Aveo Pharmaceuticals (AVEO) 10-Q7 Nov 132013 Q3 Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
Document and Entity Information	Sep. 30, 2013	Nov. 01, 2013
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'AVEO	'
Entity Registrant Name	'AVEO PHARMACEUTICALS INC	'
Entity Central Index Key	'0001325879	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	51,862,392

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:	'	'
Cash and cash equivalents	$50,420	$76,134
Marketable securities	79,942	84,468
Accounts receivable	8,893	20,649
Prepaid expenses and other current assets	7,232	9,430
Total current assets	146,487	190,681
Property and equipment, net	12,766	12,867
Other assets	303	321
Restricted cash	3,558	3,600
Total assets	163,114	207,469
Current liabilities:	'	'
Accounts payable	6,137	10,628
Accrued expenses	12,154	19,543
Loans payable, net of discount	10,043	6,809
Deferred revenue	1,294	1,294
Deferred rent	864	856
Other liabilities	1,238	'
Total current liabilities	31,730	39,130
Loans payable, net of current portion and discount	11,549	19,228
Deferred revenue, net of current portion	17,421	18,391
Deferred rent, net of current portion	16,604	10,544
Other liabilities	'	1,238
Stockholders' equity:	'	'
Preferred stock, $.001 par value: 5,000 shares authorized; no shares issued and outstanding	'	'
Common stock, $.001 par value: 100,000 shares authorized; 52,219 and 43,780 shares issued and outstanding at September 30, 2013 and December 31, 2012, respectively	52	44
Additional paid-in capital	496,314	439,173
Accumulated other comprehensive income (loss)	8	-19
Accumulated deficit	-410,564	-320,260
Total stockholders' equity	85,810	118,938
Total liabilities and stockholders' equity	$163,114	$207,469

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	'	'
Preferred stock, shares outstanding	'	'
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	52,219	43,780
Common stock, shares outstanding	52,219	43,780

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Collaboration revenue	$323	$1,018	$970	$3,755
Operating expenses:	'	'	'	'
Research and development	19,414	21,099	56,579	67,325
General and administrative	4,440	9,300	24,213	27,469
Restructuring	77	'	8,013	'
Operating Expenses, Total	23,931	30,399	88,805	94,794
Loss from operations	-23,608	-29,381	-87,835	-91,039
Other income and expense:	'	'	'	'
Other income (expense), net	32	46	-120	279
Interest expense	-756	-888	-2,451	-2,613
Interest income	26	101	102	459
Other expense, net	-698	-741	-2,469	-1,875
Net loss	($24,306)	($30,122)	($90,304)	($92,914)
Net loss per share - basic and diluted	($0.47)	($0.69)	($1.78)	($2.14)
Weighted average number of common shares outstanding	51,443	43,430	50,719	43,336

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net loss	($24,306)	($30,122)	($90,304)	($92,914)
Other comprehensive income (loss):	'	'	'	'
Unrealized gains on available-for-sale securities	43	9	1	182
Foreign currency translation adjustment	'	-27	26	-24
Comprehensive loss	($24,263)	($30,140)	($90,277)	($92,756)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities	'	'
Net loss	($90,304)	($92,914)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	2,839	1,752
Net loss on disposal of fixed assets	77	40
Impairment of property and equipment	65	'
Stock-based compensation	3,162	6,110
Non-cash interest expense	225	299
Amortization of premium and discount on investments	870	2,162
Changes in operating assets and liabilities:	'	'
Accounts receivable	11,756	-2,088
Prepaid expenses and other current assets	2,190	-1,724
Other noncurrent assets	18	-187
Restricted cash	42	-2,849
Accounts payable	-4,491	1,355
Accrued expenses	-7,294	4,069
Deferred revenue	-970	-970
Other liabilities	'	-1,249
Deferred rent	6,068	3,836
Net cash used in operating activities	-75,747	-82,358
Investing activities	'	'
Purchases of property and equipment	-3,011	-4,183
Purchases of marketable securities	-154,225	-109,996
Proceeds from maturities and sales of marketable securities	157,881	264,361
Net cash provided by investing activities	645	150,182
Financing activities	'	'
Proceeds from issuance of common stock, net of issuance costs	53,638	'
Proceeds from issuance of stock for stock-based compensation arrangements	384	1,297
Proceeds from refinancing of loans payable	'	3,672
Principal payments on loans payable	-4,660	-2,172
Net cash provided by financing activities	49,362	2,797
Net (decrease) increase in cash and cash equivalents	-25,740	70,621
Effect of exchange rate changes on cash and cash equivalents	26	-24
Cash and cash equivalents at beginning of period	76,134	43,506
Cash and cash equivalents at end of period	50,420	114,103
Supplemental cash flow information	'	'
Cash paid for interest	$2,283	$2,306

Organization

Organization	9 Months Ended
Organization	Sep. 30, 2013
Organization	'
	(1) Organization
	AVEO Pharmaceuticals, Inc. (the “Company”), which does business as AVEO Oncology™, is a cancer therapeutics company committed to discovering and developing targeted cancer therapies to impact patients’ lives. The Company’s product candidates are directed against important mechanisms, or targets, known or believed to be involved in cancer.
	The Company and its partner Astellas Pharma, Inc. (“Astellas”) are evaluating tivozanib, the Company’s lead product candidate, in the BATON phase 2 clinical trials of tivozanib in colorectal and breast cancer. The BATON (Biomarker Assessment of Tivozanib in Oncology) program is a series of clinical trials assessing biomarkers in solid tumors that may be predictive of clinical response to tivozanib. Patient enrollment was completed earlier this year for BATON-CRC, a phase 2 clinical trial being conducted by Astellas evaluating tivozanib in combination with modified FOLFOX6 (mFOLFOX6) compared to Avastin^® (bevacizumab) in combination with mFOLFOX6 as first-line therapy in patients with advanced metastatic colorectal cancer, or CRC. Results are expected in 2014. The Company’s phase 2 BATON-BC clinical trial is evaluating the efficacy and safety of tivozanib in combination with paclitaxel compared to placebo in combination with paclitaxel in patients with locally recurrent or metastatic triple negative breast cancer. Patient enrollment in this clinical trial has been slower than anticipated, and the Company expects to reassess enrollment rates and the impact on its plans in this indication in the coming months.
	The Company also has a pipeline of monoclonal antibodies, including AV-203, a clinical stage monoclonal antibody that targets the ERBB3 (HER3) receptor, which the Company has partnered with Biogen Idec, Inc., and ficlatuzumab, a product candidate for which the Company has completed a phase 2 clinical study. Both AV-203 and ficlatuzumab were derived from the Company’s Human Response Platform™, a novel method of building preclinical models of human cancer. The Company has also initiated a program focusing on cachexia (AV-380), a serious and common complication of advanced cancer and a number of chronic diseases that is characterized by symptoms of unintentional weight loss, progressive muscle wasting, and a loss of appetite. In connection with this program, the Company recently nominated an AV-380 development candidate and initiated cell line development.
	The Company has generated an accumulated deficit as of September 30, 2013 of $410.6 million and will require substantial additional capital for research and the development of its preclinical and clinical product candidates.
	As used throughout these condensed consolidated financial statements, the term “AVEO,” refers to AVEO Pharmaceuticals, Inc. and its subsidiaries, AVEO Pharma Limited and AVEO Securities Corporation, both of which are wholly-owned.

Basis_of_Presentation

Basis of Presentation	9 Months Ended
Basis of Presentation	Sep. 30, 2013
Basis of Presentation	'
	(2) Basis of Presentation
	These condensed consolidated financial statements include the accounts of the Company and its subsidiaries. The Company has eliminated all significant intercompany accounts and transactions in consolidation.
	The accompanying condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring accruals and revisions of estimates, considered necessary for a fair presentation of the condensed consolidated financial statements have been included. Interim results for the three and nine months ended September 30, 2013 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2013 or any other future period.
	The information presented in the condensed consolidated financial statements and related footnotes at September 30, 2013, and for the three and nine months, respectively, ended September 30, 2013 and 2012, is unaudited and the condensed consolidated balance sheet amounts and related footnotes at December 31, 2012 have been derived from the Company’s audited financial statements. For further information, refer to the consolidated financial statements and accompanying footnotes included in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2012, which was filed with the U.S. Securities and Exchange Commission (“SEC”) on March 11, 2013.

Significant_Accounting_Policie

Significant Accounting Policies	9 Months Ended
Significant Accounting Policies	Sep. 30, 2013
Significant Accounting Policies	'
	(3) Significant Accounting Policies
	Revenue Recognition
	The Company’s revenues are generated primarily through collaborative research, development and commercialization agreements. The terms of these agreements generally contain multiple elements, or deliverables, which may include (i) licenses, or options to obtain licenses, to the Company’s technology, (ii) research and development activities to be performed on behalf of the collaborative partner, and (iii) in certain cases, services in connection with the manufacturing of pre-clinical and clinical material. Payments to the Company under these arrangements typically include one or more of the following: non-refundable up-front license fees; option exercise fees; funding of research and/or development efforts; milestone payments; and royalties on future product sales.
	When evaluating multiple element arrangements, the Company considers whether the deliverables under the arrangement represent separate units of accounting. This evaluation requires subjective determinations and requires management to make judgments about the individual deliverables and whether such deliverables are separable from the other aspects of the contractual relationship. In determining the units of accounting, management evaluates certain criteria, including whether the deliverables have standalone value, based on the consideration of the relevant facts and circumstances for each arrangement. The consideration received is allocated among the separate units of accounting using the relative selling price method, and the applicable revenue recognition criteria are applied to each of the separate units.
	The Company determines the estimated selling price for deliverables within each agreement using vendor-specific objective evidence (“VSOE”) of selling price, if available, third-party evidence (“TPE”) of selling price if VSOE is not available, or best estimate of selling price if neither VSOE nor TPE is available. Determining the best estimate of selling price for a deliverable requires significant judgment. The Company typically uses best estimate of selling price to estimate the selling price for licenses to the Company’s proprietary technology, since the Company often does not have VSOE or TPE of selling price for these deliverables. In those circumstances where the Company utilizes best estimate of selling price to determine the estimated selling price of a license to the Company’s proprietary technology, the Company considers market conditions as well as entity-specific factors, including those factors contemplated in negotiating the agreements and internally developed models that include assumptions related to the market opportunity, estimated development costs, probability of success and the time needed to commercialize a product candidate pursuant to the license. In validating the Company’s best estimate of selling price, the Company evaluates whether changes in the key assumptions used to determine the best estimate of selling price will have a significant effect on the allocation of arrangement consideration among multiple deliverables.
	The Company typically receives non-refundable up-front payments when licensing its intellectual property in conjunction with a research and development agreement. When management believes the license to its intellectual property does not have stand-alone value from the other deliverables to be provided in the arrangement, the Company generally recognizes revenue attributed to the license on a straight-line basis over the Company’s contractual or estimated performance period, which is typically the term of the Company’s research and development obligations. If management cannot reasonably estimate when the Company’s performance obligation ends, then revenue is deferred until management can reasonably estimate when the performance obligation ends. When management believes the license to its intellectual property has stand-alone value, the Company generally recognizes revenue attributed to the license upon delivery. The periods over which revenue should be recognized are subject to estimates by management and may change over the course of the research and development agreement. Such a change could have a material impact on the amount of revenue the Company records in future periods.
	Payments or reimbursements resulting from the Company’s research and development efforts for those arrangements where such efforts are considered as deliverables are recognized as the services are performed and are presented on a gross basis so long as there is persuasive evidence of an arrangement, the fee is fixed or determinable, and collection of the related receivable is reasonably assured. Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the accompanying balance sheets.
	At the inception of each agreement that includes milestone payments, the Company evaluates whether each milestone is substantive and at risk to both parties on the basis of the contingent nature of the milestone. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance, and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required to achieve the respective milestone and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment.
	The Company aggregates its milestones into four categories: (i) clinical and development milestones, (ii) regulatory milestones, (iii) commercial milestones, and (iv) patent-related milestones. Clinical and development milestones are typically achieved when a product candidate advances into a defined phase of clinical research or completes such phase. For example, a milestone payment may be due to the Company upon the initiation of a phase 3 clinical trial for a new indication, which is the last phase of clinical development and could eventually contribute to marketing approval by the U.S. Food and Drug Administration (“FDA”) or other global regulatory authorities. Regulatory milestones are typically achieved upon acceptance of the submission for marketing approval of a product candidate or upon approval to market the product candidate by the FDA or other global regulatory authorities. For example, a milestone payment may be due to the Company upon the FDA’s acceptance of a New Drug Application (“NDA”). Commercial milestones are typically achieved when an approved pharmaceutical product reaches certain defined levels of net sales by the licensee, such as when a product first achieves global sales or annual sales of a specified amount. Patent-related milestones are typically achieved when a patent application is filed or a patent is issued with respect to certain intellectual property related to the applicable collaboration.

