognizes compensation expense for all stock-based payment awards made to the

Company’s employees, consultants and directors based on estimated fair values. The valuation of stock option
awards is determined at the date of grant using the Black-Scholes option pricing model. This model requires
inputs such as the expected term of the option, expected volatility and risk-free interest rate. To establish an
estimate of expected term, the Company considers the vesting period and contractual period of the award and its
historical experience of stock option exercises, post-vesting cancellations and volatility. The estimate of expected
volatility is based on the Company’s historical volatility. The risk-free rate is based on the yield available on
United States Treasury zero-coupon issues. To establish an estimate of forfeiture rate, the Company considers its
historical experience of option forfeitures and terminations.

The fair value of stock option awards was estimated using the Black-Scholes model with the following

weighted average assumptions for the years ended December 31, 2012, 2011 and 2010:

Year Ended December 31,

2012

2011

2010

Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected volatility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk-free interest rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0%
92%
0.82%
5.6 years

0%
88%
1.48%
5.4 years

0%
79%
1.67%
5.3 years

The valuation of RSUs is determined at the date of grant using the closing stock price. The forfeiture rate

impacts the amount of aggregate compensation for both stock options and RSUs. To establish an estimate of
forfeiture rate, the Company used an independent third party to consider the Company’s historical experience of
option forfeitures and terminations.

The following table shows total stock-based compensation expense included in the consolidated statements

of comprehensive loss for the years ended December 31, 2012, 2011 and 2010 (in thousands):

Research and development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selling, general and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$2,391
1,893

$3,672
4,087

$2,302
2,611

Total stock-based compensation expense . . . . . . . . . . . . . . . . . . . .

$4,284

$7,759

$4,913

Year Ended December 31,

2012

2011

2010

F-29

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

There was no capitalized stock-based compensation cost as of December 31, 2012 or 2011, and there were
no recognized tax benefits related to the Company’s stock-based compensation expense during the years ended
December 31, 2012 or 2011.

10. Capital Stock

Series B Preference Shares

In December 2003, the Company issued 2,959 Series B preference shares to Genentech, Inc. in repayment

of $29.6 million of the outstanding balance under a convertible subordinated debt agreement. Pursuant to the
rights of the Series B preference shares, the holder of Series B preference shares was not entitled to receive any
dividends on the Series B preference shares. The Series B preference shares ranked senior with respect to rights
on liquidation, winding-up and dissolution of the Company to all classes of common stock. Upon any voluntary
or involuntary liquidation, dissolution or winding-up of the Company, the holder of Series B preference shares
would have been entitled to receive $10,000 per Series B preference share (or $29.6 million in the aggregate)
before any distribution was made on the common stock. The holder of the Series B preference shares had no
voting rights, except as required under Bermuda law.

The holder of Series B preference shares had the right to convert Series B preference shares into shares of
common stock at a conversion price equal to $116.25 per share, subject to adjustment in certain circumstances.

In April of 2011, the 2,959 Series B convertible preference shares were converted by Genentech into

254,560 shares of common stock. The $29.6 million liquidation preference associated with the Series B
preference shares was eliminated as a result of this conversion.

Equity Line of Credit

In July of 2010, the Company entered into a common share purchase agreement (the “2010 Purchase
Agreement”) with Azimuth, pursuant to which the Company obtained a committed equity line of credit facility
(the “2010 Facility”) under which the Company could sell up to $30 million of its registered common stock to
Azimuth over a 12-month period, subject to certain conditions and limitations. The 2010 Purchase Agreement
provided that the Company could determine, in its sole discretion, the timing, dollar amount and floor price per
share of each draw down under the 2010 Facility, subject to certain conditions and limitations and that the
number and price of shares sold in each draw down were generally to be determined by a contractual formula
designed to approximate fair market value, less a discount. The 2010 Purchase Agreement also provided that
from time to time and in the Company’s sole discretion, it could grant Azimuth the right to exercise one or more
options to purchase additional shares during each draw down pricing period for the amount of shares based upon
the maximum option dollar amount and the option threshold price specified by the Company. The Company also
agreed to issue 111,111 shares of common stock to Azimuth upon execution of the agreement relating to the
2010 Facility, in consideration of Azimuth’s execution and delivery of that agreement. Shares under the 2010
Facility and the shares the Company agreed to issue to Azimuth upon execution of the agreement relating to the
2010 Facility were sold pursuant to a prospectus which forms a part of a registration statement declared effective
by the SEC on May 29, 2008. In August of 2010, the Company sold a total of 3,421,407 shares of common stock
under the 2010 Facility for aggregate gross proceeds of $14.2 million, representing the maximum number of
shares that could be sold under the 2010 Facility. As a result, the 2010 Facility is no longer in effect, and no
additional shares can be issued thereunder.

Registered Direct Offerings

In June of 2009, the Company entered into a definitive agreement with certain institutional investors to sell
695,652 units, with each unit consisting of one share of the Company’s common stock and a warrant to purchase

F-30

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

0.50 of a share of common stock, for gross proceeds of approximately $12.0 million, before deducting placement
agent fees and estimated offering expenses of $0.8 million, in a second registered direct offering. The investor
purchased the units at a price of $17.25 per unit. The warrants, which represent the right to acquire an aggregate
of up to 347,826 shares of common stock, are exercisable at any time on or prior to December 10, 2014 at an
exercise price of $19.50 per share. As of December 31, 2012 all of these warrants were outstanding.

