10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 10-Q

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

For the quarterly period ended March 31, 2013

or

o 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	52-2154066
(State or other jurisdiction of incorporation or organization)	(I.R.S.  Employer Identification No.)
2910 Seventh Street, Berkeley, California 94710	(510) 204-7200
(Address of principal executive offices, including zip code)	(Telephone Number)

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 x    No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).   Yes x    No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act).

Large accelerated filer o	Accelerated filer x	Non-accelerated filer o	Smaller reporting company o
	(Do not check if a 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  o    No  x

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.

Class	Outstanding at May 6, 2013
Common Stock, $0.0075 par value	82,893,328

XOMA CORPORATION

FORM 10-Q

TABLE OF CONTENTS

		Page
PART I	FINANCIAL INFORMATION
Item 1.	Condensed Consolidated Financial Statements (unaudited)
	Condensed Consolidated Balance Sheets as of March 31, 2013 and December 31, 2012	1
	Condensed Consolidated Statements of Comprehensive Loss for the Three Months Ended March 31, 2013 and 2012	2
	Condensed Consolidated Statements of Cash Flows for the Three Months Ended March 31, 2013 and 2012	3
	Notes to Condensed Consolidated Financial Statements	4
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	13
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	20
Item 4.	Controls and Procedures	21
PART II	OTHER INFORMATION
Item 1.	Legal Proceedings	21
Item 1A.	Risk Factors	21
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	41
Item 3.	Defaults Upon Senior Securities	41
Item 4.	Mine Safety Disclosure	41
Item 5.	Other Information	41
Item 6.	Exhibits	41
Signatures		42

i

PART I - FINANCIAL INFORMATION

ITEM 1.  CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (unaudited)

XOMA CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS

(in thousands, except share and per share amounts)

	March 31, 2013			December 31, 2012
	(unaudited)			(Note 1)
ASSETS
Current assets:
Cash and cash equivalents	$	50,379		$	45,345
Short-term investments		19,996			39,987
Trade and other receivables, net		6,270			8,249
Prepaid expenses and other current assets		3,062			2,256
Total current assets		79,707			95,837
Property and equipment, net		7,861			8,143
Other assets		1,378			1,696
Total assets	$	88,946		$	105,676
LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY
Current liabilities:
Accounts payable	$	4,194		$	3,867
Accrued and other liabilities		5,410			13,045
Deferred revenue		3,756			3,409
Interest bearing obligation – current		4,085			3,391
Accrued Interest on interest bearing obligations – current		1,662			121
Total current liabilities		19,107			23,833
Deferred revenue – long-term		5,857			6,315
Interest bearing obligations – long-term		37,017			37,653
Contingent warrant liabilities		27,841			15,001
Other liabilities - long term		33			1,407
Total liabilities		89,855			84,209
Stockholders’ (deficit) equity:
Common stock, $0.0075 par value, 138,666,666 shares authorized, 82,887,828 and 82,447,274 shares outstanding at March 31, 2013 and December 31, 2012, respectively		618			615
Additional paid-in capital		980,467			977,962
Accumulated comprehensive income		11			8
Accumulated deficit		(982,005	)		(957,118	)
Total stockholders’ (deficit) equity		(909	)		21,467
Total liabilities and stockholders’ (deficit) equity	$	88,946		$	105,676

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

(Note 1) The condensed consolidated balance sheet as of December 31, 2012 has been derived from the audited consolidated financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.

1

XOMA CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(unaudited)

(in thousands, except per share amounts)

	Three months ended March 31,
	2013			2012
Revenues:
License and collaborative fees	$	399		$	1,014
Contract and other		8,796			8,844
Net product sales		258			7
Total revenues		9,453			9,865
Operating expenses:
Research and development		16,590			15,771
Selling, general and administrative		4,124			4,679
Restructuring		17			3,777
Cost of sales		46			-
Total operating expenses		20,777			24,227
Loss from operations		(11,324	)		(14,362	)
Other income (expense):
Interest expense		(1,172	)		(1,042	)
Other income (expense)		449			(664	)
Revaluation of contingent warrant liabilities		(12,840	)		(14,357	)
Net loss	$	(24,887	)	$	(30,425	)
Basic and diluted net loss per share of common stock	$	(0.30	)	$	(0.69	)
Shares used in computing basic and diluted net loss per share of common stock		82,595			44,353
Other comprehensive loss:
Net loss	$	(24,887	)	$	(30,425	)
Net unrealized gains on available-for-sale securities		3			-
Comprehensive loss	$	(24,884	)	$	(30,425	)

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

2

XOMA CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(unaudited)

(in thousands)

	Three Months Ended March 31,
	2013			2012
Cash flows from operating activities:
Net loss	$	(24,887	)	$	(30,425	)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation		780			1,265
Common stock contribution to 401(k)		828			1,134
Stock-based compensation expense		1,619			674
Accrued interest on interest bearing obligations		1,542			394
Revaluation of contingent warrant liabilities		12,840			14,357
Restructuring charge related to long-lived assets		-			1,707
Amortization of debt discount, final payment fee on debt, and debt issuance costs		603			467
Unrealized (gain) loss on foreign currency exchange		(440	)		376
Unrealized loss (gain) on foreign exchange options		189			276
Other non-cash adjustments		(4	)		(43	)
Changes in assets and liabilities:
Trade and other receivables, net		1,997			2,168
Prepaid expenses and other assets		(802	)		(1,651	)
Accounts payable and accrued liabilities		(7,128	)		(3,221	)
Deferred revenue		(111	)		884
Other liabilities		(1,554	)		(37	)
Net cash used in operating activities		(14,528	)		(11,675	)
Cash flows from investing activities:
Proceeds from maturities of investments		20,000			-
Net purchase of property and equipment		(498	)		(548	)
Net cash provided by (used in) investing activities		19,502			(548	)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs		60			39,480
Principal payments of debt		-			(714	)
Net cash provided by financing activities		60			38,766
Net increase in cash and cash equivalents		5,034			26,543
Cash and cash equivalents at the beginning of the period		45,345			48,344
Cash and cash equivalents at the end of the period	$	50,379		$	74,887
Supplemental Cash Flow Information:
Cash paid for:
Interest	$	333		$	195
Non-cash investing and financing activities:
Issuance of warrants	$	-		$	6,386
Interest added to principal balances on long-term debt	$	290		$	398

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

3

XOMA CORPORATION

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(unaudited)

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 commercial operations. XOMA focuses its scientific research on allosteric modulation, which offers opportunities for new classes of therapeutic antibodies to treat a wide range of human diseases.  XOMA is developing its lead product candidate gevokizumab (IL-1 beta modulating antibody) with Les Laboratoires Servier (“Servier”) through a global Phase 3 clinical development program and ongoing proof-of-concept studies in other IL-1-mediated diseases. XOMA’s scientific research also has produced the XMet platform, which consists of three classes of preclinical antibodies, including selective insulin receptor modulators that could offer new approaches in the treatment of diabetes.  In order to retain significant value from its scientific discoveries, XOMA initiated commercial operations in January 2012 through the licensing of U.S. commercial rights to Servier’s ACEON® (perindopril erbumine) and certain U.S. rights to a patent-protected portfolio of fixed dose combination (“FDC”) product candidates where perindopril is combined with other active ingredients to treat cardiovascular disease.

2.  Basis of Presentation and Significant Accounting Policies

Basis of Presentation

The condensed consolidated financial statements include the accounts of XOMA and its subsidiaries. All intercompany accounts and transactions were eliminated during consolidation. The unaudited financial statements were prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q. These financial statements and related disclosures have been prepared with the assumption that users of the interim financial information have read or have access to the audited financial statements for the preceding fiscal year. Accordingly, these statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012, filed with the U.S. Securities and Exchange Commission (“SEC”) on March 12, 2013.

In management’s opinion, the unaudited condensed consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, which are necessary to present fairly the Company’s consolidated financial position as of March 31, 2013, the consolidated results of the Company’s operations and the Company’s cash flows for the three months ended March 31, 2013 and 2012. The interim results of operations are not necessarily indicative of the results that may occur for the full fiscal year or future periods.

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, stock-based compensation, and restructuring liabilities. 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 adjustments to revenues previously reported.

Long-lived Assets

The Company reviews the carrying values and depreciation lives 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 the three months ended March 31, 2012, the Company recorded an impairment loss of $0.8 million and accelerated depreciation of $0.9 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.

4

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 the first quarter of 2013.

The Company has not experienced any significant credit losses and does not generally require collateral on receivables. For the three months ended March 31, 2013, two customers represented 79% and 18% of total revenue and 56% and 39% of the accounts receivable balance.

For the three months ended March 31, 2012, these two customers represented 49% and 40% of total revenues. As of December 31, 2012, there were receivables outstanding from these two customers representing 58% and 35% of the accounts receivable balance.

Newly Adopted Accounting Pronouncements

In February 2013, Accounting Standards Codification Topic 220, Comprehensive Income was amended to require companies to report, in one place, information about reclassifications out of accumulated other comprehensive income. Accordingly, a company can present this information on the face of the financial statements, if certain requirements are met, or the information must be presented in the notes to the financial statements. The Company adopted this guidance as of January 1, 2013, on a retrospective basis and the items reclassified out of accumulated other comprehensive income are not material for all periods presented.

3.  Condensed Consolidated Financial Statement Detail

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.

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):

	Three Months Ended March 31,
	2013		2012
Common stock options and restricted stock units		6,459		5,722
Warrants for common stock		16,176		5,457
Total		22,635		11,179

For the three months ended March 31, 2013 and 2012, all outstanding securities were considered anti-dilutive, and therefore the calculation of basic and diluted net loss per share was the same.

Cash and Cash Equivalents

At March 31, 2013, cash and cash equivalents consisted of demand deposits of $12.4 million and money market funds of $38.0 million with maturities of less than 90 days at the date of purchase. At December 31, 2012, cash and 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.

Short-term Investments

At March 31, 2013, short-term investments consisted of U.S. treasury securities of $20.0 million with maturities of greater than 90 days and less than one year from the date of purchase. 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.

5

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 Servier (See Note 6: Long-Term Debt and Other Financings). 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 condensed consolidated statements of comprehensive loss.

The foreign exchange options were revalued at March 31, 2013 and had an aggregate fair value of $0.3 million. The Company recognized losses of $0.2 million and $0.3 million related to the revaluation for the three months ended March 31, 2013 and 2012, respectively.

Accrued Liabilities

Accrued liabilities consisted of the following at March 31, 2013 and December 31, 2012 (in thousands):

	March 31, 2013		December 31, 2012
Accrued payroll and other benefits	$	2,169	$	2,461
Accrued management incentive compensation		1,086		3,978
Accrued clinical trial costs		746		4,702
Other		1,409		1,904
Total	$	5,410	$	13,045

Contingent Warrant Liabilities

In March 2012, in connection with an underwritten offering, the Company 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 the Company 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. The Company believes the likelihood of a change in control prior to the expiration of the warrants is remote; however, due to these provisions, the Company is 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 December 31, 2012, the fair value of the warrant liability was estimated to be $15.0 million using the Black-Scholes Model. The Company revalued the warrant liability at March 31, 2013 using the Black-Scholes Model and recorded the $12.8 million increase in the fair value as a loss in the revaluation of contingent warrant liabilities line of its condensed consolidated statements of comprehensive loss. As of March 31, 2013, 14,265,970 of these warrants were outstanding and had a fair value of $27.8 million. This increase in liability is due primarily to the increase in the market value of the Company’s common stock at March 31, 2013 compared to December 31, 2012.

In February 2010, in connection with an underwritten offering, the Company issued five-year warrants to purchase 1,260,000 shares of XOMA’s common stock at an exercise price of $10.50 per share. In June 2009, the Company issued warrants to certain institutional investors as part of a registered direct offering. These 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 the Company 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. The Company believes the likelihood of a change in control prior to the expiration of the warrants is remote; however, due to these provisions, the Company is required to account for the warrants issued in February 2010 and June 2009 as liabilities at fair value. As of March 31, 2013, all of these warrants were outstanding and had an aggregate fair value of approximately $33,000.

6

4.  Fair Value Measurements

Fair value is defined as the price that would be received from selling an asset or the amount that would be 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.

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 March 31, 2013 and December 31, 2012.

Financial assets and liabilities carried at fair value as of March 31, 2013 and December 31, 2012 were classified as follows (in thousands):

	Fair Value Measurements at March 31, 2013 Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Money market funds (1)	$	37,951	$	-	$	-	$	37,951
U.S. treasury securities (2)		19,996		-		-		19,996
Foreign exchange options (3)		-		299		-		299
Total	$	57,947	$	299	$	-	$	58,246
Liabilities:
Contingent warrant liabilities	$	-	$	-	$	27,841	$	27,841
	Fair Value Measurements at December 31, 2012 Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Money market funds (1)	$	37,461	$	-	$	-	$	37,461
U.S. treasury securities (2)		39,987		-		-		39,987
Foreign exchange options (3)		-		488		-		488
Total	$	77,448	$	488	$	-	$	77,936
Liabilities:
Contingent warrant liabilities	$	-	$	-	$	15,001	$	15,001

(1)  Included in cash and cash equivalents

(2)  Included in short-term investments

(3)  Included in other assets

7

The fair value of the foreign exchange options at March 31, 2013 and December 31, 2012 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 contingent warrant liabilities was determined at March 31, 2013 and December 31, 2012 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.

The fair value of the contingent warrant liabilities was estimated using the following range of assumptions at March 31, 2013 and December 31, 2012:

	March 31, 2013			December 31, 2012
Expected volatility		40	%		40	%
Risk-free interest rate		0.3% - 0.4	%		0.3% - 0.7	%
Expected term	1.7 - 3.9 years			1.9 - 4.2 years

The following table provides a summary of changes in the fair value of the Company’s Level 3 financial liabilities for the three months ended March 31, 2013 (in thousands):

Contingent warrant liabilities	March 31, 2013
Balance at December 31, 2012	$	15,001
Net increase in fair value of contingent warrant liabilities upon revaluation		12,840
Balance at March 31, 2013	$	27,841

The net increase of $12.8 million in the estimated fair value of the contingent warrant liabilities was recognized as a loss in the revaluation of contingent warrant liabilities line of the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013.

For the three months ended March 31, 2012, the Company recognized a net increase of $14.4 million in the estimated fair value of the contingent warrant liabilities as a loss in the revaluation of contingent warrant liabilities line of the condensed consolidated statements of comprehensive loss.

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.

In connection with the streamlining of operations, the Company incurred restructuring charges in the first quarter of 2012 of $2.1 million related to severance, other termination benefits and outplacement services and $1.7 million related to the impairment and accelerated depreciation of various assets and leasehold improvements. The Company does not expect to incur additional significant restructuring charges during 2013 related to these streamlining activities.

6.  Long-Term Debt

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 March 31, 2013, 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.

8

At March 31, 2013 and December 31, 2012, the outstanding principal balance under this note agreement was $14.4 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. Due to the structure of the secured note agreement with Novartis and since there is no liquid market for this obligation, there is no practical method to estimate fair value of this long-term debt.