	Revenues from clinical and development, regulatory and patent-related milestone payments, if the milestones are deemed substantive and the milestone payments are nonrefundable, are recognized upon successful accomplishment of the milestones. The Company has concluded that the clinical and development, regulatory and patent-related milestones pursuant to its research and development arrangements are substantive. Milestones that are not considered substantive are accounted for as license payments and recognized on a straight-line basis over the remaining period of performance. Revenues from commercial milestone payments are accounted for as royalties and are recorded as revenue upon achievement of the milestone, assuming all other revenue recognition criteria are met.
	Principles of Consolidation
	The Company’s condensed consolidated financial statements include the Company’s accounts and the accounts of the Company’s subsidiaries, AVEO Pharma Limited and AVEO Securities Corporation, both of which are wholly-owned. All intercompany transactions have been eliminated.
	Research and Development Expenses
	Research and development expenses are charged to expense as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including personnel-related costs such as salaries and stock-based compensation, facilities, research-related overhead, clinical trial costs, manufacturing costs and costs of other contracted services, license fees, and other external costs.
	Nonrefundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received in accordance with the provisions of Accounting Standards Codification (“ASC”) 730, Research and Development.
	Cash and Cash Equivalents
	The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents at September 30, 2013 consisted of money market funds and corporate debt securities, including commercial paper, maintained by an investment manager. Cash equivalents at December 31, 2012 consisted of money market funds, asset-backed commercial paper, and corporate debt securities, including commercial paper, maintained by an investment manager.
	Marketable Securities
	Marketable securities at September 30, 2013 consisted of U.S. government agency securities, asset-backed securities, and corporate debt securities, including commercial paper, maintained by an investment manager. Marketable securities at December 31, 2012 consisted of municipal bonds, asset-backed commercial paper, asset-backed securities, and corporate debt securities, including commercial paper, maintained by an investment manager. Credit risk is reduced as a result of the Company’s policy to limit the amount invested in any one issue. Marketable securities consist primarily of investments which have expected average maturity dates in excess of three months, but not longer than 24 months. The Company classifies these investments as available-for-sale. Unrealized gains and losses are included in other comprehensive (loss) income until realized. The cost of securities sold is based on the specific identification method. There were no realized gains or losses recognized on the sale or maturity of securities during the three and nine months ended September 30, 2013 and 2012.

	Available-for-sale securities at September 30, 2013 and December 31, 2012 consist of the following:


			Amortized			Unrealized				Unrealized				Fair
			Cost			Gains				Losses				Value
			(in thousands)
	September 30, 2013:
	Corporate debt securities		$	45,247		$	15			$	(5	)		$	45,257
	Government agency securities			15,787			2				—				15,789
	Asset-backed securities			18,900			—				(4	)			18,896

			$	79,934		$	17			$	(9	)		$	79,942

	December 31, 2012:
	Corporate debt securities		$	58,751		$	16			$	(11	)		$	58,756
	Municipal bonds			10,545			—				—				10,545
	Asset-backed securities			6,359			—				—				6,359
	Asset-backed commercial paper			8,806			2				—				8,808

			$	84,461		$	18			$	(11	)		$	84,468

	The aggregate fair value of securities in an unrealized loss position for less than 12 months at September 30, 2013 was $26.0 million, representing fourteen securities. There were no securities that were in an unrealized loss position for greater than 12 months at September 30, 2013. The unrealized loss was caused by a temporary change in the market for those securities primarily caused by changes in market interest rates. There was no change in the credit risk of the securities. To determine whether an other-than-temporary impairment exists, the Company performs an analysis to assess whether it intends to sell, or whether it would more likely than not be required to sell, the security before the expected recovery of the amortized cost basis of the security. Where the Company intends to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is recorded in the statement of operations as an other-than-temporary impairment charge. When this is not the case, the Company performs additional analyses on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where the Company does not expect to receive cash flows, based on using a single best estimate, sufficient to recover the amortized cost basis of a security and are recognized in other income (expense), net. The Company does not believe an other-than temporary impairment exists with respect to those securities in an unrealized loss position at September 30, 2013.
	Marketable securities in an unrealized loss position at September 30, 2013 and December 31, 2012 consist of the following:


			Aggregate			Unrealized
			Fair Value			Losses
			(in thousands)
	September 30, 2013:
	Corporate debt securities		$	10,259		$	(5	)
	Government agency securities			1,619			—
	Asset-backed securities			14,078			(4	)

			$	25,956		$	(9	)

	December 31, 2012:
	Corporate debt securities		$	29,806		$	(11	)
	Asset-backed securities			6,359			—

			$	36,165		$	(11	)

	Concentrations of Credit Risk
Financial instruments that potentially subject the Company to credit risk primarily consist of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits.
Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

The Company’s credit risk related to marketable securities is reduced as a result of the Company’s policy to limit the amount invested in any one issue.
Fair Value Measurements
The Company records cash equivalents and marketable securities at fair value. ASC 820, Fair Value Measurements and Disclosures, establishes a fair value hierarchy for those instruments measured at fair value that distinguishes between fair value measurements based on market data (observable inputs) and those based on the Company’s own assumptions (unobservable inputs). The hierarchy consists of three levels:

	•		Level 1—Quoted market prices in active markets for identical assets or liabilities. Assets utilizing Level 1 inputs include money market funds.

	•		Level 2—Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Assets utilizing Level 2 inputs include U.S. government agency securities, municipal bonds, asset-backed securities, asset-backed commercial paper, and corporate bonds, including commercial paper. These investments have been initially valued at the transaction price and are subsequently valued, at the end of each reporting period, utilizing third party pricing services or other observable market data. The pricing services utilize industry standard valuation models, including both income and market based approaches and observable market inputs to determine value. These observable market inputs include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events. The Company validates the prices provided by third party pricing services by reviewing their pricing methods and matrices, obtaining market values from other pricing sources, analyzing pricing data in certain instances and confirming that the relevant markets are active. After completing its validation procedures, the Company did not adjust or override any fair value measurements provided by pricing services as of September 30, 2013 or December 31, 2012.

	•		Level 3—Unobservable inputs developed using estimates and assumptions developed by the Company, which reflect those that a market participant would use. The Company currently has no assets or liabilities recorded at fair value that utilize Level 3 inputs.
The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis in the accompanying consolidated balance sheets as of September 30, 2013 and December 31, 2012.


		Fair Value Measurements of Cash Equivalents and
		Marketable Securities as of September 30, 2013
		Level 1			Level 2				Level 3				Total
		(in thousands)
Cash equivalents		$	38,490		$	6,076			$	—			$	44,566
Marketable securities			—			79,942				—				79,942

		$	38,490		$	86,018			$	—			$	124,508



		Fair Value Measurements of Cash Equivalents and
		Marketable Securities as of December 31, 2012
		Level 1			Level 2				Level 3				Total
		(in thousands)
Cash equivalents		$	51,182		$	18,121			$	—			$	69,303
Marketable securities			—			84,468				—				84,468

		$	51,182		$	102,589			$	—			$	153,771

The carrying amounts of the Company’s financial instruments not required to be measured at fair value, which include accounts receivable and accounts payable, approximate their fair values at September 30, 2013 and December 31, 2012.
The fair value of the Company’s loans payable at September 30, 2013, computed pursuant to a discounted cash flow technique using the effective interest rate under the loan, is $22.4 million and is considered a level 2 fair value measurement. The effective interest rate considers the fair value of the warrant issued in connection with the loan, loan issuance costs and a deferred financing charge, which approximates a market interest rate.
Property and Equipment
Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the respective assets. Maintenance and repair costs are charged to expense as incurred.

Long-lived Assets
The Company reviews long-lived assets, including property and equipment, for impairment whenever changes in business circumstances indicate that the carrying amount of the asset may not be fully recoverable. The Company recognized $0.1 million of impairment losses during the nine months ending September 30, 2013.
Basic and Diluted Loss per Common Share
Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the reporting period. Diluted net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding and potentially dilutive common share equivalents outstanding during the period. Potentially dilutive common share equivalents consist of the incremental common shares issuable upon the exercise of stock options and warrants. Since the Company had a net loss for all periods presented, the effect of all potentially dilutive securities is anti-dilutive. Accordingly, under generally accepted accounting principles in the United States (“GAAP”), basic and diluted net loss per common share is presented as the same value.
The following table sets forth for the periods presented the potentially dilutive common share equivalents (prior to consideration of the treasury stock method) excluded from the calculation of net loss per common share because their inclusion would have been anti-dilutive:


		Three Months Ended							Nine Months Ended
		September 30,							September 30,
		2013			2012				2013				2012
		(in thousands)
Weighted average options outstanding			5,819			4,794				5,638				4,629
Weighted average warrants outstanding			3			10				8				10

			5,822			4,804				5,646				4,639

Stock-Based Compensation
The Company applies the provisions of ASC 718, Compensation-Stock Compensation (“ASC 718”), to share-based awards. All awards are recognized in the Company’s statements of operations on a straight-line basis over their requisite service periods. Equity-classified awards are measured based on the grant date fair values of the awards calculated using the measurement and recognition provisions of ASC 718. During the three and nine months ended September 30, 2013 and 2012, respectively, the Company recorded the following stock-based compensation expense for equity-classified awards:


		Three Months Ended							Nine Months Ended
		September 30,							September 30,
		2013			2012				2013				2012
		(in thousands)
Research and development		$	530		$	972			$	1,677			$	2,801
General and administrative			534			1,076				1,365				3,309

		$	1,064		$	2,048			$	3,042			$	6,110

Liability-classified awards are re-measured to the award’s fair value as of each balance sheet date until settled. The Company recorded $34,000 and $0.1 million in compensation expense for liability-classified awards during the three and nine months ended September 30, 2013, respectively. No costs associated with liability-classified awards were recognized during 2012.
Allocations to research and development and general and administrative expense are based upon the department to which the associated employee to whom the award was granted reported. No related tax benefits of the stock-based compensation expense have been recognized. Share-based awards issued to nonemployees are recorded at their fair values, and are periodically revalued as the equity instruments vest and are recognized as expense over the related service period.
Income Taxes
The Company provides for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities, and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse.

The Company accounts for income taxes under ASC 740, Income Taxes, which provides a comprehensive model for the financial statement recognition, measurement, presentation and disclosure of uncertain tax positions taken or expected to be taken in income tax returns. Unrecognized tax benefits represent tax positions for which reserves have been established.
Segment and Geographic Information
Operating segments are defined as components of an enterprise engaging in business activities for which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment, principally in the United States. The Company has $1.0 million of net assets located in the United Kingdom.
Use of Estimates
The preparation of financial statements in conformity with GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Recently Adopted Accounting Pronouncements
In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This newly issued accounting standard requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement where net income (loss) is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income (loss) but only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures required under GAAP that provide additional detail about those amounts. This ASU is effective for reporting periods beginning after December 15, 2012. The Company adopted this standard in the first quarter of 2013 and presents this information in the condensed consolidated financial statements. The adoption of this standard did not have an impact on the Company’s financial position or results of operations.
For a discussion of other recent accounting pronouncements adopted by the Company, please refer to Note 2, “Significant Accounting Policies,” included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012, filed with the SEC on March 11, 2013. The Company did not adopt any new accounting pronouncements during the nine months ended September 30, 2013 that had a material effect on the Company’s condensed consolidated financial statements.
Subsequent Events
The Company has evaluated all events or transactions that occurred after September 30, 2013 through the date the Company issued these financial statements.

Collaborations_and_License_Agr

Collaborations and License Agreements	9 Months Ended
Collaborations and License Agreements	Sep. 30, 2013
Collaborations and License Agreements	'
	(4) Collaborations and License Agreements
	Astellas Pharma
	In February 2011, the Company, together with its wholly-owned subsidiary AVEO Pharma Limited, entered into a Collaboration and License Agreement with Astellas (the “Astellas Agreement”), pursuant to which the Company and Astellas made plans to develop and seek to commercialize tivozanib for the treatment of a broad range of cancers. The Company and Astellas are currently evaluating tivozanib in colorectal cancer and triple negative breast cancer as part of the BATON program.
	Under the terms of the Astellas Agreement, the Company and Astellas share responsibility for continued development and commercialization of tivozanib in the United States, Canada and Mexico (collectively, “North America”) and in Europe under a joint development plan and a joint commercialization plan, respectively. Throughout the rest of the world, excluding Asia (the “Royalty Territory”), where Kyowa Hakko Kirin (“KHK”) has retained all development and commercialization rights, Astellas has an exclusive, royalty-bearing license to develop and commercialize tivozanib. The terms of the Astellas Agreement are subject to the Company’s obligations to KHK under a license agreement entered into with KHK in 2006 pursuant to which the Company acquired exclusive rights to develop and commercialize tivozanib worldwide outside of Asia.
	If tivozanib is approved for use in treating a particular indication by applicable regulatory agencies, the Company will have lead responsibility for formulating the commercialization strategy for North America under the joint commercialization plan, with each of the Company and Astellas responsible for conducting 50% of the sales efforts and medical affairs activities in North America. Astellas will have lead responsibility for commercialization activities in Europe under the joint commercialization plan, with each of the Company and Astellas responsible for conducting 50% of the medical affairs activities in the major European countries. All costs associated with each party’s conduct of development and commercialization activities (including clinical manufacturing and commercial manufacturing costs, if any) in North America and Europe, and any resulting profits or losses, are shared equally between the parties.

