Aveo Pharmaceuticals (AVEO) 10-K 6 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2015	Jun. 30, 2014
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	AVEO
Entity Registrant Name	AVEO PHARMACEUTICALS INC
Entity Central Index Key	1325879
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		52,138,394
Entity Public Float			$88,784,981

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$52,306	$50,826
Marketable securities		67,680
Accounts receivable	2,341	984
Tenant improvement allowance receivable		5,833
Restricted cash	2,997	598
Prepaid expenses and other current assets	1,484	2,998
Total current assets	59,128	128,919
Property and equipment, net	11,295	14,140
Other assets	239	290
Restricted cash		2,997
Total assets	70,662	146,346
Current liabilities:
Accounts payable	3,245	4,238
Accrued expenses	9,301	13,263
Lease exit obligation	4,981
Loans payable, net of discount	11,722	10,383
Deferred revenue	537	1,294
Other liabilities		1,238
Deferred rent	10,569	992
Total current liabilities	40,355	31,408
Loans payable, net of current portion and discount	8,930	8,822
Deferred revenue, net of current portion	231	17,098
Deferred rent, net of current portion		19,080
Other liabilities	540
Commitments and contingencies (Note 8)
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; 52,289 and 51,809 shares issued and outstanding at December 31, 2014 and 2013, respectively	52	52
Additional paid-in capital	500,582	497,177
Accumulated other comprehensive loss		-2
Accumulated deficit	-480,028	-427,289
Total stockholders' equity	20,606	69,938
Total liabilities and stockholders' equity	$70,662	$146,346

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	52,288,799	51,809,000
Common stock, shares outstanding	52,288,799	51,809,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Collaboration revenue	$18,123	$1,293	$19,286
Operating expenses:
Research and development	38,254	68,468	91,358
General and administrative	18,589	28,712	36,932
Restructuring and lease exit	11,729	8,017	2,633
Operating Expenses, Total	68,572	105,197	130,923
Loss from operations	-50,449	-103,904	-111,637
Other income and expense:
Other (expense) income, net	66	-123	247
Interest expense	-2,388	-3,127	-3,501
Interest income	32	125	497
Other expense, net	-2,290	-3,125	-2,757
Net loss	($52,739)	($107,029)	($114,394)
Basic and diluted net loss per share:
Net loss per share	($1.01)	($2.10)	($2.64)
Weighted average number of common shares outstanding	52,289	50,928	43,374

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net loss	($52,739)	($107,029)	($114,394)
Other comprehensive (loss) income:
Unrealized (losses) gains on available-for-sale securities	2	-9	174
Foreign currency translation adjustment		26	-26
Comprehensive loss	($52,737)	($107,012)	($114,246)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Equity-classified awards	Liability Classified Awards	follow-on stock offering	Common Shares	Common Shares	Common Shares	Additional Paid-in Capital	Additional Paid-in Capital	Additional Paid-in Capital	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
In Thousands, except Share data	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	Liability Classified Awards	follow-on stock offering	USD ($)	Equity-classified awards	Liability Classified Awards	follow-on stock offering	USD ($)	USD ($)
							USD ($)		USD ($)	USD ($)	USD ($)
Beginning Balance at Dec. 31, 2011	$223,541				$43			$429,531				($167)	($205,866)
Beginning Balance (in shares) at Dec. 31, 2011					43,254,000
Exercise of stock options (in shares)					220,000
Exercise of stock options	826				1			825
Stock-based compensation expense	8,007							8,007
Issuance of common stock under employee stock purchase plan (in shares)					95,000
Issuance of common stock under employee stock purchase plan	810							810
Issuance of restricted stock awards, net of forfeitures					211,000
Change in unrealized gain/loss on investments	174											174
Cumulative translation adjustment	-26											-26
Net loss	-114,394												-114,394
Ending Balance at Dec. 31, 2012	118,938				44			439,173				-19	-320,260
Ending Balance (in shares) at Dec. 31, 2012					43,780,000
Issuance of common stock to settle liability-classified share awards granted to directors (in shares)						39,000
Issuance of common stock to settle liability-classified share awards granted to directors			119							119
Exercise of stock options (in shares)					185,000
Exercise of stock options	272				1			271
Stock-based compensation expense		3,791							3,791
Issuance of common stock under employee stock purchase plan (in shares)					110,000
Issuance of common stock under employee stock purchase plan	193							193
Issuance of common stock (in shares)							7,667,000
Issuance of common stock				53,637			7				53,630
Issuance of restricted stock awards, net of forfeitures					28,000
Change in unrealized gain/loss on investments	-9											-9
Cumulative translation adjustment	26											26
Net loss	-107,029												-107,029
Ending Balance at Dec. 31, 2013	69,938				52			497,177				-2	-427,289
Ending Balance (in shares) at Dec. 31, 2013					51,809,000
Issuance of common stock to settle liability-classified share awards granted to directors (in shares)						31,000
Issuance of common stock to settle liability-classified share awards granted to directors			51							51
Stock-based compensation expense		2,750							2,750
Issuance of common stock under employee stock purchase plan (in shares)					139,000
Issuance of common stock under employee stock purchase plan	191							191
Issuance of warrants in connection with loans payable	413							413
Issuance of restricted stock awards, net of forfeitures					310,000
Change in unrealized gain/loss on investments	2											2
Net loss	-52,739												-52,739
Ending Balance at Dec. 31, 2014	$20,606				$52			$500,582					($480,028)
Ending Balance (in shares) at Dec. 31, 2014					52,289,000

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (follow-on stock offering, Additional Paid-in Capital, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
follow-on stock offering | Additional Paid-in Capital
Issuance of common stock, issuance costs	$3,865

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net loss	($52,739)	($107,029)	($114,394)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,219	3,775	2,510
Net (gain) loss on disposal of property and equipment	-127	83	42
Impairment of property and equipment	7,600	65
Stock-based compensation	2,808	3,940	8,007
Non-cash interest expense	347	285	380
Amortization of premiums and discounts on investments	221	1,041	2,446
Changes in operating assets and liabilities:
Accounts receivable	-1,357	19,665	-13,439
Tenant improvement allowance receivable	5,833	-2,593	-3,180
Prepaid expenses and other current assets	1,503	3,179	-207
Other noncurrent assets	50	31	-200
Restricted cash	598	5	-2,849
Accounts payable	-993	-6,390	1,724
Accrued expenses	-2,064	-7,838	5,254
Lease exit obligation	4,981
Deferred revenue	-17,623	-1,293	-1,293
Other liabilities			-1,249
Deferred rent	-9,505	8,672	10,719
Net cash used in operating activities	-54,248	-84,402	-105,729
Investing activities
Purchases of property and equipment	-12,942	-3,668	-9,948
Purchases of marketable securities	-42,306	-175,391	-194,584
Proceeds from maturities and sales of marketable securities	109,767	191,129	339,779
Proceeds from sale of property and equipment	191
Net cash provided by investing activities	54,710	12,070	135,247
Financing activities
Proceeds from issuance of common stock, net of issuance costs		53,637
Proceeds from issuance of stock for stock-based compensation arrangements	191	465	1,636
Proceeds from refinancing of loans payable			3,672
Proceeds from issuance of long-term debt	10,000
Payments of debt issuance cost	-1,388
Principal payments on loans payable	-7,785	-7,104	-2,172
Net cash provided by financing activities	1,018	46,998	3,136
Net increase (decrease) in cash and cash equivalents	1,480	-25,334	32,654
Effect of exchange rate changes on cash and cash equivalents		26	-26
Cash and cash equivalents at beginning of period	50,826	76,134	43,506
Cash and cash equivalents at end of period	52,306	50,826	76,134
Supplemental cash flow and noncash investing and financing activities
Cash paid for interest	2,018	2,916	3,104
Non-cash financing activity
Fair value of warrants issued in connection with long-term debt	$413

Nature_of_Business_and_Organiz

Nature of Business and Organization	12 Months Ended
	Dec. 31, 2014
Nature of Business and Organization	1	Nature of Business and Organization
	AVEO Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company committed to developing targeted therapies through biomarker insights to provide substantial improvements in patient outcomes where significant unmet medical needs exist. AVEO’s proprietary platform has delivered unique insights into cancer and related disease. AVEO’s strategy for building value is to leverage these biomarker insights and partner resources to advance the development of its clinical pipeline.
	The Company’s pipeline of product candidates includes Tivozanib, a potent, selective long half-life vascular endothelial growth factor tyrosine kinase inhibitor of all three vascular endothelial growth factors, or VEGF TKI, for which the Company previously demonstrated tivozanib’s safety and efficacy in first and second line RCC. However, the U.S. Food and Drug Administration issued a Complete Response letter denying AVEO’s application for approval of the use of tivozanib in first line advanced RCC. We are currently evaluating the opportunity for submitting a Marketing Authorization Application for tivozanib with the European Medicines Agency for the treatment of RCC based on the trials conducted to date.
	The Company also has a pipeline of monoclonal antibodies, including:
		(i)	Ficlatuzumab, a potent anti-HFG antibody that inhibits the activity of the HGF/c-Met pathway for which the Company has completed a phase 2 clinical trial, and has entered into a partnership with Biodesix, Inc. (“Biodesix”) to advance clinical development,
		(ii)	AV-203, a potent, high affinity inhibitor of ErbB3 function that has demonstrated anti-tumor activity in multiple preclinical models for which the Company has completed a phase 1 dose escalation trial,
		(iii)	AV-380, a potent humanized IgG1 inhibitory monoclonal antibody targeting growth differentiating factor-15, or GDF15, a divergent member of the TGF-ß family, for the potential treatment or prevention of cachexia. In 2012, the Company initiated a program focusing on cachexia, a serious and common complication of advanced cancer and a number of chronic diseases including chronic kidney disease, congestive heart failure and chronic obstructive pulmonary disease.
	As used throughout these consolidated financial statements, the terms “AVEO,” and the “Company”, refer to the business of AVEO Pharmaceuticals, Inc. and its subsidiaries, AVEO Pharma Limited and AVEO Securities Corporation, both of which are wholly-owned.
	The Company has an accumulated deficit as of December 31, 2014 of approximately $480.0 million, and will require substantial additional capital for research and product development. The Company believes that its existing cash and cash equivalents are sufficient to fund its operations through at least twelve months from the balance sheet date.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies	2	Significant Accounting Policies
	Revenue Recognition
	The Company’s revenues have been 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 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 current 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 consolidated financial statements include the Company’s accounts and the accounts of the Company’s wholly-owned subsidiaries, AVEO Pharma Limited and AVEO Securities Corporation. 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.
	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 December 31, 2014 consisted of money market funds, U.S. government agency securities, and corporate debt securities, including commercial paper, maintained by an investment manager totaling $36.6 million. Cash equivalents at December 31, 2013 consisted of money market funds and corporate debt securities, including commercial paper, maintained by an investment manager totaling $45.8 million. The carrying values of our cash equivalent securities approximate fair value due to their short term maturities.
	Marketable Securities
	There were no marketable securities held by the Company at December 31, 2014. Marketable securities at December 31, 2013 consisted of municipal bonds, 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 years ended December 31, 2014 and 2013.
	Available-for-sale securities at December 31, 2013 consisted of the following:
			Amortized		Unrealized			Unrealized			Fair
			Cost		Gains			Losses			Value
			(in thousands)
	Corporate debt securities (Due within 1 year)		$	52,156	$	4		$	(4	)	$	52,156
	Government agency securities (Due within 1 year)			7,519		—			—			7,519
	Asset-backed securities (Due within 1 year)			8,007		—			(2	)		8,005
			$	67,682	$	4		$	(6	)	$	67,680
	The aggregate fair value of securities in an unrealized loss position for less than 12 months at December 31, 2013 was $45.6 million, representing 18 securities. There were no securities in an unrealized loss position for greater than 12 months at December 31, 2013. The unrealized loss was caused by a temporary change in the market for these securities primarily caused by changes in markets 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. 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 these are recognized in other income (expense), net.
	Marketable securities in an unrealized loss position at December 31, 2013 consisted of the following:
			Aggregate		Unrealized
			Fair Value		Losses
			(in thousands)
	Corporate debt securities (Due within 1 year)		$	30,106	$	(4	)
	Government agency securities (Due within 1 year)			7,519		—
	Asset-backed securities (Due within 1 year)			8,005		(2	)
			$	45,630	$	(6	)
	Concentrations of Credit Risk
	Financial instruments that potentially subject the Company to credit risk primarily consist of cash, cash equivalents and available-for-sale 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. The accounting standards for fair value measurements establish a hierarchy 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 that are valued utilizing only 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 that are valued utilizing Level 2 inputs include U.S. government agency securities, asset-backed securities, 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 December 31, 2014 or December 31, 2013.
		•		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 measured at fair value on a recurring basis 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 December 31, 2014 and 2013.
			Fair Value Measurements of Cash Equivalents
			as of December 31, 2014
			Level 1		Level 2			Level 3			Total
			(in thousands)
	Cash equivalents		$	28,777	$	7,834		$	—		$	36,611
			Fair Value Measurements of Cash Equivalents and
			Marketable Securities as of December 31, 2013
			Level 1		Level 2			Level 3			Total
			(in thousands)
	Cash equivalents		$	29,865	$	15,958		$	—		$	45,823
	Marketable securities			—		67,680			—			67,680
			$	29,865	$	83,638		$	—		$	113,503
	The Company recorded a liability totaling $7.3 million associated with the exit of a portion of its leased facilities. The Company measured the fair value of the liability based on the present value of the remaining termination payments. The net cash outflows were discounted using a credit-risk adjusted rate. The Company has classified this lease liability as a Level 3 fair value measurement.
	The fair value of the Company’s loans payable at December 31, 2014 and 2013, computed pursuant to a discounted cash flow technique using the effective interest rate under the loan, was $21.3 million and $20.1 million, respectively. These fair values are considered a level 3 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 charge, which approximates a market interest rate.
	Tenant Improvement Allowance Receivable
	Under the terms of its lease agreement, the Company was entitled to be reimbursed by the Company’s landlord for certain expenditures associated with improvements made to its leased facility at 650 East Kendall Street in Cambridge, Massachusetts. Pursuant to the lease agreement, the total amount of the improvement allowance allocated to the premises was $14.9 million. Through December 2014, the Company incurred $14.9 million of such expenditures which, were partially offset against amounts due by the Company for the lease termination fee discussed in Note 8. The net proceeds were reimbursed to the Company by its landlord on September 29, 2014.
	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 $7.6 million of impairment losses for the year ended December 31, 2014 related to leasehold improvements. During the year ended December 31, 2013, the Company recognized $0.1 million of impairment losses.
Stock-Based Compensation
Under the Company’s stock-based compensation programs, the Company periodically grants stock options and restricted stock to employees, directors and nonemployee consultants. The Company also issues shares under an employee stock purchase plan. The fair value of all awards is recognized in the Company’s statements of operations over the requisite service period for each award. Awards that vest as the recipient provides service are expensed on a straight-line basis over the requisite service period. Other awards, such as performance-based awards that vest upon the achievement of specified goals, are expensed using the accelerated attribution method if achievement of the specified goals is considered probable. The Company has also granted awards that vest upon the achievement of market conditions. Per ASC 718 Share-Based Payments, market conditions must be considered in determining the estimated grant-date fair value of share-based payments and the market conditions must be considered in determining the requisite service period over which compensation cost is recognized. The Company estimates the fair value of the awards with market conditions using a Monte Carlo simulation, which utilizes several assumptions including the risk-free interest rate, the volatility of the Company’s stock and the exercise behavior of award recipients. The grant-date fair value of the awards is then recognized over the requisite service period, which represents the derived service period for the awards as determined by the Monte Carlo simulation.
The fair value of equity-classified awards to employees and directors are measured at fair value on the date the awards are granted. Awards to nonemployee consultants are recorded at their fair values and are re-measured as of each balance sheet date until the recipient’s services are complete. During the years ended December 31, 2014 and 2013, the Company recorded the following stock-based compensation expense:
		Years Ended December 31,
		2014		2013			2012
		(in thousands)
Research and development		$	899	$	1,991		$	3,566
General and administrative			1,902		1,800			4,380
Restructuring			—		—			61
Total stock-based compensation expense		$	2,801	$	3,791		$	8,007
Stock-based compensation expense is allocated to research and development and general and administrative expense based upon the department of the employee to whom each award was granted. No related tax benefits of the stock-based compensation expense have been recognized.
Income Taxes
The Company provides for income taxes using the asset-liability method. Under this method, deferred tax assets and liabilities are recognized 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. Uncertain tax positions are recognized if the position is more-likely-than-not to be sustained upon examination by a tax authority. Unrecognized tax benefits represent tax positions for which reserves have been established. The Company maintains a full valuation allowance on all deferred tax assets.
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. As of December 31, 2014, 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 accounting principles generally accepted in the United States (“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.
Recent Accounting Pronouncements
In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under US GAAP. The standard is effective for public entities for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted under US GAAP. The Company is currently evaluating what effect, if any, this standard will have on its revenue recognition policies and its financial statements, including how the standard will be adopted.
In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. This ASU is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and to provide related footnote disclosures. This guidance is effective for fiscal years beginning after December 15, 2016, with early application permitted. The Company is currently evaluating what effect, if any, the adoption of this guidance will have on the disclosures included in its consolidated financial statements.