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. The loan was fully funded in January 2011, with the proceeds converting to 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 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 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 March 31, 2013 and December 31, 2012, the outstanding principal balance under this loan was $19.2 million and $19.8 million, respectively, using the Euro to US Dollar exchange rates of 1.2816 and 1.3215, respectively. For the three months ended March 31, 2013 and 2012, the Company recorded an unrealized foreign exchange gain of $0.6 million and an unrealized foreign exchange loss of $0.6 million, 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 $0.4 million and $0.3 million in the three months ended March 31, 2013 and 2012, respectively, resulting from the amortization of the loan discount. At March 31, 2013 and December 31, 2012, the net carrying value of the loan was $14.2 million. For the three months ended March 31, 2013 and 2012, the Company recorded unrealized foreign exchange losses of $0.2 million related to the re-measurement of the loan discount.

The Company believes 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 $0.4 million and $0.3 million of related non-cash revenue during the three months ended March 31, 2013 and 2012, respectively.

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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 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.

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.

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At March 31, 2013 and December 31, 2012, the outstanding principal balance under the Amended Term Loan was $12.5 million.

Interest Expense

Interest expense and amortization of debt issuance costs and discounts, recorded as other expense in the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013 and 2012 are shown below (in thousands):

	Three Months Ended March 31,
	2013		2012
Interest expense
GECC term loan	$	545	$	417
Servier loan		525		516
Novartis note		91		99
Other		11		10
Total interest expense	$	1,172	$	1,042

7.  Income Taxes

The Company did not recognize any income tax expense for the three months ended March 31, 2013 and 2012. The Company’s effective tax rate will fluctuate from period to period due to several factors inherent in the nature of the Company’s operations and business transactions. The factors that most significantly impact this rate include the variability of licensing transactions in foreign jurisdictions.

8.  Stock-based Compensation

In the first quarter of 2013, the Board of Directors of the Company approved grants under the Company’s Long Term Incentive Plan for an aggregate of 994,053 stock options and an aggregate of 895,860 restricted stock units (“RSUs”) to certain employees of the Company. The stock options vest monthly over four years, and the RSUs vest annually over three years, in equal increments.

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 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 U.S. Treasury zero-coupon issues. The forfeiture rate impacts the amount of aggregate compensation for both stock options and RSUs. To establish an estimate of forfeiture rate, the Company considers its historical experience of option forfeitures and terminations.

The fair value of the stock options granted was estimated based on the following weighted average assumptions for three months ended March 31, 2013 and 2011:

	Three Months Ended March 31,
	2013			2012
Dividend yield		0	%		0	%
Expected volatility		92	%		92	%
Risk-free interest rate		0.78	%		1.05	%
Expected term	5.6 years			5.6 years

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Stock option activity for the three months ended March 31, 2013 was as follows:

	Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Options outstanding at December 31, 2012		6,788,383		$	8.99		7.36	$	1,531
Granted		994,053			2.92
Exercised		(19,090	)		1.97
Forfeited, expired or cancelled		(54,930	)		31.12
Options outstanding at March 31, 2013		7,708,416		$	8.07		7.54	$	4,502
Options exercisable at March 31, 2013		4,473,529		$	11.70		6.39	$	2,245

The valuation of RSUs is determined at the date of grant using the closing stock price. To establish an estimate of forfeiture rate, the Company considers its historical experience of forfeitures and terminations.

Unvested RSU activity for the three months ended March 31, 2013 is summarized below:

	Number of Shares			Weighted- Average Grant- Date Fair Value
Unvested balance at December 31, 2012		1,459,853		$	2.75
Granted		895,860			2.87
Vested		(164,998	)		2.50
Forfeited		(4,835	)		2.06
Unvested balance at March 31, 2013		2,185,880		$	2.65

The following table shows total stock-based compensation expense included in the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013 and 2012 (in thousands):

	Three Months Ended March 31,
	2013		2012
Research and development	$	997	$	385
Selling, general and administrative		622		289
Total stock-based compensation expense	$	1,619	$	674

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ITEM 2.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Forward Looking Statements

This Quarterly Report on Form 10-Q contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, which are subject to the “safe harbor” created by those sections. Forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to them. In some cases you can identify forward-looking statements by words such as “may,” “will,” “should,” “could,” “would,” “expects,” “plans,” “anticipates,” “believes,” “estimates,” “projects,” “predicts,” “potential” and similar expressions intended to identify forward-looking statements. Examples of these statements include, but are not limited to, statements regarding: the implications of interim or final results of our clinical trials, the progress of our research programs, including clinical testing, the extent to which our issued and pending patents may protect our products and technology, our ability to identify new product candidates, the potential of such product candidates to lead to the development of commercial products, our anticipated timing for initiation or completion of our clinical trials for any of our product candidates, our future operating expenses, our future losses, our future expenditures for research and development, and the sufficiency of our cash resources. Our actual results could differ materially from those anticipated in these forward-looking statements for many reasons, including the risks faced by us and described in Part II, Item 1A of this Quarterly Report on Form 10-Q and our other filings with the SEC. You should not place undue reliance on these forward-looking statements, which apply only as of the date of this Quarterly Report on Form 10-Q. You should read this Quarterly Report on Form 10-Q completely and with the understanding that our actual future results may be materially different from those we expect. Except as required by law, we assume no obligation to update these forward-looking statements, whether as a result of new information, future events or otherwise.

The following discussion and analysis should be read in conjunction with the unaudited financial statements and notes thereto included in Part I, Item 1 of this Quarterly Report on Form 10-Q and with the audited consolidated financial statements and related notes thereto included as part of our Annual Report on Form 10-K for the year ended December 31, 2012.

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 is being conducted by the National Eye Institute (“NEI”), a part of the U.S. National Institutes of Health (“NIH”). Servier is expected to institute its own proof-of-concept program for gevokizumab in indications different from ours. In November 2012, Servier began a Phase 2 study to determine gevokizumab’s potential to decrease plaque inflammation in patients with atherosclerosis.

Our proprietary preclinical pipeline includes classes of antibodies that activate, sensitize or deactivate the insulin receptor in vivo, which 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.

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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 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 the First Quarter of 2013

Gevokizumab

· In January 2013, we announced encouraging preliminary top-line data from an interim analysis of our Phase 2 proof-of-concept study to evaluate the safety and efficacy of gevokizumab for the treatment of moderate-to-severe inflammatory acne. Preliminary data from the 125-patient trial demonstrated clear activity according to the Investigator’s Global Assessment (“IGA”) parameter. Gevokizumab was well-tolerated in this trial, with no significant differences in adverse events between gevokizumab and placebo and no serious drug-related adverse events were reported.

Management Addition

· On March 18, 2013, the Company announced Tom Klein has joined the Company as Vice President, Chief Commercial Officer, a newly created position reporting to John Varian, Chief Executive Officer.

Results of Operations

Revenues

Total revenues for the three months ended March 31, 2013 and 2012, were as follows (in thousands):

	Three Months Ended March 31,
	2013		2012		Increase (Decrease)
License and collaborative fees	$	399	$	1,014	$	(615	)
Contract and other		8,796		8,844		(48	)
Product sales		258		7		251
Total revenues	$	9,453	$	9,865	$	(412	)

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License and Collaborative Fees

License and collaborative fee revenue includes fees and milestone payments related to the out-licensing of our products and technologies. The decrease in license and collaborative fee revenue for the three months ended March 31, 2013, as compared to the same period of 2012, was due primarily a $0.6 million decrease in licensing fees. The generation of future revenue related to license fees and other collaborative arrangements is dependent on our ability to attract new licensees to our antibody 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 revenues include agreements where we provide contracted research and development services to our contract and collaboration partners, including Servier and NIAID. The following table shows the activity in contract and other revenue for the three months ended March 31, 2013 and 2012 (in thousands):

	Three Months Ended March 31,
	2013		2012		Increase (Decrease)
Servier	$	7,027	$	3,649	$	3,378
NIAID		1,695		4,837		(3,142	)
Other		74		358		(284	)
Total contract and other	$	8,796	$	8,844	$	(48	)

The increase in revenue from Servier is due primarily to an increase in reimbursable clinical development activity under our agreements with Servier. The increase in clinical development activity is partially offset by a decrease in NIAID revenue due primarily to decreased activity under NIAID Contract No. HHSN272200800028C (“NIAID 3”) and the recognition of $2.0 million in revenue during the first quarter of 2012 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.

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.

Net Product Sales

Net product sales, cost of sales, and product gross margin for the three months ended March 31, 2013 were as follows (in thousands):

	Three Months Ended March 31,
	2013			2012			Increase (Decrease)
Net product sales (1)		258			7			251
Cost of sales (2)		46			-			46
Product gross margin		82	%		93	%

(1) Product sales are recorded net of prompt pay discounts, volume rebates and product returns.

(2) Cost of sales includes raw materials, third-party manufacturing and production costs, and royalties payable to Servier for ACEON® sales.

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.

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Research and development expenses were $16.6 million for the three months ended March 31, 2013, compared with $15.8 million for the same period of 2012. The increase of $0.8 million for the three months ended March 31, 2013, as compared to the same period in 2012, was due primarily to a $0.6 million increase in stock-based compensation costs. Also contributing to the increase was an increase in external manufacturing costs largely offset by a decrease in internal facility costs due to the 2012 streamlining of operations.

Salaries and related personnel costs are a significant component of research and development expenses. We recorded $7.6 million in research and development salaries and employee-related expenses for the three months ended March 31, 2013, as compared with $7.0 million for the same period of 2012. The increase of $0.6 million was due primarily to a $0.6 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, of which we expect to further decrease in 2013 due to our streamlining objective to utilize a contract manufacturing organization, which was implemented in 2012. Later-stage programs include clinical testing, regulatory affairs and manufacturing clinical supplies. The costs associated with these programs approximate the following (in thousands):

	Three Months Ended March 31,
	2013		2012
Earlier stage programs	$	9,217	$	8,333
Later stage programs		7,373		7,438
Total	$	16,590	$	15,771

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):

	Three Months Ended March 31,
	2013		2012
Internal projects	$	9,825	$	6,682
Collaborative and contract arrangements		6,765		9,089
Total	$	16,590	$	15,771

For the three months ended March 31, 2013, the gevokizumab program, for which we incurred the largest amount of expense, accounted for more than 40% but less than 50% of our total research and development expenses. A second development program, XMet, accounted for more than 20% but less than 30% of our total research and development expenses and a third development program, NIAID, accounted for more than 10% but less than 20% of our total research and development expenses. All remaining development programs accounted for less than 10% of our total research and development expenses for the three months ended March 31, 2013. For the three months ended March 31, 2012, the gevokizumab program, for which we incurred the largest amount of expense, 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 expenses and a third development program, XMet, accounted for more than 10% but less than 20% of our total research and development expenses. All remaining development programs accounted for less than 10% of our total research and development expenses for the three months ended March 31, 2012.

We expect our research and development spending in 2013 will increase due primarily 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.

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Selling, General and Administrative Expenses

Selling, general and administrative expenses include salaries and related personnel costs, facilities costs and professional fees. Selling, general and administrative expenses were $4.1 million for the three months ended March 31, 2013, compared with $4.7 million for the same period of 2012. The $0.6 million decrease for the first quarter of 2013, as compared to the same period of 2012, was due primarily to a $0.9 million decrease in professional services cost, partially offset by a $0.3 million increase in stock-based compensation.

Streamlining and Restructuring Charges

In January 2012, we implemented a streamlining of operations, which resulted in a restructuring plan 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.

In connection with the streamlining of operations, we incurred restructuring charges in the first quarter of 2012 of $2.1 million related to severance, other termination benefits and outplacement services and $1.7 million related to the impairment and accelerated depreciation of various assets and leasehold improvements. We do not expect to incur additional significant restructuring charges during 2013 related to these streamlining activities.

Other Income (Expense)

Interest Expense

Interest expense and amortization of debt issuance costs and discounts are shown below the three months ended March 31, 2013 and 2012 (in thousands):

	Three Months Ended March 31,
	2013		2012		Increase (Decrease)
Interest expense
GECC term loan	$	545	$	417	$	128
Servier loan		525		516		9
Novartis note		91		99		(8	)
Other		11		10		1
Total interest expense	$	1,172	$	1,042	$	130

The increase of $0.1 million in interest expense in 2013 as compared to 2012 was due primarily to an increase in interest expense under the GECC term loan, amended in September 2012.

Other Expense

Other expense primarily consisted of unrealized and realized (losses) gains. The following table shows the activity in other expense for the three months ended March 31, 2013 and 2012 (in thousands):

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	Three Months Ended March 31,
	2013			2012			Increase (Decrease)
Other income (expense)
Unrealized foreign exchange gain (loss) (1)	$	515		$	(402	)	$	917
Unrealized loss on foreign exchange options		(189	)		(276	)		87
Other		123			14			109
Total other income (expense)	$	449		$	(664	)	$	1,113

(1) Unrealized foreign exchange gain (loss) for the three months ended March 31, 2013 and 2012 primarily relates to the re-measurement of the €15 million Servier loan.

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 December 31, 2012, the fair value of the warrant liability was estimated to be $15.0 million using the Black-Scholes Model. We revalued the warrant liability at March 31, 2013 using the Black-Scholes Model and recorded the $12.8 million increase in the fair value as a loss in the revaluation of contingent warrant liabilities line of our condensed consolidated statements of comprehensive loss. As of March 31, 2013, 14,265,970 of these warrants were outstanding and had a fair value of $27.8 million. This increase in liability is due primarily to the increase in the market value of our common stock at March 31, 2013 compared to December 31, 2012.

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. In June 2009, we issued warrants to certain institutional investors as part of a registered direct offering. These 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 February 2010 and June 2009 as liabilities at fair value. As of March 31, 2013, all of these warrants were outstanding and had an aggregate fair value of approximately $33,000.

The following table provides a summary of the changes in fair value of contingent warrant liabilities for the three months ended March 31, 2013 (in thousands):

Contingent warrant liabilities	March 31, 2013
Balance at December 31, 2012	$	15,001
Net increase in fair value of contingent warrant liabilities upon revaluation		12,840
Balance at March 31, 2013	$	27,841

Income Taxes

We did not recognize any income tax expense for the three months ended March 31, 2013 and 2012.

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.

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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 March 31, 2013, 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):

	March 31, 2013			December 31, 2012			Change
Cash and cash equivalents	$	50,379		$	45,345		$	5,034
Short-term investments	$	19,996		$	39,987		$	(19,991	)
Working Capital	$	60,600		$	72,004		$	(11,404	)
	Three Months Ended March 31,
	2013			2012			Change
Net cash used in operating activities	$	(14,528	)	$	(11,675	)	$	(2,853	)
Net cash provided by (used in) investing activities		19,502			(548	)		20,050
Net cash provided by financing activities		60			38,766			(38,706	)
Net increase in cash and cash equivalents	$	5,034		$	26,543		$	(21,509	)

Working Capital

The decrease in working capital was due primarily to a $15.0 million decrease in cash, cash equivalents, and short-term investments, partially offset by a $2.5 million reclassification of principal and accrued interest on our interest bearing obligations from long-term to short-term.