	Under the Astellas Agreement, the Company received an initial cash payment of $125.0 million, comprised of a $75.0 million license fee and $50.0 million in research and development funding. The Company retained net proceeds of approximately $97.6 million of the initial cash payment from Astellas, after payments to KHK and strategic, legal and financial advisors. In December 2012, the Company received a $15.0 million milestone payment from Astellas in connection with the acceptance by the FDA of the NDA filing for tivozanib for the treatment of patients with advanced renal cell carcinoma (“RCC”). The milestone was considered substantive and revenue was recognized upon achievement of the milestone. The Company is also eligible to receive from Astellas an aggregate of approximately $1.2 billion in potential future milestone payments, comprised of (i) up to $65 million in substantive milestone payments upon achievement of specified clinical and development milestone events, (ii) up to $325 million in substantive milestone payments upon achievement of specified regulatory milestone events, and (iii) up to approximately $788 million in milestone payments upon the achievement of specified commercial sales events. The first anticipated clinical and development milestone will become due to the Company upon initiation of the first phase 3 clinical trial of tivozanib, if any, in breast cancer, colorectal cancer or another indication. The timing of this milestone is uncertain, as the Company has not finalized plans for its future trials, and the Company needs to complete further trials, including its phase 2 clinical trials, which do not result in any milestone payments coming due, prior to initiating any further phase 3 trials. If tivozanib is successfully developed and launched in the Royalty Territory, Astellas will be required to pay to the Company tiered, double digit royalties on net sales of tivozanib in the Royalty Territory, if any, subject to offsets under certain circumstances. The Company is required to pay KHK low to mid-teen royalties on its net sales in North America, and 30% of certain amounts the Company may receive from Astellas in connection with Astellas’ development and commercialization activities in Europe and the Royalty Territory, including up-front license fees, milestone payments and royalties.
	Unless terminated earlier in accordance with its terms, the Astellas Agreement expires (a) with respect to the Royalty Territory, on a country-by-country basis, upon the latest to occur of: (i) the expiration of the last-to-expire valid claim of an AVEO patent or joint patent covering the composition of tivozanib, (ii) the expiration of the last-to-expire valid claim of an AVEO patent or joint patent covering the use of tivozanib, but only for so long as no generic competition exists in such country, and (iii) twelve years from first commercial sale of tivozanib in such country; and (b) with respect to North America and Europe as a whole, upon the expiration of all payment obligations between the parties related to development and commercialization of tivozanib in North America and Europe. Astellas has the right to terminate the Astellas Agreement, in its entirety or solely with respect to the Royalty Territory, at any time upon 180 days prior written notice to the Company. Either party may terminate the Astellas Agreement with respect to a specified territory or country as set forth in the Astellas Agreement, if the other party fails to cure a material breach related to such territory or country, as applicable. The Company may also terminate the Astellas Agreement in its entirety upon a patent-related challenge by Astellas, its affiliates or sublicensees if such patent-related challenge is not withdrawn within 30 days following the Company’s notice to Astellas of such termination. There are no refund provisions in the Astellas Agreement.
	The Company is accounting for the joint development and commercialization activities in North America and Europe as a joint risk-sharing collaboration in accordance with ASC 808, Collaborative Arrangements. In addition, these joint development and commercialization activities were not deemed to be separate deliverables under the Astellas Agreement.
	Payments from Astellas with respect to Astellas’ share of tivozanib development and commercialization costs that have been incurred by the Company pursuant to the joint development plan are recorded as a reduction to research and development expense and general and administrative expense in the accompanying consolidated financial statements due to the joint risk-sharing nature of the activities in North America and Europe. As a result of the cost-sharing provisions in the Astellas Agreement, the Company reduced research and development expense by $2.3 million and $7.5 million during the three months ended September 30, 2013 and 2012, respectively, and by $14.9 million and $22.9 million during the nine months ended September 30, 2013 and 2012, respectively. The Company also reduced general and administrative expense by $0.4 million during the three months ended September 30, 2013 and 2012, and by $2.7 million and $1.9 million during the nine months ended September 30, 2013 and 2012, respectively, as a result of these provisions. The net amount due to the Company from Astellas pursuant to the cost-sharing provisions was $8.9 million at September 30, 2013.
	Activities under the Astellas Agreement outside of the joint development and commercialization activities in North America and Europe, including the co-exclusive license to develop and commercialize tivozanib in North America and Europe that was delivered prior to the initiation of the collaborative activities in North America and Europe, were evaluated under ASC 605-25, Revenue Recognition—Multiple Element Arrangements (“ASC 605-25”) (as amended by ASU 2009-13, Revenue Recognition (“ASU 2009-13”)) to determine if they represented a multiple element revenue arrangement. The Astellas Agreement includes the following deliverables: (1) a co-exclusive license to develop and commercialize tivozanib in North America and Europe (the “License Deliverable”); (2) a combined deliverable comprised of an exclusive royalty-bearing license to develop and commercialize tivozanib in the Royalty Territory and the Company’s obligation to provide access to clinical and regulatory information resulting from the activities in North America and Europe to Astellas for its development and commercialization of tivozanib in the Royalty Territory (the “Royalty Territory Deliverable”); and (3) the Company’s obligation to supply clinical material to Astellas for development of tivozanib in the Royalty Territory (the “Clinical Material Deliverable”). The License Deliverable is not sublicensable. Astellas has the right to sublicense the exclusive royalty-bearing license to develop and commercialize tivozanib in the Royalty Territory. The Company’s obligation to provide access to clinical and regulatory information as part of the Royalty Territory Deliverable includes the obligation to provide access, upon request, to all clinical data, regulatory filings, safety data and manufacturing data to Astellas for use in the development and commercialization of tivozanib in the Royalty Territory. The Clinical Material Deliverable includes the obligation to supply clinical material to Astellas in accordance with current good manufacturing practices applicable to clinical materials and other relevant regulatory authority requirements, upon request, for the development of tivozanib in the Royalty Territory. All of these deliverables were deemed to have stand-alone value and to meet the criteria to be accounted for as separate units of accounting under ASC 605-25. Factors considered in this determination included, among other things, the subject of the licenses and the research and development and commercial capabilities of Astellas.
	The Company allocated the up-front consideration of $125.0 million to the deliverables based on management’s best estimate of selling price of each deliverable using the relative selling price method as the Company did not have VSOE or TPE of selling price for such deliverables. The Company’s best estimate of selling price considered discounted cash flow models, the key assumptions of which included the market opportunity for commercialization of tivozanib in North America and Europe and the Royalty Territory, the probability of successfully developing and commercializing tivozanib, the remaining development costs for tivozanib, and the estimated time to commercialization of tivozanib. The Company’s analysis included the following market conditions and entity-specific factors: (a) the specific rights provided under the license to develop and commercialize tivozanib in North America and Europe and the Royalty Territory, (b) the potential indications for tivozanib pursuant to the licenses, (c) the relevant territories for the respective licenses, (d) the stage of development of tivozanib by potential indication and estimated remaining development timelines and costs for each indication, (e) the development risk by indication, (f) the market size by indication, (g) the expected product life of tivozanib assuming commercialization and (h) the competitive environment. More specifically, the Company’s discounted cash flow model included an assumption that the Company and Astellas would develop and commercialize tivozanib in North America and Europe as a monotherapy for RCC, and in combination with other known anti-cancer agents for RCC, breast cancer and colorectal cancer. Approximately 70% of the value of tivozanib in the discounted cash flow model was a result of the estimated market opportunity for tivozanib as a monotherapy for RCC. The market opportunity for commercialization of tivozanib in North America and Europe was generated using a patient-based forecasting approach, with key epidemiological, market penetration, dosing, compliance, length of treatment, and pricing assumptions derived from primary and secondary market research. While the RCC monotherapy opportunity represented the majority of the market opportunity, clinical trials for tivozanib in the breast cancer and colorectal cancer indications were in earlier stages of development at the time the Company completed the allocation and therefore had more development risk and were assigned a lower probability of success relative to the RCC indication, with a longer timeline to potential cash inflows. The probability of successfully developing and commercializing tivozanib in the various indications throughout the world (other than Asia) was estimated based on standard industry averages for similar product candidates being developed for oncology indications. The remaining development costs were estimated based upon budgets and estimated costs for ongoing and planned clinical trials in all contemplated indications. The time to commercialization was based on the Company’s estimates, which projected the launch of tivozanib for RCC monotherapy in 2013. The market opportunity for the Royalty Territory was estimated based upon a specified percentage of total projected European sales and costs of tivozanib. The Company believes that this method for estimating market opportunity outside of North America, Europe and Asia is common in the pharmaceuticals industry. The Company utilized a discount rate of 15% in its analysis, representing the weighted average cost of capital derived from returns on equity for comparable companies.
	The Company concluded that a change in the key assumptions used to determine best estimate of selling price for each license deliverable would not have a significant effect on the allocation of the consideration under the Astellas arrangement.
	The Company allocated up-front consideration of $120.2 million to the License Deliverable and up-front consideration of $4.8 million to the Royalty Territory Deliverable. The relative selling price of the Company’s obligation under the Clinical Material Deliverable had de minimis value.
	The Company recorded the $120.2 million relative selling price of the License Deliverable as collaboration revenue during the three months ended March 31, 2011 upon delivery of the license, and deferred approximately $4.8 million of revenue representing the relative selling price of the Royalty Territory Deliverable. The Company is recording the $4.8 million of revenue attributed to the Royalty Territory Deliverable ratably over the Company’s period of performance through April 2022, the remaining patent life of tivozanib. The Company estimated the period of performance considering the joint plan to develop tivozanib in several indications, including in breast cancer and colorectal cancer and potentially in other cancer indications. The clinical development of tivozanib in these indications is in earlier stages of development and, as a result, the clinical development timeline is uncertain and is expected to change as the Company obtains additional clinical data in these indications. As a result, the Company estimated the period of performance as the remaining patent life of tivozanib as it represents the longest period over which development of tivozanib could occur. The Company reassesses the period of performance at the end of each reporting period. The Company recorded approximately $0.1 million of revenue associated with the Royalty Territory Deliverable during each of the three month periods ended September 30, 2013 and 2012, and approximately $0.3 million of revenue associated with the Royalty Territory Deliverable during each of the nine month periods ended September 30, 2013 and 2012.

