Agenus (AGEN) 10-K 16 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Feb. 28, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Entity Current Reporting Status	Yes
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,016
Entity Registrant Name	AGENUS INC
Entity Central Index Key	1,098,972
Trading Symbol	AGEN
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		98,328,556
Entity Public Float			$ 287.3
Entity Voluntary Filers	No

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 71,448,016	$ 136,702,873
Short-term investments	4,988,751	34,964,730
Inventories	88,200	88,200
Accounts Receivable	11,352,022	9,800,342
Prepaid expenses	2,596,675	1,956,941
Other current assets	838,538	582,280
Total current assets	91,312,202	184,095,366
Property, plant and equipment, net of accumulated amortization and depreciation of $31,243,967 and $29,488,793 at December 31, 2016 and 2015, respectively	25,633,985	15,310,623
Goodwill	22,392,411	22,792,778
Acquired intangible assets, net of accumulated amortization of $3,193,092 and $987,394 at December 31, 2016 and 2015, respectively	16,364,726	18,759,662
Other long-term assets	1,282,662	1,270,055
Total assets	156,985,986	242,228,484
LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY
Current portion, long-term debt	146,061	146,061
Current portion, deferred revenue	2,610,719	3,829,371
Accounts payable	5,428,452	4,488,561
Accrued liabilities	27,874,703	14,165,816
Other current liabilities	4,791,265	6,304,281
Total current liabilities	40,851,200	28,934,090
Long-term debt	130,542,424	114,326,489
Deferred revenue	12,344,782	15,065,754
Contingent purchase price consideration	7,561,000	5,608,000
Other long-term liabilities	4,812,846	7,566,601
Commitments and contingencies (Notes 15 and 18)
STOCKHOLDERS’ (DEFICIT) EQUITY
Common stock, par value $0.01 per share; 240,000,000 shares authorized; 87,794,933 shares and 86,390,697 shares issued at December 31, 2016 and 2015, respectively	877,949	863,907
Additional paid-in capital	866,854,348	851,103,934
Accumulated other comprehensive loss	(1,529,559)	(2,053,143)
Accumulated deficit	(905,329,320)	(779,187,464)
Total stockholders’ (deficit) equity	(39,126,266)	70,727,550
Total liabilities and stockholders’ (deficit) equity	156,985,986	242,228,484
Series A-1 convertible preferred stock [Member]
STOCKHOLDERS’ (DEFICIT) EQUITY
Preferred stock, par value $0.01 per share; 5,000,000 shares authorized: Series A-1 convertible preferred stock; 31,620 shares designated, issued, and outstanding at December 31, 2016 and 2015; liquidation value of $32,419,678, and $32,215,432 at December 31, 2016, and 2015, respectively	316	316
Total stockholders’ (deficit) equity	$ 316	$ 316

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Property plant and equipment, accumulated amortization and depreciation	$ 31,243,967	$ 29,488,793
Acquired intangible assets, accumulated amortization	$ 3,193,092	$ 987,394
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	240,000,000
Common stock, shares issued	87,794,933	86,390,697
Series A-1 convertible preferred stock [Member]
Series A-1 convertible preferred stock, shares designated	31,620	31,620
Series A-1 convertible preferred stock, shares issued	31,620	31,620
Series A-1 convertible preferred stock, shares outstanding	31,620	31,620
Series A-1 convertible preferred stock, liquidation value	$ 32,419,678	$ 32,215,432

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Grant revenue	$ 32,404	$ 24,118	$ 504,228
Service revenue	147,456
Research and development	22,393,443	24,792,907	6,473,227
Total revenues	22,573,303	24,817,025	6,977,455
Operating expenses:
Research and development	(94,971,379)	(70,444,259)	(22,349,327)
General and administrative	(33,125,690)	(28,370,001)	(21,249,710)
Contingent purchase price consideration fair value adjustment	(1,953,000)	(6,703,700)	(6,699,300)
Operating loss	(107,476,766)	(80,700,936)	(43,320,882)
Other (expense) income:
Non-operating (expense) income	(2,202,336)	(5,968,170)	2,096,334
Interest expense, net	(17,316,073)	(6,599,083)	(1,261,626)
Loss before taxes	(126,995,175)	(93,268,188)	(42,486,174)
Income tax benefit	0	5,387,067	0
Net loss	(126,995,175)	(87,881,121)	(42,486,174)
Dividends on Series A-1 convertible preferred stock	(204,246)	(202,960)	(203,832)
Net loss attributable to common stockholders	$ (127,199,421)	$ (88,084,081)	$ (42,690,006)
Per common share data:
Basic and diluted net loss attributable to common stockholders	$ (1.46)	$ (1.13)	$ (0.71)
Weighted average number of common shares outstanding:
Basic and diluted	87,070,189	78,212,094	59,753,552
Other comprehensive income (loss):
Foreign currency translation gain (loss)	$ 677,536	$ 164,150	$ (1,778,184)
Unrealized (loss) gain on investments		(1,690)	1,764
Pension liability	(153,952)	(245,183)	(194,000)
Other comprehensive income (loss)	523,584	(82,723)	(1,970,420)
Comprehensive loss	$ (126,675,837)	$ (88,166,804)	$ (44,660,426)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' (Deficit) Equity - USD ($)	Total	Chief Executive Officer [Member]	Director [Member]	4-antibody acquisition [Member]	SECANT Yeast Display Acquisition [Member]	PhosImmune Inc. [Member]	Antibody Manufacturing Facility Acquisition [Member]	Common Stock [Member]	Common Stock [Member]Chief Executive Officer [Member]	Common Stock [Member]Director [Member]	Common Stock [Member]4-antibody acquisition [Member]	Common Stock [Member]SECANT Yeast Display Acquisition [Member]	Common Stock [Member]PhosImmune Inc. [Member]	Common Stock [Member]Antibody Manufacturing Facility Acquisition [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Chief Executive Officer [Member]	Additional Paid-in Capital [Member]Director [Member]	Additional Paid-in Capital [Member]4-antibody acquisition [Member]	Additional Paid-in Capital [Member]SECANT Yeast Display Acquisition [Member]	Additional Paid-in Capital [Member]PhosImmune Inc. [Member]	Additional Paid-in Capital [Member]Antibody Manufacturing Facility Acquisition [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Series A-1 convertible preferred stock [Member]	Series B2 convertible preferred stock [Member]
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2013	$ (4,480,703)							$ 363,912							$ 644,571,866							$ (324,792)		$ (649,092,036)	$ 316	$ 31
Balance, shares at Dec. 31, 2013								36,391,191														43,490			31,620	3,105
Net loss	(42,486,174)																							(42,486,174)
Other comprehensive income (loss)	(1,970,420)																						$ (1,970,420)
Shares sold at the market, shares								215,489
Shares sold at the market, value	600,659							$ 2,155							598,504
Shares issued in private placements, shares | Registered direct offering [Member]								22,236,000
Shares issued in private placements, value | Registered direct offering [Member]	56,191,593							$ 222,360							55,969,233
Share-based compensation	4,604,713														4,604,713
Reclassification of liability classified option grants	(487,227)														(487,227)
Vesting of nonvested shares, shares								48,239
Vesting of nonvested shares, value								$ 483							(483)
Issuance of stock for acquisition, value				$ 10,102,259							$ 33,341							$ 10,068,918
Issuance of stock for acquisition, share											3,334,079
Shares issued for compensation, shares									25,989
Shares issued for compensation, value		$ 79,200							$ 260							$ 78,940
Shares issued for acquisition liability, value	119,774							$ 351							119,423
Shares issued for acquisition liability, shares								35,124
Retirement of treasury shares, share								(43,490)														(43,490)
Retirement of treasury shares, value								$ (435)							(596,224)							$ 324,792		271,867
Stock Repurchased and Retired During Period, Value															31											$ (31)
Series B2 convertible preferred stock cancelled and extinguished																										$ (3,105)
Shares issued to repurchase convertible senior notes, value	953,765							$ 3,830							949,935
Shares issued to repurchase convertible senior notes, shares								383,038
Exercise of stock options, shares								48,381
Exercise of stock options, value	145,314							$ 484							144,830
Employee share purchases, shares								46,025
Employee share purchases, value	106,597							$ 460							106,137
Dividends on series A convertible preferred stock	(460,963)														(460,963)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2014	23,018,387							$ 627,201							715,667,633								(1,970,420)	(691,306,343)	$ 316
Balance, shares at Dec. 31, 2014								62,720,065																	31,620
Net loss	(87,881,121)																							(87,881,121)
Other comprehensive income (loss)	(82,723)																						(82,723)
Shares sold at the market, shares								12,650,000
Shares sold at the market, value	74,669,980							$ 126,500							74,543,480
Share-based compensation	8,098,650														8,098,650
Reclassification of liability classified option grants	(495,742)														(495,742)
Vesting of nonvested shares, shares								35,332
Vesting of nonvested shares, value								$ 353							(353)
Issuance of stock for acquisition, value					$ 3,000,000	$ 7,400,000	$ 500,000					$ 5,741	$ 16,315	$ 1,092					$ 2,994,259	$ 7,383,685	$ 498,908
Issuance of stock for acquisition, share												574,140	1,631,521	109,211
Shares sold under Stock Purchase Agreement, shares								7,763,968
Shares sold under Stock Purchase Agreement, values	35,000,001							$ 77,640							34,922,361
Issuance of shares related to milestone achievement, shares								80,493
Issuance of shares related to milestone achievement, values	344,541							$ 805							343,736
Issuance of warrants	3,038,438														3,038,438
Issuance of stock for settlement of contingent royalty obligation, shares								300,000
Issuance of stock for settlement of contingent royalty obligation value	2,142,000							$ 3,000							2,139,000
Exercise of stock options, shares								462,428
Exercise of stock options, value	1,766,861							$ 4,624							1,762,237
Employee share purchases, shares								63,539
Employee share purchases, value	208,278							$ 636							207,642
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2015	70,727,550							$ 863,907							851,103,934								(2,053,143)	(779,187,464)	$ 316
Balance, shares at Dec. 31, 2015								86,390,697																	31,620
Net loss	(126,995,175)																							(126,995,175)
Other comprehensive income (loss)	523,584																						523,584
Shares sold at the market, shares								496,520
Shares sold at the market, value	2,167,070							$ 4,965							2,162,105
Share-based compensation	13,323,616														13,323,616
Reclassification of liability classified option grants	(318,677)														(318,677)
Vesting of nonvested shares, shares								570,037														(185,117)
Vesting of nonvested shares, value	(768,236)							$ 5,701							(5,701)							$ (768,236)
Issuance of shares related to milestone achievement, shares								157,513
Issuance of shares related to milestone achievement, values	$ 886,798							$ 1,575							885,223
Shares issued for compensation, shares										23,110
Shares issued for compensation, value			$ 161,563							$ 231							$ 161,332
Retirement of treasury shares, share								(188,184)														188,184
Retirement of treasury shares, value								$ (1,882)							(1,632,554)							$ 781,117		853,319
Exercise of stock options, shares	224,012							224,012														(3,067)
Exercise of stock options, value	$ 729,804							$ 2,240							740,445							$ (12,881)
Employee share purchases, shares								121,228
Employee share purchases, value	435,837							$ 1,212							434,625
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2016	$ (39,126,266)							$ 877,949							$ 866,854,348								$ (1,529,559)	$ (905,329,320)	$ 316
Balance, shares at Dec. 31, 2016								87,794,933																	31,620