Cash Used in Operating Activities

Net cash used in operating activities was $14.5 million for the three months ended March 31, 2013, compared with $11.7 million for the same period in 2012. Net cash used in operating activities was $2.8 million higher in the first quarter of 2013 due primarily to a decrease in accounts payable and other accrued liabilities of $7.1 million during the first quarter of 2013 associated with timing of payments, compared to a $3.2 million decrease during the first quarter of 2012.

Cash Provided by (Used in) Investing Activities

Net cash provided by investing activities was $19.5 million for the three months ended March 31, 2013, compared with net cash used in investing activities of $0.5 million for the same period of 2012. $20.1 million change in cash provided by investing activities was due primarily to the maturity of $20.0 million in short-term investments during the first quarter of 2013. Cash used in investing activities for the three months ended March 31, 2012, primarily consisted of fixed asset purchases.

Cash Provided by Financing Activities

Net cash provided by financing activities was $0.1 million for the three months ended March 31, 2013, compared with $38.8 million for the same period of 2012. Cash provided by financing activities in the first quarter of 2013 related to net proceeds received from employee stock purchases. Cash provided by financing activities in the first quarter of 2012 related to net proceeds received from the issuance of common stock and warrants of $36.2 million in the March 2012 underwritten public offering and net proceeds of $3.2 million received from the issuance of common stock under the 2011 ATM Agreement, offset by $0.7 million of principal payments on our loan with GECC.

Net proceeds received during the first quarters of 2013 and 2012 were used to continue development of our gevokizumab product candidate and for other working capital and general corporate purposes.

*           *           *

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We have incurred significant operating losses and negative cash flows from operations since our inception. At March 31, 2013, we had cash, cash equivalents, and short-term investments of $70.4 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 loan agreement with GECC, our March 2012 and October 2012 public offerings, biodefense contracts and licensing transactions and other sources of funding that we believe to be available, we estimate 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.

Critical Accounting Estimates

Critical accounting estimates are those that require significant judgment and/or estimates by management at the time that the financial statements are prepared such that materially different results might have been reported if other assumptions had been made. We consider certain accounting policies including, but not limited to, revenue recognition, research and development expense, long-lived assets, contingent warrant liabilities, derivative instruments and stock-based compensation to be critical policies. There have been no significant changes in our critical accounting estimates during the three months ended March 31, 2013, as compared with those previously disclosed in our Annual Report on Form 10-K for the fiscal year ended December 31, 2012, filed with the SEC on March 12, 2013.

ITEM 3.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Interest Rate Risk

We are exposed to market risks in the ordinary course of our business. These risks primarily include risk related to interest rate sensitivities. Our market risks related to interest rate sensitivities at March 31, 2013, have not changed materially from those discussed in Item 7A of our Form 10-K for the year ended December 31, 2012 filed with the SEC.

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 March 31, 2013, the €15.0 million outstanding principal balance under the Servier Loan Agreement would have equaled approximately $19.2 million using the March 31, 2013 Euro to USD exchange rate of 1.2816. 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 2014 and January 2016, respectively. Upfront premiums paid on these foreign exchange option contracts totaled $1.5 million and they had an aggregate fair value of $0.3 million at March 31, 2013. Our use of derivative financial instruments represents risk management; we do not enter into derivative financial contracts for trading purposes.

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ITEM 4.  CONTROLS AND PROCEDURES

Evaluation of Controls and Procedures

Under the supervision and with the participation of our management, including our Chief Executive Officer (our principal executive officer) and our Vice President, Finance, Chief Financial Officer and Secretary (our principal financial and principal accounting officer), we conducted an evaluation of our disclosure controls and procedures, as such term is defined under Rule 13a-15(e) promulgated under the Securities Exchange Act of 1934, as amended, as of the end of the period covered by this report. 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 are effective as of the end of the period covered by this report in timely alerting them to material information relating to us and our consolidated subsidiaries required to be included in our periodic SEC filings.

Changes in Internal Control

There have been no changes in our internal controls over financial reporting during our most recent fiscal quarter that have materially affected, or are reasonably likely to materially affect, our internal controls over financial reporting.

PART II – OTHER INFORMATION

ITEM 1.  LEGAL PROCEEDINGS

None.

ITEM 1A.  RISK FACTORS

This Quarterly Report on Form 10-Q contains forward-looking information based on our current expectations. Because our actual results may differ materially from any forward-looking statements made by or on behalf of us, this section includes a discussion of important factors that could affect our actual future results, including, but not limited to, our revenues, expenses, operating results, cash flows, net loss and loss per share. Additional risks and uncertainties not presently known to us also may impair our business operations.  You should carefully consider these risk factors, together with all of the other information included in this Quarterly Report on Form 10-Q as well as our other publicly available filings with the U.S. Securities and Exchange Commission, or SEC.

We have marked with an asterisk (*) those risks described below that reflect substantive changes from, or additions to, the risks described in our Annual Report on Form 10-K for the year ended December 31, 2012.

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.

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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.

Based on our cash, cash equivalents and short-term investments of $70.4 million at March 31, 2013, 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 March 31, 2013, we had an accumulated deficit of $982.0 million.

For the three months ended March 31, 2013, we had a net loss of approximately $24.9 million, or $0.30 per share of common stock (basic and diluted). For the three months ended March 31, 2012, we had a net loss of approximately $30.4 million, or $0.69 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 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.

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· 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 and was 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 March 31, 2013, the €15.0 million outstanding principal balance under this Servier Loan Agreement would have equaled approximately $19.2 million using the March 31, 2013 Euro-to-U.S.-dollar exchange rate of 1.2816.

· 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. 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.

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 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.

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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.

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.

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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:

· clinical development and testing;

· manufacturing;

· 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 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.

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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.

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.

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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.

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 May 6, 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 82,893,328 were issued and outstanding as of May 6, 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 May 6, 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 May 6, 2013, 14,265,970 of these warrants were outstanding.

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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 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, 2013, through May 6, 2013, the share price of our common stock has ranged from a high of $3.67 to a low of $2.43. 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.

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.

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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 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.

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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 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.

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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 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.

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· 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 May 6, 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 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:

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· significantly greater financial resources;

· larger research and development and marketing staffs;

· 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. On March 1, 2013, Novartis announced that they received EU approval for Ilaris in patients suffering acute gouty arthritis attacks which cannot gain relief from current treatments. It is administered as a single 150 mg subcutaneous injection. 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, and in January 2013 they obtained FDA approval for NOMID, a severe form 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 noninfectious intermediate, posterior or pan-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.

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:

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· 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.

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.

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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.

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:

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· 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 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.

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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 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.

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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 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 March 31, 2013, the Company has excluded the NOLs and R&D credits that will expire as a result of the annual limitations. 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.

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 167 employees as of May 6, 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 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.

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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 March 31, 2013, 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 March 31, 2013, 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 May 6, 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 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.

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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 2.  UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

None.

ITEM 3.  DEFAULTS UPON SENIOR SECURITIES

None.

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

ITEM 5.  OTHER INFORMATION

On May 8, 2013, the Company issued a press release announcing the Company’s financial results for the first quarter ended March 31, 2013. A copy of the press release is furnished as Exhibit 99.1 to this report.

ITEM 6.  EXHIBITS

See Index to Exhibits at the end of this Report, which is incorporated by reference here. The Exhibits listed in the accompanying Index to Exhibits are filed as part of this report.

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SIGNATURES

Pursuant to the requirements 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.

	XOMA Corporation
Date:  May 8, 2013	By:	/s/ JOHN VARIAN
		John Varian Chief Executive Officer (principal executive officer) and Director
Date: May 8, 2013	By:	/s/ FRED KURLAND
		Fred Kurland Vice President, Finance, Chief Financial Officer and Secretary (principal financial and principal accounting officer)

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EXHIBIT INDEX

		Incorporation By Reference
Exhibit Number	Exhibit Description	Form	SEC File No.	Exhibit	Filing Date
3.1	Certificate of Incorporation of XOMA Corporation	8-K	000-14710	3.1	01/03/2012
3.2	Certificate of Amendment of Certificate of Incorporation of XOMA Corporation	8-K	000-14710	3.1	05/31/2012
3.3	By-laws of XOMA Corporation	8-K	000-14710	3.2	01/03/2012
4.1	Reference is made to Exhibits 3.1, 3.2 and 3.3
4.2	Specimen of Common Stock Certificate	8-K	000-14710	4.1	01/03/2012
4.3	Form of Certificate of Designations of Series A Preferred Stock	8-K	000-14710	3.1	01/03/2012
4.4	Form of Amended and Restated Warrant (June 2009 Warrants)	8-K	000-14710	10.6	02/02/2010
4.5	Form of Warrant (February 2010 Warrants)	8-K	000-14710	10.2	02/02/2010
4.6	Form of Warrant (December 2011 Warrants)	10-K	000-14710	4.9	03/14/2012
4.7	Form of Warrant (March 2012 Warrants)	8-K	000-14710	4.1	03/07/2012
4.8	Form of Warrant (September 2012 Warrants)	8-K	000-14710	4.10	10/03/2012
10.1+	Officer Employment Agreement by and between XOMA Corporation and Thomas Klein dated March 18, 2013
31.1+	Certification of Chief Executive Officer, as required by Rule 13a-14(a) or Rule 15d-14(a)
31.2+	Certification of Chief Financial Officer, as required by Rule 13a-14(a) or Rule 15d-14(a)
32.1+	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)
99.1+	Press Release dated May 8, 2013
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)

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		Incorporation By Reference
Exhibit Number	Exhibit Description	Form	SEC File No.	Exhibit	Filing Date
101.LAB+	XBRL Taxonomy Extension Labels Linkbase Document(2)
101.PRE+	XBRL Taxonomy Extension Presentation Linkbase Document(2)

+ Filed herewith

(1) This certification accompanies the Form 10-Q 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-Q), 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.

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EX-10.1

Exhibit 10.1

OFFICER EMPLOYMENT AGREEMENT

This Officer Employment Agreement (“Agreement”), dated this 18th day of March, 2013, by and between XOMA Corporation (“XOMA” or the “Company”), a Delaware corporation with its principal office at 2910 Seventh Street, Berkeley, California, and Thomas Klein (“Employee”), an individual residing at 1277 Balboa Street, Burlingame, California 94010.

WHEREAS, the Company wishes to enter into this Agreement to retain or assure the Company of the continued services of Employee; and

WHEREAS, Employee is willing to enter into this Agreement and to serve or to continue to serve in the employ of the Company upon the terms and conditions hereinafter provided;

NOW, THEREFORE, in consideration of the mutual covenants herein contained, the parties hereto hereby agree as follows:

1.           Employment.  The Company agrees to employ or to continue to employ Employee, and Employee agrees to be or continue to be employed by the Company, for the period referred to in Section 3 hereof and upon the other terms and conditions herein provided.

2.           Position and Responsibilities.   Employee shall devote his reasonable best efforts and substantially all of his time and attention to his employment by the Company.  He shall perform the duties of Vice President and Chief Commercial Officer and/or such other reasonable duties as may be determined from time to time by the Chief Executive Officer of the Company (“John Varian”).During his employment with the Company, Employee may not accept part time consulting or other business or non-profit opportunities without first obtaining written approval from the CEO.   

3.           Term of Employment. This Agreement shall become effective and the term of employment pursuant to this Agreement shall commence on March 18, 2013 and continue until March 18, 2014.  This Agreement will be automatically extended (without further action by the parties) for an additional one–year term thereafter and again on each subsequent one-year anniversary thereof unless it is terminated by either the Employee or the Company at any time with thirty (30) days prior written notice, unless Employee is otherwise terminated by the Company or he/she resigns from the Company pursuant to Section 6 hereof.

4.           Compensation and Reimbursement of Expenses.

(a)           Compensation. For all services rendered by Employee as Vice President and Chief Commercial Officer during his employment under this Agreement, the Company shall pay Employee as compensation a base salary at a rate of not less than $380,000.00 per annum. In addition, Employee shall be a participant in the Company’s Management Incentive Compensation Plan (‘MICP”).  All taxes and governmentally required withholding shall be deducted in conformity with applicable laws.

(b)           Share Options.  Employee will be granted share options and/or other share or share-based awards from time to time as per the Company’s standard practices and subject to approval by the Company’s Board of Directors.

(c)           Reimbursement of Expenses. The Company shall pay or reimburse Employee for all reasonable travel and other expenses incurred by Employee in performing his obligations under this Agreement in a manner consistent with past Company practice. The Company further agrees to furnish Employee with such assistance and accommodations as shall be suitable to the character of Employee’s position with the Company, adequate for the performance of his duties and consistent with past Company practice.

5.           Participation in Benefit Plans. The payments provided in Section 4 hereof are in addition to benefits Employee is entitled to under any group hospitalization, health, dental care, disability insurance, surety bond, death benefit plan, travel and/or accident insurance, other allowance and/or executive compensation plan, including, without limitation, any senior staff incentive plan, capital accumulation programs, restricted or non-restricted share purchase plan, share option plan, retirement income or pension plan or other present or future group employee benefit plan or program of the Company for which key executives are or shall become eligible, and Employee shall be eligible to receive during the period of his employment under this Agreement, all benefits and emoluments for which key executives are eligible under every such plan or program to the extent permissible under the general terms and provisions of such plans or programs and in accordance with the provisions thereof.

6.           Termination of Employment.

(a)           Termination by Employee.  As provided in Section 3, Employee has the right to terminate his employment with the Company at any time and for any reason.  Employee will not be entitled to any severance pay or other benefits from the Company if he/she terminates his employment with the Company, except if such termination is for Good Reason in accordance with the terms hereof.  In case of termination of this Agreement for Good Reason by Employee, Employee shall be entitled to the  severance pay and other benefits set forth in Section 7 hereof.  “Good Reason” shall mean, unless remedied by the Company within sixty (60) days after the receipt of written notice from the Employee as provided below or consented to in writing by the Employee, (i) the material diminution of any material duties or responsibilities of the Employee; or (ii) a material reduction in the Employee's base salary; provided, however, that the Employee must have given written notice to the Company of the existence of any such condition within ninety (90) days after the initial existence thereof (and the failure to provide such timely notice will constitute a waiver of the Employee’s ability to terminate employment for Good Reason as a result of such condition), and the Company will have a period of sixty (60) days from receipt of such written notice during which it may remedy the condition; provided further, however, that any termination of employment by the Employee for Good Reason must occur not later than one hundred eighty (180) days following the initial existence of the condition giving rise to such Good Reason in order to qualify for the severance pay and other benefits set forth in Section 7 hereof.

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(b)           Termination by the Company Without Cause.  Employee may be terminated by the Company without Cause (as defined below), but in such case, Employee shall be entitled to the severance pay and other benefits set forth in Section 7 hereof.

(c)           Termination Upon Death or Permanent Disability.  Except as required by law and as provided in Section 7 hereof, all benefits and other rights of Employee hereunder shall be terminated by the death or permanent disability of the Employee.  For the purposes of this Agreement, permanent disability is defined as Employee being incapable of performing his duties to the Company by reason of any medically determined physical or mental impairment that can be expected to last for a period of more than six consecutive months from the first date of the Employee’s absence due to the disability.  The Company will give Employee at least four weeks written notice of termination due to such disability.