	The Company believes the clinical and development and regulatory milestones that may be achieved under the Astellas Agreement are consistent with the definition of a milestone included in ASU 2010-17, Revenue Recognition—Milestone Method, and, accordingly, the Company will recognize payments related to the achievement of such milestones, if any, when the applicable milestones are achieved. Factors considered in this determination included scientific and regulatory risks that must be overcome to achieve each milestone, the level of effort and investment required to achieve each milestone, and the monetary value attributed to each milestone. The Company did not recognize any milestone payments under the Astellas arrangement during the nine months ended September 30, 2013 or 2012.
	Biogen Idec International GmbH
	In March 2009, the Company entered into an exclusive option and license agreement with Biogen Idec International GmbH, a subsidiary of Biogen Idec Inc., collectively referred to herein as “Biogen Idec”, regarding the development and commercialization outside of North America of the Company’s discovery-stage ERBB3-targeted antibodies for the potential treatment and diagnosis of cancer and other diseases.
	The Company accounts for the Biogen Idec arrangement pursuant to ASC 605-25. The deliverables under the arrangement include an option for a co-exclusive, worldwide license to develop and manufacture ERBB3 antibody products and an option for an exclusive license to commercialize ERBB3 antibody products in all countries in the world other than North America. The Company determined that these deliverables did not have standalone value due to the fact that the program was still in preclinical development and requires the Company’s experience to advance the development of the products. As such, the Company determined that the agreement should be accounted for as one unit of accounting.
	Under the terms of the agreement, Biogen Idec paid the Company an up-front cash payment of $5.0 million in March 2009, which is being amortized over the period of the Company’s substantial involvement, defined as the patent life of the development candidate. In addition, Biogen Idec purchased 7,500,000 shares of Series E Convertible Preferred Stock at a per share price of $4.00, resulting in gross proceeds to the Company of $30.0 million. In connection with the Company’s initial public offering in March 2010 and the related 1:4 reverse stock split of the common stock, each four shares of outstanding Series E Convertible Preferred Stock were converted into one share of common stock. The Company determined that the per share price of $4.00 paid by Biogen Idec included a premium of $1.09 per share over the fair value of the Series E Convertible Preferred Stock of $2.91 as calculated by the Company in its retrospective stock valuation. Accordingly, the Company is recognizing the premium of $8.2 million as revenue on a straight-line basis over the period of the Company’s substantial involvement. The Company earned a $5.0 million milestone payment for achievement of the first pre-clinical discovery milestone under the agreement in June 2009, the achievement of which was not considered at risk; such milestone payment was therefore deferred and is being recognized over the period of substantial involvement. The Company earned a second $5.0 million milestone payment upon selection of a development candidate in March 2010. This milestone was considered substantive and was included in revenue for the quarter ended March 31, 2010. The Company earned a third $5.0 million milestone payment based on achieving the GLP toxicology initiation milestone in June 2011. This milestone was considered substantive and was included in revenue for the quarter ended June 30, 2011. The Company could potentially also receive an option exercise fee and regulatory milestone payments of up to $45.0 million in the aggregate if Biogen Idec exercises its option to obtain exclusive rights to commercialize ERBB3 antibody products in its territory. The first regulatory milestone that the Company could potentially receive is a $25.0 million payment due upon the receipt of the first regulatory approval of a licensed product from the EMA. The Company does not expect to achieve this milestone in the near future. The Company did not earn any milestones under the Biogen arrangement during the nine months ended September 30, 2013 or 2012.
	If Biogen Idec exercises its exclusive option under the agreement, Biogen Idec will pay the Company royalties on Biogen Idec’s sales of ERBB3 antibody products in its territory, and the Company will pay Biogen Idec royalties on the Company’s sale of ERBB3 antibody products in North America.
	Under the agreement, the Company recorded revenue of $0.2 million and $0.6 million during the three months and nine month periods ended September 30, 2013, respectively, and $0.2 million and $0.6 million during the three and nine month periods ended September 30, 2012, respectively.
	OSI Pharmaceuticals Inc.
	In September 2007, the Company entered into a collaboration and license agreement with OSI Pharmaceuticals, Inc. (a wholly-owned subsidiary of Astellas US Holding Inc., a holding company owned by Astellas Pharma Inc.), or OSI, which provided for the use of the Company’s proprietary in vivo models by the Company’s scientists at its facilities, use of the Company’s bioinformatics tools and other target validation and biomarker research to further develop and advance OSI’s small molecule drug discovery and translational research related to cancer and other diseases. In July 2009, the Company and OSI expanded the strategic partnership, and the Company granted OSI a non-exclusive license to use the Company’s proprietary bioinformatics platform, and non-exclusive perpetual licenses to use bioinformatics data and the Company’s proprietary gene index related to a specific target pathway. Further, as part of the expanded strategic partnership, the Company granted OSI an option, exercisable upon payment of an option fee, to receive non-exclusive perpetual rights to certain elements of the Company’s Human Response Platform and to use the Company’s bioinformatics platform, and the Company granted OSI the right to obtain certain of its tumor models and tumor archives. In November 2010, OSI exercised its option under the July 2009 expanded agreement providing the right for OSI to license certain elements of the Company’s proprietary technology platform, including components of the Human Response Platform for the identification/characterization of novel epithelial-mesenchymal transition agents and proprietary patient selection biomarkers, in support of OSI’s clinical development programs. The Company received $12.5 million of upfront payments from OSI and research funding payments on a quarterly basis that were recognized as revenue through July 2011. In addition, OSI purchased 1,833,334 shares of the Company’s Series C Convertible Preferred Stock and 3,750,000 shares of the Company’s Series E Convertible Preferred Stock that were converted into shares of common stock in connection with the Company’s initial public offering. The Company determined that both equity issuances included a premium, which was recognized as additional license revenue through July 2011. The Company completed the transfer of the relevant technology to OSI in July 2011. The Company also recognized $25.0 million relating to the option exercise by OSI over the technology transfer period, which was completed in July 2011.
	Under the July 2009 expanded agreement, if all applicable milestones are achieved, all remaining payments for the successful achievement of discovery, development and commercialization milestones could total, in the aggregate, over $46.0 million, comprised of approximately (i) $8.4 million in substantive milestone payments upon achievement of specified clinical and development milestone events, (ii) $20.7 million in substantive milestone payments upon achievement of specified regulatory milestone events, and (iii) $17.5 million in milestone payments upon the achievement of specified sales amounts. In addition, the Company is eligible to receive up to $24.0 million in biomarker-related milestones.
	In May 2012, the Company earned a patent-related milestone payment of $250,000 upon filing of a patent application by OSI, and the Company also earned a clinical and development milestone payment of $750,000 for commencement by OSI of GLP toxicology studies. Since these milestones were considered substantive, they were recorded as revenue during the nine month periods ended September 30, 2012.
	The next milestone payment that the Company could potentially receive pursuant to this agreement is a $2.0 million clinical and development milestone for phase 1 clinical trial dosing in the United States. The Company does not expect to achieve this milestone in the near future. The next regulatory milestone payment the Company could potentially receive pursuant to this agreement is $7.0 million upon the filing of an NDA with the FDA. The Company does not expect to achieve this milestone in the near future. Upon commercialization of products under the agreement, the Company is eligible to receive tiered royalty payments on sales of products by OSI, its affiliates and sublicensees. All of the milestone payments that were earned prior to July 2011 are for selection of targets, delivery of models, delivery of tumor archives or delivery of cell lines.
	Centocor Ortho Biotech
	In May 2011, the Company entered into an exclusive license agreement (the “Centocor License Agreement”) with Centocor Ortho Biotech Inc. (“Centocor”), for the worldwide development and commercialization of the Company’s internally-discovered antibodies targeting the RON receptor (Recepteur d’Origine Nantais), including the grant to Centocor of an exclusive, worldwide license to the Company’s proprietary RON-driven tumor models. The Company also granted Centocor a non-exclusive, non-sublicensable, worldwide license to the Company’s proprietary list of human genes intended to predict correlation of response to RON-targeted antibodies (the “RON index”). On September 7, 2012, the Company received notice from Centocor of termination of the Centocor License Agreement, effective on December 6, 2012, at which point all rights to and the responsibility for future research and development, manufacturing and commercialization activities and costs of the RON antibody program granted to Centocor under the Centocor License Agreement returned to the Company.
	In connection with the Centocor License Agreement, the Company received a one-time cash payment in the amount of $7.5 million and a separate equity investment in the amount of approximately $7.5 million through the purchase by Johnson & Johnson Development Corporation, an affiliate of Centocor, of 438,340 newly issued shares of the Company’s common stock at a purchase price of $17.11 per share. Centocor also funded certain research which the Company conducted during the term of the Centocor License Agreement, which, as noted above, terminated on December 6, 2012.
	The Company recorded revenue of $0.7 million and $1.8 million for the three and nine months ended September 30, 2012, respectively, pursuant to the license agreement.
	Kirin Brewery
	In December 2006, the Company entered into an exclusive license agreement, with the right to grant sublicenses, subject to certain restrictions, with Kirin Brewery Co. Ltd. (now Kyowa Hakko Kirin) (“KHK”) to research, develop, manufacture and commercialize tivozanib, pharmaceutical compositions thereof and associated biomarkers in all territories in the world except for Asia (the “KHK Agreement”). Upon entering into the KHK Agreement, the Company made a cash payment in the amount of $5.0 million.

	In March 2010, the Company made a $10.0 million milestone payment to KHK in connection with the dosing of the first patient in the Company’s phase 3 clinical trial of tivozanib for the treatment of patients with advanced RCC. The Company recorded $22.5 million of research and development expense during the year ended December 31, 2011 associated with a payment made to KHK related to the up-front license payment received under the Astellas Agreement. In December 2012, the Company made a $12.0 million milestone payment to KHK in connection with the acceptance by the FDA of the Company’s NDA filing for tivozanib for the treatment of patients with advanced RCC, all of which was expensed as research and development expense during the year ended December 31, 2012. In connection with this payment, $6.0 million was reimbursed from Astellas and recorded as a reduction of research and development expense.
	Under the KHK Agreement, the Company may be required to (i) make future milestone payments upon the achievement of specified regulatory milestones in the United States, (ii) pay tiered royalty payments on net sales it makes of tivozanib in its territory ranging from the low to mid-teens as a percentage of the Company’s net sales of tivozanib, and (iii) pay 30% of certain amounts the Company receives under the Astellas Agreement in connection with Astellas’ development and commercialization activities in Europe and the Royalty Territory related to tivozanib, including up-front license fees, milestone payments and royalties the Company may receive from Astellas, other than amounts the Company receives in respect of research and development funding or equity investments, subject to certain limitations.

Accrued_Expenses

Accrued Expenses	9 Months Ended
Accrued Expenses	Sep. 30, 2013
Accrued Expenses	'
	(5) Accrued Expenses
	Accrued expenses consisted of the following as of September 30, 2013 and December 31, 2012:


		September 30,		December 31,
		2013		2012
		(in thousands)
	Clinical expenses	$	7,154	$	6,688
	Salaries and benefits		2,336		6,015
	Restructuring		838		1,653
	Professional fees		595		430
	Accrued interest		217		275
	Medical affairs		104		583
	Collaboration expenses		—		1,807
	Pre-commercialization expenses		—		924
	Other		910		1,168

		$	12,154	$	19,543

Loans_Payable

Loans Payable	9 Months Ended
Loans Payable	Sep. 30, 2013
Loans Payable	'
	(6) Loans Payable
	On May 28, 2010, the Company entered into a loan and security agreement (the “Loan Agreement”) with Hercules Technology II, L.P. and Hercules Technology III, L.P., affiliates of Hercules Technology Growth (collectively, “Hercules”), pursuant to which the Company received a loan in the aggregate principal amount of $25.0 million. The Company was initially required to repay the aggregate principal balance under the Loan Agreement in 30 equal monthly installments of principal starting on April 1, 2011. However, the Loan Agreement provided that such date would be extended under certain circumstances. During 2011, the Company triggered two possible extensions to the date from which principal payments were to be made and, as a result, the initial date for principal repayment was extended to January 1, 2012. On March 31, 2012, the Company entered into an amendment to the Loan Agreement, pursuant to which the Company increased the principal amount under the Loan Agreement to $26.5 million. Under the amendment to the Loan Agreement, the date on which the Company was required to begin repaying the aggregate principal balance was extended to April 1, 2013, at which point the Company began repaying such balance in 30 equal monthly installments. The Company accounted for this amendment as a loan modification in accordance with ASC 470-50, Debt—Modifications and Extinguishments.
	Per annum interest is payable on the principal balance of the loan at the greater of 11.9% and an amount equal to 11.9% plus the prime rate of interest minus 4.75%, provided however, that the per annum interest shall not exceed 15.0%. The Company must make interest payments on the loan each month following the date of borrowing under the Loan Agreement. The unpaid principal balance and all accrued but unpaid interest will be due and payable on September 1, 2015. The loan is secured by a lien on all of the Company’s personal property as of, or acquired after, the date of the Loan Agreement, except for intellectual property.