ATM Agreements

In the third quarter of 2009, the Company entered into an At Market Issuance Sales Agreement (the “2009

ATM Agreement”), under which the Company could sell up to 1.7 million shares of its common stock from time
to time through Wm Smith & Co. (“Wm Smith”), as the agent for the offer and sale of the shares. Wm Smith
could sell these shares by any method permitted by law deemed to be an “at the market” offering as defined in
Rule 415 of the Securities Act of 1933, including but not limited to sales made directly on The NASDAQ Global
Market, on any other existing trading market for the Company’s common stock or to or through a market maker.
Wm Smith could also sell the shares in privately negotiated transactions, subject to the Company’s approval. The
Company paid Wm Smith a commission equal to 3% of the gross proceeds of all shares sold through it as sales
agent under the 2009 ATM Agreement but in no event less than $0.02 per share. Shares sold under the 2009
ATM Agreement were sold pursuant to a prospectus which formed a part of a registration statement declared
effective by the Securities and Exchange Commission (the “SEC”) on May 29, 2008. From the inception of the
2009 ATM Agreement through October of 2010, the Company sold a total of 1.7 million shares of common stock
through Wm Smith for aggregate gross proceeds of $12.2 million, including 1.4 million shares sold in 2010 for
aggregate gross proceeds of $9.3 million. Total offering expenses related to these sales from inception to October
of 2010 were $0.4 million.

In the third quarter of 2010, the Company entered into an At Market Issuance Sales Agreement (the “2010

ATM Agreement”), with Wm Smith and McNicoll, Lewis & Vlak LLC (the “Agents”), under which the
Company could sell shares of its common stock from time to time through the Agents, as the agents for the offer
and sale of the shares, in an aggregate amount not to exceed the amount that can be sold under the Company’s
registration statement on Form S-3 (File No. 333-148342) filed with the SEC on December 26, 2007 and
declared effective by the SEC on May 29, 2008. The Agents could sell the shares by any method permitted by
law deemed to be an “at the market” offering as defined in Rule 415 of the Securities Act of 1933, as amended
(the “Securities Act”), including without limitation sales made directly on The NASDAQ Global Market, on any
other existing trading market for the Company’s common stock or to or through a market maker. The Agents
could also sell the shares in privately negotiated transactions, subject to the Company’s prior approval. From the
inception of the 2010 ATM Agreement through May of 2011, the Company sold a total of 7,560,862 shares of its
common stock under this agreement for aggregate gross proceeds of $34.0 million, including 821,386 shares sold
in 2011 for aggregate gross proceeds of $4.4 million. Total offering expenses incurred related to sales under the
2010 ATM Agreement from inception to May of 2011 were $1.0 million, including $0.1 million incurred in
2011. In May of 2011, 2010 ATM Agreement expired by its terms, and there will be no further issuances under
this facility.

On February 4, 2011, the Company entered into an At Market Issuance Sales Agreement (the “2011 ATM

Agreement”), with McNicoll, Lewis & Vlak LLC (now known as MLV & Co. LLC, “MLV”), under which it
may sell shares of its common stock from time to time through the MLV, as the agent for the offer and sale of the
shares, in an aggregate amount not to exceed the amount that can be sold under the Company’s registration
statement on Form S-3 (File No. 333-172197) filed with the SEC on February 11, 2011 and amended on
March 10, 2011, June 3, 2011 and January 3, 2012, which was most recently declared effective by the SEC on
January 17, 2012. MLV may sell the shares by any method permitted by law deemed to be an “at the market”
offering as defined in Rule 415 of the Securities Act, including without limitation sales made directly on The

F-31

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

NASDAQ Global Market, on any other existing trading market for the Company’s common stock or to or
through a market maker. MLV also may sell the shares in privately negotiated transactions, subject to our prior
approval. The Company will pay MLV a commission equal to 3% of the gross proceeds of the sales price of all
shares sold through it as sales agent under the 2011 ATM Agreement. From the inception of the 2011 ATM
Agreement through December 31, 2012, the Company sold a total of 7,572,327 shares of common stock under
this agreement for aggregate gross proceeds of $14.6 million. No shares of common stock have been sold under
this agreement since February 3, 2012. Total offering expenses incurred related to sales under the 2011 ATM
Agreement from inception to December 31, 2012, were $0.5 million.

Underwritten Offering

In February of 2010, the Company completed an underwritten offering of 2.8 million units, with each unit
consisting of one share of the Company’s common stock and a warrant to purchase 0.45 of a share of common
stock, for gross proceeds of approximately $21 million. As of December 31, 2012 all of these warrants were
outstanding.

On March 9, 2012, the Company completed an underwritten public offering of 29,669,154 shares of its
common stock, and accompanying warrants to purchase one half of a share of common stock for each share
purchased, at a public offering price of $1.32 per share. Total gross proceeds from the offering were
approximately $39.2 million, before deducting underwriting discounts and commissions and offering expenses
totaling approximately $3.0 million. The warrants, which represent the right to acquire an aggregate of up to
14,834,577 shares of common stock, are immediately exercisable and have a five-year term and an exercise price
of $1.76 per share. As of December 31, 2012, 14,265,970 of these warrants were outstanding.