(d)           Termination by the Company for Cause.  The Company may terminate Employee’s employment for cause, in which case, Employee will not be entitled to any severance pay.  For the purposes of this Agreement, the Company will have Cause to terminate Employee’s employment as the result of:

(i)       willful material fraud or material dishonesty in connection with Employee’s performance hereunder;

(ii)       failure by Employee to materially perform the material duties of his job as Vice President, Research and Chief Commercial Officer, as documented pursuant to the Company’s performance management process and procedures;

(iii)       material breach of this Agreement or the Company’s policies set forth on the Company’s Intranet Portal under “Policy Manual”;

(iv)       misappropriation of a material business opportunity of the Company;

(v)       misappropriation of any Company funds or property;  or

(vi)       conviction of, or the entering of, a plea of guilty, or no contest, with respect to a felony or the equivalent thereof.

(e)           Notice and Opportunity to Cure.  Notwithstanding the foregoing, it shall be a condition precedent to the Company’s right to terminate the Employee’s employment for the reasons set forth in Sections 6(d)(ii) or (iii) of this Agreement that (i) the Company shall first have given the Employee written notice stating with specificity the reason for the termination (“breach”) and (ii) if such breach is capable of cure or remedy, Employee will have a period of thirty (30) days after the notice is given to remedy the breach, unless such breach cannot be cured or remedied within thirty (30) days, in which case the period for remedy or cure shall be extended for a reasonable time (not to exceed an additional thirty (30) days), provided the Employee has made and continues to make a diligent effort to effect such remedy or cure.

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(f)           Resignation from the Board of Directors of the Company (“Board”).  If Employee is a member of the Board at the time of termination of his employment with the Company (regardless of the reason(s) therefor), Employee shall be deemed to have resigned from the Board effective as of the date of such termination of employment, unless Employee and the Company agree otherwise in writing.

(g)           Return of Company Property.  Upon termination of employment for any reason, Employee shall immediately return to the Company all documents, telephones, computers, pagers, keys, credit cards, other property and records of the Company, and all copies thereof, within Employee’s possession, custody or control.

7.           Severance Pay and Other Benefits.  The following provisions of this Section 7 shall apply upon the occurrence of an event of termination as provided in Section 6(a) for Good Reason, Section 6(b) or Section 6(c).

(a)           Cash Severance Pay.  The Company shall pay Employee, or in the event of his subsequent death or permanent disability, his beneficiary or beneficiaries of his estate, as the case may be, as severance pay or liquidated damages, or both, (i) a severance payment in an amount equal to 0.75 times Employee’s annual base salary as in effect immediately prior to the termination, and (ii) a severance payment equal to  a prorated portion of the Employee’s annual target bonus in effect for the fiscal year in which the termination occurs calculated by multiplying the annual target bonus by a fraction, the numerator of which shall be the number of calendar months (including a portion of any such month) during which the Employee was employed by the Company prior to the occurrence of the termination during such fiscal year, and the denominator of which shall be 12; provided that, if Employee is terminated other than for Cause under Section 6(d) above, after December 31 of any year in which he/she was a participant in the MICP, Employee shall be entitled to receive his bonus payment for the year just ended consistent with his performance against his MICP objectives.  Such severance payments shall be in lieu of any other severance payment to which the Employee shall be entitled as a result of such termination pursuant to this Agreement, any other employment agreement with or offer letter from the Company or any of its affiliates or the Company’s or any of its affiliate’s then existing severance plans and policies, except in those circumstances where the provisions of the Change of Control Severance Agreement between Employee and XOMA Corporation, by such agreement’s express terms, apply, in which case the provisions of such agreement providing for severance payment(s) to Employee as a result of such termination shall apply in lieu of the provisions of this Agreement relating thereto.  The severance payment described in Section 7(a)(i) above, shall be paid in monthly installments over nine (9) months (the “Severance Payment Period”), with the first two (2) of such monthly installments being paid after expiration of any revocation period therefore and sixty (60) days after the date of termination and the remaining monthly installments being paid monthly thereafter until fully paid. The severance payments described in Section 7(a)(ii) above, shall be paid in a lump sum sixty (60) days after the date of termination; provided, however, that all of such severance payments shall be subject to the requirements of Section 7(c) and Section 7(e) below.

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(b)           Group Health Coverage and Certain Other Benefits.  In addition, during a period of nine (9) months following an event of termination under Section 6(a), for Good Reason only, or Section 6(b), (i) the Company shall pay for the full cost of the coverage   of the Employee and Employee’s spouse and eligible dependents under any group health plans of the Company on the date of such termination of employment at the same level of health (i.e., medical, vision and dental) coverage and benefits as in effect for the Employee or such covered dependents on the date immediately preceding the date of the Employee’s termination; provided, however, that (A)  Employee and Employee’s spouse and eligible dependents each constitutes a qualified beneficiary, as defined in Section 4980B(g)(1) of the Internal Revenue Code of 1986, as amended (the “Code”); and (B)  Employee elects continuation coverage pursuant to the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended (“COBRA”), within the time period prescribed pursuant to COBRA; and (ii) if Employee is, at the time of such termination, an eligible participant in the Company’s mortgage differential program, the Company shall continue to make mortgage assistance payments to Employee pursuant to such program as in effect at the time of such termination.  Notwithstanding the foregoing, the payments by the Company for such group health coverage and/or mortgage assistance, as applicable, shall cease prior to the expiration of the nine (9) month period in this Section 7(b) upon the employment of the Employee by another employer.  Furthermore, if, at the time of the termination of Employee’s employment under paragraph 6(a), Employee is the obligor of a “forgivable” loan (i.e., a loan which by its terms is to be considered forgiven by the Company and paid by the obligor in circumstances other than actual repayment) from the Company, then, notwithstanding any provisions of such loan to the contrary, the outstanding balance of such loan shall be immediately due and payable, together with any accrued and unpaid interest thereon.

(c)           Section 409A of the Code.  Notwithstanding any provision to the contrary in this Agreement, if the Employee is deemed on the date of his  “separation from service” (within the meaning of Treas. Reg. Section 1.409A-1(h)) with the Company to be a “specified employee” (within the meaning of Treas. Reg. Section 1.409A-1(i)), then with regard to any payment or benefit (including, without limitation, any mortgage assistance payment or loan forgiveness referred to above) that is considered deferred compensation under Section 409A of the code payable on account of a “separation from service” that is required to be delayed pursuant to Section 409A(a)(2)(B) of the Code (after taking into account any applicable exceptions to such requirement), such payment or benefit shall be made or provided on the date that is the earlier of (i) the expiration of the six (6)-month period measured from the date of the Employee’s “separation from service,” or (ii) the date of the Employee’s death (the “Delay Period”).  Upon the expiration of the Delay Period, all payments and benefits delayed pursuant to this Section 7(c) (whether they would have otherwise been payable in a single sum or in installments in the absence of such delay) shall be paid or reimbursed to the Employee in a lump sum and any remaining payments and benefits due under this Agreement shall be paid or provided in accordance with the normal payment dates specified for them herein.  Notwithstanding any provision of this Agreement to the contrary, for purposes of any provision of this Agreement providing for the payment of any amounts or benefits upon or following a termination of employment, references to the Employee’s “termination of employment” (and corollary terms) with the Company shall be construed to refer to Employee’s “separation from service” (within the meaning of Treas. Reg. Section 1.409A-1(h)) with the Company.

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(d)           Outplacement Program.  Upon the occurrence of an event of termination under Section 6(a) for Good Reason or Section 6(b), Employee will immediately become entitled to participate in a six (6) month executive outplacement program provided by an executive outplacement service selected by the Company, at the Company’s expense not to exceed eight thousand dollars ($8,000) paid directly to the outplacement service.

(e)           Release of Claims.  As a condition of entering into this Agreement and receiving the severance benefits under this Section 7, Employee agrees to execute, on or before the date that is fifty (50) days following the date of termination, and not revoke a release of claims agreement substantially in the form attached hereto as Exhibit A upon the termination of the Employee’s employment with the Company.  Such release shall not, however, apply to the rights and claims of the Employee under this Agreement, any indemnification agreement between the Employee and XOMA Corporation (or its successor or acquirer), the by-laws of XOMA Corporation (or its successor or acquirer), the share award agreements between the Employee and XOMA Corporation (or its successor or acquirer), or any employee benefit plan of which the Employee is a participant and under which all benefits due under such plan have not yet been paid or provided.

8.           Post-Termination Obligations. All payments and benefits provided to Employee under this Agreement shall be subject to Employee’s compliance with the following provisions during the term of his employment and for the Severance Payment Period:

(a)           Confidential Information and Competitive Conduct. Employee shall not, to the detriment of the Company, or any of its affiliates, disclose or reveal to any unauthorized person any trade secret or other confidential information relating to the Company or its affiliates or to any businesses operated by them, and Employee confirms that such information constitutes the exclusive property of the Company. Employee shall not otherwise act or conduct herself/himself to the material detriment of the Company or its affiliates, or in a manner which is inimical or contrary to the interests thereof. Employee recognizes that the possible restrictions on his activities which may occur as a result of his performance of his obligations under this Section 8 are required for the reasonable protection of the Company and its investments

(b)           Agreement Not to Solicit Employees.  Employee agrees that during the term of his employment with the Company or any entity owned by or affiliated with the Company (whether pursuant to this Agreement or otherwise), and for one (1) year following the termination thereof for any reason whatsoever, he/she will not, either directly or indirectly, on his own behalf or in the service or on behalf of others, solicit or divert, attempt to solicit or divert or induce or attempt to induce to discontinue employment with the Company, or any subsidiary or affiliate thereof, any person employed by the Company, or any subsidiary or affiliate thereof, whether or not such employee is a full time employee or a temporary employee of the Company, or any subsidiary or affiliate thereof, and whether or not such employment is for a determined period or is at-will.

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(c)           Non-Disparagement.  The Employee and the Company agree to refrain from (i) any defamation, libel or slander or any communication of any facts or opinions that might tend to disparage, degrade or harm the reputation of the other and its respective officers, directors, employees, representatives, investors, shareholders, administrators, affiliates, divisions, subsidiaries, predecessor and successor corporations and assigns or (ii) tortious interference with the contracts and relationships of the other and its respective officers, directors, employees, representatives, investors, shareholders, administrators, affiliates, divisions, subsidiaries, predecessor and successor corporations and assigns.

(d)           Failure of Employee to Comply. If, for any reason other than death or disability, Employee shall, without written consent of the Company, fail to comply with the provisions of Sections 8(a), (b) or (c)  above, (i) his rights to any future payments or other benefits hereunder shall terminate immediately; (ii) the Company’s obligations to make such payments and provide such benefits shall cease immediately; and (iii) Employee shall refund to the Company all termination payments received by Employee pursuant to this Agreement.

(e)           Understanding of Covenants.  The Employee represents that the Employee (i) is familiar with the foregoing covenants not to compete, not to solicit  and not to disparage, and (ii) is fully aware of the Employee’s obligations hereunder, including, without limitation, the reasonableness of the length of time, scope and geographic coverage of the covenant not to compete.

(f)           Remedies. Employee agrees that monetary damages would not be adequate compensation for any loss incurred by the Company by reason of a breach of the provisions of this Section 8 and hereby agrees to waive the defense in any action for specific performance that a remedy at law would be adequate.

9.           General Provisions.

(a)           Binding Agreement. This Agreement shall be binding upon, and inure to the benefit of, Employee and the Company and their respective permitted successors and assigns.

(b)           Compliance with Section 409A of the Code.

(i)           It is intended that this Agreement will comply with Section 409A of the Code and any regulations and guidelines promulgated thereunder (collectively, “Section 409A”), to the extent the Agreement is subject thereto, and the Agreement shall be interpreted on a basis consistent with such intent.  If an amendment of the Agreement is necessary in order for it to comply with Section 409A, the parties hereto will negotiate in good faith to amend the Agreement in a manner that preserves the original intent of the parties to the extent reasonably possible.  No action or failure to act pursuant to this Section 9(b) shall subject the Company to any claim, liability, or expense, and the Company shall not have any obligation to indemnify or otherwise protect the Employee from the obligation to pay any taxes, interest or penalties pursuant to Section 409A.

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(ii)           With respect to any reimbursement or in-kind benefit arrangements of the Company and its subsidiaries that constitute deferred compensation for purposes of Section 409A, except as otherwise permitted by Section 409A, the following conditions shall be applicable: (A) the amount eligible for reimbursement, or in-kind benefits provided, under any such arrangement in one calendar year may not affect the amount eligible for reimbursement, or in-kind benefits to be provided, under such arrangement in any other calendar year (except that the health and dental plans may impose a limit on the amount that may be reimbursed or paid), (B) any reimbursement must be made on or before the last day of the calendar year following the calendar year in which the expense was incurred, and (C) the right to reimbursement or in-kind benefits is not subject to liquidation or exchange for another benefit.  Whenever a payment under this Agreement specifies a payment period with reference to a number of days (e.g., “payment shall be made within thirty (30) days after termination of employment”), the actual date of payment within the specified period shall be within the sole discretion of the Company.  Whenever payments under this Agreement are to be made in installments, each such installment shall be deemed to be a separate payment for purposes of Section 409A.

(c)           Notices.  Notices and all other communications contemplated by this Agreement shall be in writing and shall be deemed to have been duly given when personally delivered or when mailed by U.S. registered or certified mail, return receipt requested and postage prepaid.  In the case of the Employee, mailed notices shall be addressed to the Employee at the home address that the Employee most recently communicated to the Company in writing.  In the case of the Company, mailed notices shall be addressed to its corporate headquarters, and all notices shall be directed to the attention of its Secretary.

10.           Successors and Assigns.

(a)           Company’s Successors.  Any successor to the Company (whether direct or indirect and whether by purchase, lease, merger, amalgamation, consolidation, liquidation or otherwise) to all or substantially all of the Company’s business and/or assets shall assume the Company’s obligations under this Agreement and agree expressly to perform the Company’s obligations under this Agreement in the same manner and to the same extent as the Company would be required to perform such obligations in the absence of a succession.  For all purposes under this Agreement, the term “Company” shall include any successor to the Company’s business and/or assets which executes and delivers the assumption agreement described in this subsection (a) or which becomes bound by the terms of this Agreement by operation of law.

(b)           Employee’s Successors.  Without the written consent of the Company, the Employee shall not assign or transfer this Agreement or any right or obligation under this Agreement to any other person or entity.  Notwithstanding the foregoing, the terms of this Agreement and all rights of the Employee hereunder shall inure to the benefit of, and be enforceable by, the Employee’s personal or legal representatives, executors, administrators, successors, heirs, distributees, devisees and legatees.

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11.           Miscellaneous Provisions.

(a)           Amendment of Agreement. This Agreement may not be modified or amended except by an instrument in writing signed by the parties hereto.