Consolidated Statements of Sto6

Consolidated Statements of Stockholders' (Deficit) Equity (Parenthetical)	12 Months Ended
	Dec. 31, 2014$ / shares
Series A convertible preferred stock [Member]
Dividends on series A convertible preferred stock, per share	$ 14.58

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net loss	$ (126,995,175)	$ (87,881,121)	$ (42,486,174)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,947,787	1,957,591	1,583,960
Share-based compensation	13,188,364	7,438,308	4,672,256
Non-cash interest expense	16,530,437	5,626,918	619,846
Loss on disposal of assets	14,733		4,583
Change in fair value of contingent obligations	1,953,000	13,567,000	3,579,159
In-process research and development purchase		12,245,231
Loss on extinguishment of debt		154,117
Bargain purchase		(1,522,377)
Deferred tax benefit		(5,387,067)
Change in fair value of assumed convertible notes			(201,092)
Changes in operating assets and liabilities:
Accounts receivable	(1,549,798)	(9,331,622)	1,200
Inventories		7,500	(95,700)
Prepaid expenses	(650,824)	(703,424)	(254,045)
Accounts payable	419,708	2,668,064	(45,902)
Deferred revenue	(3,939,619)	15,957,820	(3,610,811)
Accrued liabilities and other current liabilities	18,275,940	9,565,639	(1,316,169)
Other operating assets and liabilities	(2,155,364)	(11,538,019)	(685,696)
Net cash used in operating activities	(79,960,811)	(47,175,441)	(38,234,585)
Cash flows from investing activities:
Cash paid for acquisitions		(7,182,069)
Cash acquired in acquisition			514,470
Purchases of plant and equipment	(12,519,738)	(3,591,335)	(2,819,764)
Purchases of available-for-sale securities	(54,884,101)	(34,993,100)	(14,507,806)
Proceeds from sale of available-for-sale securities	85,000,000	14,534,486
Net cash provided by (used in) investing activities	17,596,161	(31,232,018)	(16,813,100)
Cash flows from financing activities:
Net proceeds from sale of equity	2,167,070	109,669,980	56,792,252
Proceeds from employee stock purchases and option exercises	1,183,598	1,975,139	251,911
Purchase of treasury shares to satisfy tax withholdings	(667,050)
Financing of plant and equipment			(39,156)
Proceeds from issuance of long-term debt		109,000,000
Debt issuance costs		(1,774,323)
Payments of debt		(1,111,111)	(3,333,334)
Payment of contingent purchase price consideration		(8,180,000)
Payment under a purchase agreement for in-process research and development	(5,000,000)
Payment of preferred stock dividends			(460,963)
Payment of contingent royalty obligation		(20,000,000)	(400,000)
Payment of capital lease obligation	(144,658)
Net cash (used in) provided by financing activities	(2,461,040)	189,579,685	52,810,710
Effect of exchange rate changes on cash	(429,167)	(183,873)	599,525
Net (decrease) increase in cash and cash equivalents	(65,254,857)	110,988,354	(1,637,450)
Cash and cash equivalents, beginning of period	136,702,873	25,714,519	27,351,969
Cash and cash equivalents, end of period	71,448,016	136,702,873	25,714,519
Supplemental cash flow information:
Cash paid for interest	1,120,000	1,053,447	675,391
Supplemental disclosures - non-cash activities:
Purchases of plant and equipment in accounts payable and accrued liabilities	695,466	105,245
Contingent purchase price consideration			9,721,000
Issuance of common stock, $0.01 par value, as payment of long-term debt including accrued and unpaid interest			953,765
Milestone obligation [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock	886,798
Directors Compensation [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock	$ 161,332
Contingent royalty obligation [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		2,142,000
Contingent purchase price obligation [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		344,541
PhosImmune Inc. [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		7,400,000
Contingent purchase price consideration		2,484,000
Antibody Manufacturing Facility Acquisition [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		500,000
SECANT Yeast Display technology [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		$ 3,000,000
4-antibody acquisition [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock			$ 10,102,259