	The Loan Agreement required a deferred charge of $1.3 million which was paid in May 2012 related to the amendment of the Loan Agreement. The Loan Agreement also includes an additional deferred charge of $1.2 million due in June 2014 which has been recorded as a loan discount and is being amortized to interest expense over the term of the Loan Agreement using the effective interest rate method. The Company recorded a long-term liability for the full amount of the charge since the payment of such amount is not contingent on any future event. The Company incurred approximately $193,000 in loan issuance costs paid directly to the lenders under the Loan Agreement, which were offset against the loan proceeds and are accounted for as a loan discount. As part of the Loan Agreement, the Company issued warrants to the lenders on June 2, 2010 to purchase up to 156,641 shares of the Company’s common stock at an exercise price equal to $7.98 per share. The Company recorded the relative fair value of the warrants of approximately $780,000 as stockholders’ equity and as a discount to the related loan outstanding and is amortizing the value of the discount to interest expense over the term of the loan using the effective interest method. The relative fair value of the warrants was calculated using the Black-Scholes option-pricing model with the following assumptions: volatility of 64.12%, an expected term equal to the contractual life of the warrant (seven years), a risk-free interest rate of 2.81% and no dividend yield. The resulting effective interest rate for the loans outstanding under the Loan Agreement is approximately 13.1%.
	The Loan Agreement defines events of default, including the occurrence of an event that results in a material adverse effect upon the Company’s business operations, properties, assets or condition (financial or otherwise), its ability to perform its obligations under and in accordance with the terms of the Loan Agreement, or upon the ability of the lenders to enforce any of their rights or remedies with respect to such obligations, or upon the collateral under the Loan Agreement, the related liens or the priority thereof. Hercules also received an option, subject to the Company’s written consent, not to be unreasonably withheld, to purchase, either with cash or through conversion of outstanding principal under the loan, up to $2.0 million of equity of the Company sold in any sale by the Company to third parties of equity securities resulting in at least $10.0 million in net cash proceeds to the Company, subject to certain exceptions. The Company has evaluated the embedded conversion option, and has concluded that it does not need to be bifurcated and separately accounted for. No amount will be recognized for the conversion feature until such time as the conversion feature is exercised and it can be determined whether a beneficial conversion feature exists. As of September 30, 2013, the lenders have not asserted any events of default under the loan. While the Company does not believe that there has been a material adverse change, as defined in the Loan Agreement, it is possible that Hercules could take the position that the adverse outcome relating to the development and commercialization of tivozanib for RCC, including the FDA informing the Company that it would not approve the NDA for tivozanib for the treatment of patients with advanced RCC and the related shareholder litigation described below in Item 1, Note 9—Legal Action, constitute a material adverse change, and, accordingly, an event of default, which could trigger a repayment of all principal and interest due under the loan unless such event of default is waived by Hercules. As of September 30, 2013, the principal balance outstanding was $21.8 million.
	Future minimum payments under the loans payable outstanding as of September 30, 2013 are as follows (amounts in thousands):


	Years Ending December 31:
	2013 (3 months remaining)		3,077
	2014		13,546
	2015		9,309

			25,932
	Less amount representing interest		(2,855	)
	Less discount		(247	)
	Less deferred charges		(1,238	)
	Less current portion		(10,043	)

	Loans payable, net of current portion	$	11,549

Stockbased_Compensation

Stock-based Compensation	9 Months Ended
Stock-based Compensation	Sep. 30, 2013
Stock-based Compensation	'
	(7) Stock-based Compensation
	Stock Plans
	The Company issued stock options and restricted stock awards during the nine months ended September 30, 2013 and 2012.
	A summary of the status of the Company’s stock option activity at September 30, 2013 and changes during the nine months then ended is presented in the table and narrative below:


		Options			Weighted-		Weighted-		Aggregate
					Average		Average		Intrinsic Value
					Exercise Price		Remaining
							Contractual
							Term
	Outstanding at December 31, 2012		4,638,388		$	9.86
	Granted		2,709,840		$	4.96
	Exercised		(139,903	)	$	1.37
	Forfeited		(1,983,719	)	$	10.26

	Outstanding at September 30, 2013		5,224,606		$	7.4		6.41	$	210,279

	Vested or expected to vest at September 30, 2013		4,518,190		$	7.8		5.95	$	210,279

	Exercisable at September 30, 2013		3,029,547		$	8.55		4.42	$	210,279

	The aggregate intrinsic value in the table above represents the value (the difference between the Company’s closing common stock price on the last trading day during the nine months ended September 30, 2013 and the exercise price of the options, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on September 30, 2013. As of September 30, 2013, there was $5.4 million of total unrecognized stock-based compensation expense related to stock options granted under the Company’s 2002 Stock Incentive Plan and 2010 Stock Incentive Plan (the “plans”). The expense is expected to be recognized over a weighted-average period of 2.0 years.
	Stock-based awards to employees are required to be measured at fair value. The Company uses the Black-Scholes pricing model in order to calculate the estimated fair value of its stock option grants. This model requires the Company to make assumptions with respect to factors such as volatility, interest rate, dividend yield and term. Because the Company only completed its initial public offering in March 2010, it has not had sufficient history as a publicly traded company to support a calculation of expected term and volatility. As such, the Company has used a weighted-average volatility considering the Company’s own volatility since March 2010, and the volatilities of several peer companies. For purposes of identifying similar entities, the Company considered characteristics such as industry, length of trading history, market capitalization and similar product pipelines. The Company utilized a weighted average method of using its own historical volatility data for the quarters that it has been public, along with data it obtained with respect to its peer companies. Due to the lack of available option activity data, the Company elected to use the “simplified” method for “plain vanilla” options to estimate the expected term of the stock option grants. Under this approach, the weighted-average expected life is presumed to be the average of the vesting term and the contractual term of the option. Additionally, under the provisions of ASC 718, the Company is required to include an estimate of the value of the awards that will be forfeited in calculating compensation costs, which the Company estimates based upon actual historical forfeitures. The forfeiture estimates are recognized over the requisite service period of the awards on a straight-line basis. The risk-free interest rate is determined based upon the United States Treasury’s rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the options being valued. The Company does not expect to pay dividends in the foreseeable future.
	During the three and nine months ended September 30, 2013 and 2012, respectively, the assumptions used in the Black-Scholes pricing model for new grants were as follows:


		Three Months Ended
		September 30,
		2013		2012
	Volatility factor	71.13%		64.84%
	Expected term (in years)	6.25		6.25
	Risk-free interest rates	1.72%		0.83%
	Dividend yield	—		—


		Nine Months Ended
		September 30,
		2013		2012
	Volatility factor	64.22-72.65%		64.30-64.94%
	Expected term (in years)	5.50-6.25		5.50-6.25
	Risk-free interest rates	1.01-1.71%		0.83-1.33%
	Dividend yield	—		—
	The restricted stock activity for the nine months ended September 30, 2013 is as follows:


		Number of Shares			Weighted-
					Average
					Fair Value
	Unvested at December 31, 2012		245,020		$	13.31
	Granted		689,678			5.23
	Cancelled		(172,280	)		9.14
	Expired		—			—
	Vested/Released		(32,500	)		14.16

	Unvested at September 30, 2013		729,918		$	6.62

	The Company reversed $2.0 million of previously recognized stock-based compensation expense during the nine months ending September 30, 2013 associated with restricted stock awards that are no longer probable of vesting. As of September 30, 2013, there was $0.1 million of total unrecognized stock-based compensation expense related to restricted stock awards granted under the plans. The expense is expected to be recognized over a weighted-average period of 0.8 year.

Strategic_Restructurings

Strategic Restructurings	9 Months Ended
	Sep. 30, 2013
Strategic Restructurings	'
	(8) Strategic Restructurings
	In October 2012, the Company announced a strategic restructuring designed to optimize resources and reduce expenses. The Company’s restructuring and projected cost savings are being achieved through a combination of reduced spending on early stage research programs and a reduction in force of 48 positions, as well as the elimination of 30 previously open positions.
	In connection with the receipt of a Complete Response Letter from the FDA informing the Company that the FDA would not approve the Company’s NDA for tivozanib for the treatment of patients with advanced RCC, the Company announced a strategic restructuring in June 2013 to refocus the Company’s efforts on the on-going clinical development of tivozanib in colorectal and breast cancer and on the advancement of key pipeline and preclinical assets. As part of this restructuring, the Company decided not to pursue the development of tivozanib in RCC. This restructuring has been substantially completed. The Company expects this restructuring to be fully completed by December 31, 2013.
	The following table summarizes the components of the Company’s restructuring activity recorded in operating expenses and in accrued expenses in the accompanying condensed consolidated balance sheet:


		Restructuring		Restructuring		Restructuring			Restructuring
		amounts accrued at		expense		amounts			amounts
		December 31,		incurred		paid			accrued at
		2012		during the nine		during the nine			September 30,
				months ended		months ended			2013
				September 30,		September 30,
				2013		2013
		(in thousands)
	Employee severance, benefits and related costs.	$	1,653	$	7,618	$	(8,488	)	$	783
	Contract termination costs		—		82		(27	)		55

	Total		1,653		7,700		(8,515	)		838
	Restructuring expense for the nine months ended September 30, 2013 includes impairment charges of $0.3 million.

Legal_Actions

Legal Actions	9 Months Ended
Legal Actions	Sep. 30, 2013
Legal Actions	'
	(9) Legal Actions
	Two class action lawsuits have been filed against the Company and certain of the Company’s officers in the United States District Court for the District of Massachusetts, one on May 9, 2013, captioned Paul Sanders v. Aveo Pharmaceuticals, Inc., et al., No. 1:13-cv-11157-JLT, and the other on May 31, 2013, captioned Christine Krause v. AVEO Pharmaceuticals, Inc., et al., No. 1:13-cv-11320-JLT, respectively. Each complaint purports to be brought on behalf of shareholders who purchased the Company’s common stock between January 3, 2012 and May 1, 2013. Each complaint generally alleges that the Company and certain of the Company’s officers violated Sections 10(b) and/or 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder by making allegedly false and/or misleading statements concerning the phase 3 trial design and results for the Company’s TIVO-1 study in an effort to lead investors to believe that the drug would receive approval from the FDA. Each complaint seeks unspecified damages, interest, attorneys’ fees, and other costs. The Company denies any allegations of wrongdoing and intends to vigorously defend against these lawsuits. However, there is no assurance that the Company will be successful in defense or that insurance will be available or adequate to fund any settlement or judgment or the litigation costs of these actions. Moreover, the Company is unable to predict the outcome or reasonably estimate a range of possible loss at this time.
	On July 3, 2013, the Company received a subpoena from the SEC requesting documents and information concerning tivozanib, including related communications with the FDA, investors and others. The Company is fully cooperating with the SEC regarding this fact-finding inquiry. The SEC has informed the Company that this inquiry should not be construed as an indication that any violations of law have occurred or that the SEC has any negative opinion of any person, entity or security.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2013
Revenue Recognition	'
	Revenue Recognition
	The Company’s revenues are generated primarily through collaborative research, development and commercialization agreements. The terms of these agreements generally contain multiple elements, or deliverables, which may include (i) licenses, or options to obtain licenses, to the Company’s technology, (ii) research and development activities to be performed on behalf of the collaborative partner, and (iii) in certain cases, services in connection with the manufacturing of pre-clinical and clinical material. Payments to the Company under these arrangements typically include one or more of the following: non-refundable up-front license fees; option exercise fees; funding of research and/or development efforts; milestone payments; and royalties on future product sales.
	When evaluating multiple element arrangements, the Company considers whether the deliverables under the arrangement represent separate units of accounting. This evaluation requires subjective determinations and requires management to make judgments about the individual deliverables and whether such deliverables are separable from the other aspects of the contractual relationship. In determining the units of accounting, management evaluates certain criteria, including whether the deliverables have standalone value, based on the consideration of the relevant facts and circumstances for each arrangement. The consideration received is allocated among the separate units of accounting using the relative selling price method, and the applicable revenue recognition criteria are applied to each of the separate units.
	The Company determines the estimated selling price for deliverables within each agreement using vendor-specific objective evidence (“VSOE”) of selling price, if available, third-party evidence (“TPE”) of selling price if VSOE is not available, or best estimate of selling price if neither VSOE nor TPE is available. Determining the best estimate of selling price for a deliverable requires significant judgment. The Company typically uses best estimate of selling price to estimate the selling price for licenses to the Company’s proprietary technology, since the Company often does not have VSOE or TPE of selling price for these deliverables. In those circumstances where the Company utilizes best estimate of selling price to determine the estimated selling price of a license to the Company’s proprietary technology, the Company considers market conditions as well as entity-specific factors, including those factors contemplated in negotiating the agreements and internally developed models that include assumptions related to the market opportunity, estimated development costs, probability of success and the time needed to commercialize a product candidate pursuant to the license. In validating the Company’s best estimate of selling price, the Company evaluates whether changes in the key assumptions used to determine the best estimate of selling price will have a significant effect on the allocation of arrangement consideration among multiple deliverables.
	The Company typically receives non-refundable up-front payments when licensing its intellectual property in conjunction with a research and development agreement. When management believes the license to its intellectual property does not have stand-alone value from the other deliverables to be provided in the arrangement, the Company generally recognizes revenue attributed to the license on a straight-line basis over the Company’s contractual or estimated performance period, which is typically the term of the Company’s research and development obligations. If management cannot reasonably estimate when the Company’s performance obligation ends, then revenue is deferred until management can reasonably estimate when the performance obligation ends. When management believes the license to its intellectual property has stand-alone value, the Company generally recognizes revenue attributed to the license upon delivery. The periods over which revenue should be recognized are subject to estimates by management and may change over the course of the research and development agreement. Such a change could have a material impact on the amount of revenue the Company records in future periods.
	Payments or reimbursements resulting from the Company’s research and development efforts for those arrangements where such efforts are considered as deliverables are recognized as the services are performed and are presented on a gross basis so long as there is persuasive evidence of an arrangement, the fee is fixed or determinable, and collection of the related receivable is reasonably assured. Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the accompanying balance sheets.
	At the inception of each agreement that includes milestone payments, the Company evaluates whether each milestone is substantive and at risk to both parties on the basis of the contingent nature of the milestone. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance, and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required to achieve the respective milestone and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment.
	The Company aggregates its milestones into four categories: (i) clinical and development milestones, (ii) regulatory milestones, (iii) commercial milestones, and (iv) patent-related milestones. Clinical and development milestones are typically achieved when a product candidate advances into a defined phase of clinical research or completes such phase. For example, a milestone payment may be due to the Company upon the initiation of a phase 3 clinical trial for a new indication, which is the last phase of clinical development and could eventually contribute to marketing approval by the U.S. Food and Drug Administration (“FDA”) or other global regulatory authorities. Regulatory milestones are typically achieved upon acceptance of the submission for marketing approval of a product candidate or upon approval to market the product candidate by the FDA or other global regulatory authorities. For example, a milestone payment may be due to the Company upon the FDA’s acceptance of a New Drug Application (“NDA”). Commercial milestones are typically achieved when an approved pharmaceutical product reaches certain defined levels of net sales by the licensee, such as when a product first achieves global sales or annual sales of a specified amount. Patent-related milestones are typically achieved when a patent application is filed or a patent is issued with respect to certain intellectual property related to the applicable collaboration.