(b)           Waiver. No term or condition of this Agreement shall be deemed to have been waived except by written instrument of the party charged with such waiver. No such written waiver shall be deemed a continuing waiver unless specifically stated therein, and each such waiver shall operate only as to the specific term or condition waived.

12.           Severability. In the event any provision of this Agreement or any part hereof is held invalid, such invalidity shall not affect any remaining part of such provision or any other provision. If any court construes any provision of this Agreement to be illegal, void or unenforceable because of the duration or the area or matter covered thereby, such court shall reduce the duration, area or matter of such provision, and, in its reduced form, such provision shall then be enforceable and shall be enforced.

13.           Governing Law. This Agreement has been executed and delivered in the State of California, and its validity interpretation, performance, and enforcement shall be governed by the laws of said State.  The parties agree that any legal disputes concerning this Agreement, or Employee’s next employment, will be filed in Alameda County, California.

14.           Legal Fees. If any action or proceeding in arbitration or law is commenced to enforce any of the provisions or rights under this Agreement or Exhibit A hereto, the unsuccessful party to such action or proceeding, as determined by arbitration or by the court in a final judgment or decree, will pay the successful party all costs, expenses, and reasonable attorney’s fees incurred therein by such party (including, without limitation, such costs, expenses and fees on any appeal), and if such successful party will recover judgment in any such action or proceedings, such costs, expenses and attorneys’ fees will be included as part of such judgment.

15.           Arbitration.  All claims or controversies between Employee and the Company relating in any manner whatsoever to Employee’s employment with the Company or the termination of that employment shall be resolved by arbitration in front of one neutral arbitrator in accordance with the then applicable Employment Dispute Resolution rules of the American Arbitration Association (“the AAA Rules”).  Claims subject to arbitration shall include contract claims, tort claims and claims relating to compensation and stock options, as well as claims based on any federal, state, or local law, statute, or regulation, including but not limited to any claims arising under Title VII of the Civil Rights Act of 1964, the Age Discrimination in Employment Act, the Americans with Disabilities Act, and the California Fair Employment and Housing Act (“Arbitrable Claims”).  However, claims for unemployment insurance, claims under applicable workers’ compensation laws, and claims under the National Labor Relations Act shall not be subject to arbitration.  The arbitrator shall apply the same substantive law, with the same statutes of limitations and same remedies that would apply if the claims were brought in a court of law.  The arbitrator shall have the authority to consider and decide pre-hearing motions, including dispositive motions.

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16.           Counterparts.  This Agreement may be executed in one or more counterparts, each of which shall be deemed to be an original but all of which together will constitute one and the same instrument

IN WITNESS WHEREOF, each of the parties hereto has signed this Agreement, and it shall be effective as of March 18, 2013.

XOMA CORPORATION

/s/ John Varian

John Varian

Chief Executive Officer

/s/ Thomas Klein

Thomas Klein

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EXHIBIT A

FORM RELEASE OF CLAIMS AGREEMENT

This Release of Claims Agreement (this “Agreement”) is made and entered into by and between XOMA Corporation (the “Company”) and _________________ (the “Employee”).

WHEREAS, the Employee was employed by the Company; and

WHEREAS, the Company and the Employee have entered into an Officer Employment Agreement effective as of ________________ ___, 2013 (the “Employment Agreement”).

NOW THEREFORE, in consideration of the mutual promises made herein and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Company and the Employee (collectively referred to as the “Parties”) desiring to be legally bound do hereby agree as follows:

1.      Termination.  The Employee’s employment with the Company terminated on ___________, 20__.

2.      Consideration.  Subject to and in consideration of the Employee’s full and complete release of claims as provided herein, the Company has agreed to pay the Employee certain benefits and the Employee has agreed to provide certain benefits to the Company, both as set forth in the Employment Agreement.

3.      Release of Claims.  The Employee agrees that the foregoing consideration represents settlement in full of all currently outstanding obligations owed to the Employee by the Company.  The Employee, on the Employee’s own behalf and the Employee’s respective heirs, family members, executors and assigns, hereby fully and forever releases the Company and its past, present and future officers, agents, directors, employees, investors, shareholders, administrators, affiliates, divisions, subsidiaries, parents, predecessor and successor corporations, and assigns, from, and agrees not to sue or otherwise institute or cause to be instituted any legal or administrative proceedings concerning any claim, duty, obligation or cause of action relating to any matters of any kind, whether presently known or unknown, suspected or unsuspected, that the Employee may possess arising from any omissions, acts or facts that have occurred up until and including the Effective Date (as defined below) of this Agreement including, without limitation:

(a)      any and all claims relating to or arising from the Employee’s employment relationship with the Company and the termination of that relationship;

(b)      any and all claims relating to, or arising from, the Employee’s right to purchase, or actual purchase of shares of stock of the Company, including, without limitation, any claims for fraud, misrepresentation, breach of fiduciary duty, breach of duty under applicable state corporate law and securities fraud under any state or federal law;

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(c)      any and all claims based on contract, tort or statute including, but not limited to, claims for wrongful discharge of employment, termination in violation of public policy, discrimination, breach of contract (both express and implied), breach of a covenant of good faith and fair dealing (both express and implied), promissory estoppel, negligent or intentional infliction of emotional distress, negligent or intentional misrepresentation, negligent or intentional interference with contract or prospective economic advantage, unfair business practices, defamation, libel, slander, negligence, personal injury, assault, battery, invasion of privacy, false imprisonment and conversion;

(d)      any and all claims for violation of any federal, state or municipal statute, including, but not limited to, Title VII of the Civil Rights Act of 1964, the Civil Rights Act of 1991, the Age Discrimination in Employment Act of 1967, the Americans with Disabilities Act of 1990, the Fair Labor Standards Act, the Employee Retirement Income Security Act of 1974, The Worker Adjustment and Retraining Notification Act, the California Fair Employment and Housing Act, and/or the California Labor Code and all amendments to each such Act/statute  as well as the regulations issued thereunder;

(e)      any and all claims for violation of the federal or any state constitution;

(f)      any and all claims arising out of any other laws and regulations relating to employment or employment discrimination; and

(g)      any and all claims for attorneys’ fees and costs.

The Employee agrees that the release set forth in this Section 3 shall be and remain in effect in all respects as a complete general release as to the matters released.  Notwithstanding the foregoing, this release does not extend to any obligations now or subsequently incurred under this Agreement, the post-termination obligations set forth in Section 8 of the Employment Agreement, the Indemnification Agreement between the Employee and the Company (or its successor or acquirer), the outstanding stock award agreements between the Employee and the Company (or its successor or acquirer), or any employee benefit plan of which the Employee is a participant and under which all benefits due under such plan have not yet been paid or provided.

4.      Acknowledgment of Waiver of Claims under ADEA.  The Employee acknowledges that the Employee is waiving and releasing any rights the Employee may have under the Age Discrimination in Employment Act of 1967 (“ADEA”) and that this waiver and release is knowing and voluntary.  The Employee and the Company agree that this waiver and release does not apply to any rights or claims that may arise under the ADEA after the Effective Date of this Agreement.  The Employee acknowledges that the consideration given for this waiver and release agreement is in addition to anything of value to which the Employee was already entitled.  The Employee further acknowledges that the Employee has been advised by this writing that (a) the Employee should consult with an attorney prior to executing this Agreement; (b) the Employee has at least twenty-one (21) days within which to consider this Agreement; (c) the Employee has seven (7) days following the execution of this Agreement by the Parties to revoke the Agreement; and (d) this Agreement shall not be effective until the revocation period has expired.  Any revocation should be in writing and delivered to the Legal Department at the Company by the close of business on the seventh (7th) day from the date that the Employee signs this Agreement.

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5.      Civil Code Section 1542.  The Employee represents that the Employee is not aware of any claims against the Company other than the claims that are released by this Agreement.  The Employee acknowledges that the Employee has been advised by legal counsel and is familiar with the provisions of California Civil Code Section 1542, which provides as follows:

A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN HER OR HIS FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HER OR HIM MUST HAVE MATERIALLY AFFECTED HER OR HIS SETTLEMENT WITH THE DEBTOR.

The Employee, being aware of said code section, agrees to expressly waive any rights the Employee may have thereunder, as well as under any other statute or common law principles of similar effect.

6.      No Pending or Future Lawsuits.  The Employee represents that the Employee has no injuries that have not yet been reported to the Company’s workers’ compensation carrier and no lawsuits, claims or actions pending in the Employee’s name, or on behalf of any other person or entity, against the Company or any other person or entity referred to herein.  The Employee also represents that the Employee does not intend to bring any claims on the Employee’s own behalf or on behalf of any other person or entity against the Company or any other person or entity referred to herein except, if necessary, with respect to the agreements listed in the last sentence of Section 4 of this Agreement.

7.      Confidentiality.  The Employee agrees to use the Employee’s best efforts to maintain in confidence the existence of this Agreement, the contents and terms of this Agreement, and the consideration for this Agreement (hereinafter collectively referred to as “Release Information”).  The Employee agrees to take every reasonable precaution to prevent disclosure of any Release Information to third parties and agrees that there will be no publicity, directly or indirectly, concerning any Release Information.  The Employee agrees to take every precaution to disclose Release Information only to those attorneys, accountants, governmental entities and family members who have a reasonable need to know of such Release Information.

8.      No Adverse Cooperation.  The Employee agrees the Employee will not act in any manner that might damage the business of the Company.  The Employee agrees that the Employee will not counsel or assist any attorneys or their clients in the presentation or prosecution of any disputes, differences, grievances, claims, charges or complaints by any third party against the Company and/or any officer, director, employee, agent, representative, shareholder or attorney of the Company, unless compelled under a subpoena or other court order to do so.

9.      Costs.  The Parties shall each bear their own costs, expert fees, attorneys’ fees and other fees incurred in connection with this Agreement.

10.    Authority.  The Company represents and warrants that the undersigned has the authority to act on behalf of the Company and to bind the Company and all who may claim through it to the terms and conditions of this Agreement.  The Employee represents and warrants that the Employee has the capacity to act on the Employee’s own behalf and on behalf of all who might claim through the Employee to bind them to the terms and conditions of this Agreement.

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11.    No Representations.  The Employee represents that the Employee has had the opportunity to consult with an attorney, and has carefully read and understands the scope and effect of the provisions of this Agreement.  Neither party has relied upon any representations or statements made by the other party hereto which are not specifically set forth in this Agreement.

12.    Severability.  In the event that any provision hereof becomes or is declared by a court of competent jurisdiction to be illegal, unenforceable or void, this Agreement shall continue in full force and effect without said provision.

13.    Entire Agreement.  This Agreement and the Employment Agreement and the agreements and plans referenced therein represent the entire agreement and understanding between the Company and the Employee concerning the Employee’s separation from the Company, and supersede and replace any and all prior agreements and understandings concerning the Employee’s relationship with the Company and the Employee’s compensation by the Company.  This Agreement may only be amended in writing signed by the Employee and an executive officer of the Company.

14.    Governing Law.  This Agreement shall be governed by the internal substantive laws, but not the choice of law rules, of the State of California.

15.    Effective Date.  This Agreement is effectiveeight (8) days after it has been signed by the Parties (the “Effective Date”) unless it is revoked by the Employee within seven (7) days of the execution of this Agreement by the Employee.

16.    Counterparts.  This Agreement may be executed in counterparts, and each counterpart shall have the same force and effect as an original and shall constitute an effective, binding agreement on the part of each of the undersigned.

17.    Voluntary Execution of Agreement.  This Agreement is executed voluntarily and without any duress or undue influence on the part or behalf of the Parties hereto, with the full intent of releasing all claims.  The Parties acknowledge that:

(a)      they have read this Agreement;

(b)      they have been represented in the preparation, negotiation and execution of this Agreement by legal counsel of their own choice or that they have voluntarily declined to seek such counsel;

(c)      they understand the terms and consequences of this Agreement and of the releases it contains; and

(d)      they are fully aware of the legal and binding effect of this Agreement.

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IN WITNESS WHEREOF, the Parties have executed this Agreement on the respective dates set forth below.

XOMA CORPORATION

By:

Title:

Date:

EMPLOYEE

Date:

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EX-31.1

Exhibit 31.1

CERTIFICATION

I, John Varian, certify that:

1. I have reviewed this quarterly report on Form 10-Q 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) and 15d-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 officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

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

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

Date:  May 8, 2013	/s/    JOHN VARIAN
	John Varian Chief Executive Officer

EX-31.2

Exhibit 31.2

CERTIFICATION

I, Fred Kurland, certify that:

1. I have reviewed this quarterly report on Form 10-Q 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) and 15d-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 officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

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

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

Date:  May 8, 2013	/s/    FRED KURLAND
	Fred Kurland Vice President, Finance, Chief Financial Officer and Secretary

EX-32.1

Exhibit 32.1

CERTIFICATION

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.           The Company’s Quarterly Report on Form 10-Q for the period ended March 31, 2013, to which this Certification is attached as Exhibit 32.1 (the “Periodic Report”), fully complies with the requirements of Section 13(a) or Section 15(d) of the Exchange Act; and

2.           The information contained in the Periodic Report 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 8th day of May, 2013.

/s/    JOHN VARIAN

John Varian

Chief Executive Officer

/s/    FRED KURLAND

Fred Kurland

Vice President, Finance, Chief Financial Officer and Secretary

This certification accompanies the Form 10-Q 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-Q), irrespective of any general incorporation language contained in such filing.

EX-99.1

Exhibit 99.1

XOMA Highlights Recent Achievements and Reports Financial Results for First Quarter 2013

BERKELEY, Calif., May 8, 2013 -- XOMA Corporation (Nasdaq: XOMA), a leader in the discovery and development of therapeutic antibodies, today reported its operational highlights and financial results for the quarter ended March 31, 2013.

· Announced encouraging interim results from gevokizumab Phase 2 study for moderate to severe acne vulgaris, the first indication in a program of three proof-of-concept (“POC”) studies for gevokizumab.  The data generated supports further development in this indication.

· Focused on advancing the gevokizumab Phase 3 EYEGUARD™ pivotal studies in non-infectious uveitis (“NIU”).

· Advanced the second gevokizumab Phase 2 POC study in patients with erosive osteoarthritis of the hand (“EOA”).

· Appointed Tom Klein as Vice President, Chief Commercial Officer, a newly created position.

XOMA reported total revenues of $9.5 million in the first quarter of 2013, compared with $9.9 million in the corresponding period of 2012.  The small decrease in 2013 revenues was due primarily to a reduction in contract and other revenue associated with NIAID contracts.  For the quarter ended March 31, 2013, XOMA had a net loss of $24.9 million (or $0.30 per share), compared with a net loss of $30.4 million, or $0.69 per share, for the quarter ended March 31, 2012.  The net loss for the first quarters of 2013 and 2012 included a non-cash charge of $12.8 million (or $0.16 per share) and $14.4 million (or $0.33 per share), respectively, both of which were related to the revaluation of contingent warrant liabilities, which resulted primarily from the appreciation of XOMA’s stock price.  Excluding these non-cash charges, net loss in the first quarters of 2013 and 2012 was $12.0 million (or $0.15 per share) and $16.0 million (or $0.36 per share), respectively.