Loss_Per_Common_Share

Loss Per Common Share	12 Months Ended
	Dec. 31, 2014
Loss Per Common Share	3	Loss Per Common Share
	Basic loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted loss per share is computed by dividing net loss by the weighted-average number of common shares and dilutive common share equivalents then outstanding which exclude unvested restricted stock. Potential common share equivalents consist of restricted stock awards and 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, basic and diluted net loss per common share is the same.
	The following table sets forth for the periods presented the potential common shares (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:
			Outstanding at
			Years Ended December 31,
			2014		2013		2012
			(in thousands)
	Options outstanding			5,817		4,297		4,638
	Warrants outstanding			609		—		—
				6,426		4,297		4,638

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2014
Property and Equipment	4	Property and Equipment
	Property and equipment consists of the following:
			Estimated	December 31,			December 31,
			Useful Life	2014			2013
				(in thousands)
	Laboratory equipment		5 years	$	7,671		$	8,660
	Computer equipment and software		3 years		3,913			4,398
	Office furniture		5 years		893			930
	Leasehold improvements		Shorter of asset’s useful life		14,433			11,959
			or remaining term of lease
	Construction in process		—		—			3,193
					26,910			29,140
	Less accumulated depreciation and amortization				(15,615	)		(15,000	)
	Property and equipment, net			$	11,295		$	14,140
	Depreciation expense for the years ended December 31, 2014, 2013 and 2012 was $6.2 million, $3.8 million and $2.5 million, respectively. In September 2014, the Company entered into a Lease Termination Agreement, pursuant to which the Company agreed to surrender the remaining 49,185 square feet of leased space no later than September 24, 2015. As a result, the Company revised the estimated useful life of its leasehold improvements related to this space, resulting in an increase in depreciation expense of approximately $2.4 million during the year ended December 31, 2014.

Accrued_Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2014
Accrued Expenses	5	Accrued Expenses
	Accrued expenses consisted of the following:
			December 31,		December 31,
			2014		2013
			(in thousands)
	Manufacturing and distribution		$	3,216	$	1,362
	Clinical expenses			2,312		5,319
	Salaries and benefits			1,744		2,027
	Professional fees			685		811
	Restructuring			—		587
	Property and equipment			—		1,905
	Other			1,344		1,252
			$	9,301	$	13,263

Loans_Payable

Loans Payable	12 Months Ended
	Dec. 31, 2014
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 required to repay the aggregate principal balance under the Loan Agreement in 30 equal monthly installments of principal starting on 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.
	On September 24, 2014, the Company further amended the Loan Agreement with Hercules (the “Amended Loan Agreement”). Pursuant to the Amended Loan Agreement, the Company received a new loan in the aggregate principal amount of $10.0 million and amended the terms of the Original Loan Agreement with an outstanding principal balance of $11.6 million.
	Pursuant to the Amended Loan Agreement, the Company is not required to make principal payments on the new $10.0 million loan until November 1, 2015; provided, that such date may be extended if the Company achieves certain performance milestones, after which time, the Company is required to make 30 principal and interest payments with the entire loan due and payable on January 1, 2018. With respect to the original loan, the Company is only required to pay interest until January 1, 2015, at which time the Company is required to repay the loan in 12 monthly installments of principal and interest. The Amended Loan Agreement has an end-of-term payment of approximately $0.5 million due on January 1, 2018 or on such earlier date as the new loan is prepaid. This end-of-term payment 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 accounted for the Amended Loan Agreement as a loan modification in accordance with ASC 470-50, Debt—Modifications and Extinguishments.
	Per annum interest is payable on principal balance of both loans 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%. With respect to the new loan of $10.0 million, the unpaid principal balance and all accrued but unpaid interest will be due and payable on January 1, 2018, and with respect to the existing loan with a principal balance of $11.6 million, the unpaid principal balance and all accrued but unpaid interest will be due and payable on January 1, 2016.
	In addition to the obligations and covenants currently existing under the Loan Agreement, the Amended Loan Agreement contains a financial covenant, whereby the Company has agreed to maintain, with respect to the new loan of $10.0 million, a liquidity ratio equal to or greater than 1.25 to 1.00 of the then outstanding loan balance or the equivalent of $12.5 million in unrestricted and unencumbered cash and cash equivalents assuming a principal balance of $10.0 million. The financial covenant shall not apply after such time that the Company receives favorable data both with respect to its phase 2 clinical trial of ficlatuzumab and a phase 1 clinical trial of AV-380.
	The Loan Agreement required a deferred financing charge of $1.3 million which was paid in May 2012 related to the amendment of the Loan Agreement. The Loan Agreement also included an additional deferred financing charge of $1.2 million which was paid in June 2014. These amounts were recorded as a loan discount and are being amortized to interest expense over the term of the loan borrowed under the Loan Agreement using the effective interest rate method. The Company recorded a liability for the full amount of the charge since the payment of such amount was not contingent on any future event. The Company paid approximately $0.2 million in loan issuance costs directly to Hercules 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, on June 2, 2010, the Company issued warrants to the lenders to purchase up to 156,641 shares of the Company’s common stock at an exercise price equal to $7.98 per share to Hercules. The Company recorded the relative fair value of the warrants of approximately $0.8 million 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 original loan using the effective interest method. On July 21, 2011, Hercules exercised these warrants and they are no longer outstanding.
	As part of the Amended Loan Agreement, on September 24, 2014, the Company issued warrants to the lenders to purchase up to 608,696 shares of the Company’s common stock at an exercise price equal to $1.15 per share to Hercules. The Company recorded the relative fair value of the warrants of approximately $0.4 million 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 71.81%, an expected term equal to the contractual life of the warrants (five years), a risk-free interest rate of 1.82% and no dividend yield. The resulting effective interest rate for the loans outstanding under the Amended Loan Agreement is approximately 16.14%.
	As part of the Loan Agreement, 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 December 31, 2014, the outstanding aggregate principal balance under both loans was $21.6 million.
	The loans are secured by a lien on all of our personal property (other than intellectual property), whether owned as of, or acquired after, the date of the amended loan agreement. The Amended 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 Amended 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. As of December 31, 2014, Hercules has not asserted any events of default and the Company does not believe that there has been a material adverse change as defined in the loan agreement. The Company has classified the principal amount of the loans as current and non-current on its consolidated balance sheet based upon the expected timing of the remaining payments.
	Future minimum payments under the loans payable outstanding as of December 31, 2014 are as follows (amounts in thousands):
	Years Ending December 31:
	2015		$	14,166
	2016			4,644
	2017			4,644
	2018			2,096
				25,550
	Less amount representing interest			(3,398	)
	Less discount			(960	)
	Less deferred charges			(540	)
	Less current portion			(11,722	)
	Loans payable, net of current portion and discount		$	8,930