Consolidated Statements of Cas8

Consolidated Statements of Cash Flows (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01	$ 0.01	$ 0.01
Milestone obligation [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	0.01
Directors Compensation [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01
Contingent royalty obligation [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		0.01
Contingent purchase price obligation [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		0.01
PhosImmune Inc. [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		0.01
Antibody Manufacturing Facility Acquisition [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		0.01
SECANT Yeast Display technology [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		$ 0.01
4-antibody acquisition [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value			$ 0.01

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2016
Description Of Business [Abstract]
Description of Business	(1) Description of Business Agenus Inc. (including its subsidiaries, collectively referred to as “Agenus,” the “Company,” “we,” “us,” and “our”) is a clinical stage immuno-oncology company focused on the discovery and development of therapies that engage the body’s immune system to fight cancer. Our approach to cancer immunotherapy involves a diverse portfolio of antibody-based therapeutics, adjuvants and cancer vaccine platforms. We, in collaboration with our partners, have developed a number of immuno-modulatory antibodies against important nodes of immune regulation. These include antibodies targeting CTLA-4, GITR and OX40 that are in clinical development, and our anti-PD-1 antibody anticipated to enter the clinic in the first half of 2017. Our discovery pipeline consists of a number of proprietary checkpoint modulating (“CPM”) antibodies against innovative targets such as TIGIT and 4-1BB (also known as CD137). We believe that tailored combination therapies are essential to combat some of the most resistant cancers. Accordingly, our immune education strategy focuses on pursing antibodies as well as vaccine candidates in conjunction with adjuvants. We are developing a comprehensive immuno-oncology portfolio driven by the following platforms and programs, which we intend to utilize individually and in combination: • our antibody discovery platforms, including our Retrocyte Display™, SECANT ® • our antibody candidate programs, including our CPM programs; • our vaccine programs, including Prophage™, AutoSynVax™ and PhosPhoSynVax TM our saponin-based vaccine adjuvants, principally our QS-21 Stimulon ® Our business activities have included product research and development, intellectual property prosecution, manufacturing, regulatory and clinical affairs, corporate finance and development activities, and support of our collaborations. Our product candidates require clinical trials and approvals from regulatory agencies, as well as acceptance in the marketplace. Part of our strategy is to develop and commercialize some of our product candidates by continuing our existing arrangements with academic and corporate collaborators and licensees and by entering into new collaborations. Our cash, cash equivalents, and short-term investments at December 31, 2016 were $76.4 million, a decrease of $95.3 million from December 31, 2015. Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Cash, cash equivalents and short-term investments $ 148.2 $ 123.3 $ 95.4 $ 76.4 Decrease in cash, cash equivalents and short-term investments $ 23.5 $ 24.9 $ 27.9 $ 19.0 Cash used in operating activities $ 21.5 $ 18.5 $ 23.8 $ 16.0 Reported net loss $ 31.8 $ 28.3 $ 40.8 $ 26.1 We have incurred significant losses since our inception. As of December 31, 2016 we had an accumulated deficit of $905.3 million. Since our inception, we have financed our operations primarily through the sale of equity and convertible and other notes, and interest income earned on cash, cash equivalents, and short-term investment balances. We believe that, based on our current plans and activities, our cash, cash equivalents and short-term investments balance of $76.4 million as of December 31, 2016, along with the $80.0 million received from Incyte Corporation (“Incyte”) in February 2017 in connection with amending our collaboration agreement, and issuing additional shares pursuant to a share purchase agreement, will be sufficient to satisfy our liquidity requirements for more than one year from when these financial statements were issued. We continue to monitor the likelihood of success of our key initiatives and are prepared to discontinue funding of such activities if they do not prove to be feasible, restrict capital expenditures and/or reduce the scale of our operations. Research and development program costs include compensation and other direct costs plus an allocation of indirect costs, based on certain assumptions, and our review of the status of each program. Our product candidates are in various stages of development and significant additional expenditures will be required if we start new trials, encounter delays in our programs, apply for regulatory approvals, continue development of our technologies, expand our operations, and/or bring our product candidates to market. The eventual total cost of each clinical trial is dependent on a number of factors such as trial design, length of the trial, number of clinical sites, and number of patients. The process of obtaining and maintaining regulatory approvals for new therapeutic products is lengthy, expensive, and uncertain. Because our CPM antibody programs are pre-clinical, we are unable to reliably estimate the cost of completing research and development programs, the timing of bringing such programs to various markets, or substantial partnering or out-licensing arrangements, and, therefore, are unable to determine when, if ever, material cash inflows from operating activities are likely to commence. We will continue to adjust our spending as needed in order to preserve liquidity.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	(2) Summary of Significant Accounting Policies (a) Basis of Presentation and Principles of Consolidation The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles and include the accounts of Agenus and our wholly-owned subsidiaries. All significant intercompany transactions and accounts have been eliminated in consolidation. Certain reclassifications have been made to previously reported amounts to conform to the current presentation. (b) Segment Information We are managed and operated as one business segment. The entire business is managed by a single executive operating committee that reports to the chief executive officer. We do not operate separate lines of business with respect to any of our product candidates or geographic locations. Accordingly, we do not prepare discrete financial information with respect to separate product areas or by location and do not have separately reportable segments as defined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 280, Segment Reporting. (c) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We base those estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates. (d) Cash and Cash Equivalents We consider all highly liquid investments purchased with maturities at acquisition of three months or less to be cash equivalents. Cash equivalents consist primarily of money market funds and U.S. Treasury Bills. (e) Investments We classify investments in marketable securities at the time of purchase. At December 31, 2016 and 2015, all marketable securities are classified as available for sale and as such, the investments are recorded at fair value. Gains and losses on the sale of marketable securities are recognized in operations based on the specific identification method. At December 31, 2016 and 2015, our investments consisted of institutional money market funds and U.S. Treasury Bills. (f) Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk are primarily cash equivalents, investments, and accounts receivable. We invest our cash, cash equivalents and short-term investments in accordance with our investment policy, which specifies high credit quality standards and limits the amount of credit exposure from any single issue, issuer, or type of investment. We carry balances in excess of federally insured levels, however, we have not experienced any losses to date from this practice. (g) Inventories Inventories are stated at the lower of cost or market. Cost has been determined using standard costs that approximate the first-in, first-out method. Inventory as of December 31, 2016 and 2015 consisted solely of finished goods. (h) Accounts Receivable Accounts receivable are primarily amounts due from our collaboration partner as a result of research and development services provided and reimbursements under co-funded research and development programs. We considered the need for an allowance for doubtful accounts and have concluded that no allowance was needed as of December 31, 2016 and 2015, as the estimated risk of loss on our accounts receivable was determined to be minimal. (i) Property, Plant and Equipment Property, plant and equipment, including software developed for internal use, are carried at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Amortization of leasehold improvements is computed over the shorter of the lease term or estimated useful life of the asset. Additions and improvements are capitalized, while repairs and maintenance are charged to expense as incurred. Amortization and depreciation of plant and equipment was $2.7 million, $1.4 million, and $1.1 million, for the years ended December 31, 2016, 2015, and 2014, respectively. (j) Fair Value of Financial Instruments The estimated fair values of all of our financial instruments, excluding debt, approximate their carrying amounts in the consolidated balance sheets. The fair value of our outstanding debt is based on a present value methodology. The outstanding principal amount of our debt, including the current portion, was $114.1 million and $114.1 million at December 31, 2016 and 2015, respectively. (k) Revenue Recognition Revenue for services under research and development contracts are recognized as the services are performed, or as clinical trial materials are provided. Non-refundable milestone payments that represent the completion of a separate earnings process are recognized as revenue when earned. License fees and royalties are recognized as they are earned. Grant revenue is recognized when the related expense is recorded. Revenue recognized from collaborative agreements is based upon the provisions of ASC 605-25, Revenue Recognition – Multiple-Element Arrangements (l) Foreign Currency Transactions Gains and losses from our foreign currency based accounts and transactions, such as those resulting from the translation and settlement of receivables and payables denominated in foreign currencies, are included in the consolidated statements of operations within other (expense) income. We do not currently use derivative financial instruments to manage the risks associated with foreign currency fluctuations. We recorded foreign currency losses of $2.1 million, $866,000, and $773,000, for the years ended December 31, 2016, 2015, and 2014, respectively. (m) Research and Development Research and development expenses include the costs associated with our internal research and development activities, including salaries and benefits, share-based compensation, occupancy costs, clinical manufacturing costs, related administrative costs, and research and development conducted for us by outside advisors, such as sponsored university-based research partners and clinical study partners. We account for our clinical study costs by estimating the total cost to treat a patient in each clinical trial and recognizing this cost based on estimates of when the patient receives treatment, beginning when the patient enrolls in the trial. Research and development expenses also include the cost of clinical trial materials shipped to our research partners. Research and development costs are expensed as incurred. (n) Share-Based Compensation We account for share-based compensation in accordance with the provisions of ASC 718, Compensation—Stock Compensation Equity-Based Payments to Non-Employees. (o) Income Taxes Income taxes are accounted for under the asset and liability method with deferred tax assets and liabilities recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which such items are expected to be reversed or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations in the period that includes the enactment date. Deferred tax assets are recognized when they are more likely than not expected to be realized. (p) Net Loss Per Share Basic income and loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding (including common shares issuable under our Directors’ Deferred Compensation Plan). Diluted income per common share is calculated by dividing net income attributable to common stockholders by the weighted average