“We focused our first quarter activities on advancing the gevokizumab Phase 3 pivotal studies in patients with NIU and on executing our second gevokizumab proof-of-concept study in patients with erosive osteoarthritis of the hand.  Based upon the enrollment in the EOA study, we anticipate receiving the top-line data around Labor Day,” stated John Varian, Chief Executive Officer of XOMA.  “In addition, we are very pleased with the initial results from our first gevokizumab Phase 2 POC study in patients with moderate to severe inflammatory acne which we announced early in the quarter.  We believe the data establishes that IL-1 beta plays a role in moderate to severe inflammatory acne, and the feedback from key opinion leaders in dermatology supports further development.  We look forward to the results from our EOA study to inform our decision as to our next Phase 3 indication.”

“The second highlight of our first quarter was attracting Tom Klein to join XOMA as our first Chief Commercial Officer,” Mr. Varian continued.  “We are in the position to begin planning for gevokizumab’s future as a commercial product, and Tom’s expertise in marketing pharmaceutical products to the specialist provider will be invaluable as we select our next Phase 3 indication and near the completion of our EYEGUARD program.”

Research and development expenses for the first quarter of 2013 were $16.6 million, compared with $15.8 million in the corresponding period of 2012.  General and administrative expenses were $4.1 million in the first quarter of 2013, a 12 percent reduction from the $4.7 million incurred in the first quarter of 2012.  As a result of the company’s streamlining activities announced in January 2012, XOMA recorded a charge of $3.8 million during the first quarter of 2012.

On March 31, 2013, XOMA had cash, cash equivalents, and short-term investments of $70.4 million.  The Company ended December 31, 2012, with cash, cash equivalents, and short-term investments of $85.3 million.

2013 Guidance

The company reconfirmed its anticipated cash used in ongoing operating activities during 2013 will be approximately$50 million, primarily reflecting the costs associated with conducting the EYEGUARD-A, EYEGUARD-B and EYEGUARD-C Phase 3 clinical trials.  This guidance initially was provided on March 12, 2013.

Investor Conference Call and Webcast

XOMA will host a conference call and webcast today, May 8, 2013, at 4:30 p.m. ET.  The webcast can be accessed via the Investors section of XOMA's website at http://investors.xoma.com/events.cfm and will be available for replay until close of business on August 8, 2013.

Telephone numbers for the live audiocast are 877-369-6589 (U.S./Canada) and 408-337-0122 (international).  A telephonic replay will be available beginning approximately two hours after the conclusion of the call until close of business on May 15, 2013.  Telephone numbers for the replay are 855-859-2056 (U.S./Canada) and 404-537-3406 (international), passcode 42348170.

About Gevokizumab

Gevokizumab is a potent monoclonal antibody with unique allosteric modulating properties and the potential to treat patients with a wide variety of inflammatory and other diseases. Gevokizumab binds strongly to interleukin-1 beta (IL-1 beta), a pro-inflammatory cytokine that has been shown to be involved in non-infectious uveitis, including Behçet's uveitis, cardiovascular disease, and other auto-inflammatory diseases. By binding to IL-1 beta, gevokizumab inhibits the activation of the IL-1 receptor, thereby modulating the cellular signaling events that produce inflammation. Gevokizumab has been studied in over 500 patients, with approximately 300 patients on treatment for six months, and has been shown to be well-tolerated. Information about gevokizumab clinical studies can be found at www.clinicaltrials.gov.

About XOMA

XOMA combines a portfolio of innovative therapeutic antibodies, both in late-stage clinical development and in preclinical research, with its recently launched commercial operations. XOMA focuses its antibody research and development on allosteric modulation, which offers opportunities for new classes of therapeutic antibodies to treat a wide range of human diseases. XOMA is developing its lead product gevokizumab (IL-1 beta modulating antibody) with Servier through a global Phase 3 program in non-infectious uveitis and ongoing proof-of-concept studies in other IL-1-mediated diseases. XOMA's scientific research also produced the XMet program, which consists of three classes of preclinical antibodies, including Selective Insulin Receptor Modulators (SIRMs) that could have a major effect on the treatment of diabetes.

More detailed information can be found at www.xoma.com.

Forward-Looking Statements

Certain statements contained in this press release including, but not limited to, statements related to anticipated timing of initiation and completion of clinical trials and proof-of-concept trials, anticipated size of clinical trials, continued sales of approved products, sufficiency of our cash resources and anticipated levels of cash utilization, 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. These statements are based on assumptions that may not prove accurate, and 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. Potential risks to XOMA meeting these expectations are described in more detail in XOMA's most recent filing on Form 10-K and in other SEC filings. Consider such risks carefully when considering XOMA's prospects. Any forward-looking statement in this press release represents XOMA's views only as of the date of this press release and should not be relied upon as representing its views as of any subsequent date. XOMA disclaims any obligation to update any forward-looking statement, except as required by applicable law.

XOMA Corporation

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(unaudited)

(in thousands, except per share amounts)

	Three months ended March 31,
	2013			2012
Revenues:
License and collaborative fees	$	399		$	1,014
Contract and other		8,796			8,844
Net product sales		258			7
Total revenues		9,453			9,865
Operating expenses:
Research and development		16,590			15,771
Selling, general and administrative		4,124			4,679
Restructuring		17			3,777
Cost of sales		46			-
Total operating expenses		20,777			24,227
Loss from operations		(11,324	)		(14,362	)
Other income (expense):
Interest expense		(1,172	)		(1,042	)
Other (expense) income		449			(664	)
Revaluation of contingent warrant liabilities		(12,840	)		(14,357	)
Net loss	$	(24,887	)	$	(30,425	)
Basic and diluted net loss per share of common stock	$	(0.30	)	$	(0.69	)
Shares used in computing basic and diluted net loss per share of common stock		82,595			44,353
Other comprehensive loss:
Net loss	$	(24,887	)	$	(30,425	)
Net unrealized gains on available-for-sale securities		3			-
Comprehensive loss	$	(24,884	)	$	(30,425	)

XOMA Corporation

CONDENSED CONSOLIDATED BALANCE SHEETS

(in thousands)

	March 31, 2013			December 31, 2012
	(unaudited)
ASSETS
Current assets:
Cash and cash equivalents	$	50,379		$	45,345
Short-term investments		19,996			39,987
Trade and other receivables, net		6,270			8,249
Prepaid expenses and other current assets		3,062			2,256
Total current assets		79,707			95,837
Property and equipment, net		7,861			8,143
Other assets		1,378			1,696
Total assets	$	88,946		$	105,676
LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY
Current liabilities:
Accounts payable	$	4,194		$	3,867
Accrued and other liabilities		5,410			13,045
Deferred revenue		3,756			3,409
Interest bearing obligation – current		4,085			3,391
Accrued Interest on interest bearing obligations – current		1,662			121
Total current liabilities		19,107			23,833
Deferred revenue – long-term		5,857			6,315
Interest bearing obligations – long-term		37,017			37,653
Contingent warrant liabilities		27,841			15,001
Other liabilities – long term		33			1,407
Total liabilities		89,855			84,209
Stockholders’ (deficit) equity:
Common stock, $0.0075 par value, 138,666,666 authorized, 82,887,828 and 82,447,274 shares Outstanding at March 31, 2013 and December 31, 2012, respectively		618			615
Additional paid-in capital		980,467			977,962
Accumulated comprehensive income		11			8
Accumulated deficit		(982,005	)		(957,118	)
Total stockholders’ (deficit) equity		(909	)		21,467
Total liabilities and stockholders' (deficit) equity	$	88,946		$	105,676

Contingent warrant liabilities	March 31, 2013
Balance at December 31, 2011	$	15,001
Net increase in fair value of contingent warrant liabilities upon revaluation		12,840
Balance at March 31, 2013	$	27,841

CONTACT: XOMA Corporation

Company and Investor Contact:

Ashleigh Barreto

510-204-7482

barreto@xoma.com

Juliane Snowden

The Oratorium Group, LLC

jsnowden@oratoriumgroup.com

Media Contact:

Canale Communications

Carolyn Hawley

619-849-5375

carolyn@canalecomm.com

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Stock-based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Stock-based awards weighted average assumptions [Abstract]
Dividend yield (in hundredths)	0.00%	0.00%
Expected volatility (in hundredths)	92.00%	92.00%
Risk free interest rate (in hundredths)	0.78%	1.05%
Expected term	5 years 7 months 6 days	5 years 7 months 6 days
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,619	$ 674
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	997	385
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	622	289
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Stock option activity [Roll Forward]
Options outstanding beginning of period (in shares)	6,788,383
Granted (in shares)	994,053
Exercised (in shares)	(19,090)
Forfeited, expired or cancelled (in shares)	(54,930)
Options outstanding end of period (in shares)	7,708,416
Options exercisable at end period (in shares)	4,473,529
Stock options activity, weighted average exercise price [Roll Forward]
Options outstanding, beginning of period (in dollars per share)	$ 8.99
Granted (in dollars per share)	$ 2.92
Exercised (in dollars per share)	$ 1.97
Forfeited, expired or cancelled (in dollars per share)	$ 31.12
Options outstanding, end of period (in dollars per share)	$ 8.07
Options exercisable weighted average exercise price (in dollars per share)	$ 11.70
Additional Disclosures [Abstract]
Options outstanding weighted average remaining contractual term beginning of period	7 years 4 months 10 days
Options outstanding weighted average remaining contractual term end of period	7 years 4 months 10 days
Options exercisable weighted average remaining contractual term	6 years 4 months 20 days
Options outstanding, aggregate intrinsic value at beginning of period	1,531
Options outstanding, aggregate intrinsic value at end of period	4,502
Options exercisable, aggregate intrinsic value	$ 2,245
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Unvested RSU activity [Roll Forward]
Unvested balance beginning of period (in shares)	1,459,853
Granted (in shares)	895,860
Vested (in shares)	(164,998)
Forfeited (in shares)	(4,835)
Unvested balance end of period (in shares)	2,185,880
Unvested RSU activity, weighted average grant date fair value [Roll Forward]
Unvested balance, beginning of period (in dollars per share)	$ 2.75
Granted (in dollars per share)	$ 2.87
Vested (in dollars per share)	$ 2.50
Forfeited (in dollars per share)	$ 2.06
Unvested balance, end of period (in dollars per share)	$ 2.65
Long Term Incentive Plan [Member] | Stock Options [Member]
Stock option activity [Roll Forward]
Granted (in shares)	994,053

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Fair Value Measurements

3 Months Ended

Mar. 31, 2013

Fair Value Measurements [Abstract]

Fair Value Measurements

4.  Fair Value Measurements

Fair value is defined as the price that would be received from selling an asset or the amount that would be 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.

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 March 31, 2013 and December 31, 2012.

Financial assets and liabilities carried at fair value as of March 31, 2013 and December 31, 2012 were classified as follows (in thousands):

	Fair Value Measurements at March 31, 2013 Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Money market funds (1)	$	37,951	$	-	$	-	$	37,951
U.S. treasury securities (2)		19,996		-		-		19,996
Foreign exchange options (3)		-		299		-		299
Total	$	57,947	$	299	$	-	$	58,246
Liabilities:
Contingent warrant liabilities	$	-	$	-	$	27,841	$	27,841

	Fair Value Measurements at December 31, 2012 Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Money market funds (1)	$	37,461	$	-	$	-	$	37,461
U.S. treasury securities (2)		39,987		-		-		39,987
Foreign exchange options (3)		-		488		-		488
Total	$	77,448	$	488	$	-	$	77,936
Liabilities:
Contingent warrant liabilities	$	-	$	-	$	15,001	$	15,001

(1)  Included in cash and cash equivalents

(2)  Included in short-term investments

(3)  Included in other assets

The fair value of the foreign exchange options at March 31, 2013 and December 31, 2012 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 contingent warrant liabilities was determined at March 31, 2013 and December 31, 2012 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.

The fair value of the contingent warrant liabilities was estimated using the following range of assumptions at March 31, 2013 and December 31, 2012:

	March 31, 2013			December 31, 2012
Expected volatility		40	%		40	%
Risk-free interest rate		0.3% - 0.4	%		0.3% - 0.7	%
Expected term	1.7 - 3.9 years			1.9 - 4.2 years

The following table provides a summary of changes in the fair value of the Company's Level 3 financial liabilities for the three months ended March 31, 2013 (in thousands):

Contingent warrant liabilities	March 31, 2013
Balance at December 31, 2012	$	15,001
Net increase in fair value of contingent warrant liabilities upon revaluation		12,840
Balance at March 31, 2013	$	27,841

The net increase of $12.8 million in the estimated fair value of the contingent warrant liabilities was recognized as a loss in the revaluation of contingent warrant liabilities line of the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013.

For the three months ended March 31, 2012, the Company recognized a net increase of $14.4 million in the estimated fair value of the contingent warrant liabilities as a loss in the revaluation of contingent warrant liabilities line of the condensed consolidated statements of comprehensive loss.

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Condensed Consolidated Financial Statement Detail

3 Months Ended

Mar. 31, 2013

Condensed Consolidated Financial Statement Detail [Abstract]

Condensed Consolidated Financial Statement Detail

3.  Condensed Consolidated Financial Statement Detail

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.

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):

	Three Months Ended March 31,
	2013		2012
Common stock options and restricted stock units		6,459		5,722
Warrants for common stock		16,176		5,457
Total		22,635		11,179

For the three months ended March 31, 2013 and 2012, all outstanding securities were considered anti-dilutive, and therefore the calculation of basic and diluted net loss per share was the same.

Cash and Cash Equivalents

At March 31, 2013, cash and cash equivalents consisted of demand deposits of $12.4 million and money market funds of $38.0 million with maturities of less than 90 days at the date of purchase. At December 31, 2012, cash and 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.

Short-term Investments

At March 31, 2013, short-term investments consisted of U.S. treasury securities of $20.0 million with maturities of greater than 90 days and less than one year from the date of purchase. 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.

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 Servier (See Note 6: Long-Term Debt and Other Financings). 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 condensed consolidated statements of comprehensive loss.

The foreign exchange options were revalued at March 31, 2013 and had an aggregate fair value of $0.3 million. The Company recognized losses of $0.2 million and $0.3 million related to the revaluation for the three months ended March 31, 2013 and 2012, respectively.

Accrued Liabilities

Accrued liabilities consisted of the following at March 31, 2013 and December 31, 2012 (in thousands):

	March 31, 2013		December 31, 2012
Accrued payroll and other benefits	$	2,169	$	2,461
Accrued management incentive compensation		1,086		3,978
Accrued clinical trial costs		746		4,702
Other		1,409		1,904
Total	$	5,410	$	13,045

Contingent Warrant Liabilities

In March 2012, in connection with an underwritten offering, the Company 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 the Company 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. The Company believes the likelihood of a change in control prior to the expiration of the warrants is remote; however, due to these provisions, the Company is 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 December 31, 2012, the fair value of the warrant liability was estimated to be $15.0 million using the Black-Scholes Model. The Company revalued the warrant liability at March 31, 2013 using the Black-Scholes Model and recorded the $12.8 million increase in the fair value as a loss in the revaluation of contingent warrant liabilities line of its condensed consolidated statements of comprehensive loss. As of March 31, 2013, 14,265,970 of these warrants were outstanding and had a fair value of $27.8 million. This increase in liability is due primarily to the increase in the market value of the Company's common stock at March 31, 2013 compared to December 31, 2012.