Collaboration_and_License_Agre

Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2014
Collaboration and License Agreements	7	Collaboration and License Agreements
	(a) Out-License Agreements
	Ophthotech Corporation
	In November 2014 the Company entered into a Research and Exclusive Option Agreement, or Option Agreement, with Ophthotech Corporation pursuant to which the Company provided Ophthotech an exclusive option to enter into a definitive license agreement whereby the Company would grant Ophthotech the right to develop and commercialize the Company’s VEGF factor tyrosine kinase inhibitor, tivozanib, outside of Asia for the potential diagnosis, prevention and treatment of non-oncologic diseases or conditions of the eye in humans.
	Pursuant to this Option Agreement, the Company granted to Ophthotech an exclusive, royalty free license or sublicense, as applicable, under intellectual property rights controlled by the Company solely to perform the research and development activities related to the use of tivozanib for the specific purposes outlined in the agreement during the option period (as defined below). These activities include formulation work for ocular administration, preclinical research and the conduct of a phase 1/2a, proof of concept clinical trial of a product containing tivozanib in patients with wet age-related macular degeneration, (the “POC Study”).
	Ophthotech paid the Company $500,000 in consideration for the grant of the option. Such amount is non-refundable and not creditable against any other amounts due under the agreement. The Company is obligated to make available to Ophthotech, at no cost to Ophthotech, certain quantities of tivozanib hydrochloride solely for conducting its option period research including manufacturing additional quantities of tivozanib in the event stability data indicates that the current supply will expire prior to the end of February 2017.
	During the option period, if Ophthotech elects to continue the development of tivozanib for non-oncologic diseases of the eye, the Company is entitled to receive a one-time milestone payment of $2.0 million upon acceptance of the first Investigational New Drug application for the purpose of conducting a human clinical study of tivozanib in ocular diseases (the “IND Submission Milestone Payment”). The Company is also entitled to receive a one-time milestone payment of $6.0 million (the “Clinical Efficacy Milestone Payment”), on the earlier of (a) December 31, 2016 and (b) the later to occur of: (i) the achievement of a clinical milestone in the POC Study (the “Clinical Efficacy Milestone”) and (ii) the earlier of (A) the date twelve (12) months after our and Ophthotech’s agreement as to the form and substance of the KHK Amendment (as defined below) or (B) the date ninety (90) days after the entry into the KHK Amendment, subject to the Company’s right to terminate the Option Agreement on 90 days’ written notice (the date on which such payment is due, referred to as the “Clinical Efficacy Milestone Payment Trigger Date”).
	Ophthotech may exercise the option at any time until the latest to occur of: (i) twelve (12) months after the achievement of the Clinical Efficacy Milestone, (ii) ninety (90) days after the Clinical Efficacy Milestone Payment Trigger Date, and (iii) thirty (30) days after the Company and Ophthotech agree as to the definitive form of license agreement, which the Company refers to as the option period.
	During the Option Period, the Company will not grant a license to any third party that would preclude the Company from being able to grant to Ophthotech the rights and licenses that are contemplated by the definitive license agreement, and the Company will not engage in any research, development or commercialization of tivozanib in the field covered by the contemplated definitive license agreement, except as specified in the Option Agreement.
	The terms of the Option Agreement are subject to the Company’s obligations to Kyowa Hakko Kirin (“KHK”), under a license agreement entered into by the Company with KHK in 2006, pursuant to which the Company acquired exclusive rights to develop and commercialize tivozanib for all human diseases outside of Asia (the “KHK License Agreement”). A percentage of all payments received by the Company under the Option Agreement and any definitive license agreement must be paid to KHK. The Company is required to maintain the KHK Agreement in effect, and not enter into any amendment or termination thereof that would adversely affect the Company’s rights, during the option period.
	During the option period, the Company and Ophthotech are obligated to negotiate in good faith the form and substance of a definitive license agreement, as well as the form and substance of an amendment to the Company’s license agreement with KHK (the “KHK Amendment”) to modify certain rights and obligations of the parties and sublicensees thereunder, particularly with respect to rights to improvements that are not specifically related to tivozanib, and regulatory affairs matters.
	Upon exercise of the option, Ophthotech is required to pay the Company a one-time option exercise fee of $2.0 million in addition to the IND Submission Milestone Payment if such payment has not then been previously paid. If upon exercise of the option, the Clinical Efficacy Milestone Payment Trigger Date has not yet occurred, the Company shall be entitled to the Clinical Efficacy Milestone Payment at such time that the Clinical Efficacy Milestone Payment Date does occur if the license agreement remains in effect as of such date. The license agreement, if entered into upon Ophthotech’s exercise of the Option, will provide for the Company to be entitled to receive (i) $10.0 million upon meeting certain efficacy and safety endpoints in phase 2 clinical trials that would enable the commencement of a phase 3 clinical trial, (ii) $20.0 million upon marketing approval in the United States, (iii) $20.0 million upon marketing approval in the UK, Germany, Spain, Italy and France and (iv) up to $45.0 million in sales-based milestone payments. Ophthotech would also be required to pay tiered, double digit royalties, up to the mid-teens, on net sales of tivozanib or products containing tivozanib.
	Either party may terminate the Option Agreement in the event of an uncured material breach of the Option Agreement by the other party which remains uncured for a period of ninety (90) days (or thirty (30) days for a breach relating to non-payment), or upon bankruptcy or like proceedings relating to the other party. Ophthotech may terminate the Option Agreement at any time upon ninety (90) days’ prior written notice to us. In addition, the Company may terminate the Option Agreement upon thirty (30) days’ prior written notice to Ophthotech if Ophthotech challenges certain patents controlled by the Company related to tivozanib. Unless terminated as provided above, the Option Agreement will expire upon the expiration of the option or the entry into the definitive license agreement.
	Activities under the agreement with Ophthotech were evaluated under ASC 605-25 Revenue Recognition—Multiple Element Arrangements, or ASC 605-25, to determine whether such activities represented a multiple element revenue arrangement. The agreement with Ophthotech includes the following non-contingent deliverables: the Company’s obligation to grant an exclusive option to Ophthotech to enter into a License Agreement to develop and commercialize products incorporating tivozanib for treatment of AMD and other diseases of the eye outside of Asia during the Option Period; the Company’s obligation to enter into an amendment with KHK to modify the terms of the existing KHK agreement to negotiate a mutually acceptable form of license agreement; and the Company’s obligation to transfer research-grade tivozanib API for Ophthotech to conduct the Option Period research.
	The Company determined that the delivered Option Grant Deliverable, or the Company’s obligation to grant an exclusive option to Ophthotech to enter into a License Agreement to develop and commercialize products incorporating tivozanib for treatment of AMD and other diseases of the eye outside of Asia during the Option Period, did not have standalone value from the remaining deliverables since Ophthotech could not obtain the intended benefit of the option without the remaining deliverables. Similarly, the remaining deliverables have no standalone value without the Option Grant Deliverable. The Company is accounting for the deliverables as one unit of accounting.
	Under the agreement, the Company received a cash payment of $0.5 million during the year ended December 31, 2014. The Company deferred the payment and is recording the deferred revenue over the Company’s period of performance, which is estimated to be through December 2016. The Company recorded approximately $38,000 of revenue during the year ended December 31, 2014.
	Biodesix
	In April 2014, the Company entered into a worldwide agreement with Biodesix to develop and commercialize its hepatocyte growth factor (“HGF”) inhibitory antibody ficlatuzumab, with BDX004, a proprietary companion diagnostic test developed by Biodesix and derived from VeriStrat®, a serum protein test that is commercially available to help physicians guide treatment decisions for patients with advanced non-small cell lung cancer (“NSCLC”). Under the agreement, the Company granted Biodesix perpetual, non-exclusive rights to certain intellectual property, including all clinical and biomarker data related to ficlatuzumab, to develop and commercialize BDX004. Biodesix granted the Company perpetual, non-exclusive rights to certain intellectual property, including diagnostic data related to BDX004, with respect to the development and commercialization of ficlatuzumab; each license includes the right to sublicense, subject to certain exceptions. Pursuant to a joint development plan to be agreed upon by a joint steering committee, the Company retains primary responsibility for clinical development of ficlatuzumab in a proof of concept (“POC”) clinical study of ficlatuzumab for NSCLC, in which VeriStrat will be used to select clinical trial subjects, referred to as the NSCLC POC Trial. The NSCLC POC Trial will be fully funded by Biodesix up to a maximum of $15.0 million, referred to as the “Cap”. After the Cap is reached, the Company and Biodesix will share equally in the costs of the NSCLC trial, and the Company and Biodesix will each be responsible for 50% of development and regulatory costs associated with all future clinical trials agreed-upon by Biodesix and the Company, including all milestone payments and royalties payable to third parties, if any.
	Pending marketing approval of ficlatuzumab and subject to a commercialization agreement to be entered into after receipt of results from the NSCLC POC Trial, each party would share equally in commercialization profits and losses, subject to the Company’s right to be the lead commercialization party.
	Biodesix is solely responsible for the BDX004 development costs, as well as BDX004 sales and marketing costs. Subject to and following the approval of the BDX004 test as a companion diagnostic for ficlatuzumab, Biodesix has agreed to make the BDX004 test available and use commercially reasonable efforts to seek reimbursement in all geographies where ficlatuzumab is approved. The Company has agreed to reimburse Biodesix a pre-specified amount, under certain circumstances for BDX004 tests performed.
	Prior to the first commercial sale of ficlatuzumab and after the earlier of (i) the Cap being reached or (ii) the completion of the NSCLC POC Trial, each party has the right to elect to discontinue participating in further development or commercialization efforts with respect to ficlatuzumab, which is referred to as an “Opt-Out”. If either AVEO or Biodesix elects to Opt-Out, with such party referred to as the “Opting -Out Party”, then the Opting-Out Party shall not be responsible for any future costs associated with developing and commercializing ficlatuzumab other than any ongoing clinical trials. After election of an Opt-Out, the non-opting out party shall have sole decision-making authority with respect to further development and commercialization of ficlatuzumab. Additionally, the Opting-Out Party shall be entitled to receive, if ficlatuzumab is successfully developed and commercialized, a royalty equal to 10% of net sales of ficlatuzumab throughout the world, if any, subject to offsets under certain circumstances.
	If Biodesix elects to Opt-Out, it will continue to be responsible for its development and commercialization obligations with respect to BDX004. If AVEO elects to Opt-Out, it will continue to make the existing supply of ficlatuzumab available to Biodesix for the purposes of enabling Biodesix to complete the development of ficlatuzumab, and Biodesix will have the right to commercialize ficlatuzumab.
	Prior to any Opt-Out, the parties shall share equally in any payments received from a third party licensee; provided, however, after any Opt-Out, the Opting-Out Party shall be entitled to receive only a reduced portion of such third party payments. The agreement will remain in effect until the expiration of all payment obligations between the parties related to development and commercialization of ficlatuzumab, unless earlier terminated.
	Activities under the agreement with Biodesix were evaluated under ASC 605-25 Revenue Recognition—Multiple Element Arrangements, or ASC 605-25, to determine whether such activities represented a multiple element revenue arrangement. The agreement with Biodesix includes the following non-contingent deliverables: perpetual, non-exclusive rights to certain intellectual property including clinical and biomarker data related to ficlatuzumab for use in developing and commercializing BDX004; the Company’s obligation to deliver technology improvements and data developed during the NSCLC POC Trial to Biodesix; the Company’s obligation to participate in the joint steering committee during the NSCLC POC Trial; the Company’s obligation to perform certain development activities associated with the NSCLC POC Trial; and the Company’s obligation to supply clinical material for use in conducting the NSCLC POC Trial; and the Company’s obligation to deliver clinical specimens and data during the NSCLC POC Trial. The Company concluded that any deliverables that would be delivered after the NSCLC POC Trial is complete are contingent deliverables because these services are contingent upon the results of the NSCLC POC Trial. As these deliverables are contingent, and are not at an incremental discount, they are not evaluated as deliverables at the inception of the arrangement. These contingent deliverables will be evaluated and accounted for separately as each related contingency is resolved. As of December 31, 2014, no contingent deliverables had been provided by the Company.
	The Company determined that the delivered item, or the perpetual, non-exclusive rights to certain intellectual property for use in developing and commercializing BDX004 did not have standalone value from the remaining deliverables since Biodesix could not obtain the intended benefit of the license without the remaining deliverables. Since the remaining deliverables will be performed over the same period of performance there is no difference in accounting for the deliverables as one unit or multiple units of accounting, and therefore, the Company is accounting for the deliverables as one unit of accounting.
	The Company records the consideration earned while conducting the NSCLC POC Trial, which consists of reimbursements from Biodesix for expenses related to the trial under the Cap, as a reduction to research and development expense using the proportional performance method over the respective period of performance. As a result of the cost sharing provisions in the agreement, the Company reduced research and development expenses by approximately $2.7 million during the year ended December 31, 2014. The amount due to the Company from Biodesix pursuant to the cost-sharing provision was $1.8 million at December 31, 2014.
	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 “Biogen Idec”) regarding the development and commercialization of the Company’s discovery-stage ErbB3-targeted antibodies for the potential treatment and diagnosis of cancer and other diseases outside of North America. Under the agreement, the Company is responsible for developing ErbB3 antibodies through completion of the first phase 2 clinical trial designed in a manner that, if successful, will generate data sufficient to support advancement to a phase 3 clinical trial.
	In March 2014, the Company and Biogen Idec amended the exclusive option and license agreement (the “Amendment”). Pursuant to the Amendment, Biogen agreed to the termination of its rights and obligations under the agreement, including Biogen’s option to (i) obtain a co-exclusive (with AVEO) worldwide license to develop and manufacture ErbB3 targeted antibodies and (ii) obtain exclusive commercialization rights to ErbB3 products in countries in the world other than North America. As a result, AVEO has worldwide rights to AV-203. Pursuant to the Amendment, AVEO is obligated to use reasonable efforts to seek a collaboration partner for the purpose of funding further development and commercialization of ErbB3 targeted antibodies. AVEO is also obligated to pay Biogen a percentage of milestone payments received by AVEO from future partnerships after March 28, 2016 and single digit royalty payments on net sales related to the sale of ErbB3 products, if any, up to cumulative maximum amount of $50 million.
	The deliverables under the original arrangement included 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 required the Company’s experience to advance development of the product candidates. As such, the Company determined that the original agreement should be accounted for as one unit of accounting.
	Under the terms of the original agreement, Biogen Idec made up-front and milestone-based cash payments totaling $20.0 million. Of the $20.0 million received, $10.0 million was associated with milestones that were considered substantive and these amounts were included in revenue when they were earned. The remaining $10.0 million was amortized as additional license revenue over the Company’s period of substantial involvement.
	The Company concluded that the Amendment materially modified the terms of the agreement and, as a result, required the application of ASC 605-25. Based upon the terms of the Amendment, the remaining deliverables included the Company’s obligation to seek a collaboration partner to fund further development of the program and the Company’s obligation to continue development and commercialization of the licensed products if a collaboration partner is secured (“Development Deliverable”). The Company concluded that its obligation to use best efforts to seek a collaboration partner does not have standalone value from the Development Deliverable upon delivery and thus the deliverables should be treated as a single unit of accounting.
	Upon modifying the arrangement, the Company had $14.7 million of deferred revenue remaining to be amortized. The Company is not entitled to receive any further consideration from Biogen Idec under the amended arrangement. The Company allocated a portion of the remaining deferred revenue to the undelivered unit of accounting based upon the Company’s best estimate of the selling price, as the Company determined that neither VSOE or TPE were available. The Company determined the best estimate of selling price to be approximately $0.6 million and recognized the remaining $14.1 million as collaboration revenue in March 2014. The deferred revenue associated with the undelivered unit of accounting is being recognized on a straight-line basis over the expected period of performance, or through December 2015, based upon the Company’s historical experience with marketing its product candidates to potential partners.
	The best estimate of selling price was based upon a cost approach pursuant to which the Company estimated the costs expected to be incurred in executing a partnership agreement and then applied a reasonable markup. The Company estimated future cash outflows for several possible outcomes, including the execution of a partnership at different times within a reasonable range and partnerships of differing complexity. The Company estimated its cash outflows for each scenario based upon the expected costs associated with the relevant employees and the expected level of effort to be expended to seek and execute a partnership. The Company’s analysis also considered the legal charges that it anticipates it will incur. Changes to the Company’s assumptions within the reasonable range of possible values would not have a material impact on the amounts recorded in current or future periods.
	Under the agreement, the Company recorded revenue of $14.5 million, $0.9 million and $0.9 million during the years ended December 31, 2014, 2013 and 2012, respectively.
	Astellas Pharma Inc.
	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 intended to develop and commercialize tivozanib for the treatment of a broad range of cancers. Under the terms of the Astellas Agreement, the Company and Astellas shared responsibility for continued development and commercialization of tivozanib in North America and in Europe under a joint development plan and a joint commercialization plan, respectively. Throughout the rest of the world (the “Royalty Territory”), excluding Asia, where KHK has retained all development and commercialization rights, Astellas had an exclusive, royalty-bearing license to develop and commercialize tivozanib. The terms of the Astellas Agreement were 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.
	In June 2013, the Company received a complete response letter from the U.S. Department of Food and Drug Administration, or FDA, informing the Company that the FDA will not approve in its present form the Company’s New Drug Application, or NDA, for tivozanib for the treatment of patients with advanced renal cell carcinoma, or RCC. In January 2014, AVEO and Astellas jointly decided to discontinue a phase 2 breast cancer clinical trial due to insufficient enrollment. Further, Astellas elected in February 2014 to terminate the Astellas Agreement as a result of the limited scope of development for tivozanib moving forward. This termination became effective on August 11, 2014, at which time the tivozanib rights returned to the Company. In accordance with the Astellas Agreement, committed development costs, including the costs of completing certain tivozanib clinical development activities, will be shared equally. There are no refund provisions in the Astellas Agreement.
	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. The milestone was considered substantive and revenue was recognized upon achievement of the milestone.
	The Company accounted 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 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 incurred by the Company pursuant to the joint development plan were 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 $3.5 million, $15.8 million and $34.1 million during the years ended December 31, 2014, 2013, and 2012, respectively. The Company also reduced general and administrative expense by $0.1 million, $2.8 million, and $3.3 million during the years ended December 31, 2014, 2013 and 2012, respectively, as a result of the cost-sharing provisions in the Astellas Agreement. The net amount due to the Company from Astellas pursuant to the cost-sharing provisions was $0.6 million at December 31, 2014.
	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 to determine if they represented a multiple element revenue arrangement. The Astellas Agreement included 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”). 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. 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 arrangement consideration.
	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 was 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. Upon being notified that the collaboration would be terminated effective August 2014, the Company reassessed the period of performance associated with the Royalty Territory Deliverable and accelerated the recognition of the remaining deferred revenue such that the balance would be recognized through August 2014. This change in estimate resulted in the recognition of an additional $3.1 million during the year ended December 31, 2014. The Company recorded approximately $3.6 million, $0.4 million, and $0.4 million of revenue associated with the Royalty Territory Deliverable during the years ended December 31, 2014, 2013, and 2012, respectively.
	Under the agreement, the Company received cash payments related to reimbursable payments and milestone payments of $4.1 million, $40.1 million, and $39.8 million during the years ended December 31, 2014, 2013 and 2012, respectively, and recorded revenue of $3.6 million, $0.4 million and $15.4 million during the years ended December 31, 2014, 2013 and 2012, respectively.
	(b) In-license Agreements
	Kirin Brewery Co. Ltd. (KHK)
	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. 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, 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, including a possible milestone payment of $18.0 million to KHK in connection with the FDA granting marketing approval 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 (including a potential $4.5 million milestone payable to KHK in connection with the acceptance by the EMA of the filing of a Marketing Authorization Application and $9.0 million to KHK in connection with the EMA granting marketing approval in Europe), other than amounts the Company receives in respect of research and development funding or equity investments, subject to certain limitations.
	The license agreement will remain in effect until the expiration of all of the Company’s royalty and sublicense revenue obligations to KHK unless either party elects to terminate the license agreement earlier. If the Company fails to meet its obligations under the agreements and is unable to cure such failure within specified time periods, KHK can terminate the agreement, resulting in a loss of the Company’s rights to tivozanib and an obligation to assign or license to KHK any intellectual property rights the Company may have in tivozanib.
	St. Vincent’s Hospital
	In July 2012, the Company entered into a license agreement with St Vincent’s Hospital Sydney Limited, which the Company refers to as St. Vincent’s, under which the Company obtained an exclusive, worldwide license, with the right to grant sublicenses subject to certain restrictions, under specified patent rights and related know-how, to research, develop, manufacture and commercialize products for human therapeutic, preventative and palliative applications that benefit from inhibition or decreased expression or activity of MIC-1, which the Company refers to as GDF15. The Company is exploiting this license in its AV-380 program for cachexia. The Company has a right of first negotiation to obtain an exclusive license to certain improvements that St. Vincent’s or third parties may make to licensed therapeutic products. Under the license agreement, St. Vincent’s also granted us non-exclusive rights for certain related diagnostic products and research tools.
	Under the license agreement, the Company is obligated to use diligent efforts to conduct research and clinical development and commercially launch at least one licensed therapeutic product, and to maximize profits from licensed therapeutic products for the benefit of us and St. Vincent’s. Subject to certain conditions, the Company has also agreed to achieve specified research, development and regulatory milestones by specified dates. If the Company does not achieve a given milestone by the agreed date, the Company has the option of paying the amount the Company would have been obligated to pay had the Company timely achieved the milestone, and, if the Company does so, St. Vincent’s will not have the right to terminate the license agreement based on its failure to timely achieve such milestone.
	The Company has also agreed that, for as long as there is a valid claim in the licensed patents, the Company will not, and the Company will ensure that its affiliates and its sublicensees do not, develop or commercialize any product, other than a licensed therapeutic product, for the treatment, prevention or prophylaxis of cachexia, decreased appetite or body weight, that binds to GDF15 or the GDF15 receptor and that is a GDF15 antagonist, and will not license or induce any other person to do the same.
	In connection with entering into the license agreement with St. Vincent’s, the Company paid St. Vincent’s an upfront license fee of $0.7 million and a low five-figure amount to reimburse St. Vincent’s for patent-related expenses it incurred with respect to a specified licensed patent.
	Under the Company’s license agreement with St. Vincent’s, the Company may be required to:
		•	make milestone payments, up to an aggregate total of $9.2 million, upon achievement of specified research, development and regulatory milestones for the first three indications for licensed therapeutic products, some of which payments may be increased by a mid to high double-digit percentage rate for milestones payments made after the Company grants any sublicense under the license agreement, depending on the sublicensed territory or territories;
		•	pay tiered royalty payments equal to a low-single-digit percentage of any net sales the Company or its sublicensees make of licensed therapeutic products. The royalty rate escalates within the low-single-digit range during each calendar year based on increasing licensed therapeutic product sales during such calendar year. The Company’s royalty payment obligations for a licensed therapeutic product in a particular country end on the later of 10 years after the date of first commercial sale of such licensed therapeutic product in such country or expiration of the last-to-expire valid claim of the licensed patents covering such licensed therapeutic product in such country, and are subject to offsets under certain circumstances;
		•	pay St. Vincent’s sublicensing fees of up to an aggregate amount in the low-to-mid six-digits, depending on the sublicensed territory or territories, at the time the Company grants any sublicense; and
		•	reimburse St. Vincent’s for some or all of the reasonable costs and expenses it incurs in patent management, filing, prosecuting and maintaining the licensed patents.
	The license agreement will remain in effect until the later of 10 years after the date of first commercial sale of licensed therapeutic products in the last country in which a commercial sale is made, or expiration of the last-to-expire valid claim of the licensed patents, unless the Company elects, or St. Vincent’s elects, to terminate the license agreement earlier.
Either party has the right to terminate the agreement in connection with a material breach of the agreement by the other party that remains uncured for a specified cure period, or in connection with events relating to the other party’s insolvency or bankruptcy, or if a force majeure event continues for more than 4 months.
St. Vincent’s has the right to terminate the agreement due to any patent-related challenge by the Company, its affiliates or any sublicensee, or if the Company or its affiliates or any sublicensee cause or induce any other person to make a patent-related challenge, and such challenge continues after a specified cure period.
The Company has the right to terminate the agreement on 6 months’ notice if the Company terminates its GDF15 research and development programs as a result of the failure of a licensed therapeutic product in pre-clinical or clinical development, or if the Company forms the reasonable view that further GDF15 research and development is not commercially viable, and the Company is not then in breach of any of its obligations under the agreement. If the Company forms the reasonable view that further GDF15 research and development is not commercially viable and terminate the agreement before the Company starts a phase 1 clinical trial on a licensed therapeutic product, the Company will be required to pay St. Vincent’s a low-to-mid six-figure termination payment.
Any termination of the agreement, in whole or in part, will result in a loss of the Company’s rights to the relevant licensed patents and know-how. If St. Vincent’s terminates the agreement in its entirety due to the Company’s breach, insolvency or a patent-related challenge, or the Company terminates the agreement due to a development failure or lack of commercial viability, as described above, St. Vincent’s will have a non-exclusive license from us to certain intellectual property rights and know-how relating to the licensed therapeutic products, and the Company must transfer to St. Vincent’s certain then-existing regulatory approvals and related documents for the licensed therapeutic products.
Other License Agreements
The Company has entered into various cancelable license agreements for patented technology and other technology related to research projects, including technology to humanize ficlatuzumab, AV-203 and other antibody product candidates. The Company is obligated to pay annual maintenance payments of $25,000, which are recognized as research and development expense over the maintenance period. Under an additional agreement, if the parties agree to the use of the licensed technology in development of a product, the Company will be required to make a $1.0 million license payment per product. Three of these agreements also include development and sales-based milestones of up to $22.5 million, $5.5 million and $4.2 million per product, respectively, and single digit royalties as a percentage of sales.
Certain other research agreements require the Company to remit royalties in amounts ranging from 0.5% to 1.5% based on net sales of products utilizing the licensed technology. Total license expense incurred under these other license agreements amounted to $0.3 million during the year ended December 31, 2012. No expenses were incurred during the years ended December 31, 2014 and 2013. The Company has not paid any royalties to date.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies	8	Commitments and Contingencies
	Operating Leases
	The Company leases office and has leased lab space and equipment under various operating lease agreements. Rent expense under the operating leases amounted to $4.1 million, $9.4 million and $7.8 million for the years ended December 31, 2014, 2013 and 2012, respectively. For the year ended December 31, 2014, $3.1 million of rent expense is included within lease exit costs on the Company’s statement of operations.
	On November 4, 2011, the Company entered into a lease agreement with the Massachusetts Institute of Technology, to lease an additional 11,500 square feet of office space located at 12 Emily Street in Cambridge, Massachusetts. The lease commenced on December 15, 2011 and expired on February 28, 2014.
	On May 9, 2012, the Company entered into a lease agreement with BMR-650 E KENDALL B LLC (“BMR”), under which the Company agreed to lease 126,065 square feet of space located at 650 East Kendall Street, Cambridge, Massachusetts to be used for office, research and laboratory space. The initial term of the lease agreement was approximately twelve years and seven months (the “initial term”). The Company’s occupancy of the space occurred in two phases. The Company began the phase one occupancy on January 4, 2013 when the Company began to move some employees to occupy 26,734 square feet of office space (the “phase 1 space”). The Company began the second phase when the remainder of the Company’s employees moved into the remaining space (the “phase 2 space”) and during the second half of 2014. Rent payments with respect the phase 1 space commenced on January 1, 2013, and rent payments for the phase 2 space commenced on November 1, 2013 for the phase 2 space. The initial base rent expense for both the phase 1 space and the phase 2 space is $54.50 per rentable square foot per year, with 3% increases on each anniversary of the phase 1 space rent commencement date. In addition to the base rent, the Company is also responsible for its share of operating expenses and real estate taxes. In accordance with the terms of the lease agreement, the Company maintains a letter of credit securing its obligations under the lease agreement of approximately $2.9 million. The Company has determined that the lease should be classified as an operating lease. As the Company gained access to both the phase 1 space and the phase 2 space beginning in May 2012, the Company recognized rent expense of approximately $4.3 million, $6.7 million and $4.9 million related to the lease during the years ended December 31, 2014, 2013 and 2012, respectively.
	In order to make the space usable for the Company’s operations, substantial improvements were made to the space. These improvements were planned, managed and carried out by the Company and the improvements were tailored to the Company’s needs. BMR agreed to reimburse the Company for up to $14.9 million of the improvements, and the Company bore all risks associated with any cost overruns that may be incurred. As such, the Company determined it was the owner of the improvements and, as such, the Company accounted for tenant improvement reimbursements from BMR as a lease incentive. The Company recorded a deferred lease incentive (included as a component of the deferred rent balance in the accompanying consolidated balance sheets) and the incentive is being amortized as an offset to rent expense over the term of the lease. Rent expense, inclusive of the escalating rent payments, is being recognized on a straight-line basis over the initial term of the lease agreement. Refer to Footnote 14 for further discussion regarding the termination of this lease.
	Future annual minimum lease payments under all non-cancelable operating leases at December 31, 2014 is $1.7 million for the year ending December 31, 2015.
	Employment Agreements
	Certain key executives are covered by severance and change in control agreements. Under these agreements, if the executive’s employment is terminated without cause or if the executive terminates his employment for good reason, such executive will be entitled to receive severance equal to his base salary, benefits and prorated bonuses for a period of time equal to either 12 months or 18 months, depending on the terms of such executive’s individual agreement. In addition, in December 2007, the Company approved a key employee change in control severance benefits plan, which was amended in November 2009, and which provides for severance and other benefits under certain qualifying termination events upon a change in control for a period of time ranging from 6 months to 18 months, depending upon the position of the key employee.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes	9	Income Taxes
	The Company accounts for income taxes under the provisions of ASC 740. For the years ended December 31, 2014 and 2013, the Company did not have any federal, state, or foreign income tax expense as it generated taxable losses in all filing jurisdictions. For the year ended December 31, 2011, the Company was able to utilize net operating loss carryforwards (NOLs) to fully offset taxable income in all filing jurisdictions.
	A reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2014, 2013 and 2012:
			December 31,			December 31,			December 31,
			2014			2013			2012
	Income tax computed at federal statutory tax rate			34	%		34	%		34	%
	State taxes, net of federal benefit			5.3	%		5.1	%		5.1	%
	Research and development credits			2.6	%		2	%		0.1	%
	Permanent differences			(0.8	)%		(0.9	)%		(1.2	)%
	Foreign rate differential			0	%		(0.2	)%		(0.4	)%
	Other			(5.7	)%		(0.5	)%		(0.2	)%
	Change in valuation allowance			(35.4	)%		(39.5	)%		(37.4	)%
	Total			0	%		0	%		0	%
	Prior to 2011, the Company had incurred net operating losses from inception. At December 31, 2014, the Company had domestic federal, state, and UK net operating loss carryforwards of approximately $424.0 million, $316.1 million, and $6.9 million respectively, available to reduce future taxable income, which expire at various dates. The federal net operating loss carryforwards expire beginning in 2024 through 2034 and the state loss carryforwards begin to expire in 2030 and continue through 2034. The Company also had federal and state research and development tax credit carryforwards of approximately $9.7 million and $4.5 million, respectively, available to reduce future tax liabilities and which expire at various dates. The federal credits expire beginning in 2022 through 2034 and the state credits begin to expire in 2015. The net operating loss and research and development carryforwards are subject to review and possible adjustment by the Internal Revenue Service and may be limited in the event of certain changes in the ownership interest of significant stockholders.
	The Company’s net deferred tax assets as of December 31, 2014 and 2013 are as follows:
			2014			2013
			(in thousands)
	NOL carryforwards		$	162,248		$	134,023
	Research and development credits			12,721			11,357
	Deferred revenue			302			7,224
	Other temporary differences			11,135			15,158
	Valuation allowance			(186,406	)		(167,762	)
			$	—		$	—
	A full valuation allowance has been recorded in the accompanying consolidated financial statements to offset these deferred tax assets because the future realizability of such assets is uncertain. This determination is based primarily on the Company’s historical losses. Accordingly, future favorable adjustments to the valuation allowance may be required, if and when circumstances change. The valuation allowance increased by $18.6 million during the year ended December 31, 2014, primarily due to the generation of net operating loss carryforwards.
	As of December 31, 2014, the Company had federal and state net operating losses of approximately $4.1 million related to excess tax deductions that have been excluded from the above table. The benefit of these net operating losses will be recognized as an increase in additional paid in capital when it results in a reduction in taxable income.
	The Company applies FASB Interpretation No. 48, “Accounting for Uncertainty in Income Taxes, an interpretation of FAS 109” (codified within ASC 740, Income Taxes), 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. The Company adopted this accounting guidance on January 1, 2009 and recorded $1.2 million of unrecognized tax benefits upon adoption. A full valuation allowance has been provided against the Company’s deferred tax assets, so that the effect of the unrecognized tax benefits is to reduce the gross amount of the deferred tax asset and the corresponding valuation allowance. Since the Company has incurred net operating losses since inception, it has never been subject to a revenue agent review. The Company is currently open to examination under the statute of limitations by the Internal Revenue Service and state jurisdictions for the tax years ended 2011 through 2014. Carryforward tax attributes generated in years past may still be adjusted upon future examination if they have or will be used in a future period. The Company is currently not under examination by the Internal Revenue Service or any other jurisdictions for any tax years.
	The Company may from time to time be assessed interest or penalties by major tax jurisdictions. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. No interest and penalties have been recognized by the Company to date.
	The Company anticipates that the amount of unrecognized tax benefits recorded will not change in the next twelve months.
	The following is a reconciliation of the Company’s gross uncertain tax positions at December 31, 2014 and 2013:
			Year ended			Year ended
			December 31,			December 31,
			2014			2013
			(in thousands)
	Amount established upon adoption		$	1,200		$	1,200
	Additions for current year tax positions			—			—
	Additions for prior year tax positions			—			—
	Reductions of prior year tax positions			—			—
	Balance as of end of year		$	1,200		$	1,200