	Revenues from clinical and development, regulatory and patent-related milestone payments, if the milestones are deemed substantive and the milestone payments are nonrefundable, are recognized upon successful accomplishment of the milestones. The Company has concluded that the clinical and development, regulatory and patent-related milestones pursuant to its research and development arrangements are substantive. Milestones that are not considered substantive are accounted for as license payments and recognized on a straight-line basis over the remaining period of performance. Revenues from commercial milestone payments are accounted for as royalties and are recorded as revenue upon achievement of the milestone, assuming all other revenue recognition criteria are met.
Principles of Consolidation	'
	Principles of Consolidation
	The Company’s condensed consolidated financial statements include the Company’s accounts and the accounts of the Company’s subsidiaries, AVEO Pharma Limited and AVEO Securities Corporation, both of which are wholly-owned. All intercompany transactions have been eliminated.
Research and Development Expenses	'
	Research and Development Expenses
	Research and development expenses are charged to expense as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including personnel-related costs such as salaries and stock-based compensation, facilities, research-related overhead, clinical trial costs, manufacturing costs and costs of other contracted services, license fees, and other external costs.
	Nonrefundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received in accordance with the provisions of Accounting Standards Codification (“ASC”) 730, Research and Development.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents at September 30, 2013 consisted of money market funds and corporate debt securities, including commercial paper, maintained by an investment manager. Cash equivalents at December 31, 2012 consisted of money market funds, asset-backed commercial paper, and corporate debt securities, including commercial paper, maintained by an investment manager.
Marketable Securities	'
	Marketable Securities
	Marketable securities at September 30, 2013 consisted of U.S. government agency securities, asset-backed securities, and corporate debt securities, including commercial paper, maintained by an investment manager. Marketable securities at December 31, 2012 consisted of municipal bonds, asset-backed commercial paper, asset-backed securities, and corporate debt securities, including commercial paper, maintained by an investment manager. Credit risk is reduced as a result of the Company’s policy to limit the amount invested in any one issue. Marketable securities consist primarily of investments which have expected average maturity dates in excess of three months, but not longer than 24 months. The Company classifies these investments as available-for-sale. Unrealized gains and losses are included in other comprehensive (loss) income until realized. The cost of securities sold is based on the specific identification method. There were no realized gains or losses recognized on the sale or maturity of securities during the three and nine months ended September 30, 2013 and 2012.

	Available-for-sale securities at September 30, 2013 and December 31, 2012 consist of the following:


			Amortized		Unrealized			Unrealized			Fair
			Cost		Gains			Losses			Value
			(in thousands)
	September 30, 2013:
	Corporate debt securities		$	45,247	$	15		$	(5	)	$	45,257
	Government agency securities			15,787		2			—			15,789
	Asset-backed securities			18,900		—			(4	)		18,896

			$	79,934	$	17		$	(9	)	$	79,942

	December 31, 2012:
	Corporate debt securities		$	58,751	$	16		$	(11	)	$	58,756
	Municipal bonds			10,545		—			—			10,545
	Asset-backed securities			6,359		—			—			6,359
	Asset-backed commercial paper			8,806		2			—			8,808

			$	84,461	$	18		$	(11	)	$	84,468

	The aggregate fair value of securities in an unrealized loss position for less than 12 months at September 30, 2013 was $26.0 million, representing fourteen securities. There were no securities that were in an unrealized loss position for greater than 12 months at September 30, 2013. The unrealized loss was caused by a temporary change in the market for those securities primarily caused by changes in market interest rates. There was no change in the credit risk of the securities. To determine whether an other-than-temporary impairment exists, the Company performs an analysis to assess whether it intends to sell, or whether it would more likely than not be required to sell, the security before the expected recovery of the amortized cost basis of the security. Where the Company intends to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is recorded in the statement of operations as an other-than-temporary impairment charge. When this is not the case, the Company performs additional analyses on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where the Company does not expect to receive cash flows, based on using a single best estimate, sufficient to recover the amortized cost basis of a security and are recognized in other income (expense), net. The Company does not believe an other-than temporary impairment exists with respect to those securities in an unrealized loss position at September 30, 2013.
	Marketable securities in an unrealized loss position at September 30, 2013 and December 31, 2012 consist of the following:


			Aggregate		Unrealized
			Fair Value		Losses
			(in thousands)
	September 30, 2013:
	Corporate debt securities		$	10,259	$	(5	)
	Government agency securities			1,619		—
	Asset-backed securities			14,078		(4	)

			$	25,956	$	(9	)

	December 31, 2012:
	Corporate debt securities		$	29,806	$	(11	)
	Asset-backed securities			6,359		—

			$	36,165	$	(11	)

Concentrations of Credit Risk	'
	Concentrations of Credit Risk
	Financial instruments that potentially subject the Company to credit risk primarily consist of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits.
	Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

	The Company’s credit risk related to marketable securities is reduced as a result of the Company’s policy to limit the amount invested in any one issue.
Fair Value Measurements	'
	Fair Value Measurements
	The Company records cash equivalents and marketable securities at fair value. ASC 820, Fair Value Measurements and Disclosures, establishes a fair value hierarchy for those instruments measured at fair value that distinguishes between fair value measurements based on market data (observable inputs) and those based on the Company’s own assumptions (unobservable inputs). The hierarchy consists of three levels:

		•		Level 1—Quoted market prices in active markets for identical assets or liabilities. Assets utilizing Level 1 inputs include money market funds.

		•		Level 2—Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Assets utilizing Level 2 inputs include U.S. government agency securities, municipal bonds, asset-backed securities, asset-backed commercial paper, and corporate bonds, including commercial paper. These investments have been initially valued at the transaction price and are subsequently valued, at the end of each reporting period, utilizing third party pricing services or other observable market data. The pricing services utilize industry standard valuation models, including both income and market based approaches and observable market inputs to determine value. These observable market inputs include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events. The Company validates the prices provided by third party pricing services by reviewing their pricing methods and matrices, obtaining market values from other pricing sources, analyzing pricing data in certain instances and confirming that the relevant markets are active. After completing its validation procedures, the Company did not adjust or override any fair value measurements provided by pricing services as of September 30, 2013 or December 31, 2012.

		•		Level 3—Unobservable inputs developed using estimates and assumptions developed by the Company, which reflect those that a market participant would use. The Company currently has no assets or liabilities recorded at fair value that utilize Level 3 inputs.
	The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis in the accompanying consolidated balance sheets as of September 30, 2013 and December 31, 2012.


			Fair Value Measurements of Cash Equivalents and
			Marketable Securities as of September 30, 2013
			Level 1		Level 2			Level 3			Total
			(in thousands)
	Cash equivalents		$	38,490	$	6,076		$	—		$	44,566
	Marketable securities			—		79,942			—			79,942

			$	38,490	$	86,018		$	—		$	124,508



			Fair Value Measurements of Cash Equivalents and
			Marketable Securities as of December 31, 2012
			Level 1		Level 2			Level 3			Total
			(in thousands)
	Cash equivalents		$	51,182	$	18,121		$	—		$	69,303
	Marketable securities			—		84,468			—			84,468

			$	51,182	$	102,589		$	—		$	153,771

	The carrying amounts of the Company’s financial instruments not required to be measured at fair value, which include accounts receivable and accounts payable, approximate their fair values at September 30, 2013 and December 31, 2012.
	The fair value of the Company’s loans payable at September 30, 2013, computed pursuant to a discounted cash flow technique using the effective interest rate under the loan, is $22.4 million and is considered a level 2 fair value measurement. The effective interest rate considers the fair value of the warrant issued in connection with the loan, loan issuance costs and a deferred financing charge, which approximates a market interest rate.
Property and Equipment	'
	Property and Equipment
	Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the respective assets. Maintenance and repair costs are charged to expense as incurred.
Long-lived Assets	'
	Long-lived Assets
	The Company reviews long-lived assets, including property and equipment, for impairment whenever changes in business circumstances indicate that the carrying amount of the asset may not be fully recoverable. The Company recognized $0.1 million of impairment losses during the nine months ending September 30, 2013.
Basic and Diluted Loss per Common Share	'
	Basic and Diluted Loss per Common Share
	Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the reporting period. Diluted net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding and potentially dilutive common share equivalents outstanding during the period. Potentially dilutive common share equivalents consist of the incremental common shares issuable upon the exercise of stock options and warrants. Since the Company had a net loss for all periods presented, the effect of all potentially dilutive securities is anti-dilutive. Accordingly, under generally accepted accounting principles in the United States (“GAAP”), basic and diluted net loss per common share is presented as the same value.
	The following table sets forth for the periods presented the potentially dilutive common share equivalents (prior to consideration of the treasury stock method) excluded from the calculation of net loss per common share because their inclusion would have been anti-dilutive:


			Three Months Ended					Nine Months Ended
			September 30,					September 30,
			2013		2012			2013			2012
			(in thousands)
	Weighted average options outstanding			5,819		4,794			5,638			4,629
	Weighted average warrants outstanding			3		10			8			10

				5,822		4,804			5,646			4,639

Stock-Based Compensation	'
	Stock-Based Compensation
	The Company applies the provisions of ASC 718, Compensation-Stock Compensation (“ASC 718”), to share-based awards. All awards are recognized in the Company’s statements of operations on a straight-line basis over their requisite service periods. Equity-classified awards are measured based on the grant date fair values of the awards calculated using the measurement and recognition provisions of ASC 718. During the three and nine months ended September 30, 2013 and 2012, respectively, the Company recorded the following stock-based compensation expense for equity-classified awards:


			Three Months Ended					Nine Months Ended
			September 30,					September 30,
			2013		2012			2013			2012
			(in thousands)
	Research and development		$	530	$	972		$	1,677		$	2,801
	General and administrative			534		1,076			1,365			3,309

			$	1,064	$	2,048		$	3,042		$	6,110

	Liability-classified awards are re-measured to the award’s fair value as of each balance sheet date until settled. The Company recorded $34,000 and $0.1 million in compensation expense for liability-classified awards during the three and nine months ended September 30, 2013, respectively. No costs associated with liability-classified awards were recognized during 2012.
	Allocations to research and development and general and administrative expense are based upon the department to which the associated employee to whom the award was granted reported. No related tax benefits of the stock-based compensation expense have been recognized. Share-based awards issued to nonemployees are recorded at their fair values, and are periodically revalued as the equity instruments vest and are recognized as expense over the related service period.
Income Taxes	'
	Income Taxes
	The Company provides for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities, and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse.