number of common shares outstanding (including common shares issuable under our Directors’ Deferred Compensation Plan) plus the dilutive effect of outstanding instruments such as warrants, stock options, nonvested shares, convertible preferred stock, and convertible notes. Because we reported a net loss attributable to common stockholders for all periods presented, diluted loss per common share is the same as basic loss per common share, as the effect of utilizing the fully diluted share count would have reduced the net loss per common share. Therefore, the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as of December 31, 2016, 2015, and 2014, as they would be anti-dilutive: Year Ended 2016 2015 2014 Warrants 4,351,450 4,351,450 2,951,450 Stock options 11,693,400 8,345,835 6,525,724 Nonvested shares 1,942,476 1,730,604 78,828 Convertible preferred stock 333,333 333,333 333,333 (q) Goodwill Goodwill represents the excess of cost over the fair value of net assets of businesses acquired. Goodwill is not amortized, but instead tested for impairment at least annually. Annually we assess whether there is an indication that goodwill is impaired, or more frequently if events and circumstances indicate that the asset might be impaired during the year. We perform our annual impairment test as of October 31 of each year. The first step of our impairment analysis compares our fair value to our net book value to determine if there is an indicator of impairment. We operate as a single operating segment and single reporting unit and our fair value is based on our quoted market price of our common stock to derive the market capitalization as of the date of the impairment test. ASC 350, Intangibles, Goodwill and Other (r) In-process Research and Development Acquired in-process research and development (“IPR&D”) represents the fair value assigned to research and development assets that have not reached technological feasibility. The value assigned to acquired IPR&D is determined by estimating the costs to develop the acquired technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the net cash flows to present value. The revenue and costs projections used to value acquired IPR&D are, as applicable, reduced based on the probability of success of developing a new drug. Additionally, the projections consider the relevant market sizes and growth factors, expected trends in technology, and the nature and expected timing of new product introductions by us and our competitors. The rates utilized to discount the net cash flows to their present value are commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections. Upon the acquisition of IPR&D, we complete an assessment of whether our acquisition constitutes the purchase of a single asset or a group of assets. We consider multiple factors in this assessment, including the nature of the technology acquired, the presence or absence of separate cash flows, the development process and stage of completion, quantitative significance and our rationale for entering into the transaction. If we acquire an asset or group of assets that do not meet the definition of a business under applicable accounting standards, then the acquired IPR&D is expensed on its acquisition date. Future costs to develop these assets are recorded to research and development expense as they are incurred. We review amounts capitalized as acquired IPR&D for impairment at least annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of the assets might not be recoverable. When performing our impairment assessment, we have the option to first assess qualitative factors to determine whether it is necessary to recalculate the fair value of our acquired IPR&D. If we elect this option and believe, as a result of the qualitative assessment, that it is more-likely-than-not that the fair value of our acquired IPR&D is less than its carrying amount, we calculate the fair value using the same methodology as described above. If the carrying value of our acquired IPR&D exceeds its fair value, then the intangible asset is written-down to its fair value. Alternatively, we may elect to not first assess qualitative factors and immediately recalculate the fair value of our acquired IPR&D. No IPR&D impairments were recognized for the years presented. (s) Accounting for Asset Retirement Obligations We record the fair value of an asset retirement obligation as a liability in the period in which we incur a legal obligation associated with the retirement of tangible long-lived assets that result from the acquisition, construction, development, and/or normal use of the assets. A legal obligation is a liability that a party is required to settle as a result of an existing or enacted law, statute, ordinance, or contract. We are also required to record a corresponding asset that is depreciated over the life of the asset. Subsequent to the initial measurement of the asset retirement obligation, the obligation will be adjusted at the end of each period to reflect the passage of time (accretion) and changes in the estimated future cash flows underlying the obligation. Changes in the liability due to accretion are charged to the consolidated statement of operations, whereas changes due to the timing or amount of cash flows are an adjustment to the carrying amount of the related asset. Our asset retirement obligations primarily relate to the expiration of our facility lease and anticipated costs to be incurred based on our lease terms. (t) Long-lived Assets If required based on certain events and circumstances, recoverability of assets to be held and used, other than goodwill and intangible assets not being amortized, is measured by a comparison of the carrying amount of an asset to the undiscounted future net cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset exceeds its estimated future undiscounted cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Authoritative guidance requires companies to separately report discontinued operations and extends that reporting to a component of an entity that either has been disposed of (by sale, abandonment, or in a distribution to owners) or is classified as held for sale. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. (u) Recent Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 requires management to evaluate, at each annual or interim reporting period, whether there are conditions or events that exist that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. ASU 2014-15 is effective for annual periods ending after December 15, 2016 and earlier application is permitted. The adoption of ASU 2014-15 did not have an effect on the Company’s consolidated financial statements or disclosures as the Company concluded there were no conditions or events that existed at the time these consolidated financial statements were issued that raise substantial doubt about the Company’s ability to continue as a going concern. In April 2015, the FASB issued ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, ). In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) requires lessees to recognize a right-of-use asset and a lease liability on their balance sheets for all leases with terms greater than twelve months. Based on certain criteria, leases will be classified as either financing or operating, with classification affecting the pattern of expense recognition in the income statement. for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted In March 2016, the FASB issued ASU 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, (“ASU 2016-09”). ASU 2016-09 provides for the simplification of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 applies to all entities and is effective for the annual effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted for any entity in any interim or annual period. We do not expect the impact of ASU 2016-09 to be material to our financial position and results of operations. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, which provides guidance regarding the definition of a business, with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 is effective for the Company in the first quarter of 2018, with early adoption permitted, and prospective application required. We will apply the provisions of ASU 2016-09 to any relevant transactions no later than the first quarter of 2018 and may consider earlier adoption for relevant transactions which occur in 2017.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Acquisitions	(3) Business Acquisitions 4-Antibody On January 10, 2014, we entered into a Share Exchange Agreement (the “Share Exchange Agreement”) providing for our acquisition of all of the outstanding capital stock of Agenus Switzerland Inc. (formerly known as 4-Antibody AG) (“4-AB”), from the shareholders of 4-AB (the “4-AB Shareholders”). The transaction closed on February 12, 2014 (the “Closing Date”). In exchange for their shares, the 4-AB Shareholders received an aggregate of 3,334,079 shares of our common stock paid upon closing and valued at $10.1 million. Contingent milestone payments of up to $40.0 million (the “contingent purchase price consideration”), payable in cash or shares of our common stock at our option, are due to the 4-AB Shareholders as follows: (i) $20.0 million upon our market capitalization exceeding $300.0 million for 10 consecutive trading days prior to the earliest of (a) the fifth anniversary of the Closing Date (b) the sale of the 4-AB or (c) the sale of Agenus; (ii) $10.0 million upon our market capitalization exceeding $750.0 million for 30 consecutive trading days prior to the earliest of (a) the tenth anniversary of the Closing Date (b) the sale of 4-AB, or (c) the sale of Agenus, and (iii) $10.0 million upon our market capitalization exceeding $1.0 billion for 30 consecutive trading days prior to the earliest of (a) the tenth anniversary of the Closing Date, (b) the sale of 4-AB, or (c) the sale of Agenus. We assigned an acquisition date fair value of $9.7 million to the contingent purchase price consideration. During January 2015, the first milestone noted above was achieved. This acquisition provided us with the Retrocyte Display technology platform for the rapid discovery and optimization of fully-human and humanized monoclonal antibodies against a wide array of molecular targets and a portfolio of CPM antibodies. PhosImmune Inc. On December 23, 2015 (the “PhosImmune Closing Date”), we entered into a Purchase Agreement with PhosImmune Inc., a privately-held Virginia corporation (“PhosImmune”), the securityholders of PhosImmune (the “PhosImmune Securityholders”) and Fanelli Haag PLLC, as representative of the PhosImmune Securityholders providing for the acquisition of all outstanding securities of PhosImmune. On the PhosImmune Closing Date, in exchange for their shares, the PhosImmune Securityholders received $2.5 million in cash and an aggregate of 1,631,521 of our common stock paid upon closing and valued at $7.4 million. Contingent milestone payments up to $35.0 million payable in cash and/or stock at our option are due as follows: (i) $5.0 million upon the closing trading price of our common stock equals or exceeds $8.00 for 60 consecutive trading days prior to the earlier of (a) the fifth anniversary of the PhosImmune Closing Date or (b) the sale of Agenus; (ii) $15.0 million if the closing trading price of our common stock equals or exceeds $13.00 for 60 consecutive trading days prior to the earlier of (a) the tenth anniversary of the PhosImmune Closing Date or (b) the sale of Agenus; and (iii) $15.0 million if the closing trading price of our common stock equals or exceeds $19.00 for 60 consecutive trading days prior to the earlier of (a) the tenth anniversary of the PhosImmune Closing Date or (b) the sale of Agenus. We assigned an acquisition date fair value of $2.5 million to the contingent purchase price consideration. This acquisition expands our immuno-oncology pipeline and strengthens our neoantigen capabilities to enable the development of best-in-class cancer vaccines and other novel therapies. Antibody Manufacturing Facility On November 5, 2015, we entered into Asset Purchase Agreement (the “Asset Purchase Agreement”) providing for our acquisition of an antibody manufacturing pilot plant and related capabilities from XOMA Corporation (“XOMA”). The transaction closed on December 31, 2015. As consideration for the purchased assets, we paid XOMA $4.7 million in cash and issued XOMA 109,211 shares of our common stock valued at $500,000. XOMA is entitled to receive an additional 109,211 shares of our common stock subject to the satisfaction of conditions set forth in the Asset Purchase Agreement. We do not believe it is probable that XOMA will satisfy these conditions and therefore have not ascribed a value to the contingent consideration. The transaction with XOMA provides us with an antibody pilot manufacturing facility enabling the production and manufacture of CPM antibodies under our programs and those of our collaborations. In accordance with the guidance of ASC 805 Business Combinations