Common_Stock_and_Warrants

Common Stock and Warrants	12 Months Ended
	Dec. 31, 2014
Common Stock and Warrants	10	Common Stock and Warrants
	As of December 31, 2014, the Company had 100,000,000 authorized shares of common stock, $0.001 par value, of which 52,288,799 shares were issued and outstanding.
	As part of the Amended Loan Agreement with Hercules Technology II, L.P. and Hercules Technology III, L.P., affiliates of Hercules Technology Growth (collectively, “Hercules”), on September 24, 2014, the Company issued warrants to the lenders to purchase up to 608,696 shares of the Company’s common stock at an exercise price equal to $1.15 per share to Hercules. All warrants issued during the year remain outstanding as of December 31, 2014.
	Public Offering
	In January 2013, the Company completed an underwritten public offering of its common stock. The total number of shares sold was 7,667,050 including the underwriters’ exercise of their over-allotment option, at the public offering price of $7.50 per share. Aggregate net proceeds to the Company were approximately $53.6 million, after deducting $3.9 million in offering related expenses and underwriting discounts and commissions.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Stock-Based Compensation	11	Stock-Based Compensation
	Stock Incentive Plan—Overview
	The Company maintains the 2010 Stock Incentive Plan (the “Plan”) for employees, consultants, advisors, and directors. The Plan provides for the grant of equity awards such as stock options and restricted stock. The Plan has been amended at various times since its approval. In March 2013, the Company’s board of directors amended the Plan to increase the number of shares of common stock reserved for issuance to 7,875,000 shares, plus the number of shares of common stock subject to awards granted under the Company’s 2002 Incentive Plan which expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by us, up to a maximum of 625,000 shares. This amendment also adopted a fungible share pool whereby any award that is a full-value award (i.e. any restricted stock award, restricted stock unit award, or other stock-based award with a per share price or per unit purchase price lower than 100% of fair market value on the date of the grant) is counted against the share limits under the Plan as 1.5 shares for each one share of common stock subject to such full-value award. In June 2014, the Company’s stockholders approved an amendment to the Plan, which increased the annual per participant share limit under the Plan from 250,000 to 1,000,000 shares per fiscal year. No other amendments to the Plan were made.
	The Company has reserved 9,018,151 shares of common stock under the Plan, and at December 31, 2014, the Company has 2,826,499 shares available for future issuance under the Plan. Shares issued upon exercise of options are generally issued from new shares of the Company. The Plan provides that the exercise price of incentive stock options cannot be less than 100% of the fair market value of the common stock on the date of the award for participants who own less than 10% of the total combined voting power of stock of the Company and not less than 110% for participants who own more than 10% of the total combined voting power of the stock of the Company. Options and restricted stock granted under the Plan vest over periods as determined by the Board, which generally are equal to four years. Options generally expire ten years from the date of grant.
	Stock Incentive Plan—Employee Stock Options
	The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option-pricing model using the assumptions noted in the following table:
			Years Ended December 31,
			2014		2013	2012
	Volatility		69.38%-77.92%		64.22%-72.65%	64.30%-66.05%
	Expected Term (in years)		5.50-6.25		5.50-6.25	5.50-6.25
	Risk-Free Interest Rates		1.81%-2.02%		1.01%-2.10%	0.83%-1.33%
	Dividend Yield		—		—	—
	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.
	The Company does not have sufficient history to support a calculation of volatility and expected term using only its historical data. 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, similar vesting terms and in-the-money option status. Due to 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, 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. During the years ending December 31, 2014, 2013 and 2012 the Company estimated its forfeiture rates to be 62%, 49% and 18%, respectively. Based upon these assumptions, the weighted-average grant date fair value of stock options granted during the years ended December 31, 2014, 2013, and 2012 was $1.15, $4.32 and $7.40 per share, respectively.
	During the year ended December 31, 2014 the Company issued stock options to purchase 2,250,000 shares of common stock that contain market and performance –based vesting conditions that were not deemed probable of vesting at December 31, 2014. As of December 31, 2014, there was $1.9 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 (collectively, the “Plans”). The expense is expected to be recognized over a weighted-average period of 3.2 years. The intrinsic value of options exercised was $0.5 million and $1.9 million for the years ended December 31, 2013 and 2012, respectively. No options were exercised during the year ended December 31, 2014.
	The following table summarizes the activity of the Plans for the year ended December 31, 2014:
			Number of			Weighted-		Weighted-		Aggregate
			Options			Average		Average		Intrinsic
						Exercise		Remaining		Value
						Price		Contractual
								Life
								(in years)
	Outstanding at December 31, 2013			4,296,694		$	7.36
	Granted			2,992,100		$	1.59
	Forfeited			(544,232	)	$	4.15
	Expired			(927,249	)	$	8.89
	Outstanding at December 31, 2014			5,817,313		$	4.45		3.52		—
	Exercisable at December 31, 2014			3,461,864		$	6.24		3.38		—
	Vested or expected to vest at December 31, 2014			2,632,700		$	7.09		3.04		—
	Stock Incentive Plan—Nonemployee Stock Options
	During 2014, the Company granted nonqualified options to purchase 225,000 shares of common stock to nonemployee consultants, with an average exercise price of $1.47 per share. There were no stock options granted to nonemployee consultants during 2013 or 2012. The Company valued these options using the Black-Scholes option-pricing model and recognized expense related to these awards using the accelerated attribution method. The unvested options held by consultants have been revalued using the Company’s estimate of fair value at each reporting period over the vesting period. Stock-based compensation expense of approximately $0.1 million was recorded during the year ended December 31, 2014 relating to nonemployee stock option awards.
	Stock Incentive Plan—Restricted Stock
	The Company periodically grants awards of restricted stock to employees. These awards typically vest upon completion of the requisite service period or upon achievement of specified performance targets.
	The following table summarizes the restricted stock activity for the year ended December 31, 2014:
			Number of Shares			Weighted-
						Average
						Price
	Unvested at December 31, 2013			241,500		$	2.5
	Granted			501,000			1.62
	Cancelled			(191,620	)		1.92
	Expired			—			—
	Vested/Released			(73,280	)		2.5
	Unvested at December 31, 2014			477,600		$	1.81
	The fair value of restricted stock awards that vested was $0.2 million, $0.5 million, and $0.5 million for the years ended December 31, 2014, 2013, and 2012, respectively. As of December 31, 2014, there was $0.1 million of total unrecognized stock-based compensation expense related to restricted stock awards granted under the Plan. The expense is expected to be recognized over a weighted-average period of 0.9 years if all performance targets are met.
	Employee Stock Purchase Plan
	In February 2010, the Board of Directors adopted the 2010 Employee Stock Purchase Plan (the “ESPP”) pursuant to which the Company may sell up to an aggregate of 250,000 shares of Common Stock. The ESPP was approved by the Company’s stockholders in February 2010. The plan was amended in March 2013 to increase the total number of shares available under the ESPP for the Company to sell to 764,000. The ESPP allows eligible employees to purchase common stock at a price per share equal to 85% of the lower of the fair market value of the common stock at the beginning or end of each six month period during the term of the ESPP. The first offering period began on July 1, 2010.
	Pursuant to the ESPP, the Company sold a total of 139,032 shares of common stock during the year ended December 31, 2014 at purchase prices of $1.53 and $0.71, respectively, which represent 85% of the closing price of the Company’s common stock on June 30, 2014 and December 31, 2014, respectively. For the year ended December 31, 2013, the Company sold a total of 109,610 shares of common stock at purchase prices of $2.13 and $1.56, respectively, which represent 85% of the closing price of the Company’s common stock on June 28, 2013 and December 31, 2013, respectively. For the year ended December 31, 2012, the Company sold a total of 94,592 shares of common stock at purchase prices of $10.34 and $6.84, respectively, which represent 85% of the closing price of the Company’s common stock on June 29, 2012 and December 31, 2012, respectively. The total stock-based compensation expense recorded as a result of the ESPP was approximately $0.2 million, $0.2 million and $0.3 million during the years ended December 31, 2014, 2013 and 2012, respectively.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2014
Employee Benefit Plan	12	Employee Benefit Plan
	In 2002, the Company established the AVEO Pharmaceuticals, Inc. 401(k) Plan (the “401(k) Plan”) for its employees, which is designed to be qualified under Section 401(k) of the Internal Revenue Code. Eligible employees are permitted to contribute to the 401(k) Plan within statutory and 401(k) Plan limits. The Company makes matching contributions of 50% of the first 5% of employee contributions. The Company made matching contributions of $0.1 million, $0.4 million, and $0.6 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Strategic_Restructuring