On October 29, 2012, the Company completed an underwritten public offering of 13,333,333 shares of its

common stock, at a public offering price of $3.00 per share. In addition, the Company has granted the
underwriters a 30-day option to purchase up to an additional 1,999,999 shares of common stock on the same
terms and conditions, solely to cover over-allotments, if any. Total gross proceeds from the offering were
approximately $40.0 million, before deducting underwriting discounts and commissions and offering expenses
totaling approximately $3.0 million.

11. Commitments and Contingencies

Collaborative Agreements, Royalties and Milestone Payments

The Company is obligated to pay royalties, ranging generally from 1.5% to 14% of the selling price of the
licensed component and up to 40% of any sublicense fees to various universities and other research institutions
based on future sales or licensing of products that incorporate certain products and technologies developed by
those institutions.

In addition, the Company has committed to make potential future “milestone” payments to third parties as

part of licensing and development programs. Payments under these agreements become due and payable only
upon the achievement of certain developmental, regulatory and/or commercial milestones. Because it is uncertain
if and when these milestones will be achieved, such contingencies, aggregating up to $96 million (assuming one
product per contract meets all milestones events) have not been recorded on the consolidated balance sheet. The
Company is unable to determine precisely when and if payment obligations under the agreements will become
due as these obligations are based on milestone events, the achievement of which is subject to a significant
number of risks and uncertainties.

F-32

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

Leases

As of December 31, 2012, the Company leased administrative, research facilities, and office equipment
under operating leases expiring on various dates through May 2014. These leases generally require the Company
to pay taxes, insurance, maintenance and minimum lease payments.

The Company estimates future minimum lease payments as of December 31, 2012 to be (in thousands):

2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating
Leases (a)

2,662
795

Minimum lease payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$3,457

(a) Operating leases are net of future sublease income of $0.9 million.

Total rental expense, including other costs required under the Company’s leases, was approximately $4.5

million, $5.1 million and $5.1 million for the years ended December 31, 2012, 2011 and 2010, respectively.
Rental expense based on leases allowing for escalated rent payments are recognized on a straight-line basis. The
Company is required to restore certain of its leased property to certain conditions in place at the time of lease.
The Company believes these costs will not be material to its operations.

In 2012, the Company vacated and subleased two of its leased facilities, which housed its large scale

manufacturing operations and associated quality functions. The Company does not expect to incur any significant
restructuring charges during 2013 in connection with lease payments for these buildings as these payments will
be offset by future sublease income.

As a result of the restructuring in the second quarter of 2009, the Company vacated one of its leased
buildings. Effective December 2010, the Company entered into a sublease agreement for this building through
May of 2014. For the year ended December 31, 2012, the Company recognized $0.1 million in sublease income
under this agreement. The Company will receive future sublease income of $0.2 million under this agreement.

Subsequent to December 31, 2012, the Company renewed its operating lease agreements in three buildings

for a ten year period.

Legal Proceedings

On April 8, 2011, four complaints were filed in the United States District Court for the Eastern District of

Michigan. The cases are captioned: Muniz v. Genentech, et al., 5:11-cv-11489-JCO-RSW; Tifenthal v.
Genentech, et al., 2:11-cv-11488-DPH-LJM; Blair v. Genentech, et al., 2:11-cv-11463-SFC-MJH; and Marsh v.
Genentech, et al., 2:11-cv-11462-RHC-MKM. The complaints alleged claims against Genentech and the
Company (“Defendants”) for alleged strict liability failure to warn, negligence, breach of warranty, and fraud by
concealment based on injuries alleged to have occurred as a result of the plaintiffs’ treatment with RAPTIVA®.
The complaints sought unspecified compensatory and punitive damages. All four cases were transferred to the
United States District Court for the Western District of Michigan. On October 26, 2011, the Court granted the
Motions to Dismiss filed by Defendants in all four actions. On September 6, 2012, the 6th Circuit Court of
Appeals affirmed the judgment in favor of Defendants and, on October 12, 2012, denied a petition for en banc
rehearing. The deadline for seeking appellate review by the United States Supreme Court has expired.

F-33

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

On June 13, 2011, a complaint was filed in the Supreme Court for the State of New York, Onondaga
County. The case is captioned: McConnell v. Genentech, et al., 5:11-cv-1309-GLS-DEP. Defendants removed
the case to the United States District Court for the Northern District of New York on November 3, 2011. The
complaint asserted claims against Genentech and the Company (“Defendants”) for alleged strict liability
defective design and manufacture, strict liability failure to warn, negligence, breach of warranty, and loss of
consortium based on injuries alleged to have occurred as a result of the plaintiff’s treatment with RAPTIVA®.
The complaint sought unspecified compensatory and punitive damages. On December 21, 2012, the case was
dismissed with prejudice pursuant to a settlement agreement.

12. Concentration of Risk, Segment and Geographic Information

Concentration of Risk

Cash equivalents and receivables are financial instruments, which potentially subject the Company to
concentrations of credit risk, as well as liquidity risk for certain cash equivalents such as money market funds.
The Company has not encountered such issues during 2012.

The Company has not experienced any significant credit losses and does not generally require collateral on

receivables. For the year ended December 31, 2012, two customers represented 47% and 33% of total revenue
and as of December 31, 2012, these two customers represented 58% and 35% of the accounts receivable balance.

For the year ended December 31, 2011, two customers represented 61% and 32% of total revenue and as of
December 31, 2011, these two customers represented 57% and 43% of the accounts receivable balance. For the
year ended December 31, 2010, three customers represented 64%, 13%, and 11% of total revenue.