Asset Purchase Agreement

Asset Purchase Agreement	12 Months Ended
	Dec. 31, 2016
Asset Purchase Agreement [Abstract]
Asset Purchase Agreement	(4) Asset Purchase Agreements Celexion, LLC On April 7, 2015 (the “Celexion Closing Date”), we entered into an Asset Purchase Agreement (the “Celexion Purchase Agreement”) with Celexion, LLC (“Celexion”) and each of the members of Celexion, pursuant to which, we acquired Celexion’s SECANT yeast display antibody discovery platform, its full-length IgG antibody library, its technology for the discovery of molecules targeting cell membrane-associated antigens, and certain other related intellectual property assets (collectively, the “Purchased Assets”). As consideration for the Purchased Assets, on the Celexion Closing Date we paid Celexion $1.0 million in cash and issued Celexion 574,140 shares of our common stock valued at approximately $5.23 per share. As additional consideration for the Purchased Assets, we agreed under the Celexion Purchase Agreement to pay to Celexion (i) $1.0 million in cash payable on each of the 9-month and 18-month anniversaries of the Celexion Closing Date and (ii) $4.0 million on each of the 12-month and 24-month anniversaries of the Celexion Closing Date payable at our discretion in cash, shares of our common stock, or any combination thereof. If we elect to pay any of the additional consideration in shares of our common stock, such shares will be issued at a price per share equal to the simple average of the daily closing volume weighted average price over the 20 trading days preceding the date of issuance. We agreed to file one or more registration statements under the Securities Act to cover the resale of all shares issued as consideration under the Celexion Purchase Agreement. In May 2015, we filed a registration statement covering the resale of the 574,140 shares issued to Celexion on the Celexion Closing Date, and the SEC declared the registration statement effective in June 2015. This transaction was accounted for as an asset acquisition in accordance with ASC 805 Business Combinations Research and Development

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	(5) Goodwill and Acquired Intangible Assets The following table sets forth the changes in the carrying amount of goodwill for year ended December 31, 2016 (in thousands): Balance, December 31, 2015 $ 22,793 Effect of foreign currency (401 ) Balance, December 31, 2016 $ 22,392 Acquired intangible assets consisted of the following at December 31, 2016 and 2015 (in thousands): As of December 31, 2016 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 7-15 years $ 16,358 $ (2,384 ) $ 13,973 Trademarks 4.5 years 791 (505 ) 286 Other 2-6 years 563 (303 ) 260 In-process research and development Indefinite 1,846 — 1,846 Total $ 19,558 $ (3,193 ) $ 16,365 As of December 31, 2015 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 15 years $ 16,472 $ (542 ) $ 15,931 Trademarks 4.5 years 812 (339 ) 473 Other 3 years 567 (107 ) 460 In-process research and development Indefinite 1,896 — 1,896 Total $ 19,747 $ (987 ) $ 18,760 The weighted average amortization period of our finite-lived intangible assets is approximately 9 years. Amortization expense for the years ended December 31, 2016, 2015, and 2014 was $2.2 million, $525,000, and $462,000, respectively. Amortization expense related to acquired intangibles is estimated at $2.2 million for 2017, $2.0 million for 2018, and $1.9 million for each of 2019, 2020, and 2021. The acquired IPR&D asset relates to the six pre-clinical CPM antibody programs acquired in the Agenus Switzerland transaction. IPR&D acquired in a business combination is capitalized at fair value until the underlying project is completed and is subject to impairment testing. Once the project is completed, the carrying value of IPR&D is amortized over the estimated useful life of the asset. Post-acquisition research and development expenses related to the acquired IPR&D are expensed as incurred.