Strategic Restructuring	12 Months Ended
	Dec. 31, 2014
Strategic Restructuring	13	Strategic Restructuring
	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 further strategic restructuring in June 2013 to refocus the Company’s efforts on the then 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 was completed as of December 31, 2013 and resulted in costs totaling $8.0 million, which includes impairment charges of $0.3 million.
	The following table summarizes the components of the Company’s restructuring activity recorded in operating expenses and in accrued expenses in the accompanying consolidated balance sheet:
			Restructuring		Restructuring		Restructuring			Restructuring
			amounts accrued at		expense		amounts			amounts
			December 31,		incurred		paid			accrued at
			2013		during the year ended		during the year ended			December 31,
					December  31,		December  31,			2014
					2014		2014
			(in thousands)
	Employee severance, benefits and related costs.		$	587		—	$	(587	)		—
			Restructuring		Restructuring		Restructuring			Restructuring
			amounts accrued at		expense		amounts			amounts
			December 31,		incurred		paid			accrued at
			2012		during the year ended		during the year ended			December 31,
					December  31,		December  31,			2013
					2013		2013
			(in thousands)
	Employee severance, benefits and related costs.		$	1,653	$	7,674	$	(8,740	)	$	587
	Contract termination costs			—		82		(82	)		—
	Total			1,653		7,756		(8,822	)		587

Facility_Lease_Exit

Facility Lease Exit

12 Months Ended

Dec. 31, 2014

Facility Lease Exit

14

Facility Lease Exit

During the year ended December 31, 2014, the Company completed the planned build-out of portions of the office space it leases at 650 E. Kendall Street in Cambridge, Massachusetts. Upon completion of these build-outs, the Company ceased use of these spaces and recorded liabilities totaling $15.2 million for lease exit costs. The fair value of these liabilities was determined using the credit-adjusted risk-free rate to discount the estimated future net cash outflows associated with the space that met the cease use criteria. The estimate of future net cash outflows included the Company’s expected minimum rental payments and incremental operating, utility and tax payments to the landlord less the amount of sublease income that the Company estimates it could reasonably expect to obtain during the remainder of the lease period.

On September 24, 2014, the Company entered into the Lease Termination Agreement pursuant to which the Company immediately surrendered an aggregate of 76,980 square feet of leased space that it had previously ceased using earlier in 2014. In connection with the Lease Termination Agreement, the Company agreed to pay the landlord a termination fee totaling $15.6 million to be settled as follows: fifty percent of the fee, or $7.8 million, was to be credited against amounts due the Company for tenant improvements, and the remaining fifty percent will be paid in nine equal monthly installments of $0.9 million commencing on October 1, 2014. Upon signing the Lease Termination Agreement, the Company recorded an additional $1.9 million of Lease Exit charges. The initial $7.8 million fee was credited by the landlord against the Company’s tenant improvement allowance of $14.7 million, resulting in a net payment to the Company of $6.8 million which was received in September 2014. The Company also agreed to surrender the remaining 49,185 square feet of leased space upon 90 days written notice upon a date that is no earlier than March 24, 2015 and no later than September 24, 2015. In February 2015, the Company provided notice that it will surrender the remaining space on May 29, 2015. Pursuant to the Lease Termination Agreement, the Company revised the estimated useful life of its leasehold improvements related to this office space and is amortizing such assets through September 2015. Similarly, the Company has accelerated the amortization of its deferred rent and leasehold improvement allowance associated with this office space through September 2015. Upon the surrender of the remaining space, the Company will have no further rights or obligations with respect to the lease.

In connection with the Lease Termination Agreement, the Company has recorded a liability related to the remaining half of the lease termination fee. The fair value of this liability was determined using the credit-adjusted risk-free rate to discount the payment stream related to this portion of the termination fee. The Company recorded the fair value of this liability, or $5.0 million, as lease exit liability at December 31, 2014.

The following table summarizes the components of the Company’s lease exit activity recorded in current liabilities:

Lease Exit

Accretion

Amounts

Amounts offset against

Amounts

Expense

Expense

paid

tenant receivable

accrued at

incurred

incurred

during the year ended

during the year ended

December 31,

during the year ended

during the year ended

December 31,

December 31, 2014

2014

December 31,

December 31,

2014

2014

2014

(in thousands)

Lease exit costs

$

17,142

$

974

$

(5,313

)

$

(7,822

)

$

4,981

In addition to the $17.1 million of expense included in the table above, lease exit expenses also include the write-off $14.0 million of deferred rent associated with the portions of the facility that met the cease use criteria under ASC 420-10 and leasehold improvements totaling $7.6 million during the year ended December 31, 2014 as the Company’s estimates of sublease income would not recover the value of the leasehold improvements.

Quarterly_Results_Unaudited

Quarterly Results (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Results (Unaudited)	15	Quarterly Results (Unaudited)
			Three Months Ended
			March 31,			June 30,			September 30,			December 31,
			2014			2014			2014			2014
			(in thousands, except per share data)
			(unaudited)
	Collaboration revenue		$	15,289		$	1,846		$	873		$	115
	Restructuring			3,859			5,165			1,403			1,302
	Operating expenses			17,322			14,146			13,569			11,806
	Loss from operations			(5,892	)		(17,465	)		(14,099	)		(12,993	)
	Other expense, net			(558	)		(494	)		(337	)		(901	)
	Net loss		$	(6,450	)	$	(17,959	)	$	(14,436	)	$	(13,894	)
	Net loss per share—basic and diluted		$	(0.12	)	$	(0.35	)	$	(0.28	)	$	(0.27	)
			Three Months Ended
			March 31,			June 30,			September 30,			December 31,
			2013			2013			2013			2013
			(in thousands, except per share data)
			(unaudited)
	Collaboration revenue		$	323		$	324		$	323		$	323
	Restructuring			67			7,869			77			4
	Operating expenses			33,478			31,396			23,931			16,392
	Loss from operations			(33,155	)		(31,072	)		(23,608	)		(16,069	)
	Other expense, net			(930	)		(841	)		(698	)		(656	)
	Net loss		$	(34,085	)	$	(31,913	)	$	(24,306	)	$	(16,725	)
	Net loss per share—basic and diluted		$	(0.69	)	$	(0.62	)	$	(0.47	)	$	(0.32	)