Segment Information

The Company has determined that it operates in one segment as it only reports operating results on an
aggregate basis to the chief operating decision maker of the Company. The Company’s property and equipment
is held primarily in the United States.

Geographic Information

Revenue attributed to the following geographic regions for each of the three years ended December 31,

2012, 2011 and 2010 was as follows (in thousands):

United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Europe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Asia Pacific . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$14,134
18,454
1,194

$20,447
35,718
2,031

$25,306
4,728
3,607

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$33,782

$58,196

$33,641

Year ended December 31,

2012

2011

2010

F-34

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—(Continued)

XOMA Corporation

13. Quarterly Financial Information (unaudited)

The following is a summary of the quarterly results of operations for the years ended December 31, 2012

and 2011:

Consolidated Statements of Operations

Quarter Ended

March 31

June 30

September 30 December 31

(In thousands, except per share amounts)

2012
Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 9,865 $ 9,275
(22,765)
Total operating costs and expenses . . . . . . . . . . . . . . . . . . . . . . . . .
(2,665)
Other (expense) income, net (1) . . . . . . . . . . . . . . . . . . . . . . . . . . .
Income tax benefit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
—
(16,155)
Net (loss) income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(24,227)
(16,063)
—
(30,425)

$ 7,251
(23,404)
(10,772)
74
(26,851)

$ 7,391
(20,010)
14,985
—
2,366

Basic and diluted net (loss) income per share of common stock . . . . $

(0.69) $ (0.24)

$

(0.39)

$

0.03

2011
Total revenues (2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 15,595 $ 16,525
(24,394)
Total operating costs and expenses . . . . . . . . . . . . . . . . . . . . . . . . .
(261)
Other income (expense), net
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
—
Income tax expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(8,130)
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(22,716)
801
(15)
(6,335)

$ 16,229
(23,147)
375
—
(6,543)

$ 9,847
(21,894)
312
—
(11,735)

Basic and diluted net loss per share of common stock . . . . . . . . . . $

(0.22) $ (0.27)

$

(0.20)

$

(0.34)

(1) Fluctuations in 2012 primarily relate to (losses) gains on the revaluation of the contingent warrant liabilities.

(2) Revenue in the first three quarters of 2011 includes the recognition of $14.9 million of the non-recurring

license fee received as consideration for the collaboration with Servier entered into in December 2010.

F-35

[THIS PAGE INTENTIONALLY LEFT BLANK]

Exhibit
Number

Exhibit Description

Form SEC File No.

Exhibit

Filing Date

Incorporation By Reference

3.1

3.2

3.3

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

4.9

4.10

4.11

4.12

10.1*

10.2*

10.3*

10.4*

10.5*

10.6*

10.7*

Certificate of Incorporation of XOMA Corporation

Certificate of Amendment of Certificate of
Incorporation of XOMA Corporation

8-K

8-K

000-14710

000-14710

3.1

3.1

01/03/2012

05/31/2012

By-laws of XOMA Corporation

8-K

000-14710

3.2

01/03/2012

Reference is made to Exhibits 3.1, 3.2 and 3.3

Specimen of Common Stock Certificate

Shareholder Rights Agreement dated as of February 26,
2003 by and between XOMA Ltd. and Mellon Investor
Services LLC as Rights Agent

Amendment to Shareholder Rights Agreement dated
December 21, 2010 between XOMA Ltd. and Wells
Fargo Bank, N.A. as Rights Agent

Amendment No. 2 to Shareholder Rights Agreement
dated December 31, 2011 between XOMA Corporation
and Wells Fargo Bank, N.A. as Rights Agent

Amendment No. 3 to Shareholder Rights Agreement
dated March 5, 2012 between XOMA Corporation and
Wells Fargo Bank, N.A. as Rights Agent

Form of Certificate of Designations of Series A
Preferred Stock

Form of Amended and Restated Warrant (June 2009
Warrants)

8-K

00014710

10-K 000-14710

4.1

4.1

01/03/2012

05/14/2003

10-K 000-14710

4.1A 03/10/2011

8-K

000-14710

4.2

01/03/2012

8-K

000-14710

4.2

03/07/2012

8-K

000-14710

3.1

01/03/2012

8-K

000-14710

10.6

02/02/2010

Form of Warrant (February 2010 Warrants)

8-K

000-14710

10.2

02/02/2010

4.9

4.1

03/14/2012

03/07/2012

Form of Warrant (December 2011 Warrants)

10-K 000-14710

Form of Warrant (March 2012 Warrants)

Form of Warrant (September 2012 Warrants)

8-K

8-K

000-14710

000-14710

4.10

10/03/2012

1981 Share Option Plan as amended and restated

S-8

333-171429

10.1

12/27/2010

Form of Share Option Agreement for 1981 Share Option
Plan

10-K 000-14710

10.1A 03/11/2008

Restricted Share Plan as amended and restated

S-8

333-171429

10.1

12/27/2010

Form of Share Option Agreement for Restricted Share
Plan

10-K 000-14710

10.2A 03/11/2008

2007 CEO Share Option Plan

8-K

000-14710

10.7

08/07/2007

1992 Directors Share Option Plan as amended and
restated

Form of Share Option Agreement for 1992 Directors
Share Option Plan (initial grants)

S-8

333-171429

10.1

12/27/2010

10-K 000-14710

10.3A 03/11/2008

Exhibit
Number

10.8*

Exhibit Description

Form SEC File No.