Investments

Investments	12 Months Ended
	Dec. 31, 2016
Cash And Cash Equivalents [Abstract]
Investments	(6) Investments Cash Equivalents and Short-term Investments Cash equivalents and short-term investments consisted of the following as of December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Cost Estimated Fair Value Cost Estimated Fair Value Institutional Money Market Funds $ 38,913 $ 38,913 $ 106,370 $ 106,370 U.S. Treasury Bills 14,978 14,978 54,945 54,961 Total $ 53,891 $ 53,891 $ 161,315 $ 161,331 We received proceeds of approximately $85.0 million, $14.5 million, and $0 from the maturity of U.S. Treasury Bills classified as short-term investments for the years ended December 31, 2016, 2015, and 2014, respectively. No securities were sold before their maturity in 2016. As a result of the short-term nature of our investments, there were minimal unrealized holding gains or losses as of December 31, 2016 and 2015, and 2014. Of the investments listed above, $48.9 million and $126.4 million have been classified as cash equivalents on our consolidated balance sheet as of December 31, 2016 and 2015, respectively. Approximately $5.0 million and $35.0 million were classified as short-term investments as of December 31, 2016 and 2015, respectively.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	(7) Property, Plant and Equipment Property, plant and equipment, net as of December 31, 2016 and 2015 consist of the following (in thousands): 2016 2015 Estimated Depreciable Lives Land $ 2,230 $ 2,230 Indefinite Building and building improvements 4,605 2,900 35 years Furniture, Fixtures, and other 3,993 2,168 3 to 10 years Laboratory and manufacturing equipment 16,107 12,241 4 to 10 years Leasehold improvements 23,154 18,938 2 to 12 years Software and computer equipment 6,789 6,323 3 years 56,878 44,800 Less accumulated depreciation and amortization (31,244 ) (29,489 ) Total $ 25,634 $ 15,311

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	(8) Income Taxes We are subject to taxation in the U.S. and in various state, local, and foreign jurisdictions. We remain subject to examination by U.S. Federal, state, local, and foreign tax authorities for tax years 2013 through 2016. With a few exceptions, we are no longer subject to U.S. Federal, state, local, and foreign examinations by tax authorities for the tax year 2012 and prior. However, net operating losses from the tax year 2012 and prior would be subject to examination if and when used in a future tax return to offset taxable income. Our policy is to recognize income tax related penalties and interest, if any, in our provision for income taxes and, to the extent applicable, in the corresponding income tax assets and liabilities, including any amounts for uncertain tax positions. As of December 31, 2016, we had available net operating loss carryforwards of $682.2 million and $178.1 million for Federal and state income tax purposes, respectively, which are available to offset future Federal and state taxable income, if any, and expire between 2017 and 2036. At December 31, 2016, the Company had additional federal and state net operating loss carryforwards of $0.9 million related to excess stock based compensation tax benefits for which the benefit will be recorded to additional paid-in capital when recognized. The tax effect of temporary differences and net operating loss and tax credit carryforwards that give rise to significant portions of the deferred tax assets and deferred tax liabilities as of December 31, 2016 and 2015 are presented below (in thousands). 2016 2015 Deferred tax assets: U.S. Federal and State net operating loss carryforwards $ 241,572 $ 221,139 Foreign net operating loss carryforwards 13,075 8,412 Research and development tax credits 17,723 19,475 Share-based compensation 13,165 10,339 Other 15,513 7,123 Total deferred tax assets 301,048 266,488 Less: valuation allowance (295,502 ) (260,057 ) Net deferred tax assets 5,546 6,431 Deferred tax liabilities (6,197 ) (7,093 ) Net deferred tax liability $ (651 ) $ (662 ) In assessing the realizablility of deferred tax assets, we consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the net operating loss and tax credit carryforwards can be utilized or the temporary differences become deductible. We consider projected future taxable income and tax planning strategies in making this assessment. In order to fully realize the deferred tax asset, we will need to generate future taxable income sufficient to utilize net operating losses prior to their expiration. Based upon our history of not generating taxable income due to our business activities focused on product development, we believe that it is more likely than not that deferred tax assets will not be realized through future earnings. Accordingly, a valuation allowance has been established for deferred tax assets which will not be offset by the reversal of deferred tax liabilities. The valuation allowance on the deferred tax assets increased by $35.3 million and $25.9 million during the years ended December 31, 2016 and 2015, respectively. The net operating loss includes amounts pertaining to tax deductions relating to stock exercises for which any subsequently recognized tax benefit will be recorded as an increase to additional paid-in capital. Income tax benefit was $5.4 million for the year ended December 31, 2015 and nil for each of the years ended December 31, 2016 and 2014, respectively. The income tax benefit of $5.4 million for the year ended December 31, 2015 was entirely related to a deferred tax benefit recognized as a result of deferred tax liabilities recorded in connection with our acquisitions of PhosImmune and certain assets from XOMA. Income taxes recorded differed from the amounts computed by applying the U.S. Federal income tax rate of 34% to loss before income taxes as a result of the following (in thousands). 2016 2015 2014 Computed “expected” Federal tax benefit $ (42,781 ) $ (31,669 ) $ (14,445 ) (Increase) reduction in income taxes benefit resulting from: Change in valuation allowance 35,471 25,908 14,043 (Decrease) increase due to uncertain tax positions (203 ) 203 117 State and local income benefit, net of Federal income tax benefit (3,452 ) (3,869 ) (642 ) Net operating loss expirations — — 996 Foreign rate differential 4,398 (314 ) 726 Other, net 6,567 4,354 (795 ) Income tax benefit $ — $ (5,387 ) $ — A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): 2016 2015 2014 Balance, January 1 $ 5,481 $ 5,778 $ 5,649 Increase related to current year positions — 203 90 (Decrease) increase related to previously recognized positions (203 ) (500 ) 39 Balance, December 31 $ 5,278 $ 5,481 $ 5,778 These unrecognized tax benefits would all impact the effective tax rate if recognized. There are no positions which we anticipate could change within the next twelve months.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Accrued and Other Current Liabilities	(9) Accrued and Other Current Liabilities Accrued liabilities consist of the following as of December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Payroll $ 6,504 $ 4,600 Professional fees 2,373 3,343 Contract manufacturing costs 10,492 3,886 Research services 5,639 1,698 Leasehold improvements 1,280 — Other 1,587 638 Total $ 27,875 $ 14,166 Other current liabilities consisted of the following as of December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Current portion of deferred purchase price (Note 4) $ 3,948 $ 5,906 Other 843 398 Total $ 4,791 $ 6,304