Legal_Actions

Legal Actions	12 Months Ended
	Dec. 31, 2014
Legal Actions	16	Legal Actions
	Two class action lawsuits have been filed against the Company and certain present and former officers and members of the Company’s board of directors, (Tuan Ha-Ngoc, David N. Johnston, William Slichenmyer and Ronald DePinho), in the United States District Court for the District of Massachusetts, one captioned Paul Sanders v. Aveo Pharmaceuticals, Inc., et al., No. 1:13-cv-11157-JLT, filed on May 9, 2013, and the other captioned Christine Krause v. AVEO Pharmaceuticals, Inc., et al., No. 1:13-cv-11320-JLT, filed on May 31, 2013. On December 4, 2013, the District Court consolidated the complaints as In re AVEO Pharmaceuticals, Inc. Securities Litigation et al., No. 1:13-cv-11157-DJC, and an amended complaint was filed on February 3, 2014. The amended complaint purports to be brought on behalf of shareholders who purchased the Company’s common stock between January 3, 2012 and May 1, 2013. The amended complaint generally alleges that the Company and certain of its present and former officers and directors 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 our TIVO-1 study in an effort to lead investors to believe that the drug would receive approval from the FDA. The amended complaint seeks unspecified damages, interest, attorneys’ fees, and other costs. On April 4, 2014, the Company filed a motion to dismiss the consolidated class action complaint with prejudice. Lead plaintiffs filed an opposition to the motion to dismiss on June 10, 2014, and the Company filed a reply to the opposition on July 10, 2014. The Court heard oral argument on the Company’s motion to dismiss on July 22, 2014. The Company denies any allegations of wrongdoing and intends to vigorously defend against this lawsuit. However, there is no assurance that the Company will be successful in our defense or that insurance will be available or adequate to fund any settlement or judgment or the litigation costs of the action. 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.
	On April 4, 2014, Karen J. van Ingen, a purported purchaser of AVEO stock, filed a derivative complaint allegedly on behalf of AVEO in the United States District Court for the District of Massachusetts, Civil Action No. 1:14-cv-11672-DJC, naming AVEO, as a nominal defendant and also naming as defendants present and former members of the Company’s board of directors, including Tuan Ha-Ngoc, Henri A. Termeer, Kenneth M. Bate, Anthony B. Evnin, Robert Epstein, Raju Kucherlapati, Robert C. Young, and Kenneth E. Weg. The complaint alleges breach of fiduciary duty and abuse of control between January 2012 and May 2013 with respect to allegedly misleading statements and omissions regarding tivozanib. The complaint seeks, among other relief, unspecified damages, costs and expenses, including attorneys’ fees, an order requiring the Company to implement certain corporate governance reforms, restitution from the defendants and such other relief as the court might find just and proper. On July 25, 2014, defendants filed a motion to dismiss the derivative complaint with prejudice. Plaintiff filed an opposition to the motion to dismiss on September 23, 2014, and the Company filed a reply to the opposition on October 23, 2014. The Court heard oral argument on the Company’s motion to dismiss on January 7, 2015. The Company denies any allegations of wrongdoing and intends to vigorously defend this lawsuit. However, there is no assurance that the Company will be successful in its defense or that insurance will be available or adequate to fund any settlement or judgment or the litigation costs of this action. Moreover, the Company is unable to predict the outcome or reasonably estimate a range of possible loss at this time.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events	17	Subsequent Events
	On January 6, 2015, the Board of the Company approved a strategic restructuring of the Company that will eliminate the Company’s internal research function and align the Company’s resources with the Company’s future strategic plans.
	As part of this restructuring, the Company eliminated approximately two-thirds of the Company’s workforce, or 40 positions across the organization. The Company expects the restructuring to be fully completed by March 31, 2015. The Company currently expects to incur total restructuring charges of approximately $4.5 million, consisting of severance and benefit costs associated with the targeted staff reductions, which will be included in its results of operations for the first quarter of 2015. As a result of its strategic restructuring, the also Company intends to dispose of its laboratory equipment through sale during the first quarter of 2015. The Company expects to incur an impairment charge of approximately $0.3 million during the first quarter of 2015.
	In February 2015, the Company entered into an at-the-market issuance sales agreement with MLV & Co. LLC (“MLV”), pursuant to which the Company may issue and sell shares of its common stock from time to time up to an aggregate amount of $17.9 million, at the Company’s option, through MLV as its sales agent. Sales of common stock through MLV may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including by means of ordinary brokers’ transactions at market prices, in block transactions or as otherwise agreed by the Company and MLV. Subject to the terms and conditions of the sales agreement between the Company and MLV (the “Sales Agreement”), MLV will use commercially reasonable efforts to sell the common stock based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company is not obligated to make any sales of its common stock under the Sales Agreement. Any shares sold will be sold pursuant to an effective shelf registration statement on Form S-3. The Company will pay MLV a commission of up to 3% of the gross proceeds. The Sales Agreement may be terminated by the Company at any time.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Revenue Recognition	Revenue Recognition
	The Company’s revenues have been 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 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 current 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 consolidated financial statements include the Company’s accounts and the accounts of the Company’s wholly-owned subsidiaries, AVEO Pharma Limited and AVEO Securities Corporation. 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.
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 December 31, 2014 consisted of money market funds, U.S. government agency securities, and corporate debt securities, including commercial paper, maintained by an investment manager totaling $36.6 million. Cash equivalents at December 31, 2013 consisted of money market funds and corporate debt securities, including commercial paper, maintained by an investment manager totaling $45.8 million. The carrying values of our cash equivalent securities approximate fair value due to their short term maturities.
Marketable Securities	Marketable Securities
	There were no marketable securities held by the Company at December 31, 2014. Marketable securities at December 31, 2013 consisted of municipal bonds, 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 years ended December 31, 2014 and 2013.
	Available-for-sale securities at December 31, 2013 consisted of the following:
			Amortized		Unrealized			Unrealized			Fair
			Cost		Gains			Losses			Value
			(in thousands)
	Corporate debt securities (Due within 1 year)		$	52,156	$	4		$	(4	)	$	52,156
	Government agency securities (Due within 1 year)			7,519		—			—			7,519
	Asset-backed securities (Due within 1 year)			8,007		—			(2	)		8,005
			$	67,682	$	4		$	(6	)	$	67,680
	The aggregate fair value of securities in an unrealized loss position for less than 12 months at December 31, 2013 was $45.6 million, representing 18 securities. There were no securities in an unrealized loss position for greater than 12 months at December 31, 2013. The unrealized loss was caused by a temporary change in the market for these securities primarily caused by changes in markets 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. 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 these are recognized in other income (expense), net.
	Marketable securities in an unrealized loss position at December 31, 2013 consisted of the following:
			Aggregate		Unrealized
			Fair Value		Losses
			(in thousands)
	Corporate debt securities (Due within 1 year)		$	30,106	$	(4	)
	Government agency securities (Due within 1 year)			7,519		—
	Asset-backed securities (Due within 1 year)			8,005		(2	)
			$	45,630	$	(6	)
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 available-for-sale 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. The accounting standards for fair value measurements establish a hierarchy 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 that are valued utilizing only 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 that are valued utilizing Level 2 inputs include U.S. government agency securities, asset-backed securities, 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 December 31, 2014 or December 31, 2013.
		•		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 measured at fair value on a recurring basis 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 December 31, 2014 and 2013.
			Fair Value Measurements of Cash Equivalents
			as of December 31, 2014
			Level 1		Level 2			Level 3			Total
			(in thousands)
	Cash equivalents		$	28,777	$	7,834		$	—		$	36,611
			Fair Value Measurements of Cash Equivalents and
			Marketable Securities as of December 31, 2013
			Level 1		Level 2			Level 3			Total
			(in thousands)
	Cash equivalents		$	29,865	$	15,958		$	—		$	45,823
	Marketable securities			—		67,680			—			67,680
			$	29,865	$	83,638		$	—		$	113,503
	The Company recorded a liability totaling $7.3 million associated with the exit of a portion of its leased facilities. The Company measured the fair value of the liability based on the present value of the remaining termination payments. The net cash outflows were discounted using a credit-risk adjusted rate. The Company has classified this lease liability as a Level 3 fair value measurement.
	The fair value of the Company’s loans payable at December 31, 2014 and 2013, computed pursuant to a discounted cash flow technique using the effective interest rate under the loan, was $21.3 million and $20.1 million, respectively. These fair values are considered a level 3 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 charge, which approximates a market interest rate.
Tenant Improvement Allowance Receivable	Tenant Improvement Allowance Receivable
	Under the terms of its lease agreement, the Company was entitled to be reimbursed by the Company’s landlord for certain expenditures associated with improvements made to its leased facility at 650 East Kendall Street in Cambridge, Massachusetts. Pursuant to the lease agreement, the total amount of the improvement allowance allocated to the premises was $14.9 million. Through December 2014, the Company incurred $14.9 million of such expenditures which, were partially offset against amounts due by the Company for the lease termination fee discussed in Note 8. The net proceeds were reimbursed to the Company by its landlord on September 29, 2014.
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 $7.6 million of impairment losses for the year ended December 31, 2014 related to leasehold improvements. During the year ended December 31, 2013, the Company recognized $0.1 million of impairment losses.
Stock-Based Compensation	Stock-Based Compensation
	Under the Company’s stock-based compensation programs, the Company periodically grants stock options and restricted stock to employees, directors and nonemployee consultants. The Company also issues shares under an employee stock purchase plan. The fair value of all awards is recognized in the Company’s statements of operations over the requisite service period for each award. Awards that vest as the recipient provides service are expensed on a straight-line basis over the requisite service period. Other awards, such as performance-based awards that vest upon the achievement of specified goals, are expensed using the accelerated attribution method if achievement of the specified goals is considered probable. The Company has also granted awards that vest upon the achievement of market conditions. Per ASC 718 Share-Based Payments, market conditions must be considered in determining the estimated grant-date fair value of share-based payments and the market conditions must be considered in determining the requisite service period over which compensation cost is recognized. The Company estimates the fair value of the awards with market conditions using a Monte Carlo simulation, which utilizes several assumptions including the risk-free interest rate, the volatility of the Company’s stock and the exercise behavior of award recipients. The grant-date fair value of the awards is then recognized over the requisite service period, which represents the derived service period for the awards as determined by the Monte Carlo simulation.
	The fair value of equity-classified awards to employees and directors are measured at fair value on the date the awards are granted. Awards to nonemployee consultants are recorded at their fair values and are re-measured as of each balance sheet date until the recipient’s services are complete. During the years ended December 31, 2014 and 2013, the Company recorded the following stock-based compensation expense:
			Years Ended December 31,
			2014		2013			2012
			(in thousands)
	Research and development		$	899	$	1,991		$	3,566
	General and administrative			1,902		1,800			4,380
	Restructuring			—		—			61
	Total stock-based compensation expense		$	2,801	$	3,791		$	8,007
	Stock-based compensation expense is allocated to research and development and general and administrative expense based upon the department of the employee to whom each award was granted. No related tax benefits of the stock-based compensation expense have been recognized.
Income Taxes	Income Taxes
	The Company provides for income taxes using the asset-liability method. Under this method, deferred tax assets and liabilities are recognized 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. Uncertain tax positions are recognized if the position is more-likely-than-not to be sustained upon examination by a tax authority. Unrecognized tax benefits represent tax positions for which reserves have been established. The Company maintains a full valuation allowance on all deferred tax assets.
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. As of December 31, 2014, 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 accounting principles generally accepted in the United States (“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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under US GAAP. The standard is effective for public entities for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted under US GAAP. The Company is currently evaluating what effect, if any, this standard will have on its revenue recognition policies and its financial statements, including how the standard will be adopted.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. This ASU is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and to provide related footnote disclosures. This guidance is effective for fiscal years beginning after December 15, 2016, with early application permitted. The Company is currently evaluating what effect, if any, the adoption of this guidance will have on the disclosures included in its consolidated financial statements.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Available-For-Sale Securities	Available-for-sale securities at December 31, 2013 consisted of the following:
		Amortized		Unrealized			Unrealized			Fair
		Cost		Gains			Losses			Value
		(in thousands)
	Corporate debt securities (Due within 1 year)	$	52,156	$	4		$	(4	)	$	52,156
	Government agency securities (Due within 1 year)		7,519		—			—			7,519
	Asset-backed securities (Due within 1 year)		8,007		—			(2	)		8,005
		$	67,682	$	4		$	(6	)	$	67,680
Marketable Securities in Unrealized Loss Position	Marketable securities in an unrealized loss position at December 31, 2013 consisted of the following:
		Aggregate		Unrealized
		Fair Value		Losses
		(in thousands)
	Corporate debt securities (Due within 1 year)	$	30,106	$	(4	)
	Government agency securities (Due within 1 year)		7,519		—
	Asset-backed securities (Due within 1 year)		8,005		(2	)
		$	45,630	$	(6	)
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 December 31, 2014 and 2013.
		Fair Value Measurements of Cash Equivalents
		as of December 31, 2014
		Level 1		Level 2			Level 3			Total
		(in thousands)
	Cash equivalents	$	28,777	$	7,834		$	—		$	36,611
		Fair Value Measurements of Cash Equivalents and
		Marketable Securities as of December 31, 2013
		Level 1		Level 2			Level 3			Total
		(in thousands)
	Cash equivalents	$	29,865	$	15,958		$	—		$	45,823
	Marketable securities		—		67,680			—			67,680
		$	29,865	$	83,638		$	—		$	113,503
Equity-classified awards
Stock-Based Compensation Expense	During the years ended December 31, 2014 and 2013, the Company recorded the following stock-based compensation expense:
		Years Ended December 31,
		2014		2013			2012
		(in thousands)
	Research and development	$	899	$	1,991		$	3,566
	General and administrative		1,902		1,800			4,380
	Restructuring		—		—			61
	Total stock-based compensation expense	$	2,801	$	3,791		$	8,007

Loss_Per_Common_Share_Tables

Loss Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2014
Potential Common Shares Excluded from Calculation of Net Loss Per Common Share	The following table sets forth for the periods presented the potential common shares (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:
		Outstanding at
		Years Ended December 31,
		2014		2013		2012
		(in thousands)
	Options outstanding		5,817		4,297		4,638
	Warrants outstanding		609		—		—
			6,426		4,297		4,638

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property and Equipment	Property and equipment consists of the following:
		Estimated	December 31,			December 31,
		Useful Life	2014			2013
			(in thousands)
	Laboratory equipment	5 years	$	7,671		$	8,660
	Computer equipment and software	3 years		3,913			4,398
	Office furniture	5 years		893			930
	Leasehold improvements	Shorter of asset’s useful life		14,433			11,959
		or remaining term of lease
	Construction in process	—		—			3,193
				26,910			29,140
	Less accumulated depreciation and amortization			(15,615	)		(15,000	)
	Property and equipment, net		$	11,295		$	14,140

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2014
Accrued Expenses	Accrued expenses consisted of the following:
		December 31,		December 31,
		2014		2013
		(in thousands)
	Manufacturing and distribution	$	3,216	$	1,362
	Clinical expenses		2,312		5,319
	Salaries and benefits		1,744		2,027
	Professional fees		685		811
	Restructuring		—		587
	Property and equipment		—		1,905
	Other		1,344		1,252
		$	9,301	$	13,263

Loans_Payable_Tables

Loans Payable (Tables)	12 Months Ended
	Dec. 31, 2014
Future Minimum Payments Under Loans Payable	Future minimum payments under the loans payable outstanding as of December 31, 2014 are as follows (amounts in thousands):
	Years Ending December 31:
	2015	$	14,166
	2016		4,644
	2017		4,644
	2018		2,096
			25,550
	Less amount representing interest		(3,398	)
	Less discount		(960	)
	Less deferred charges		(540	)
	Less current portion		(11,722	)
	Loans payable, net of current portion and discount	$	8,930

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Reconciliation of Expected Income Tax Benefit	A reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2014, 2013 and 2012:
		December 31,			December 31,			December 31,
		2014			2013			2012
	Income tax computed at federal statutory tax rate		34	%		34	%		34	%
	State taxes, net of federal benefit		5.3	%		5.1	%		5.1	%
	Research and development credits		2.6	%		2	%		0.1	%
	Permanent differences		(0.8	)%		(0.9	)%		(1.2	)%
	Foreign rate differential		0	%		(0.2	)%		(0.4	)%
	Other		(5.7	)%		(0.5	)%		(0.2	)%
	Change in valuation allowance		(35.4	)%		(39.5	)%		(37.4	)%
	Total		0	%		0	%		0	%
Company Net Deferred Tax Assets	The Company’s net deferred tax assets as of December 31, 2014 and 2013 are as follows:
		2014			2013
		(in thousands)
	NOL carryforwards	$	162,248		$	134,023
	Research and development credits		12,721			11,357
	Deferred revenue		302			7,224
	Other temporary differences		11,135			15,158
	Valuation allowance		(186,406	)		(167,762	)
		$	—		$	—
Reconciliation of Gross Uncertain Tax Positions	The following is a reconciliation of the Company’s gross uncertain tax positions at December 31, 2014 and 2013:
		Year ended			Year ended
		December 31,			December 31,
		2014			2013
		(in thousands)
	Amount established upon adoption	$	1,200		$	1,200
	Additions for current year tax positions		—			—
	Additions for prior year tax positions		—			—
	Reductions of prior year tax positions		—			—
	Balance as of end of year	$	1,200		$	1,200

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Assumptions used in Black-Scholes Pricing Model for New Grants	The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option-pricing model using the assumptions noted in the following table:
		Years Ended December 31,
		2014		2013	2012
	Volatility	69.38%-77.92%		64.22%-72.65%	64.30%-66.05%
	Expected Term (in years)	5.50-6.25		5.50-6.25	5.50-6.25
	Risk-Free Interest Rates	1.81%-2.02%		1.01%-2.10%	0.83%-1.33%
	Dividend Yield	—		—	—
Stock Option Activity	The following table summarizes the activity of the Plans for the year ended December 31, 2014:
		Number of			Weighted-		Weighted-		Aggregate
		Options			Average		Average		Intrinsic
					Exercise		Remaining		Value
					Price		Contractual
							Life
							(in years)
	Outstanding at December 31, 2013		4,296,694		$	7.36
	Granted		2,992,100		$	1.59
	Forfeited		(544,232	)	$	4.15
	Expired		(927,249	)	$	8.89
	Outstanding at December 31, 2014		5,817,313		$	4.45		3.52		—
	Exercisable at December 31, 2014		3,461,864		$	6.24		3.38		—
	Vested or expected to vest at December 31, 2014		2,632,700		$	7.09		3.04		—
Restricted Stock Activity	The following table summarizes the restricted stock activity for the year ended December 31, 2014:
		Number of Shares			Weighted-
					Average
					Price
	Unvested at December 31, 2013		241,500		$	2.5
	Granted		501,000			1.62
	Cancelled		(191,620	)		1.92
	Expired		—			—
	Vested/Released		(73,280	)		2.5
	Unvested at December 31, 2014		477,600		$	1.81

Strategic_Restructuring_Tables

Strategic Restructuring (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring Activity Recorded in Operating Expenses and in 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 consolidated balance sheet:
		Restructuring		Restructuring		Restructuring			Restructuring
		amounts accrued at		expense		amounts			amounts
		December 31,		incurred		paid			accrued at
		2013		during the year ended		during the year ended			December 31,
				December  31,		December  31,			2014
				2014		2014
		(in thousands)
	Employee severance, benefits and related costs.	$	587		—	$	(587	)		—
		Restructuring		Restructuring		Restructuring			Restructuring
		amounts accrued at		expense		amounts			amounts
		December 31,		incurred		paid			accrued at
		2012		during the year ended		during the year ended			December 31,
				December  31,		December  31,			2013
				2013		2013
		(in thousands)
	Employee severance, benefits and related costs.	$	1,653	$	7,674	$	(8,740	)	$	587
	Contract termination costs		—		82		(82	)		—
	Total		1,653		7,756		(8,822	)		587

Facility_Lease_Exit_Tables

Facility Lease Exit (Tables)

12 Months Ended

Dec. 31, 2014

Components of Lease Exit Activity Recorded in Current Liabilities

The following table summarizes the components of the Company’s lease exit activity recorded in current liabilities:

Lease Exit

Accretion

Amounts

Amounts offset against

Amounts

Expense

Expense

paid

tenant receivable

accrued at

incurred

incurred

during the year ended

during the year ended

December 31,

during the year ended

during the year ended

December 31,

December 31, 2014

2014

December 31,

December 31,

2014

2014

2014

(in thousands)

Lease exit costs

$

17,142

$

974

$

(5,313

)

$

(7,822

)

$

4,981

Quarterly_Results_Unaudited_Ta

Quarterly Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Quarterly Results
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2014			2014			2014			2014
		(in thousands, except per share data)
		(unaudited)
	Collaboration revenue	$	15,289		$	1,846		$	873		$	115
	Restructuring		3,859			5,165			1,403			1,302
	Operating expenses		17,322			14,146			13,569			11,806
	Loss from operations		(5,892	)		(17,465	)		(14,099	)		(12,993	)
	Other expense, net		(558	)		(494	)		(337	)		(901	)
	Net loss	$	(6,450	)	$	(17,959	)	$	(14,436	)	$	(13,894	)
	Net loss per share—basic and diluted	$	(0.12	)	$	(0.35	)	$	(0.28	)	$	(0.27	)
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
		(in thousands, except per share data)
		(unaudited)
	Collaboration revenue	$	323		$	324		$	323		$	323
	Restructuring		67			7,869			77			4
	Operating expenses		33,478			31,396			23,931			16,392
	Loss from operations		(33,155	)		(31,072	)		(23,608	)		(16,069	)
	Other expense, net		(930	)		(841	)		(698	)		(656	)
	Net loss	$	(34,085	)	$	(31,913	)	$	(24,306	)	$	(16,725	)
	Net loss per share—basic and diluted	$	(0.69	)	$	(0.62	)	$	(0.47	)	$	(0.32	)