In February 2010, in connection with an underwritten offering, the Company issued five-year warrants to purchase 1,260,000 shares of XOMA's common stock at an exercise price of $10.50 per share. In June 2009, the Company issued warrants to certain institutional investors as part of a registered direct offering. These 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 the Company 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. The Company believes the likelihood of a change in control prior to the expiration of the warrants is remote; however, due to these provisions, the Company is required to account for the warrants issued in February 2010 and June 2009 as liabilities at fair value. As of March 31, 2013, all of these warrants were outstanding and had an aggregate fair value of approximately $33,000.

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CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 50,379	$ 45,345	[1]
Short-term investments	19,996	39,987	[1]
Trade and other receivables, net	6,270	8,249	[1]
Prepaid expenses and other current assets	3,062	2,256	[1]
Total current assets	79,707	95,837	[1]
Property and equipment, net	7,861	8,143	[1]
Other assets	1,378	1,696	[1]
Total assets	88,946	105,676	[1]
Current liabilities:
Accounts payable	4,194	3,867	[1]
Accrued and other liabilities	5,410	13,045	[1]
Deferred revenue	3,756	3,409	[1]
Interest bearing obligation - current	4,085	3,391	[1]
Accrued Interest on interest bearing obligations - current	1,662	121	[1]
Total current liabilities	19,107	23,833	[1]
Deferred revenue - long-term	5,857	6,315	[1]
Interest bearing obligations - long-term	37,017	37,653	[1]
Contingent warrant liabilities	27,841	15,001	[1]
Other liabilities - long term	33	1,407	[1]
Total liabilities	89,855	84,209	[1]
Stockholders' (deficit) equity:
Common stock, $0.0075 par value, 138,666,666 shares authorized, 82,887,828 and 82,447,274 shares outstanding at March 31, 2013 and December 31, 2012, respectively	618	615	[1]
Additional paid-in capital	980,467	977,962	[1]
Accumulated comprehensive income	11	8	[1]
Accumulated deficit	(982,005)	(957,118)	[1]
Total stockholders' (deficit) equity	(909)	21,467	[1]
Total liabilities and stockholders' (deficit) equity	$ 88,946	$ 105,676	[1]

[1] The condensed consolidated balance sheet as of December 31, 2012 has been derived from the audited consolidated financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012.

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Description of Business

3 Months Ended

Mar. 31, 2013

Description of Business [Abstract]

Description of Business

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 commercial operations. XOMA focuses its scientific research on allosteric modulation, which offers opportunities for new classes of therapeutic antibodies to treat a wide range of human diseases.  XOMA is developing its lead product candidate gevokizumab (IL-1 beta modulating antibody) with Les Laboratoires Servier ("Servier") through a global Phase 3 clinical development program and ongoing proof-of-concept studies in other IL-1-mediated diseases. XOMA's scientific research also has produced the XMet platform, which consists of three classes of preclinical antibodies, including selective insulin receptor modulators that could offer new approaches in the treatment of diabetes.  In order to retain significant value from its scientific discoveries, XOMA initiated commercial operations in January 2012 through the licensing of U.S. commercial rights to Servier's ACEON® (perindopril erbumine) and certain U.S. rights to a patent-protected portfolio of fixed dose combination ("FDC") product candidates where perindopril is combined with other active ingredients to treat cardiovascular disease. 

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Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012
Warrant Liabilities [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Expected volatility (in hundredths)	40.00%			40.00%
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ 15,001
Net increase in fair value of contingent warrant liabilities upon revaluation	12,840		14,400
Balance, end of period	27,841			15,001
Warrant Liabilities [Member] | Minimum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate (in hundredths)	0.30%			0.30%
Expected term	1 year 8 months 12 days			1 year 10 months 24 days
Warrant Liabilities [Member] | Maximum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate (in hundredths)	0.40%			0.70%
Expected term	3 years 10 months 24 days			4 years 2 months 12 days
Recurring [Member]
Assets:
Money market funds	37,951	[1]		37,461	[1]
U.S. treasury securities	19,996	[2]		39,987	[2]
Foreign exchange options	299	[3]		488	[3]
Total	58,246			77,936
Liabilities:
Contingent warrant liabilities	27,841			15,001
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Money market funds	37,951	[1]		37,461	[1]
U.S. treasury securities	19,996	[2]		39,987	[2]
Foreign exchange options	0	[3]		0	[3]
Total	57,947			77,448
Liabilities:
Contingent warrant liabilities	0			0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Money market funds	0	[1]		0	[1]
U.S. treasury securities	0	[2]		0	[2]
Foreign exchange options	299	[3]		488	[3]
Total	299			488
Liabilities:
Contingent warrant liabilities	0			0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Money market funds	0	[1]		0	[1]
U.S. treasury securities	0	[2]		0	[2]
Foreign exchange options	0	[3]		0	[3]
Total	0			0
Liabilities:
Contingent warrant liabilities	$ 27,841			$ 15,001

[1] Included in cash and cash equivalents

[2] Included in short-term investments

[3] Included in other assets

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Long-Term Debt (Details)	3 Months Ended					3 Months Ended		6 Months Ended				12 Months Ended			1 Months Ended	3 Months Ended					3 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Mar. 31, 2013 Novartis Note [Member] USD ($)	Mar. 31, 2012 Novartis Note [Member] USD ($)	Dec. 31, 2012 Novartis Note [Member] USD ($)	Mar. 31, 2013 Servier Loan [Member] USD ($)	Mar. 31, 2012 Servier Loan [Member] USD ($)	Jul. 15, 2013 Servier Loan [Member]	Jan. 15, 2013 Servier Loan [Member]	Jul. 15, 2012 Servier Loan [Member]	Jan. 15, 2012 Servier Loan [Member]	Dec. 31, 2012 Servier Loan [Member] USD ($)	Dec. 31, 2011 Servier Loan [Member] USD ($)	Mar. 31, 2013 Servier Loan [Member] EUR (€)	Sep. 30, 2012 General Electric Capital Corporation Term Loan [Member] USD ($)	Mar. 31, 2013 General Electric Capital Corporation Term Loan [Member] USD ($)	Mar. 31, 2012 General Electric Capital Corporation Term Loan [Member] USD ($)	Dec. 31, 2012 General Electric Capital Corporation Term Loan [Member] USD ($)	Sep. 27, 2012 General Electric Capital Corporation Term Loan [Member] USD ($)	Dec. 31, 2011 General Electric Capital Corporation Term Loan [Member] USD ($)	Mar. 31, 2013 Other Financings [Member] USD ($)	Mar. 31, 2012 Other Financings [Member] USD ($)
Debt Instrument [Line Items]
Maturity date			Jun. 30, 2015													Jun. 15, 2015
Research and development expenses funded through loan facility, maximum (in hundredths)			75.00%
Maximum borrowing capacity under loan agreement			$ 50,000,000											€ 15,000,000
Variable rate basis			six-month LIBOR			Euro Inter-Bank Offered Rate ("EURIBOR")
Basis spread on variable rate (in hundredths)			2.00%
Interest rate at period end (in hundredths)	2.51%
Outstanding principal balance			14,400,000		14,400,000	19,200,000						19,800,000				12,500,000		12,500,000	3,100,000	10,000,000
Periodic Payment, Principal															347,222
Proceeds from loan													19,500,000		4,600,000
Increase (Decrease) in term loan obligation															12,500,000
Initial interest rate during period (in hundredths)												3.22%
Interest rate during period (in hundredths)								2.33%	2.80%	3.54%	3.83%
Unamortized discount on debt						8,900,000
Unrealized foreign exchange gain (loss)	440,000	(376,000)				600,000	(600,000)
Unrealized foreign exchange gains related to re-measurement of loan discount						200,000	200,000
Euro to US Dollar exchange rates																1.2816	1.3215
Amortization period for loan discount						5 years
Amortization of debt discount						400,000	300,000
Carrying value of the loan						14,200,000						14,200,000
Recognition of deferred revenue						400,000	300,000
Debt issuance costs															200,000	1,300,000
Final payment fee																500,000			875,000
Fixed interest rate accrued (in hundredths)																11.71%			10.90%
Number of monthly installments															27	42
Prepayment premium year one (in hundredths)																3.00%
Prepayment premium year two (in hundredths)																2.00%
Prepayment premium year thereafter (in hundredths)																1.00%
Aggregate number of unregistered shares of common stock called by warrants (in shares)																263,158			39,346
Warrants exercise price (in dollars per share)																$ 1.14			$ 3.54
Immediate Term for warrants exercisable (in years)															5 years	5 years
Fair value of warrant liability	33,000															200,000			100,000
Interest expense and amortization of debt issuance costs [Abstract]
Interest expense	$ 1,172,000	$ 1,042,000	$ 91,000	$ 99,000		$ 525,000	$ 516,000									$ 545,000	$ 417,000				$ 11,000	$ 10,000

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Basis of Presentation and Significant Accounting Policies

3 Months Ended

Mar. 31, 2013

Basis of Presentation and Significant Accounting Policies [Abstract]

Basis of Presentation and Significant Accounting Policies

2.  Basis of Presentation and Significant Accounting Policies

Basis of Presentation

The condensed consolidated financial statements include the accounts of XOMA and its subsidiaries. All intercompany accounts and transactions were eliminated during consolidation. The unaudited financial statements were prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q. These financial statements and related disclosures have been prepared with the assumption that users of the interim financial information have read or have access to the audited financial statements for the preceding fiscal year. Accordingly, these statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2012, filed with the U.S. Securities and Exchange Commission ("SEC") on March 12, 2013.

In management's opinion, the unaudited condensed consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, which are necessary to present fairly the Company's consolidated financial position as of March 31, 2013, the consolidated results of the Company's operations and the Company's cash flows for the three months ended March 31, 2013 and 2012. The interim results of operations are not necessarily indicative of the results that may occur for the full fiscal year or future periods.

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, stock-based compensation, and restructuring liabilities. 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 adjustments to revenues previously reported.

Long-lived Assets

The Company reviews the carrying values and depreciation lives 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 the three months ended March 31, 2012, the Company recorded an impairment loss of $0.8 million and accelerated depreciation of $0.9 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.

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 the first quarter of 2013.

The Company has not experienced any significant credit losses and does not generally require collateral on receivables. For the three months ended March 31, 2013, two customers represented 79% and 18% of total revenue and 56% and 39% of the accounts receivable balance.

For the three months ended March 31, 2012, these two customers represented 49% and 40% of total revenues. As of December 31, 2012, there were receivables outstanding from these two customers representing 58% and 35% of the accounts receivable balance.

Newly Adopted Accounting Pronouncements

In February 2013, Accounting Standards Codification Topic 220, Comprehensive Income was amended to require companies to report, in one place, information about reclassifications out of accumulated other comprehensive income. Accordingly, a company can present this information on the face of the financial statements, if certain requirements are met, or the information must be presented in the notes to the financial statements. The Company adopted this guidance as of January 1, 2013, on a retrospective basis and the items reclassified out of accumulated other comprehensive income are not material for all periods presented.

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CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Stockholders' (deficit) equity:
Common stock, par value (in dollars per share)	$ 0.0075	$ 0.0075
Common stock, shares authorized (in shares)	138,666,666	138,666,666
Common stock, shares outstanding (in shares)	82,887,828	82,447,274

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Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2013

Long-Term Debt [Abstract]

Interest expense and amortization of debt issuance costs

Interest expense and amortization of debt issuance costs and discounts, recorded as other expense in the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013 and 2012 are shown below (in thousands):

	Three Months Ended March 31,
	2013		2012
Interest expense
GECC term loan	$	545	$	417
Servier loan		525		516
Novartis note		91		99
Other		11		10
Total interest expense	$	1,172	$	1,042

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Document and Entity Information	3 Months Ended
	Mar. 31, 2013	May 06, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	XOMA Corp
Entity Central Index Key	0000791908
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		82,893,328
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2013

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Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Stock-based Compensation [Abstract]

Weighted average assumptions

The fair value of the stock options granted was estimated based on the following weighted average assumptions for three months ended March 31, 2013 and 2011:

	Three Months Ended March 31,
	2013			2012
Dividend yield		0	%		0	%
Expected volatility		92	%		92	%
Risk-free interest rate		0.78	%		1.05	%
Expected term	5.6 years			5.6 years

Stock option activity

Stock option activity for the three months ended March 31, 2013 was as follows:

	Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Options outstanding at December 31, 2012		6,788,383		$	8.99		7.36	$	1,531
Granted		994,053			2.92
Exercised		(19,090	)		1.97
Forfeited, expired or cancelled		(54,930	)		31.12
Options outstanding at March 31, 2013		7,708,416		$	8.07		7.54	$	4,502
Options exercisable at March 31, 2013		4,473,529		$	11.70		6.39	$	2,245

Unvested RSU activity

Unvested RSU activity for the three months ended March 31, 2013 is summarized below:

				Weighted-
	Number of			Average Grant-
	Shares			Date Fair Value
Unvested balance at December 31, 2012		1,459,853		$	2.75
Granted		895,860			2.87
Vested		(164,998	)		2.50
Forfeited		(4,835	)		2.06
Unvested balance at March 31, 2013		2,185,880		$	2.65

Stock-based compensation expense

The following table shows total stock-based compensation expense included in the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013 and 2012 (in thousands):

	Three Months Ended March 31,
	2013		2012
Research and development	$	997	$	385
Selling, general and administrative		622		289
Total stock-based compensation expense	$	1,619	$	674

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CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
License and collaborative fees	$ 399	$ 1,014
Contract and other	8,796	8,844
Net product sales	258	7
Total revenues	9,453	9,865
Operating expenses:
Research and development	16,590	15,771
Selling, general and administrative	4,124	4,679
Restructuring	17	3,777
Cost of sales	46	0
Total operating expenses	20,777	24,227
Loss from operations	(11,324)	(14,362)
Other income (expense):
Interest expense	(1,172)	(1,042)
Other income (expense)	449	(664)
Revaluation of contingent warrant liabilities	(12,840)	(14,357)
Net loss	(24,887)	(30,425)
Basic and diluted net loss per common stock (in dollars per share)	$ (0.3)	$ (0.69)
Shares used in computing basic and diluted net loss per share of common stock (in shares)	82,595	44,353
Other comprehensive loss:
Net loss	(24,887)	(30,425)
Net unrealized gains on available-for-sale securities	3	0
Comprehensive loss	$ (24,884)	$ (30,425)

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Income Taxes

3 Months Ended

Mar. 31, 2013

Income Taxes [Abstract]

Income Taxes

7.  Income Taxes

The Company did not recognize any income tax expense for the three months ended March 31, 2013 and 2012. The Company's effective tax rate will fluctuate from period to period due to several factors inherent in the nature of the Company's operations and business transactions. The factors that most significantly impact this rate include the variability of licensing transactions in foreign jurisdictions.