Equity

Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Equity	(10) Equity Effective June 14, 2016, our certificate of incorporation was amended to increase the number of authorized shares of common stock from 140,000,000 to 240,000,000. Under the terms and conditions of the Certificate of Designation creating the Series A-1 Preferred Stock, this stock is convertible by the holder at any time into our common stock, is non-voting, has an initial conversion price of $94.86 per common share, subject to adjustment, and is redeemable by us at its face amount ($31.6 million), plus any accrued and unpaid dividends, on or after September 24, 2013. The Certificate of Designation does not contemplate a sinking fund. The Series A-1 Preferred Stock ranks senior to our common stock. In a liquidation, dissolution, or winding up of the Company, the Series A-1 Preferred Stock’s liquidation preference must be fully satisfied before any distribution could be made to the holders of the common stock. Other than in such a liquidation, no terms of the Series A-1 Preferred Stock affect our ability to declare or pay dividends on our common stock as long as the Series A-1 Preferred Stock’s dividends are accruing. The liquidation value of this Series A-1 Preferred stock is equal to $1,000 per share outstanding plus any accrued unpaid dividends. Dividends in arrears with respect to the Series A-1 Preferred Stock were approximately $800,000 or $25.29 per share, and $595,000, or $18.82 per share, at December 31, 2016 and 2015, respectively. In September 2007, we issued 270,562 shares of our common stock at a price of $18.48 per share to a single institutional investor. In conjunction with this transaction, we also issued to the investor 10,000 shares of our new series B1 convertible preferred stock and 5,250 shares of our new series B2 convertible preferred stock. All shares of the series B1 convertible preferred stock have been converted. Shares of the series B2 convertible preferred stock permit the investor to purchase common shares for consideration of up to 35% of the total dollar amount previously invested pursuant to the agreement with the investor, including conversions of the series B1 convertible preferred stock, at a purchase price equal to the lesser of $24.96 per common share or a price calculated based on the then-prevailing price of our common stock, with such right expiring seven years from the date of issuance. In April 2009, we issued 988,202 shares of our common stock upon conversion of 2,145 shares of our series B2 convertible preferred stock via cashless conversions. Upon completion of the conversions, 3,105 shares of our series B2 convertible preferred stock were still outstanding although no further shares could be converted into shares of common stock (other than in the event of a change of control) as the maximum number of shares (as defined in the agreement) had been issued. The total number of shares of common stock issued or issuable to the holder of the class B convertible preferred stock cannot exceed 19.9% of our outstanding common stock. No dividends are paid on the class B convertible preferred stock and there are no liquidation preferences. On September 7, 2014, all 3,105 shares of our issued and outstanding Series B2 Convertible Preferred Stock remained unconverted and were canceled and extinguished in accordance with the Certificate of Designation. In January 2008, we entered into a private placement agreement (the “January 2008 private placement”) pursuant to which we sold 1,451,450 shares of common stock for $18.00 for each share sold. Investors also received (i) 10-year warrants to purchase, at an exercise price of $18.00 per share, up to 1,451,450 shares of common stock and (ii) unit warrants to purchase, at an exercise price of $18.00 per unit, contingent upon a triggering event as defined in the January 2008 private placement documents, (a) up to 1,451,450 shares of common stock and (b) additional 10-year warrants to purchase, at an exercise price of $18.00 per share, up to 1,451,450 additional shares of common stock. In accordance with the terms of the January 2008 private placement, the 10-year warrants became exercisable for a period of 9.5 years as of July 9, 2008. Our private placement in April 2008 qualified as a triggering event, and therefore the unit warrants became exercisable for a period of eighteen months as of July 9, 2008. The unit warrants expired unexercised in January 2010. In February 2008, we filed a registration statement covering the resale of the 1,451,450 shares of common stock issued and the 1,451,450 shares issuable upon the exercise of the 10-year warrants issued in the January 2008 private placement. The Securities and Exchange Commission (the “SEC”) declared the resale registration statement effective on February 14, 2008. In connection with the January 2008 private placement, of the 1,451,450 warrants issued, 284,785 of the warrants were issued to Garo Armen, our CEO. In August 2009, we entered into a private placement agreement under which we issued and sold (i) 730,994 shares of our common stock, (ii) six-month warrants to purchase up to 365,495 additional shares of common stock at an exercise price of $13.86 per share, and (iii) four-year warrants to purchase up to 328,946 additional shares of common stock at an exercise price of $15.00 per share, for $13.68 for each share sold generating gross proceeds of $10.0 million. The warrants were not exercisable for the first six months following the closing, which occurred on August 4, 2009. Subsequently, we filed, and the SEC declared effective, a registration statement covering the resale of the 730,994 shares of our common stock issued and the 694,441 shares issuable upon the exercise of the related warrants issued in this private placement. The six-month and four-year warrants expired unexercised in July 2010 and February 2014, respectively. As part of all private placement agreements, we agreed to register the shares of common stock and the shares of common stock underlying the warrants (with the exception of the unit warrants from the January 2008 private placement) issued to the investors with the SEC within contractually specified time periods. As noted above, we filed registration statements covering all required shares. In December 2012, we entered into an Amended and Restated At Market Sales Issuance Agreement (the “2012 ATM Program”) with MLV & Co. LLC, (“MLV”) to increase the number of shares of common stock available for offer and sale under the 2012 ATM Program to an aggregate of ten million shares. During the year ended December 31, 2014, we sold an aggregate of 215,000 shares of our common stock in at the market offerings under the 2012 ATM Program and received net proceeds of $601,000 after deducting offering costs of approximately $20,000. These offerings were made under effective shelf registration statements and proceeds from the offerings were used for general corporate purposes. During September 2013, we sold approximately 3,333,000 shares of our common stock and warrants to purchase 1,000,000 shares of our common stock in a registered direct public offering raising net proceeds of approximately $9.5 million, after deducting offering expenses. The common stock and warrants were sold in units, with each unit consisting of one share of common stock and a warrant to purchase 0.3 of a share of common stock. Subject to certain ownership limitations, the warrants became exercisable beginning 6 months following issuance and will expire five years from the date they become exercisable, at an exercise price of $3.75 per share. The number of shares issuable upon exercise of the warrants and the exercise price of the warrants are adjustable in the event of stock splits, stock dividends, combinations of shares and similar recapitalization transactions. In February 2014, we issued and sold 22,236,000 shares of our common stock in a public underwritten offering. Net proceeds after deducting offering expenses were approximately $56.0 million. This offering was made under an effective shelf registration statement and proceeds from the offering are being used for general corporate purposes. In February 2014, our Board of Directors retired 43,490 shares of our treasury stock then outstanding and returned those shares to authorized and unissued shares of our common stock. In October 2014, we filed a Registration Statement on Form S-3, declared effective by the SEC on October 23, 2014 (the “2014 Registration Statement”), covering the offering of up to $150.0 million of common stock, preferred stock, warrants, debt securities and units. The 2014 Registration Statement included a prospectus covering the offering, issuance and sale of up to 10 million shares of our common stock from time to time in “at the market offerings” pursuant to an At Market Sales Issuance Agreement entered into with MLV on October 10, 2014 (the “2014 ATM Program”). On October 10, 2014, we exercised our right under 2012 ATM Program to terminate the 2012 ATM Program upon effectiveness of the 2014 Registration Statement. During the year ended December 31, 2016 we sold an aggregate of 497,000 shares of our common stock in at the market offerings under the 2014 ATM Program and received net proceeds of $2.2 million after deducting offering costs of approximately $67,000. On January 9, 2015, in connection with the execution of the Collaboration Agreement, we also entered into the Stock Purchase Agreement (the “Stock Purchase Agreement”) with Incyte Corporation, pursuant to which Incyte purchased approximately 7.76 million shares of our common stock (the “Shares”) in February 2015 for an aggregate purchase price of $35.0 million, or approximately $4.51 per share. Under the Stock Purchase Agreement we agreed to register the Shares for resale under the Securities Act of 1933, as amended (the "Securities Act"). Subsequently, we filed, and the SEC declared effective, a registration statement covering the resale of the 7,760,000 shares of our common stock issued. On February 14, 2017, we entered into an additional Stock Purchase Agreement with Incyte, pursuant to which Incyte purchased 10 million shares of our common stock at a price of $6.00 per share. See Note 22 for further details. In connection with the January 2015 achievement of the first contingent milestone, pursuant to the Agenus Switzerland Share Exchange Agreement, we issued a total of 80,493 shares of our common stock valued at approximately $345,000 as payment of a portion of our obligation. In May 2015, we issued and sold 12,650,000 shares of our common stock in an underwritten public offering. Net proceeds after deducting offering expenses were approximately $75.0 million. In September 2015, in accordance with the terms of the Assignment and Termination Agreement detailed in Note 16, we issued 300,000 shares of our common stock to Ingalls valued at $2.1 million. In September 2016, in accordance with the terms of the Technology Transfer and License Agreement with Iontas Limited (“Iontas”), we issued 157,313 shares of our common stock to Iontas valued at approximately $887,000.