Nature_of_Business_and_Organiz1

Nature of Business and Organization - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Organization [Line Items]
Accumulated deficit	($480,028)	($427,289)

Significant_Accounting_Policie3

Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	Segment	Securities
	Securities
Significant Accounting Policies [Line Items]
Gain (loss) recognized on sale security	$0	$0
Marketable securities	0	67,680,000
Aggregate fair value of securities in unrealized loss position less than twelve months		45,600,000
Number of securities with a unrealized loss position less than twelve months		18
Aggregate fair value of securities in unrealized loss position greater than twelve months		0
Assets measured at level 3 on recurring basis	0
Liabilities measured at level 3 on recurring basis	0
Tenant improvement allowance	14,900,000
Improvement costs incurred	14,900,000
Impairment losses	7,600,000	100,000
Number of operating segments	1
Money Market Funds, U.S. Government Agency Securities, And Corporate Debt Securities, Including Commercial Paper
Significant Accounting Policies [Line Items]
Cash equivalents	36,600,000
Money Market Funds And Corporate Debt Securities, Including Commercial Paper
Significant Accounting Policies [Line Items]
Cash equivalents		45,800,000
Level 3
Significant Accounting Policies [Line Items]
Lease exit liability, fair value	7,300,000
Fair value of loan payable	21,300,000	20,100,000
Minimum
Significant Accounting Policies [Line Items]
Marketable securities maturity term	3 months
Maximum
Significant Accounting Policies [Line Items]
Marketable securities maturity term	24 months
United Kingdom
Significant Accounting Policies [Line Items]
Net assets located in the United Kingdom	$1,000,000

Available_for_Sale_Securities_

Available for Sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		$67,682,000
Unrealized Gains		4,000
Unrealized Losses		-6,000
Fair Value	0	67,680,000
Corporate debt securities | Due within 1 year
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		52,156,000
Unrealized Gains		4,000
Unrealized Losses		-4,000
Fair Value		52,156,000
Government agency securities | Due within 1 year
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		7,519,000
Fair Value		7,519,000
Asset-backed Securities | Due within 1 year
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		8,007,000
Unrealized Losses		-2,000
Fair Value		$8,005,000

Marketable_Securities_in_Unrea

Marketable Securities in Unrealized Loss Position (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments, Unrealized Loss Position [Line Items]
Aggregate Fair Value	$45,630
Unrealized Losses	-6
Corporate debt securities | Due within 1 year
Investments, Unrealized Loss Position [Line Items]
Aggregate Fair Value	30,106
Unrealized Losses	-4
Government agency securities | Due within 1 year
Investments, Unrealized Loss Position [Line Items]
Aggregate Fair Value	7,519
Asset-backed Securities | Due within 1 year
Investments, Unrealized Loss Position [Line Items]
Aggregate Fair Value	8,005
Unrealized Losses	($2)

Summary_of_Cash_Equivalents_an

Summary of Cash Equivalents and Marketable Securities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$0	$67,680,000
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	36,611,000	45,823,000
Marketable securities		67,680,000
Cash Equivalents, and Marketable Securities Fair Value Disclosure, Total		113,503,000
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	28,777,000	29,865,000
Cash Equivalents, and Marketable Securities Fair Value Disclosure, Total		29,865,000
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	7,834,000	15,958,000
Marketable securities		67,680,000
Cash Equivalents, and Marketable Securities Fair Value Disclosure, Total		$83,638,000

Stock_Based_Compensation_Expen

Stock Based Compensation Expense for Equity-Classified Awards (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$2,808	$3,940	$8,007
Equity-classified awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	2,801	3,791	8,007
Equity-classified awards | Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	899	1,991	3,566
Equity-classified awards | General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	1,902	1,800	4,380
Equity-classified awards | Restructuring Charges
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense			$61

Potential_Common_Shares_Exclud

Potential Common Shares Excluded from Calculation of Net Loss Per Common Share (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount, outstanding	6,426	4,297	4,638
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount, outstanding	5,817	4,297	4,638
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount, outstanding	609

Property_and_Equipment_Detail

Property and Equipment (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, Plant, And Equipment, Gross	$26,910	$29,140
Less accumulated depreciation and amortization	-15,615	-15,000
Property and equipment, net	11,295	14,140
Laboratory Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	5 years
Property, Plant, And Equipment, Gross	7,671	8,660
Computers Equipment And Software
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Property, Plant, And Equipment, Gross	3,913	4,398
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	5 years
Property, Plant, And Equipment, Gross	893	930
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Leasehold improvements	Shorter of asset's useful life or remaining term of lease
Property, Plant, And Equipment, Gross	14,433	11,959
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, Plant, And Equipment, Gross		$3,193

Property_and_Equipment_Additio

Property and Equipment - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 24, 2014
				sqft
Property, Plant and Equipment [Line Items]
Depreciation expense	$6,219	$3,775	$2,510
3rd Amendment, Lease exit costs associated with 650 E. Kendall.
Property, Plant and Equipment [Line Items]
Lease agreement, square feet of property leased				76,980
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | upon ninety (90) days written notice
Property, Plant and Equipment [Line Items]
Lease agreement, square feet of property leased				49,185
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | upon ninety (90) days written notice | Leasehold Improvements
Property, Plant and Equipment [Line Items]
Depreciation expense	$2,400
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | upon ninety (90) days written notice | Maximum
Property, Plant and Equipment [Line Items]
Leased space surrendering date				24-Sep-15

Accrued_Expenses_Detail

Accrued Expenses (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Accrued Liabilities [Line Items]
Manufacturing and distribution	$3,216	$1,362
Clinical expenses	2,312	5,319
Salaries and benefits	1,744	2,027
Professional fees	685	811
Restructuring		587
Property and equipment		1,905
Other	1,344	1,252
Accrued expenses	$9,301	$13,263

Loans_Payable_Additional_Infor

Loans Payable - Additional Information (Detail) (USD $)	0 Months Ended				12 Months Ended			1 Months Ended
	Sep. 24, 2014	Mar. 31, 2012	Jun. 02, 2010	28-May-10	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014	Mar. 31, 2012
Debt Instrument [Line Items]
Loan payable, aggregate principal amount		$26,500,000		$25,000,000					$26,500,000
Loan payable, start date of first principal payment		1-Apr-13		1-Jan-12
Loan outstanding	11,600,000				21,600,000
Loan payable, end-of-term payment due					540,000
Loan payable, description of interest rate terms				Per annum interest is payable on principal balance of both loans 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%.
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-Jan-16
Liquidity ratio					125.00%
Unrestricted and unencumbered cash and cash equivalents					12,500,000
Interest expense					2,388,000	3,127,000	3,501,000
Loan issuance costs paid				200,000
Warrants issued to lenders as part of the new loan agreement, shares of common stock to purchase	608,696		156,641
Warrants issued to lenders as part of the new loan agreement, exercise price	$1.15		$7.98
Warrants issued to lenders as part of the new loan agreement, fair value	400,000		800,000		413,000
Assumptions used in the Black-Scholes pricing model for warrant, volatility	71.81%
Assumptions used in the Black-Scholes pricing model for warrant, expected term	5 years
Assumptions used in the Black-Scholes pricing model for warrant, risk-free interest rate	1.82%
Loan payable, effective interest rate	16.14%
Option to purchase equity, description					As part of the Loan Agreement, 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
Starting on January 1, 2012
Debt Instrument [Line Items]
Loan payable, number of installments of principal and interest					30
Loan payable, frequency of installments of principal and interest					30 equal monthly installments
Starting on January 1, 2015
Debt Instrument [Line Items]
Loan payable, number of installments of principal and interest					12
Loan payable, frequency of installments of principal and interest					12 monthly installments of principal and interest
Minimum
Debt Instrument [Line Items]
Loan payable, interest rate				11.90%
Option to purchase equity, net cash proceeds of equity securities					10,000,000
Amended Loan Agreement
Debt Instrument [Line Items]
Loan payable, aggregate principal amount	10,000,000
Loan payable, number of installments of principal and interest					30
Loan payable, frequency of installments of principal and interest					30 principal and interest payments
Loan payable, end-of-term payment due					500,000
Loan payable, due date				1-Jan-18
Loan Discount
Debt Instrument [Line Items]
Interest expense								$1,200,000	$1,300,000

Future_Minimum_Payments_Under_

Future Minimum Payments Under Loans Payable (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
2015	$14,166
2016	4,644
2017	4,644
2018	2,096
Long-term Debt, Gross, Total	25,550
Less amount representing interest	-3,398
Less discount	-960
Less deferred charges	-540
Less current portion Loans Payable Current	-11,722	-10,383
Loans payable, net of current portion and discount	$8,930	$8,822

Collaborations_and_License_Agr

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

3 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

6 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Jul. 31, 2012

Mar. 31, 2014

Jun. 30, 2011

Mar. 31, 2010

Mar. 31, 2009

Feb. 28, 2011

Mar. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Mar. 31, 2010

Dec. 31, 2006

Dec. 31, 2011

Nov. 30, 2014

Apr. 30, 2014

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

Collaboration revenue

$115,000

$873,000

$1,846,000

$15,289,000

$323,000

$323,000

$324,000

$323,000

$18,123,000

$1,293,000

$19,286,000

Amounts due from pursuant to the cost-sharing provisions

2,341,000

984,000

2,341,000

984,000

984,000

Research and development expense

38,254,000

68,468,000

91,358,000

Other License Agreements

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

Research and development expense

25,000

License payment per product

1,000,000

License expense

0

0

300,000

Maximum | Other License Agreements

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

Collaborations and license agreements, royalties payment on net sales

1.50%

1.50%

Minimum | Other License Agreements

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

Collaborations and license agreements, royalties payment on net sales

0.50%

0.50%

Credited against amounts due the Company for tenant improvements

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

Development and sales-based milestones payment

22,500,000

Will be paid in nine equal monthly installments

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

Development and sales-based milestones payment

5,500,000

Scenario 3

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

Development and sales-based milestones payment

4,200,000

St Vincent's Hospital Sydney Limited | Licensing Agreements

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

Collaborations and license agreements, potential future milestone payments, maximum amount

9,200,000

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

10 years

Termination period in case of breach of contract

4 months

St Vincent's Hospital Sydney Limited | Up-front Payment Arrangement | Licensing Agreements

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

Collaborations and license agreements, cash payment

700,000

St Vincent's Hospital Sydney Limited | MIC-1 research and development programs | Licensing Agreements

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

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

6 months

Biodesix | NSCLC POC Trial

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

Responsible percentage of development and regulatory costs after cap reached

50.00%

Collaborations and license agreements, royalties payment on net sales

10.00%

Amounts due from pursuant to the cost-sharing provisions

1,800,000

1,800,000

Biodesix | Research and development | NSCLC POC Trial

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

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

2,700,000

Biodesix | Maximum | NSCLC POC Trial

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

Funding

15,000,000

Biogen Idec

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

Collaborations and license agreements, deferred revenue

14,700,000

14,700,000

Collaborations and license agreements, relative selling price of the deliverable

600,000

Collaborations and license agreements, revenue recognized

14,100,000

Biogen Idec | Maximum

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

Royalty payments

50,000,000

Biogen Idec International GmbH | Option and License Agreement

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

Collaborations and license agreements, milestone payment received

10,000,000

10,000,000

Amortization of deferred revenue

10,000,000

Collaborations and license agreements, revenue recognized

14,500,000

900,000

900,000

Biogen Idec International GmbH | Up-front Payment Arrangement | Option and License Agreement

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

Collaborations and license agreements, payment received

20,000,000

Astellas Pharma Inc. | Astellas Agreement

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

Collaborations and license agreements, payment received

125,000,000

Amounts due from pursuant to the cost-sharing provisions

600,000

600,000

Collaborations and license agreements, relative selling price of the deliverable

125,000,000

Collaborations and license agreements, net proceeds

97,600,000

Astellas Pharma Inc. | Collaboration and License Agreement

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

Collaborations and license agreements, payment received

4,100,000

39,800,000

40,100,000

Collaborations and license agreements, revenue recognized

3,600,000

15,400,000

400,000

Astellas Pharma Inc. | Research and development | Astellas Agreement

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

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

3,500,000

15,800,000

34,100,000

Astellas Pharma Inc. | General and administrative | Astellas Agreement

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

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

100,000

2,800,000

3,300,000

Astellas Pharma Inc. | Up-front Payment Arrangement | Astellas Agreement

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

Collaborations and license agreements, payment received

75,000,000

Astellas Pharma Inc. | research and development funding | Astellas Agreement

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

Collaborations and license agreements, payment received

50,000,000

Astellas Pharma Inc. | Regulatory Milestone Events | Astellas Agreement

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

Collaborations and license agreements, payment received

15,000,000

Astellas Pharma Inc. | License Deliverable | Astellas Agreement

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

Collaborations and license agreements, relative selling price of the deliverable

120,200,000

Collaborations and license agreements, revenue recognized

120,200,000

Astellas Pharma Inc. | Royalty Territory Deliverable | Astellas Agreement

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

Collaborations and license agreements, deferred revenue

4,800,000

Collaborations and license agreements, relative selling price of the deliverable

4,800,000

Collaborations and license agreements, revenue recognized

3,600,000

400,000

400,000

Collaborations and license agreements, deferred revenue recognition period

Through April 2022

Collaborations and license agreements, revenue recognized

3,100,000

Kirin Brewery Co. Ltd.

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

Collaborations and license agreements, description of expiry term

The Company is also entitled to receive a one-time milestone payment of $6.0 million (the bClinical Efficacy Milestone Paymentb), on the earlier of (a) December 31, 2016 and (b) the later to occur of: (i) the achievement of a clinical milestone in the POC Study (the bClinical Efficacy Milestoneb) and (ii) the earlier of (A) the date twelve (12) months after our and Ophthotechbs agreement as to the form and substance of the KHK Amendment (as defined below) or (B) the date ninety (90) days after the entry into the KHK Amendment, subject to the Companybs right to terminate the Option Agreement on 90 daysb written notice (the date on which such payment is due, referred to as the bClinical Efficacy Milestone Payment Trigger Dateb).