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Long-Term Debt

3 Months Ended

Mar. 31, 2013

Long-Term Debt [Abstract]

Long-Term Debt

6.  Long-Term Debt

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 March 31, 2013, 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 March 31, 2013 and December 31, 2012, the outstanding principal balance under this note agreement was $14.4 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. Due to the structure of the secured note agreement with Novartis and since there is no liquid market for this obligation, there is no practical method to estimate fair value of this long-term debt.

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. The loan was fully funded in January 2011, with the proceeds converting to 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 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 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 March 31, 2013 and December 31, 2012, the outstanding principal balance under this loan was $19.2 million and $19.8 million, respectively, using the Euro to US Dollar exchange rates of 1.2816 and 1.3215, respectively. For the three months ended March 31, 2013 and 2012, the Company recorded an unrealized foreign exchange gain of $0.6 million and an unrealized foreign exchange loss of $0.6 million, 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 $0.4 million and $0.3 million in the three months ended March 31, 2013 and 2012, respectively, resulting from the amortization of the loan discount. At March 31, 2013 and December 31, 2012, the net carrying value of the loan was $14.2 million. For the three months ended March 31, 2013 and 2012, the Company recorded unrealized foreign exchange losses of $0.2 million related to the re-measurement of the loan discount.

The Company believes 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 $0.4 million and $0.3 million of related non-cash revenue during the three months ended March 31, 2013 and 2012, respectively.

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 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.

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 March 31, 2013 and December 31, 2012, the outstanding principal balance under the Amended Term Loan was $12.5 million.

Interest Expense

Interest expense and amortization of debt issuance costs and discounts, recorded as other expense in the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013 and 2012 are shown below (in thousands):

	Three Months Ended March 31,
	2013		2012
Interest expense
GECC term loan	$	545	$	417
Servier loan		525		516
Novartis note		91		99
Other		11		10
Total interest expense	$	1,172	$	1,042

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Streamlining and Restructuring Charges (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated			84
Number of positions eliminated (in hundredths)			34.00%
Number of positions eliminated immediately			52
Restructuring charges	$ 17	$ 3,777
Employee Severance and Other Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		2,100
Asset Impairment and Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 1,700

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Description of Business (Details)	Mar. 31, 2013 Antibody
Description of Business [Abstract]
Number classes of preclinical antibodies	3

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Condensed Consolidated Financial Statement Detail (Tables)

3 Months Ended

Mar. 31, 2013

Condensed Consolidated Financial Statement Detail [Abstract]

Outstanding securities considered anti-dilutive

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):

	Three Months Ended March 31,
	2013		2012
Common stock options and restricted stock units		6,459		5,722
Warrants for common stock		16,176		5,457
Total		22,635		11,179

Accrued liabilities

Accrued liabilities consisted of the following at March 31, 2013 and December 31, 2012 (in thousands):

	March 31, 2013		December 31, 2012
Accrued payroll and other benefits	$	2,169	$	2,461
Accrued management incentive compensation		1,086		3,978
Accrued clinical trial costs		746		4,702
Other		1,409		1,904
Total	$	5,410	$	13,045

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Stock-based Compensation

3 Months Ended

Mar. 31, 2013

Stock-based Compensation [Abstract]

Stock-based Compensation

8.  Stock-based Compensation

In the first quarter of 2013, the Board of Directors of the Company approved grants under the Company's Long Term Incentive Plan for an aggregate of 994,053 stock options and an aggregate of 895,860 restricted stock units ("RSUs") to certain employees of the Company. The stock options vest monthly over four years, and the RSUs vest annually over three years, in equal increments.

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 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 U.S. Treasury zero-coupon issues. The forfeiture rate impacts the amount of aggregate compensation for both stock options and RSUs. To establish an estimate of forfeiture rate, the Company considers its historical experience of option forfeitures and terminations.

The fair value of the stock options granted was estimated based on the following weighted average assumptions for three months ended March 31, 2013 and 2011:

	Three Months Ended March 31,
	2013			2012
Dividend yield		0	%		0	%
Expected volatility		92	%		92	%
Risk-free interest rate		0.78	%		1.05	%
Expected term	5.6 years			5.6 years

Stock option activity for the three months ended March 31, 2013 was as follows:

	Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Options outstanding at December 31, 2012		6,788,383		$	8.99		7.36	$	1,531
Granted		994,053			2.92
Exercised		(19,090	)		1.97
Forfeited, expired or cancelled		(54,930	)		31.12
Options outstanding at March 31, 2013		7,708,416		$	8.07		7.54	$	4,502
Options exercisable at March 31, 2013		4,473,529		$	11.70		6.39	$	2,245

The valuation of RSUs is determined at the date of grant using the closing stock price. To establish an estimate of forfeiture rate, the Company considers its historical experience of forfeitures and terminations.

Unvested RSU activity for the three months ended March 31, 2013 is summarized below:

				Weighted-
	Number of			Average Grant-
	Shares			Date Fair Value
Unvested balance at December 31, 2012		1,459,853		$	2.75
Granted		895,860			2.87
Vested		(164,998	)		2.50
Forfeited		(4,835	)		2.06
Unvested balance at March 31, 2013		2,185,880		$	2.65

The following table shows total stock-based compensation expense included in the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2013 and 2012 (in thousands):

	Three Months Ended March 31,
	2013		2012
Research and development	$	997	$	385
Selling, general and administrative		622		289
Total stock-based compensation expense	$	1,619	$	674

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Basis of Presentation and Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2013

Basis of Presentation and Significant Accounting Policies [Abstract]

Basis of Presentation

Basis of Presentation

The condensed consolidated financial statements include the accounts of XOMA and its subsidiaries. All intercompany accounts and transactions were eliminated during consolidation. The unaudited financial statements were prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q. These financial statements and related disclosures have been prepared with the assumption that users of the interim financial information have read or have access to the audited financial statements for the preceding fiscal year. Accordingly, these statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2012, filed with the U.S. Securities and Exchange Commission ("SEC") on March 12, 2013.

In management's opinion, the unaudited condensed consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, which are necessary to present fairly the Company's consolidated financial position as of March 31, 2013, the consolidated results of the Company's operations and the Company's cash flows for the three months ended March 31, 2013 and 2012. The interim results of operations are not necessarily indicative of the results that may occur for the full fiscal year or future periods.

Use of Estimates

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, stock-based compensation, and restructuring liabilities. 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 adjustments to revenues previously reported.

Long-lived Assets

Long-lived Assets

The Company reviews the carrying values and depreciation lives 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 the three months ended March 31, 2012, the Company recorded an impairment loss of $0.8 million and accelerated depreciation of $0.9 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.

Concentration of Risk

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 the first quarter of 2013.

The Company has not experienced any significant credit losses and does not generally require collateral on receivables. For the three months ended March 31, 2013, two customers represented 79% and 18% of total revenue and 56% and 39% of the accounts receivable balance.

For the three months ended March 31, 2012, these two customers represented 49% and 40% of total revenues. As of December 31, 2012, there were receivables outstanding from these two customers representing 58% and 35% of the accounts receivable balance.

Newly Adopted Accounting Pronouncements

Newly Adopted Accounting Pronouncements

In February 2013, Accounting Standards Codification Topic 220, Comprehensive Income was amended to require companies to report, in one place, information about reclassifications out of accumulated other comprehensive income. Accordingly, a company can present this information on the face of the financial statements, if certain requirements are met, or the information must be presented in the notes to the financial statements. The Company adopted this guidance as of January 1, 2013, on a retrospective basis and the items reclassified out of accumulated other comprehensive income are not material for all periods presented.

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Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Measurements [Abstract]

Financial assets and liabilities carried at fair value

Financial assets and liabilities carried at fair value as of March 31, 2013 and December 31, 2012 were classified as follows (in thousands):

	Fair Value Measurements at March 31, 2013 Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Money market funds (1)	$	37,951	$	-	$	-	$	37,951
U.S. treasury securities (2)		19,996		-		-		19,996
Foreign exchange options (3)		-		299		-		299
Total	$	57,947	$	299	$	-	$	58,246
Liabilities:
Contingent warrant liabilities	$	-	$	-	$	27,841	$	27,841

	Fair Value Measurements at December 31, 2012 Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Money market funds (1)	$	37,461	$	-	$	-	$	37,461
U.S. treasury securities (2)		39,987		-		-		39,987
Foreign exchange options (3)		-		488		-		488
Total	$	77,448	$	488	$	-	$	77,936
Liabilities:
Contingent warrant liabilities	$	-	$	-	$	15,001	$	15,001

(1)  Included in cash and cash equivalents

(2)  Included in short-term investments

(3)  Included in other assets

Warrant liabilities fair value assumptions

The fair value of the contingent warrant liabilities was estimated using the following range of assumptions at March 31, 2013 and December 31, 2012:

	March 31, 2013			December 31, 2012
Expected volatility		40	%		40	%
Risk-free interest rate		0.3% - 0.4	%		0.3% - 0.7	%
Expected term	1.7 - 3.9 years			1.9 - 4.2 years

Summary of changes in fair value of Level 3 financial liabilities

The following table provides a summary of changes in the fair value of the Company's Level 3 financial liabilities for the three months ended March 31, 2013 (in thousands):

Contingent warrant liabilities	March 31, 2013
Balance at December 31, 2012	$	15,001
Net increase in fair value of contingent warrant liabilities upon revaluation		12,840
Balance at March 31, 2013	$	27,841

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Condensed Consolidated Financial Statement Detail (Details)	3 Months Ended					3 Months Ended					3 Months Ended									3 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012	Dec. 31, 2012 USD ($)		Feb. 28, 2010 Five year warrants issued in February 2010 [Member] USD ($)	Mar. 31, 2013 Five year warrants issued in March 2012 [Member] USD ($)	Mar. 31, 2013 Five year warrants issued in March 2012 [Member]	Dec. 31, 2012 Five year warrants issued in March 2012 [Member] USD ($)	Mar. 31, 2012 Five year warrants issued in March 2012 [Member] USD ($)	Jun. 30, 2009 Warrants issued to private investors [Member] USD ($)	Mar. 31, 2013 Options Contract [Member] USD ($)	Mar. 31, 2012 Options Contract [Member] USD ($)	Mar. 31, 2013 Options Contract [Member] EUR (€)	Mar. 31, 2013 Option Contract 1 [Member] EUR (€)	Mar. 31, 2013 Option Contract 2 [Member] EUR (€)	Mar. 31, 2013 Demand Deposits [Member] USD ($)	Dec. 31, 2012 Demand Deposits [Member] USD ($)	Mar. 31, 2013 Money Market Funds [Member] USD ($)	Dec. 31, 2012 Money Market Funds [Member] USD ($)	Mar. 31, 2013 Common stock options and restricted stock units [Member]	Mar. 31, 2012 Common stock options and restricted stock units [Member]	Mar. 31, 2013 Warrants for common stock [Member]	Mar. 31, 2012 Warrants for common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	22,635,000	11,179,000																		6,459,000	5,722,000	16,176,000	5,457,000
Cash and Cash Equivalents [Line Items]
Cash equivalents																$ 12,400,000	$ 7,800,000	$ 38,000,000	$ 37,500,000
Short-term Investments [Abstract]
Short-term investments, U.S. treasury securities	19,996,000		39,987,000	[1]
Derivative [Line Items]
Notional amount of derivative liability													15,000,000
Number of foreign exchange option contracts											2
Derivative, amount of hedged item														1,500,000	15,000,000
Derivative, premiums											1,500,000
Derivative fair value											300,000
Derivative, loss											200,000	300,000
Accrued liabilities [Abstract]
Accrued payroll and other benefits	2,169,000		2,461,000
Accrued management incentive compensation	1,086,000		3,978,000
Accrued clinical trial costs	746,000		4,702,000
Other	1,409,000		1,904,000
Total	5,410,000		13,045,000	[1]
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)					1,260,000		14,265,970		14,834,577	347,826
Exercise price (in dollars per share)					$ 10.50				$ 1.76	$ 19.50
Fair value of warrant liability	33,000					27,800,000		15,000,000
Gain (loss) on revaluation of warrant liability						$ 12,800,000

[1] The condensed consolidated balance sheet as of December 31, 2012 has been derived from the audited consolidated financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012.

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CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Cash flows from operating activities:
Net loss	$ (24,887)		$ (30,425)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	780		1,265
Common stock contribution to 401(k)	828		1,134
Stock-based compensation expense	1,619		674
Accrued interest on interest bearing obligations	1,542		394
Revaluation of contingent warrant liabilities	12,840		14,357
Restructuring charge related to long-lived assets	0		1,707
Amortization of debt discount, final payment fee on debt, and debt issuance costs	603		467
Unrealized (gain) loss on foreign currency exchange	(440)		376
Unrealized loss (gain) on foreign exchange options	189		276
Other non-cash adjustments	(4)		(43)
Changes in assets and liabilities:
Trade and other receivables, net	1,997		2,168
Prepaid expenses and other assets	(802)		(1,651)
Accounts payable and accrued liabilities	(7,128)		(3,221)
Deferred revenue	(111)		884
Other liabilities	(1,554)		(37)
Net cash used in operating activities	(14,528)		(11,675)
Cash flows from investing activities:
Proceeds from maturities of investments	20,000		0
Net purchase of property and equipment	(498)		(548)
Net cash provided by (used in) investing activities	19,502		(548)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	60		39,480
Principal payments of debt	0		(714)
Net cash provided by financing activities	60		38,766
Net increase in cash and cash equivalents	5,034		26,543
Cash and cash equivalents at the beginning of the period	45,345	[1]	48,344
Cash and cash equivalents at the end of the period	50,379		74,887
Cash paid for:
Interest	333		195
Non-cash investing and financing activities:
Issuance of warrants	0		6,386
Interest added to principal balances on long-term debt	$ 290		$ 398

[1] The condensed consolidated balance sheet as of December 31, 2012 has been derived from the audited consolidated financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012.

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Streamlining and Restructuring Charges

3 Months Ended

Mar. 31, 2013

Streamlining and Restructuring Charges [Abstract]

Streamlining and Restructuring Charges

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.

In connection with the streamlining of operations, the Company incurred restructuring charges in the first quarter of 2012 of $2.1 million related to severance, other termination benefits and outplacement services and $1.7 million related to the impairment and accelerated depreciation of various assets and leasehold improvements. The Company does not expect to incur additional significant restructuring charges during 2013 related to these streamlining activities.

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Basis of Presentation and Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013 Customer	Mar. 31, 2012 Customer	Dec. 31, 2012 Customer
Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers	2	2	2
Revenues [Member] | Customer Concentration Risk [Member] | Customer 1 [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	79.00%	49.00%
Revenues [Member] | Customer Concentration Risk [Member] | Customer 2 [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	18.00%	40.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer 1 [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	56.00%		58.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer 2 [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	39.00%		35.00%
Property equipment building and leasehold improvements [Member]
Long-Lived Assets to be Abandoned [Line Items]
Impairment loss	0.8
Accelerated depreciation	0.9