Exhibit

Filing Date

Incorporation By Reference

Form of Share Option Agreement for 1992 Directors
Share Option Plan (subsequent grants)

10-K 000-14710

10.3B 03/11/2008

10.9*

2002 Director Share Option Plan

10.10*

10.11*

10.12*

Amended and Restated 2010 Long Term Incentive and
Stock Award Plan

Form of Stock Option Agreement for Amended and
Restated 2010 Long Term Incentive and Stock Award
Plan

Form of Restricted Stock Unit Agreement for
Amended and Restated 2010 Long Term Incentive and
Stock Award Plan

S-8

S-8

333-151416

10.10

06/04/2008

000-14710

10.1

06/01/2012

10-K 000-14710

10.6A 03/14/2012

10-K 000-14710

10.6B 03/14/2012

10.13*

Management Incentive Compensation Plan as amended
and restated

8-K

000-14710

10.3

11/06/2007

10.14*

CEO Incentive Compensation Plan

10-K 000-14710

10.4A 03/11/2008

10.15*

Amendment No. 1 to CEO Incentive Compensation
Plan

10-K 000-14710

10.7B 03/14/2012

10.16*

Bonus Compensation Plan

10-K 000-14710

10.4B 03/11/2008

10.17*

Amended and Restated 1998 Employee Stock Purchase
Plan

POS
AM

333-174730

10.2

01/03/2012

10.18

10.19

10.20

10.21*

10.22*

10.23*

10.24*

10.25*

10.26*

Form of Amended and Restated Indemnification
Agreement for Officers

Form of Amended and Restated Indemnification
Agreement for Employee Directors

Form of Amended and Restated Indemnification
Agreement for Non-employee Directors

Amended and Restated Employment Agreement
entered into between XOMA (US) LLC and Patrick J.
Scannon, dated as of December 30, 2008

Employment Agreement entered into between XOMA
(US) LLC and Fred Kurland, dated as of December 29,
2008

Amended and Restated Employment Agreement
entered into between XOMA (US) LLC and Charles C.
Wells, dated as of December 30, 2008

Employment Agreement effective as of May 31, 2011
between XOMA (US) LLC and Paul Rubin

Employment Agreement effective as of January 4,
2012 between XOMA (US) LLC and John Varian

Form of Change of Control Severance Agreement
entered into between XOMA Ltd. and certain of its
executives, with reference schedule

10-K 000-14710

10.6

03/08/2007

10-K 000-14710

10.7

03/08/2007

10-K 000-14710

10.8

03/08/2007

000-14710

10.7A 12/27/2010

000-14710

10.7B 12/27/2010

000-14710

10.7D 12/27/2010

10-
K/A

10-
K/A

10-
K/A

8-K

000-14710

10.1

06/16/2011

10-K 000-14710

10.10G 03/14/2012

10-K 000-14710

10.12

03/10/2011

Exhibit
Number

10.27*

10.28

10.29

10.30

10.31

10.32

10.33

10.34

10.35

10.36†

10.37†

10.38†

10.39†

10.40†

Exhibit Description

Form SEC File No.

Exhibit

Filing Date

Incorporation By Reference

Change of Control Agreement entered into between
XOMA Ltd. and John Varian, dated January 4, 2012

Lease of premises at 890 Heinz Street, Berkeley,
California dated as of July 22, 1987

Lease of premises at Building E at Aquatic Park Center,
Berkeley, California dated as of July 22, 1987 and
amendment thereto dated as of April 21, 1988

Lease of premises at Building C at Aquatic Park Center,
Berkeley, California dated as of July 22, 1987 and
amendment thereto dated as of August 26, 1987

Letter of Agreement regarding CPI adjustment dates for
leases of premises at Buildings C, E and F at Aquatic
Park Center, Berkeley, California dated as of July 22,
1987

Lease of premises at 2910 Seventh Street, Berkeley,
California dated March 25, 1992

Fifth amendment to lease of premises at 2910 Seventh
Street, Berkeley, California dated June 1, 2006

Lease of premises at 5860 and 5864 Hollis Street,
Emeryville, California dated as of November 2, 2001
(with addendum)

Lease of premises at 2850 Seventh Street, Second
Floor, Berkeley, California dated as of December 28,
2001 (with addendum and guaranty)

Second Amended and Restated Collaboration
Agreement dated January 12, 2005, by and between
XOMA (US) LLC and Genentech, Inc.

Agreement related to LUCENTIS® License Agreement
and RAPTIVA® Collaboration Agreement dated
September 9, 2009, by and between XOMA (Bermuda)
Ltd., XOMA (US) LLC and Genentech, Inc.