	The Company accounts for income taxes under ASC 740, Income Taxes, which provides a comprehensive model for the financial statement recognition, measurement, presentation and disclosure of uncertain tax positions taken or expected to be taken in income tax returns. Unrecognized tax benefits represent tax positions for which reserves have been established.
Segment and Geographic Information	'
	Segment and Geographic Information
	Operating segments are defined as components of an enterprise engaging in business activities for which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment, principally in the United States. The Company has $1.0 million of net assets located in the United Kingdom.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Recently Adopted Accounting Pronouncements	'
	Recently Adopted Accounting Pronouncements
	In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This newly issued accounting standard requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement where net income (loss) is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income (loss) but only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures required under GAAP that provide additional detail about those amounts. This ASU is effective for reporting periods beginning after December 15, 2012. The Company adopted this standard in the first quarter of 2013 and presents this information in the condensed consolidated financial statements. The adoption of this standard did not have an impact on the Company’s financial position or results of operations.
	For a discussion of other recent accounting pronouncements adopted by the Company, please refer to Note 2, “Significant Accounting Policies,” included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012, filed with the SEC on March 11, 2013. The Company did not adopt any new accounting pronouncements during the nine months ended September 30, 2013 that had a material effect on the Company’s condensed consolidated financial statements.
Subsequent Events	'
	Subsequent Events
	The Company has evaluated all events or transactions that occurred after September 30, 2013 through the date the Company issued these financial statements.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	9 Months Ended
Significant Accounting Policies (Tables)	Sep. 30, 2013
Available-For-Sale Securities	'
	Available-for-sale securities at September 30, 2013 and December 31, 2012 consist of the following:


		Amortized		Unrealized			Unrealized			Fair
		Cost		Gains			Losses			Value
		(in thousands)
	September 30, 2013:
	Corporate debt securities	$	45,247	$	15		$	(5	)	$	45,257
	Government agency securities		15,787		2			—			15,789
	Asset-backed securities		18,900		—			(4	)		18,896

		$	79,934	$	17		$	(9	)	$	79,942

	December 31, 2012:
	Corporate debt securities	$	58,751	$	16		$	(11	)	$	58,756
	Municipal bonds		10,545		—			—			10,545
	Asset-backed securities		6,359		—			—			6,359
	Asset-backed commercial paper		8,806		2			—			8,808

		$	84,461	$	18		$	(11	)	$	84,468

Marketable Securities in Unrealized Loss Position	'
	Marketable securities in an unrealized loss position at September 30, 2013 and December 31, 2012 consist of the following:


		Aggregate		Unrealized
		Fair Value		Losses
		(in thousands)
	September 30, 2013:
	Corporate debt securities	$	10,259	$	(5	)
	Government agency securities		1,619		—
	Asset-backed securities		14,078		(4	)

		$	25,956	$	(9	)

	December 31, 2012:
	Corporate debt securities	$	29,806	$	(11	)
	Asset-backed securities		6,359		—

		$	36,165	$	(11	)

Summary of Cash Equivalents and Marketable Securities Measured at Fair Value on Recurring Basis	'
	The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis in the accompanying consolidated balance sheets as of September 30, 2013 and December 31, 2012.


		Fair Value Measurements of Cash Equivalents and
		Marketable Securities as of September 30, 2013
		Level 1		Level 2			Level 3			Total
		(in thousands)
	Cash equivalents	$	38,490	$	6,076		$	—		$	44,566
	Marketable securities		—		79,942			—			79,942

		$	38,490	$	86,018		$	—		$	124,508



		Fair Value Measurements of Cash Equivalents and
		Marketable Securities as of December 31, 2012
		Level 1		Level 2			Level 3			Total
		(in thousands)
	Cash equivalents	$	51,182	$	18,121		$	—		$	69,303
	Marketable securities		—		84,468			—			84,468

		$	51,182	$	102,589		$	—		$	153,771

Potential Dilutive Common Share Equivalents Excluded from Calculation of Net Loss Per Common Share	'
	The following table sets forth for the periods presented the potentially dilutive common share equivalents (prior to consideration of the treasury stock method) excluded from the calculation of net loss per common share because their inclusion would have been anti-dilutive:


		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013		2012			2013			2012
		(in thousands)
	Weighted average options outstanding		5,819		4,794			5,638			4,629
	Weighted average warrants outstanding		3		10			8			10

			5,822		4,804			5,646			4,639

Stock-Based Compensation Expense for Equity-Classified Awards	'
	During the three and nine months ended September 30, 2013 and 2012, respectively, the Company recorded the following stock-based compensation expense for equity-classified awards:


		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013		2012			2013			2012
		(in thousands)
	Research and development	$	530	$	972		$	1,677		$	2,801
	General and administrative		534		1,076			1,365			3,309

		$	1,064	$	2,048		$	3,042		$	6,110

Accrued_Expenses_Tables

Accrued Expenses (Tables)	9 Months Ended
Accrued Expenses (Tables)	Sep. 30, 2013
Accrued Expenses	'
	Accrued expenses consisted of the following as of September 30, 2013 and December 31, 2012:


		September 30,		December 31,
		2013		2012
		(in thousands)
	Clinical expenses	$	7,154	$	6,688
	Salaries and benefits		2,336		6,015
	Restructuring		838		1,653
	Professional fees		595		430
	Accrued interest		217		275
	Medical affairs		104		583
	Collaboration expenses		—		1,807
	Pre-commercialization expenses		—		924
	Other		910		1,168

		$	12,154	$	19,543

Loans_Payable_Tables

Loans Payable (Tables)	9 Months Ended
Loans Payable (Tables)	Sep. 30, 2013
Future Minimum Payments Under Loans Payable	'
	Future minimum payments under the loans payable outstanding as of September 30, 2013 are as follows (amounts in thousands):


	Years Ending December 31:
	2013 (3 months remaining)		3,077
	2014		13,546
	2015		9,309

			25,932
	Less amount representing interest		(2,855	)
	Less discount		(247	)
	Less deferred charges		(1,238	)
	Less current portion		(10,043	)

	Loans payable, net of current portion	$	11,549

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	9 Months Ended
Stock-based Compensation (Tables)	Sep. 30, 2013
Stock Option Activity	'
	A summary of the status of the Company’s stock option activity at September 30, 2013 and changes during the nine months then ended is presented in the table and narrative below:


		Options			Weighted-		Weighted-		Aggregate
					Average		Average		Intrinsic Value
					Exercise Price		Remaining
							Contractual
							Term
	Outstanding at December 31, 2012		4,638,388		$	9.86
	Granted		2,709,840		$	4.96
	Exercised		(139,903	)	$	1.37
	Forfeited		(1,983,719	)	$	10.26

	Outstanding at September 30, 2013		5,224,606		$	7.4		6.41	$	210,279

	Vested or expected to vest at September 30, 2013		4,518,190		$	7.8		5.95	$	210,279

	Exercisable at September 30, 2013		3,029,547		$	8.55		4.42	$	210,279

Assumptions used in Black-Scholes Pricing Model for New Grants	'
	During the three and nine months ended September 30, 2013 and 2012, respectively, the assumptions used in the Black-Scholes pricing model for new grants were as follows:


		Three Months Ended
		September 30,
		2013		2012
	Volatility factor	71.13%		64.84%
	Expected term (in years)	6.25		6.25
	Risk-free interest rates	1.72%		0.83%
	Dividend yield	—		—


		Nine Months Ended
		September 30,
		2013		2012
	Volatility factor	64.22-72.65%		64.30-64.94%
	Expected term (in years)	5.50-6.25		5.50-6.25
	Risk-free interest rates	1.01-1.71%		0.83-1.33%
	Dividend yield	—		—
Restricted Stock Activity	'
	The restricted stock activity for the nine months ended September 30, 2013 is as follows:


		Number of Shares			Weighted-
					Average
					Fair Value
	Unvested at December 31, 2012		245,020		$	13.31
	Granted		689,678			5.23
	Cancelled		(172,280	)		9.14
	Expired		—			—
	Vested/Released		(32,500	)		14.16

	Unvested at September 30, 2013		729,918		$	6.62

Strategic_Restructurings_Table

Strategic Restructurings (Tables)	9 Months Ended
	Sep. 30, 2013
Restructuring Activity Recorded in Operating Expenses and Accrued Expenses	'
	The following table summarizes the components of the Company’s restructuring activity recorded in operating expenses and in accrued expenses in the accompanying condensed consolidated balance sheet:


		Restructuring		Restructuring		Restructuring			Restructuring
		amounts accrued at		expense		amounts			amounts
		December 31,		incurred		paid			accrued at
		2012		during the nine		during the nine			September 30,
				months ended		months ended			2013
				September 30,		September 30,
				2013		2013
		(in thousands)
	Employee severance, benefits and related costs.	$	1,653	$	7,618	$	(8,488	)	$	783
	Contract termination costs		—		82		(27	)		55

	Total		1,653		7,700		(8,515	)		838

Organization_Additional_Inform

Organization - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Organization [Line Items]	'	'
Accumulated deficit	($410,564)	($320,260)

Significant_Accounting_Policie3

Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
Significant Accounting Policies [Line Items]	'	'
Available for sale securities, aggregate fair value of securities in an unrealized loss position for less than 12 months	$26,000,000	$26,000,000
Impairment losses	'	100,000
Number of operating segments	'	1
Available For Sale Securities, Continuous Unrealized Loss Positions, Less Than 12 Months	'	'
Significant Accounting Policies [Line Items]	'	'
Available for sale securities, number of securities in an unrealized loss position	14	14
Liability Classified Awards	'	'
Significant Accounting Policies [Line Items]	'	'
Stock-based compensation expense	34,000	100,000
UNITED KINGDOM	'	'
Significant Accounting Policies [Line Items]	'	'
Net assets located in the United Kingdom	1,000,000	1,000,000
Level 2	'	'
Significant Accounting Policies [Line Items]	'	'
Fair value of loan payable	$22,400,000	$22,400,000
Minimum	'	'
Significant Accounting Policies [Line Items]	'	'
Marketable securities maturity term	'3 months	'3 months
Maximum	'	'
Significant Accounting Policies [Line Items]	'	'
Marketable securities maturity term	'24 months	'24 months

Available_for_Sale_Securities_

Available for Sale Securities (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$79,934	$84,461
Unrealized Gains	17	18
Unrealized Losses	-9	-11
Fair Value	79,942	84,468
Corporate debt securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	45,247	58,751
Unrealized Gains	15	16
Unrealized Losses	-5	-11
Fair Value	45,257	58,756
Government agency securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	15,787	'
Unrealized Gains	2	'
Fair Value	15,789	'
Municipal Bonds	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	'	10,545
Fair Value	'	10,545
Asset-backed Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	18,900	6,359
Unrealized Losses	-4	'
Fair Value	18,896	6,359
Asset-backed Securities \| Commercial Paper	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	'	8,806
Unrealized Gains	'	2
Fair Value	'	$8,808

Marketable_Securities_in_Unrea

Marketable Securities in Unrealized Loss Position (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Investments, Unrealized Loss Position [Line Items]	'	'
Aggregate Fair Value	$25,956	$36,165
Unrealized Losses	-9	-11
Corporate debt securities	'	'
Investments, Unrealized Loss Position [Line Items]	'	'
Aggregate Fair Value	10,259	29,806
Unrealized Losses	-5	-11
Government agency securities	'	'
Investments, Unrealized Loss Position [Line Items]	'	'
Aggregate Fair Value	1,619	'
Asset-backed Securities	'	'
Investments, Unrealized Loss Position [Line Items]	'	'
Aggregate Fair Value	14,078	6,359
Unrealized Losses	($4)	'

Summary_of_Cash_Equivalents_an

Summary of Cash Equivalents and Marketable Securities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable securities	$79,942	$84,468
Fair Value, Measurements, Recurring	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	44,566	69,303
Marketable securities	79,942	84,468
Cash Equivalents, and Marketable Securities Fair Value Disclosure, Total	124,508	153,771
Fair Value, Measurements, Recurring \| Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	38,490	51,182
Cash Equivalents, and Marketable Securities Fair Value Disclosure, Total	38,490	51,182
Fair Value, Measurements, Recurring \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	6,076	18,121
Marketable securities	79,942	84,468
Cash Equivalents, and Marketable Securities Fair Value Disclosure, Total	$86,018	$102,589

Potential_Dilutive_Common_Shar

Potential Dilutive Common Share Equivalents Excluded from Calculation of Net Loss Per Common Share (Detail)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share amount	5,822	4,804	5,646	4,639
Stock Options	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share amount	5,819	4,794	5,638	4,629
Warrant	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share amount	3	10	8	10

Stock_Based_Compensation_Expen

Stock Based Compensation Expense for Equity-Classified Awards (Detail) (Equity-classified awards, USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expense	$1,064,000	$2,048,000	$3,042,000	$6,110,000
Research and development	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expense	530,000	972,000	1,677,000	2,801,000
General and administrative	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expense	$534,000	$1,076,000	$1,365,000	$3,309,000

Collaborations_and_License_Agr1

Collaborations and License Agreements - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

12 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Feb. 28, 2011

Mar. 31, 2011

Sep. 30, 2013

Feb. 28, 2011

Mar. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2011

Feb. 28, 2011

Dec. 31, 2012

Feb. 28, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jul. 30, 2011

Mar. 31, 2010

Jun. 30, 2009

Mar. 31, 2009

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2009

Jul. 31, 2009

Jul. 31, 2011

Jul. 31, 2009

Sep. 30, 2013

Sep. 30, 2007

Dec. 31, 2012

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Mar. 31, 2010

Dec. 31, 2006

Dec. 31, 2011

Astellas Pharma Inc.

Biogen Idec International GmbH

OSI Pharmaceuticals, Inc.

Centocor Ortho Biotech Inc.