Collaborations and license agreements, termination

90 days

Kirin Brewery Co. Ltd. | Licensing Agreements

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

Collaborations and license agreements, cash payment

5,000,000

Collaborations and license agreements, milestone payment

10,000,000

Research and development expense

22,500,000

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

30.00%

Kirin Brewery Co. Ltd. | Collaboration and License Agreement

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

Collaborations and license agreements, milestone payment

12,000,000

Reimbursement cost

6,000,000

Kirin Brewery Co. Ltd. | Clinical Efficacy Milestone

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

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

90 days

Kirin Brewery Co. Ltd. | FDA Marketing Approval | Licensing Agreements

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

Collaborations and license agreements, potential future milestone payments, maximum amount

18,000,000

Kirin Brewery Co. Ltd. | EMA Marketing Authorization | Licensing Agreements

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

Collaborations and license agreements, potential future milestone payments, maximum amount

4,500,000

Kirin Brewery Co. Ltd. | Ema Marketing Approval | Licensing Agreements

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

Collaborations and license agreements, potential future milestone payments, maximum amount

9,000,000

Ophthotech Corporation

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

One time option exercise fee

2,000,000

Ophthotech Corporation | Option and License Agreement

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

Collaborations and license agreements, cash payment

500,000

Collaborations and license agreements, payment received

500,000

Collaboration revenue

38,000

Ophthotech Corporation | Phase Two Clinical Trials

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

Collaborations and license agreements, milestone payment received

10,000,000

Ophthotech Corporation | Marketing Approval in the United States

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

Collaborations and license agreements, milestone payment received

20,000,000

Ophthotech Corporation | Marketing Approval in the UK, Germany, Spain, Italy and France

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

Collaborations and license agreements, milestone payment received

20,000,000

Ophthotech Corporation | Sales Based Milestone Payments

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

Collaborations and license agreements, milestone payment received

45,000,000

Ophthotech Corporation | Ind Submission Milestone Payment | Option and License Agreement

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

Collaborations and license agreements, expected milestone receivable

2,000,000

Ophthotech Corporation | Clinical Efficacy Milestone | Option and License Agreement

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

Collaborations and license agreements, expected milestone receivable

$6,000,000

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 04, 2011	9-May-12
				sqft	sqft
Commitment And Contingencies [Line Items]
Rent expense	$4.10	$9.40	$7.80
Future annual minimum lease payments under all noncancelable operating leases	1.7
Maximum
Commitment And Contingencies [Line Items]
Severance and bonus payment period	18 months
Severance and bonus payment period	18 months
Minimum
Commitment And Contingencies [Line Items]
Severance and bonus payment period	12 months
Severance and bonus payment period	6 months
Massachusetts Institute of Technology
Commitment And Contingencies [Line Items]
Lease agreement, square feet of property leased				11,500
Lease agreement, expiration date				28-Feb-14
Lease commencement date				15-Dec-11
BMR-650 E KENDALL B LLC
Commitment And Contingencies [Line Items]
Lease agreement, square feet of property leased					126,065
Lease agreement, initial term					12 years 7 months
Lease agreement, number of occupancy phases of leased space					2
Lease agreement, initial base rent expense per rental square foot per year					54.5
Lease agreement, percentage of increase in base rent expense on each anniversary of phase one space rent commencement date					3.00%
Lease agreement, letter of credit outstanding					2.9
Operating lease, rent expense	4.3	6.7	4.9
Operating lease, maximum lease improvements reimbursement amount					14.9
BMR-650 E KENDALL B LLC | Phase 1 Space
Commitment And Contingencies [Line Items]
Lease agreement, square feet of property leased					26,734
Lease agreement, occupancy of leased space beginning period					4-Jan-13
Lease agreement, rent payments start date					1-Jan-13
BMR-650 E KENDALL B LLC | Phase 2 Space
Commitment And Contingencies [Line Items]
Lease agreement, rent payments start date					1-Nov-13
Restructuring and lease exit
Commitment And Contingencies [Line Items]
Rent expense	$3.10

Reconciliation_of_Expected_Inc

Reconciliation of Expected Income Tax Benefit (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Effective Tax Rates Line Items
Income tax computed at federal statutory tax rate	34.00%	34.00%	34.00%
State taxes, net of federal benefit	5.30%	5.10%	5.10%
Research and development credits	2.60%	2.00%	0.10%
Permanent differences	-0.80%	-0.90%	-1.20%
Foreign rate differential	0.00%	-0.20%	-0.40%
Other	-5.70%	-0.50%	-0.20%
Change in valuation allowance	-35.40%	-39.50%	-37.40%
Total	0.00%	0.00%	0.00%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Operating loss carryforwards, net	$4,100,000
Increase in valuation allowance	18,600,000
Unrecognized tax benefits	1,200,000	1,200,000	1,200,000
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Operating loss carryforwards, net	424,000,000
Research and development tax credit carryforwards	9,700,000
Internal Revenue Service (IRS) | Minimum
Income Taxes [Line Items]
Operating loss carryforwards, expiration year	2024
Research and development tax credit, expiration year	2022
Internal Revenue Service (IRS) | Maximum
Income Taxes [Line Items]
Operating loss carryforwards, expiration year	2034
Research and development tax credit, expiration year	2034
State and Local Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards, net	316,100,000
Research and development tax credit carryforwards	4,500,000
State and Local Jurisdiction | Minimum
Income Taxes [Line Items]
Operating loss carryforwards, expiration year	2030
Research and development tax credit, expiration year	2015
State and Local Jurisdiction | Maximum
Income Taxes [Line Items]
Operating loss carryforwards, expiration year	2034
United Kingdom
Income Taxes [Line Items]
Operating loss carryforwards, net	$6,900,000

Company_Net_Deferred_Tax_Asset

Company Net Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Income Tax Asset [Line Items]
NOL carryforwards	$162,248	$134,023
Research and development credits	12,721	11,357
Deferred revenue	302	7,224
Other temporary differences	11,135	15,158
Valuation allowance	-186,406	-167,762
Deferred Tax Assets, Net of Valuation Allowance, Total	$0	$0

Reconciliation_of_Gross_Uncert

Reconciliation of Gross Uncertain Tax Positions (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Amount established upon adoption	$1,200	$1,200
Additions for current year tax positions	0	0
Additions for prior year tax positions	0	0
Reductions of prior year tax positions	0	0
Balance as of end of year	$1,200	$1,200

Common_Stock_and_Warrants_Addi

Common Stock and Warrants - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Jan. 31, 2013	Dec. 31, 2014	Sep. 24, 2014	Jun. 02, 2010
Class of Warrant or Right [Line Items]
Common stock, shares authorized	100,000,000		100,000,000
Common stock, par value	$0.00		$0.00
Common stock, shares issued	51,809,000		52,288,799
Common stock, shares outstanding	51,809,000		52,288,799
Warrants issued to lenders as part of the new loan agreement, shares of common stock to purchase				608,696	156,641
Warrants issued to lenders as part of the new loan agreement, exercise price				$1.15	$7.98
Proceeds from issuance of common stock, net of issuance costs	$53,637
Public Offering
Class of Warrant or Right [Line Items]
Issuance of common stock, share		7,667,050
Proceeds from issuance of common stock, net of issuance costs		53,600
Issuance of common stock, issuance costs		$3,900
Underwriters Option
Class of Warrant or Right [Line Items]
Issuance of common stock, per share		$7.50

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	1 Months Ended			12 Months Ended
	Jun. 30, 2014	Mar. 31, 2013	Feb. 28, 2010	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 28, 2013	Jun. 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, number of shares authorized to sell		7,875,000
Common stock reserved for issuance				9,018,151
Number of shares for each one share of common stock subject to full-value award		1.5
Shares available for future issuance under the Plan				2,826,499
Stock options issued to purchase common stock				2,250,000
Shares of nonqualified common stock options granted to nonemployee consultants				2,992,100
Shares of nonqualified common stock options granted to nonemployee consultants, average exercise price				$1.59
Stock-based compensation expense				$2,808,000	$3,940,000	$8,007,000
Employee Stock Purchase Plan, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, number of shares authorized to sell	250,000		250,000
Employee stock purchase plan, number of additional shares available to sell	1,000,000	764,000
Stock-based compensation expense				200,000	200,000	300,000
Common stock price per share percentage as of lower of fair market value of the common stock			85.00%
employee stock purchase plan, each offering period		6 months
Employee stock purchase plan, number of share sold				139,032	109,610	94,592
Price per share of shares sold to employees	$1.53			$0.71	$1.56	$6.84	$2.13	$10.34
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards, vesting period				4 years
Awards, Expiration period				10 years
Weighted-average grant date fair value of stock options granted				$1.15	$4.32	$7.40
Share based payment award forfeiture rates				62.00%	49.00%	18.00%
Total unrecognized stock-based compensation expense				1,900,000
Total unrecognized stock-based compensation expense, weighted-average period Recognition				3 years 2 months 12 days
Intrinsic value of options exercised				0	500,000	1,900,000
Stock Options | Non Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of nonqualified common stock options granted to nonemployee consultants				225,000	0	0
Shares of nonqualified common stock options granted to nonemployee consultants, average exercise price				$1.47
Stock-based compensation expense				100,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards, vesting period				4 years
Total unrecognized stock-based compensation expense				100,000
Total unrecognized stock-based compensation expense, weighted-average period Recognition				10 months 24 days
Fair value of restricted stock awards vested				$200,000	$500,000	$500,000
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance		625,000
Stock-based award per share purchase price percentage to fair market value		100.00%
Minimum | Stock Options | Participants Who Own Less than 10% of Total Combined Voting Power
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of incentive stock options as percentage of fair market value of common stock on the date of the award				100.00%
Minimum | Stock Options | Participants Who Own More than 10% of Total Combined Voting Power
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of incentive stock options as percentage of fair market value of common stock on the date of the award				110.00%

Assumptions_Used_in_Black_Scho

Assumptions Used in Black Scholes Pricing Model for New Grants (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend Yield	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility	69.38%	64.22%	64.30%
Expected Term (in years)	5 years 6 months	5 years 6 months	5 years 6 months
Risk-Free Interest Rates	1.81%	1.01%	0.83%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility	77.92%	72.65%	66.05%
Expected Term (in years)	6 years 3 months	6 years 3 months	6 years 3 months
Risk-Free Interest Rates	2.02%	2.10%	1.33%

Stock_Option_Activity_Detail

Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Options
Outstanding at beginning of year	4,296,694
Granted	2,992,100
Forfeited	-544,232
Expired	-927,249
Outstanding at end of year	5,817,313
Exercisable at end of year	3,461,864
Vested or expected to vest at end of year	2,632,700
Weighted-Average Exercise Price
Outstanding at beginning of year	$7.36
Granted	$1.59
Forfeited	$4.15
Expired	$8.89
Outstanding at end of year	$4.45
Exercisable at end of year	$6.24
Vested or expected to vest at end of year	$7.09
Weighted-Average Remaining Contractual Term
Outstanding at end of year	3 years 6 months 7 days
Exercisable at end of year	3 years 4 months 17 days
Vested or expected to vest at end of year	3 years 15 days
Aggregate Intrinsic Value
Outstanding at end of year	$0
Exercisable at end of year	0
Vested or expected to vest at end of year	$0

Restricted_Stock_Activity_Deta

Restricted Stock Activity (Detail) (Restricted Stock, USD $)	12 Months Ended
	Dec. 31, 2014
Restricted Stock
Number of Shares
Unvested at beginning of year	241,500
Granted	501,000
Cancelled	-191,620
Expired	0
Vested/Released	-73,280
Unvested at end of year	477,600
Weighted-Average Grant-Date Fair Value
Unvested at beginning of year	$2.50
Granted	$1.62
Cancelled	$1.92
Expired	$0
Vested/Released	$2.50
Unvested at end of year	$1.81

Employee_Benefit_Plan_Addition

Employee Benefit Plan - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
401(k) Plan, matching employer contribution percentage	50.00%
401(k) Plan, employee contributions percentage	5.00%
Contributions made under the plan	$0.10	$0.40	$0.60

Strategic_Restructuring_Additi

Strategic Restructuring - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2012	Dec. 31, 2013
	Position
Restructuring Cost and Reserve [Line Items]
Restructuring plan, expected number of positions eliminated	48
Restructuring expense incurred		$7,756,000
Restructuring expense including impairment charges		$300,000
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 $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring amounts accrued, beginning balance		$1,653
Restructuring expense incurred		7,756
Restructuring amounts paid		-8,822
Restructuring amounts accrued, ending balance		587
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring amounts accrued, beginning balance	587	1,653
Restructuring expense incurred		7,674
Restructuring amounts paid	-587	-8,740
Restructuring amounts accrued, ending balance		587
Lease exit costs associated with 650 E. Kendall.
Restructuring Cost and Reserve [Line Items]
Restructuring expense incurred		82
Restructuring amounts paid		($82)

Facility_Lease_Exit_Additional

Facility Lease Exit - Additional Information (Detail) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Sep. 24, 2014
		sqft
Operating Lease Obligations [Line Items]
Tenant improvement allowance	$14,900,000
Lease exit costs associated with 650 E. Kendall.
Operating Lease Obligations [Line Items]
Lease exit liability, fair value	15,200,000
Lease Exit Expense incurred	17,142,000
Impairment of leasehold improvements	7,600,000
Lease exit costs associated with 650 E. Kendall. | Deferred rent
Operating Lease Obligations [Line Items]
Lease exit write-off cost	14,000,000
3rd Amendment, Lease exit costs associated with 650 E. Kendall.
Operating Lease Obligations [Line Items]
Lease agreement, square feet of property leased		76,980
Lease Exit Expense incurred		15,600,000
Tenant improvement allowance		14,700,000
Proceeds from landlord tenant improvements		6,800,000
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | Credited against amounts due the Company for tenant improvements
Operating Lease Obligations [Line Items]
Lease Exit Expense incurred		7,800,000
Percentage of termination fee settled		50.00%
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | Will be paid in nine equal monthly installments
Operating Lease Obligations [Line Items]
Lease exit liability, fair value	5,000,000
Percentage of termination fee settled		50.00%
Number of equal installment payments		9
Value of a monthly installment		900,000
Payments commencing date		1-Oct-14
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | upon ninety (90) days written notice
Operating Lease Obligations [Line Items]
Lease agreement, square feet of property leased		49,185
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | upon ninety (90) days written notice | Minimum
Operating Lease Obligations [Line Items]
Leased space surrendering date		24-Mar-15
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | upon ninety (90) days written notice | Maximum
Operating Lease Obligations [Line Items]
Leased space surrendering date		24-Sep-15
3rd Amendment, Lease exit costs associated with 650 E. Kendall. | Scenario 3 | Maximum
Operating Lease Obligations [Line Items]
Lease Exit Expense incurred		$1,900,000

Components_of_Lease_Exit_Activ

Components of Lease Exit Activity Recorded in Current Liabilities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Operating Lease Obligations [Line Items]
Amounts accrued	$9,301	$13,263
Lease exit costs associated with 650 E. Kendall.
Operating Lease Obligations [Line Items]
Lease Exit Expense incurred	17,142
Accretion Expense incurred	974
Amounts paid	-5,313
Amounts offset against tenant receivable	-7,822
Amounts accrued	$4,981

Summary_of_Quarterly_Results_D

Summary of Quarterly Results (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information [Line Items]
Collaboration revenue	$115	$873	$1,846	$15,289	$323	$323	$324	$323	$18,123	$1,293	$19,286
Restructuring	1,302	1,403	5,165	3,859	4	77	7,869	67	11,729	8,017	2,633
Operating expenses	11,806	13,569	14,146	17,322	16,392	23,931	31,396	33,478	68,572	105,197	130,923
Loss from operations	-12,993	-14,099	-17,465	-5,892	-16,069	-23,608	-31,072	-33,155	-50,449	-103,904	-111,637
Other expense, net	-901	-337	-494	-558	-656	-698	-841	-930	-2,290	-3,125	-2,757
Net loss	($13,894)	($14,436)	($17,959)	($6,450)	($16,725)	($24,306)	($31,913)	($34,085)	($52,739)	($107,029)	($114,394)
Net loss per share-basic and diluted	($0.27)	($0.28)	($0.35)	($0.12)	($0.32)	($0.47)	($0.62)	($0.69)	($1.01)	($2.10)	($2.64)

Legal_Proceedings_Additional_I

Legal Proceedings -Additional Information (Detail)	Dec. 31, 2014
	LegalMatter
Loss Contingencies [Line Items]
Class action lawsuits	2

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended	0 Months Ended
	Oct. 31, 2012	Dec. 31, 2013	Jan. 06, 2015	Dec. 31, 2014	Feb. 28, 2015
	Position		Position
Subsequent Event [Line Items]
Restructuring plan, expected number of positions eliminated	48
Restructuring expense including impairment charges		$300,000
Common stock sales agreement, aggregate offering amount		52,000		52,000
Subsequent Event
Subsequent Event [Line Items]
Restructuring plan, completion date			31-Mar-15
Restructuring plan, percentage of expected number of positions eliminated			66.66%
Restructuring plan, expected number of positions eliminated			40
Restructuring expense including impairment charges			300,000
Common stock sales agreement, aggregate offering amount					17,900,000
Subsequent Event | Maximum
Subsequent Event [Line Items]
Common stock sales agreement commission, percentage					3.00%
Employee Severance | Subsequent Event
Subsequent Event [Line Items]
Expected total restructuring charges			$4,500,000