License Agreement by and between XOMA Ireland
Limited and MorphoSys AG, dated as of February 1,
2002

10-K 000-14710

10.12A 03/14/2012

10-K 000-14710

10.12

03/19/1998

10-K 000-14710

10.13

03/19/1998

10-K 000-14710

10.14

03/19/1998

10-K 000-14710

10.15

03/19/1998

10-K 000-14710

10.16

03/19/1998

10-Q 000-14710

10.58

08/09/2006

10-K 000-14710

10.19

04/01/2002

10-K 000-14710

10.20

04/01/2002

10-K 000-14710

10.26C 03/15/2005

10-Q 000-14710

10.18A 11/09/2009

10-K 000-14710

10.43

02/01/2002

License Agreement, dated as of December 29, 2003, by
and between Diversa Corporation and XOMA Ireland
Limited

8-K/
A

000-14710

2

03/19/2004

GSSM License Agreement, effective as of May 2,
2008, by and between Verenium Corporation and
XOMA Ireland Limited

10-K 000-14710

10.25A 03/10/2011

10.41†

Secured Note Agreement, dated as of May 26, 2005, by
and between Chiron Corporation and XOMA (US) LLC

10-Q 000-14710

10.3

08/08/2005

Exhibit
Number

10.42†

10.43†

10.44

10.45

10.46

10.47†

10.48

10.49

10.50†

10.51

10.52

10.53†

10.54

Exhibit Description

Amended and Restated Research, Development and
Commercialization Agreement, executed November 7,
2008, by and between Novartis Vaccines and
Diagnostics, Inc. (formerly Chiron Corporation) and
XOMA (US) LLC

Amendment No. 1 to Amended and Restated Research,
Development and Commercialization Agreement,
effective as of April 30, 2010, by and between Novartis
Vaccines and Diagnostics, Inc. and XOMA (US) LLC

Manufacturing and Technology Transfer Agreement,
executed December 16, 2008, by and between Novartis
Vaccines and Diagnostics, Inc. (formerly Chiron
Corporation) and XOMA (US) LLC

Agreement dated March 8, 2005, between XOMA (US)
LLC and the National Institute of Allergy and Infectious
Diseases

Agreement dated July 28, 2006, between XOMA (US)
LLC and the National Institute of Allergy and Infectious
Diseases

Agreement dated September 15, 2008, between XOMA
(US) LLC and the National Institute of Allergy and
Infectious Diseases

Second Amendment to Agreement dated September 15,
2008, between XOMA (US) LLC and the National
Institute of Allergy and Infectious Diseases

Agreement dated September 30, 2011, between XOMA
(US) LLC and the National Institute of Allergy and
Infectious Diseases

Collaboration Agreement, dated as of November 1,
2006, between Takeda Pharmaceutical Company
Limited and XOMA (US) LLC

Incorporation By Reference

Form

SEC File
No.

Exhibit

Filing Date

10-K 000-14710

10.24C 03/11/2009

10-K 000-14710

10.25B 03/14/2012

10-K 000-14710

10.24D 03/11/2009

10-K 000-14710

10.53

03/15/2005

10-K 000-14710

10.60

08/09/2006

10-Q 000-14710

10.39

11/10/2008

10-Q 000-14710

10.24C 11/04/2010

S-4

000-14710

10.28D 10/04/2011

10-K 000-14710

10.46

03/08/2007

First Amendment to Collaboration Agreement, effective
as of February 28, 2007, between Takeda
Pharmaceutical Company Limited and XOMA (US)
LLC

10-
Q/A

000-14710

10.48

03/05/2010

Second Amendment to Collaboration Agreement,
effective as of February 9, 2009, among Takeda
Pharmaceutical Company Limited and XOMA (US)
LLC

License Agreement, effective as of August 27, 2007, by
and between Pfizer Inc. and XOMA Ireland Limited

Common Share Purchase Agreement, dated as of July
23, 2010, by and between XOMA Ltd. and Azimuth
Opportunity Ltd.

10-K 00-14710

10.31B 03/11/2009

8-K 000-14710

2

09/13/2007

8-K 000-14710

10.1

07/23/2010

Exhibit
Number

10.55

Exhibit Description

Form SEC File No.

Exhibit

Filing Date

Incorporation By Reference

Securities Purchase Agreement dated June 5, 2009,
between XOMA Ltd. and the investors named therein

8-K

000-14710

10.1

06/10/2009

10.56

Engagement Letter dated June 4, 2009

10.57†

10.58

10.59

10.60

10.61

10.62†

10.63†

10.64†

10.65†

10.66

10.67†

10.68†

Discovery Collaboration Agreement dated September
9, 2009, by and between XOMA Development
Corporation and Arana Therapeutics Limited

At Market Issuance Sales Agreement dated February 4,
2011, between XOMA Ltd. and McNicoll, Lewis &
Vlak LLC

Amendment to At Market Issuance Sales Agreement
dated December 31, 2011, between XOMA
Corporation and MLV & Co. LLC

Underwriting Agreement dated February 2, 2010

Form of Warrant Amendment Agreement dated
February 2, 2010 (June 2009 Warrants)

Royalty Purchase Agreement, dated as of August 12,
2010, by and among XOMA CDRA LLC, XOMA
(US) LLC, XOMA Ltd. and the buyer named therein

Collaboration and License Agreement dated as of
December 30, 2010, by and between XOMA Ireland
Limited, Les Laboratoires Servier and Institut de
Recherches Servier

Amended and Restated Collaboration and License
Agreement dated as of February 14, 2012, by and
between XOMA Ireland Limited, Les Laboratoires
Servier and Institut de Recherches Servier

00-14710

10.3

06/10/2009

000-14710

10.35

03/05/2010

8-K

10-
Q/A

S-3

333-172197

1.2

02/11/2011

333-172197

1.2

01/03/2012

000-14710

000-14710

10.1

10.3

02/02/2010

02/02/2010

000-14710

10.38

04/13/2011

POS
AM

8-K

8-K

10-
Q/A

10-K 000-14710

10.42

03/10/2011

10-K 000-14710

10.41A 03/14/2012

Loan Agreement dated as of December 30, 2010, by
and between XOMA Ireland Limited and Les
Laboratoires Servier