Kirin Brewery Co. Ltd.

Collaborative Arrangements, Co-promotion Agreement, Agreement

Option and License Agreement

July 2009 expanded agreement

Collaboration and License Agreement

Licensing Agreements

Collaboration and License Agreement

Licensing Agreements

North America

Europe

License Deliverable

Royalty Territory Deliverable

Up-front Payment Arrangement

Substantive Milestones

Regulatory Milestone Events

Sales Events Milestone

research and development funding

Clinical Development and Regulatory Milestone

Research and development

General and administrative

Series E Convertible Preferred Stock

Up-front Payment Arrangement

Premium on Sale of Stock

Option Exercise

Minimum

Series E Convertible Preferred Stock

Option Exercise

Substantive Milestones

Regulatory Milestone Events

Sales Events Milestone

Biomarker Related Milestones

Series C Convertible Preferred Stock

Up-front Payment Arrangement

Patent related milestone

Clinical and development milestone

Up-front Payment Arrangement

Series E Convertible Preferred Stock

Common Stock

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborations and license agreements, rights and obligations

'The Company will have lead responsibility for formulating the commercialization strategy for North America under the joint commercialization plan, with each of the Company and Astellas responsible for conducting 50% of the sales efforts and medical affairs activities in North America. Astellas will have lead responsibility for commercialization activities in Europe under the joint commercialization plan, with each of the Company and Astellas responsible for conducting 50% of the medical affairs activities in the major European countries.

Percent of the sales efforts and medical affairs activities conducted by each of the Company and counter party entity

50.00%

Collaborations and license agreements, payment received

$125,000,000

$75,000,000

$15,000,000

$50,000,000

$5,000,000

$12,500,000

$7,500,000

Collaborations and license agreements, net proceeds

97,600,000

Collaborations and license agreements, expected milestone receivable

1,200,000,000

325,000,000

788,000,000

65,000,000

25,000,000

45,000,000

46,000,000

8,400,000

20,700,000

17,500,000

24,000,000

7,000,000

2,000,000

Collaborations and license agreements, royalties payment on net sales

30.00%

Collaborations and license agreements, description of expiry term

'the Astellas Agreement expires (a)B with respect to the Royalty Territory, on a country by-country basis, upon the latest to occur of: (i)B the expiration of the last-to-expire valid claim of an AVEO patent or joint patent covering the composition of tivozanib, (ii)B the expiration of the last-to-expire valid claim of an AVEO patent or joint patent covering the use of tivozanib, but only for so long as no generic competition exists in such country, and (iii)B twelve years from first commercial sale of tivozanib in such country, and (b)B with respect to North America and Europe as a whole, upon the expiration of all payment obligations between the parties related to development and commercialization of tivozanib in North America and Europe. After the second anniversary of the effective date of the Astellas Agreement, Astellas has the right to terminate the Astellas Agreement, in its entirety or solely with respect to the Royalty Territory, at any time upon 180 days prior written notice to the Company.

Collaborations and license agreements, time period from first commercial sale of certain product upon which the agreement expires

'12 years

Collaborations and license agreements, written notice period for at will termination

'180 days

Collaborations and license agreements, termination

'30 days

Payments received and recorded as a reduction to expense pursuant to cost-sharing provisions

2,300,000

7,500,000

14,900,000

22,900,000

400,000

2,700,000

1,900,000

Amounts due from Astellas pursuant to the cost-sharing provisions

8,893,000

20,649,000

8,900,000

Collaborations and license agreements, relative selling price of the deliverable

125,000,000

120,200,000

4,800,000

Collaborations and license agreements, revenue recognized

120,200,000

100,000

300,000

200,000

600,000

8,200,000

25,000,000

Collaborations and license agreements, deferred revenue

4,800,000

Collaborations and license agreements, deferred revenue recognition period

'Through April 2022

Shares of stock sold, number of shares

7,500,000

3,750,000

1,833,334

438,340

Shares of stock sold, price per shares

$17.11

Proceeds from issuance of Convertible Preferred Stock

30,000,000

Reverse stock split, ratio

0.25

Reverse stock split, number of shares of outstanding stock converted into one share of common stock

Shares of stock sold, discount (premium) over the fair value per share

$1.09

Fair value of stock calculated in retrospective stock valuation

$2.91

Collaborations and license agreements, milestone payment received

5,000,000

250,000

750,000

Shares of stock sold, value of shares

7,500,000

Revenue

323,000

1,018,000

970,000

3,755,000

700,000

1,800,000

Collaborations and license agreements, cash payment

Collaborations and license agreements, milestone payment

12,000,000

10,000,000

Research and development expense

19,414,000

21,099,000

56,579,000

67,325,000

22,500,000

Reimbursement cost

$6,000,000

Collaborations and license agreements, potential future payment as percentage of certain amounts the Company receives under the Astellas Agreement

30.00%

Accrued_Expenses_Detail

Accrued Expenses (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Accrued Liabilities [Line Items]	'	'
Clinical expenses	$7,154	$6,688
Salaries and benefits	2,336	6,015
Restructuring	838	1,653
Professional fees	595	430
Accrued interest	217	275
Collaboration expenses	'	1,807
Pre-commercialization expenses	'	924
Other	910	1,168
Accrued expenses	12,154	19,543
Medical affairs	'	'
Schedule of Accrued Liabilities [Line Items]	'	'
Accrued expenses	$104	$583

Loans_Payable_Additional_Infor

Loans Payable - Additional Information (Detail) (USD $)	1 Months Ended			9 Months Ended
	Apr. 30, 2011	Jun. 30, 2010	31-May-10	Sep. 30, 2013	Mar. 31, 2012	31-May-11	Jun. 02, 2010	28-May-10
	Apr. 30, 2011	Jun. 30, 2010	31-May-10	Sep. 30, 2013	Mar. 31, 2012	Installment	Y	Installment
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'
Loan payable, aggregate principal amount	'	'	'	'	$26,500,000	'	'	$25,000,000
Loan payable, number of installments of principal	'	'	'	'	'	30	'	30
Loan payable, start date of first principal payment	1-Apr-13	'	1-Apr-11	'	'	'	'	'
Loan payable, description of interest rate terms	'	'	'Per annum interest is payable on the principal balance of the loan at the greater of 11.9% and an amount equal to 11.9% plus the prime rate of interest minus 4.75%,	'	'	'	'	'
Loan payable, interest rate, base rate	'	'	'	'	'	'	'	11.90%
Loan payable, interest rate, additional rate deducted from base rate	'	'	'	'	'	'	'	4.75%
Loan payable, maximum per annum interest rate	'	'	15.00%	'	'	'	'	'
Loan payable, due date	'	'	1-Sep-15	'	'	'	'	'
Deferred charge related to loan	'	'	'	1,238,000	1,300,000	'	'	'
Loan issuance costs paid	'	'	193,000	'	'	'	'	'
Warrants issued to lenders as part of the new loan agreement, shares of common stock to purchase	'	'	'	'	'	'	156,641	'
Warrants issued to lenders as part of the new loan agreement, exercise price	'	'	'	'	'	'	7.98	'
Warrants issued to lenders as part of the new loan agreement, expiration period (in years)	'	'	'	'	'	'	'7 years	'
Warrants issued to lenders as part of the new loan agreement, fair value	'	780,000	'	'	'	'	'	'
Assumptions used in the Black-Scholes pricing model for warrant, volatility	'	'	'	'	'	'	64.12%	'
Assumptions used in the Black-Scholes pricing model for warrant, expected term	'	'	'	'	'	'	7	'
Assumptions used in the Black-Scholes pricing model for warrant, risk-free interest rate	'	'	'	'	'	'	2.81%	'
Loan payable, effective interest rate	'	'	'	13.10%	'	'	'	'
Option to purchase equity, description	'	'	'	'Hercules also received an option, subject to the Company's written consent, not to be unreasonably withheld, to purchase, either with cash or through conversion of outstanding principal under the loan, up to $2.0 million of equity of the Company sold in any sale by the Company to third parties of equity securities resulting in at least $10.0 million in net cash proceeds to the Company, subject to certain exceptions.	'	'	'	'
Option to purchase equity, maximum amount	'	'	'	2,000,000	'	'	'	'
Loan outstanding	'	'	'	21,800,000	'	'	'	'
Minimum	'	'	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'
Loan payable, interest rate	'	'	'	'	'	'	'	11.90%
Option to purchase equity, net cash proceeds of equity securities	'	'	'	$10,000,000	'	'	'	'

Future_Minimum_Payments_Under_

Future Minimum Payments Under Loans Payable (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
2013	$3,077	'
2014	13,546	'
2015	9,309	'
Long-term Debt, Gross, Total	25,932	'
Less amount representing interest	-2,855	'
Less discount	-247	'
Less deferred charges	-1,238	'
Less current portion Loans Payable Current	-10,043	-6,809
Loans payable, net of current portion	$11,549	$19,228

Stock_Option_Activity_Detail

Stock Option Activity (Detail) (USD $)	9 Months Ended
Stock Option Activity (Detail) (USD $)	Sep. 30, 2013
Options	'
Outstanding at beginning of period	4,638,388
Granted	2,709,840
Exercised	-139,903
Forfeited	-1,983,719
Outstanding at end of period	5,224,606
Vested or expected to vest at September 30, 2013	4,518,190
Exercisable at September 30, 2013	3,029,547
Weighted-Average Exercise Price	'
Outstanding at beginning of period	$9.86
Granted	$4.96
Exercised	$1.37
Forfeited	$10.26
Outstanding at end of period	$7.40
Vested or expected to vest at September 30, 2013	$7.80
Exercisable at September 30, 2013	$8.55
Weighted-Average Remaining Contractual Term	'
Outstanding at September 30, 2013	'6 years 4 months 28 days
Vested or expected to vest at September 30, 2013	'5 years 11 months 12 days
Exercisable at September 30, 2013	'4 years 5 months 1 day
Aggregate Intrinsic Value	'
Outstanding at September 30, 2013	$210,279
Vested or expected to vest at September 30, 2013	210,279
Exercisable at September 30, 2013	$210,279

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Stock Options	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Total unrecognized stock-based compensation expense	$5.40
Total unrecognized stock-based compensation expense, weighted-average period Recognition	'2 years
Restricted Stock	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Total unrecognized stock-based compensation expense	0.1
Total unrecognized stock-based compensation expense, weighted-average period Recognition	'9 months 18 days
Share based compensation expense reversal of previously recognized expense	$2

Assumptions_Used_in_Black_Scho

Assumptions Used in Black Scholes Pricing Model for New Grants (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Volatility factor	71.13%	64.84%	'	'
Expected term (in years)	'6 years 3 months	'6 years 3 months	'	'
Risk-free interest rates	1.72%	0.83%	'	'
Dividend yield	'	'	'	'
Minimum	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Volatility factor	'	'	64.22%	64.30%
Expected term (in years)	'	'	'5 years 6 months	'5 years 6 months
Risk-free interest rates	'	'	1.01%	0.83%
Dividend yield	'	'	'	'
Maximum	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Volatility factor	'	'	72.65%	64.94%
Expected term (in years)	'	'	'6 years 3 months	'6 years 3 months
Risk-free interest rates	'	'	1.71%	1.33%
Dividend yield	'	'	'	'

Restricted_Stock_Activity_Deta

Restricted Stock Activity (Detail) (Restricted Stock, USD $)	9 Months Ended
	Sep. 30, 2013
Restricted Stock	'
Number of Shares	'
Unvested at beginning of period	245,020
Granted	689,678
Cancelled	-172,280
Expired	'
Vested/Released	-32,500
Unvested at end of period	729,918
Weighted-Average Grant-Date Fair Value	'
Unvested at beginning of period	$13.31
Granted	$5.23
Cancelled	$9.14
Expired	'
Vested/Released	$14.16
Unvested at end of period	$6.62

Strategic_Restructurings_Addit

Strategic Restructurings - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Oct. 31, 2012	Sep. 30, 2013
	Position	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring plan, expected number of positions eliminated	48	'
Restructuring, impairment charges	'	$0.30
Open Position	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring plan, expected number of positions eliminated	30	'

Restructuring_Activity_Recorde

Restructuring Activity Recorded in Operating Expenses and Accrued Expenses (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]	'
Restructuring amount accrued	$1,653
Restructuring expense incurred	7,700
Restructuring amounts paid	-8,515
Restructuring amount accrued	838
Employee Severance	'
Restructuring Cost and Reserve [Line Items]	'
Restructuring amount accrued	1,653
Restructuring expense incurred	7,618
Restructuring amounts paid	-8,488
Restructuring amount accrued	783
Contract Termination Costs	'
Restructuring Cost and Reserve [Line Items]	'
Restructuring expense incurred	82
Restructuring amounts paid	-27
Restructuring amount accrued	$55