10-
K/A

000-14710

10.42A 05/26/2011

Foreign Exchange and Options Master Agreement
(FEOMA) dated as of May 16, 2011, between Royal
Bank of Canada and XOMA Ltd., with letter
agreement dated May 17, 2011

Loan Agreement dated as of December 30, 2011,
among XOMA (US) LLC, as Borrower, XOMA Ltd.,
as Parent, each other loan party from time to time party
thereto, General Electric Capital Corporation, as
Agent, and each other lender from time to time party
thereto

Guaranty, Pledge and Security Agreement dated as of
December 30, 2011, among XOMA (US) LLC, each
other guarantor from time to time party thereto and
General Electric Capital Corporation, as Agent

10-Q 000-14710

10.1

08/04/2011

10-K 000-14710

10.43

03/14/2012

10-K 000-14710

10.43A 03/14/2012

Exhibit
Number

10.69†

10.70†

10.71†

10.72†

10.73

10.74

10.75

21.1 +

23.1 +

24.1 +

31.1 +

31.2 +

32.1 +

Exhibit Description

Form SEC File No.

Exhibit

Filing Date

Incorporation By Reference

Amended and Restated License and
Commercialization Agreement effective as of January
11, 2012, by and between Les Laboratoires Servier
and XOMA Ireland Limited

Amended and Restated Trademark License Agreement
entered into as of January 11, 2012, between Biofarma
and XOMA Ireland Limited

Master Services Agreement dated as of November 9,
2009, between Medpace, Inc. and XOMA (US) LLC

Amendment No. 1 to Master Services Agreement
dated as of October 4, 2011, between Medpace, Inc.
and XOMA (US) LLC

10-K 000-14710

10.44

03/14/2012

10-K 000-14710

10.44A 03/14/2012

10-K 000-14710

10.45

03/14/2012

10-K 000-14710

10.45A 03/14/2012

Underwriting Agreement, dated March 6, 2012

8-K 000-14710

1.1

03/07/2012

First Amendment to Loan Agreement, by and between
General Electric Capital Corporation, the Company as
guarantor, XOMA (US) LLC as borrower, and certain
other wholly-owned subsidiaries of the Company,
dated September 27, 2012

8-K 000-14710

10.46

10/03/2012

Underwriting Agreement, dated October 24, 2012

8-K 000-14710

1.1

10/24/2012

Subsidiaries of the Company

Consent of Independent Registered Public Accounting
Firm

Power of Attorney (included on the signature pages
hereto)

Certification of Chief Executive Officer, as required
by Rule 13a-14(a) or Rule 15d-14(a)

Certification of Chief Financial Officer, as required by
Rule 13a-14(a) or Rule 15d-14(a)

Certification of Chief Executive Officer and Chief
Financial Officer, as required by Rule 13a-14(b) or
Rule 15d-14 (b) and Section 1350 of Chapter 63 of
Title 18 of the United States Code (18 U.S.C. §1350)
(1)

101.INS + XBRL Instance Document (2)

101.SCH + XBRL Taxonomy Extension Schema Document (2)

101.CAL + XBRL Taxonomy Extension Calculation Linkbase

Document (2)

101.DEF + XBRL Taxonomy Extension Definition Linkbase

Document (2)

Exhibit
Number

Exhibit Description

Form SEC File No. Exhibit

Filing
Date

Incorporation By Reference

101.LAB + XBRL Taxonomy Extension Labels Linkbase Document (2)

101.PRE + XBRL Taxonomy Extension Presentation Linkbase

Document (2)

†

Confidential treatment has been granted with respect to certain portions of this exhibit. This exhibit omits
the information subject to this confidentiality request. Omitted portions have been filed separately with the
SEC.
Indicates a management contract or compensation plan or arrangement.
Filed herewith

*
+
(1) This certification accompanies the Form 10-K to which it relates, is not deemed filed with the Securities and
Exchange Commission and is not to be incorporated by reference into any filing of the Registrant under the
Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made
before or after the date of the Form 10-K), irrespective of any general incorporation language contained in
such filing.

(2) Pursuant to applicable securities laws and regulations, the Registrant is deemed to have complied with the
reporting obligation relating to the submission of interactive data files in such exhibits and is not subject to
liability under any anti-fraud provisions of the federal securities laws as long as the Registrant has made a
good faith attempt to comply with the submission requirements and promptly amends the interactive data
files after becoming aware that the interactive data files fail to comply with the submission requirements.
These interactive data files are deemed not filed or part of a registration statement or prospectus for
purposes of sections 11 or 12 of the Securities Act of 1933, as amended, are deemed not filed for purposes
of section 18 of the Securities Exchange Act of 1934, as amended, and otherwise are not subject to liability
under these sections.

CERTIFICATION

Exhibit 31.1

I, John Varian, certify that:

1.

I have reviewed this annual report on Form 10-K of XOMA Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state
a material fact necessary to make the statements made, in light of the circumstances under which such
statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report,

fairly present in all material respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this report;

4.

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

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to

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

b) Designed such internal control over financial reporting, or caused such internal control over financial

reporting to be designed under our supervision, to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial statements for external purposes in
accordance with generally accepted accounting principles.

c)

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

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that

occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably
likely to materially affect, the registrant’s internal control over financial reporting; and

5.

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

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

b) Any fraud, whether or not material, that involves management or other employees who have a

significant role in the registrant’s internal control over financial reporting.

Date: March 12, 2013

/S/

JOHN VARIAN
John Varian
Chief Executive Officer

CERTIFICATION

Exhibit 31.2

I, Fred Kurland, certify that:

1.

I have reviewed this annual report on Form 10-K of XOMA Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state
a material fact necessary to make the statements made, in light of the circumstances under which such
statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report,

fairly present in all material respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this report;

4.

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

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to

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

b) Designed such internal control over financial reporting, or caused such internal control over financial

reporting to be designed under our supervision, to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial statements for external purposes in
accordance with generally accepted accounting principles.

c)

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

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that

occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably
likely to materially affect, the registrant’s internal control over financial reporting; and

5.

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

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

b) Any fraud, whether or not material, that involves management or other employees who have a

significant role in the registrant’s internal control over financial reporting.

Date: March 12, 2013

/S/ FRED KURLAND
Fred Kurland

Vice President, Finance, Chief Financial Officer and Secretary

Exhibit 32.1

Pursuant to the requirement set forth in Rule 13a-14(b) of the Securities Exchange Act of 1934, as amended, (the
“Exchange Act”) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. §1350), John
Varian, Chief Executive Officer of XOMA Corporation (the “Company”), and Fred Kurland, Chief Financial
Officer of the Company, each hereby certifies that, to the best of his or her knowledge:

1.

2.

The Company’s Annual Report on Form 10-K for the year ended December 31, 2012, to which this
Certification is attached as Exhibit 32.1, fully complies with the requirements of Section 13(a) or
Section 15(d) of the Exchange Act; and

The information contained in Exhibit 32.1 fairly presents, in all material respects, the financial condition
and results of operations of the Company.

IN WITNESS WHEREOF, the undersigned have set their hands hereto as of the 12th day of March, 2013.

/S/

JOHN VARIAN
John Varian
Chief Executive Officer

/S/ FRED KURLAND
Fred Kurland
Vice President, Finance, Chief Financial Officer and Secretary

3.

This certification accompanies the Form 10-K to which it relates, is not deemed filed with the Securities and
Exchange Commission and is not to be incorporated by reference into any filing of XOMA Corporation
under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether
made before or after the date of the Form 10-K), irrespective of any general incorporation

Corporate Information

DireCtOrs

eX e Cuti Ve O ffi Cers

AnnuAL M eeti ng

W. Denman Van ness 1,2,3
Chairman of the Board
Hidden Hill Advisors

William K. Bowes, Jr. 3
Founding Partner
U.S. Venture Partners

peter Barton Hutt 3
Senior Counsel
Covington & Burling LLP

John Varian 
Chief Executive Officer

patrick J. scannon, M.D., ph.D.
Executive Vice President and  
Chief Scientific Officer

paul D. rubin, M.D.
Senior Vice President,  
Research and Development and  
Chief Medical Officer

Joseph M. Limber 2
President and Chief Executive Officer
Prometheus Laboratories Inc.

fred Kurland
Vice President, Finance,  
Chief Financial Officer and Secretary

XOMA  COrpO rAti On
2910 Seventh Street
Berkeley, CA 94710
Tel: (510) 204-7200
www.xoma.com

in DepenDent  AuDitOrs

ernst & Young LLp
San Francisco, CA

t rAnsfer  Ag ent AnD 
regis trAr

Wells fargo shareowner 
services
P.O. Box 64874
St. Paul, MN 55164
www.shareowneronline.com
Tel: (800) 468-9716 or  
(651) 450-4064

Kelvin M. neu, M.D.
Managing Director
Baker Brothers

patrick J. scannon, M.D., ph.D.
Executive Vice President and  
Chief Scientific Officer
XOMA Corporation

John Varian 
Chief Executive Officer
XOMA Corporation

timothy p. Walbert 1,3
Chairman, President and
Chief Executive Officer
Horizon Pharma, Inc.

Jack L. Wyszomierski 1,2
Former Executive Vice
President and Chief Financial Officer
VWR International, LLC

1  Audit Committee

2  Compensation Committee

3  Nominating & Governance Committee

The annual meeting of shareholders 
will be held at 9:00 a.m. PDT on  
May 23, 2013, at the Company’s offices 
at 2910 Seventh Street, Berkeley, CA

sOurCes Of 
infOrMAtiO n

XOMA’s website, with news releases, 
financial and other information, is 
accessible on the Internet at:  
www.xoma.com

seC  fO rM 10- K

A copy of XOMA’s annual report filed 
with the Securities and Exchange 
Commission on Form 10-K was made 
available to all shareholders of record 
and is available on XOMA’s website. To 
request a copy contact:

Investor Relations
XOMA Corporation
2910 Seventh Street
Berkeley, CA 94710
Tel: (510) 204-7200
investorrelations@xoma.com

trADeMArK

ACeOn® is a registered  
trademark of Biofarma

XOMA is an affirmative action,  
equal-opportunity employer.

XOMA COrpOrAtiOn

2910 Seventh Street

Berkeley, CA 94710

(510) 204-7200 

Annual Report 2012

Annual Report 2012

Annual Report 2012

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