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 31, 2016
Share Based Compensation [Abstract]
Share-Based Compensation Plans	(11) Share-based Compensation Plans Our 1999 Equity Incentive Plan, as amended (the “1999 EIP”) authorized awards of incentive stock options within the meaning of Section 422 of the Internal Revenue Code (the “Code”), non-qualified stock options, nonvested (restricted) stock, and unrestricted stock for up to 2.0 million shares of common stock (subject to adjustment for stock splits and similar capital changes and exclusive of options exchanged at the consummation of mergers) to employees and, in the case of non-qualified stock options, nonvested (restricted) stock, and unrestricted stock, to consultants and directors as defined in the 1999 EIP. The plan terminated on November 15, 2009. On March 12, 2009, our Board of Directors adopted, and on June 10, 2009, our stockholders approved, our 2009 Equity Incentive Plan (the “2009 EIP”). The 2009 EIP provides for the grant of incentive stock options intended to qualify under Section 422 of the Code, nonstatutory stock options, restricted stock, unrestricted stock and other equity-based awards, such as stock appreciation rights, phantom stock awards, and restricted stock units, which we refer to collectively as Awards, for up to 20.2 million shares of our common stock (subject to adjustment in the event of stock splits and other similar events). The Board of Directors appointed the Compensation Committee to administer the 1999 EIP and the 2009 EIP. No awards will be granted under the 2009 EIP after June 10, 2019. On March 12, 2009, our Board of Directors adopted, and on June 10, 2009, our stockholders approved, the 2009 Employee Stock Purchase Plan (the “2009 ESPP”) to provide eligible employees the opportunity to acquire our common stock in a program designed to comply with Section 423 of the Code. There are currently 166,666 shares of common stock reserved for issuance under the 2009 ESPP. Rights to purchase common stock under the 2009 ESPP are granted at the discretion of the Compensation Committee, which determines the frequency and duration of individual offerings under the plan and the dates when stock may be purchased. Eligible employees participate voluntarily and may withdraw from any offering at any time before the stock is purchased. Participation terminates automatically upon termination of employment. The purchase price per share of common stock in an offering is 85% of the lesser of its fair value at the beginning of the offering period or on the applicable exercise date and may be paid through payroll deductions, periodic lump sum payments, the delivery of our common stock, or a combination thereof. Unless otherwise permitted by the Board of Directors, no participant may acquire more than 3,333 shares of stock in any offering period. No participant is allowed to purchase shares under the 2009 ESPP if such employee would own or would be deemed to own stock possessing 5% or more of the total combined voting power or value of the Company. No offerings will be made under the 2009 ESPP after June 10, 2019. Our Director’s Deferred Compensation Plan, as amended, permits each outside director to defer all, or a portion of, their cash compensation until their service as a director ends or until a specified date into a cash account or a stock account. There are 325,000 shares of our common stock reserved for issuance under this plan. As of December 31, 2016, 72,081 shares had been issued. Amounts deferred to a cash account will earn interest at the rate paid on one-year Treasury bills with interest added to the account annually. Amounts deferred to a stock account will be converted on a quarterly basis into a number of units representing shares of our common stock equal to the amount of compensation which the participant has elected to defer to the stock account divided by the applicable price for our common stock. The applicable price for our common stock has been defined as the average of the closing price of our common stock for all trading days during the calendar quarter preceding the conversion date as reported by The Nasdaq Capital Market. Pursuant to this plan, a total of 246,627 units, each representing a share of our common stock at a weighted average common stock price of $5.45, had been credited to participants’ stock accounts as of December 31, 2016. The compensation charges for this plan were immaterial for all periods presented. On November 4, 2015, our Board of Directors adopted and approved our 2015 Inducement Equity Plan (the “2015 IEP”) in compliance with and in reliance on NASDAQ Listing Rule 5635(c)(4), which exempts inducement grants from the general requirement of the NASDAQ Listing Rules that equity-based compensation plans and arrangements be approved by stockholders. There are 1,500,000 shares of our common stock reserved for issuance under the 2015 IEP. We use the Black-Scholes option pricing model to value options granted to employees and non-employees, as well as options granted to members of our Board of Directors. All stock option grants have 10-year terms and generally vest ratably over a 3 or 4-year period. The non-cash charge to operations for the non-employee options with vesting or other performance criteria is affected each reporting period, until the non-employee options vest, by changes in the fair value of our common stock. The fair value of each option granted during the periods was estimated on the date of grant using the following weighted average assumptions: 2016 2015 2014 Expected volatility 65 % 77 % 84 % Expected term in years 4 6 6 Risk-free interest rate 1.0 % 1.6 % 1.7 % Dividend yield 0 % 0 % 0 % Expected volatility is based exclusively on historical volatility data of our common stock. The expected term of stock options granted is based on historical data and other factors and represents the period of time that stock options are expected to be outstanding prior to exercise. The risk-free interest rate is based on U.S. Treasury strips with maturities that match the expected term on the date of grant. A summary of option activity for 2016 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2015 8,345,835 $ 4.40 Granted 4,572,489 4.28 Exercised (224,012 ) 3.32 Forfeited (206,426 ) 5.99 Expired (794,486 ) 5.99 Outstanding at December 31, 2016 11,693,400 $ 4.51 7.52 $ 3,750,615 Vested or expected to vest at December 31, 2016 10,837,540 $ 4.53 7.38 $ 3,637,128 Exercisable at December 31, 2016 5,835,130 $ 4.64 6.02 $ 2,950,330 The weighted average grant-date fair values of options granted during the years ended December 31, 2016, 2015, and 2014, was $4.65, $3.55, and $1.87, respectively. The aggregate intrinsic value in the table above represents the difference between our closing stock price on the last trading day of fiscal 2016 and the exercise price, multiplied by the number of in-the-money options that would have been received by the option holders had all option holders exercised their options on December 31, 2016 (the intrinsic value is considered to be zero if the exercise price is greater than the closing stock price). This amount changes based on the fair market value of our stock. The total intrinsic value of options exercised during the years ended December 31, 2016, 2015, and 2014, determined on the dates of exercise, was $445,000, $1.2 million, and $45,000, respectively. During 2016, 2015, and 2014, all options were granted with exercise prices equal to the market value of the underlying shares of common stock on the grant date other than awards dated February 14, 2014. In February 2014, our Board of Directors approved awards subject to forfeiture in the event shareholder approval was not obtained to increase the shares available under our 2009 EIP. This approval was obtained in April 2014. Accordingly, these awards have a grant date of April 2014 with an exercise price as of the date the Board of Director's approved the awards in February 2014. As of December 31, 2016, there was $10.0 million of total unrecognized compensation cost related to stock options granted to employees and directors expected to be recognized over a weighted average period of 2.3 years. As of December 31, 2016, unrecognized expense for options granted to outside advisors for which performance (vesting) has not yet been completed but the exercise price of the option was known was $243,000. Such amount is subject to change each reporting period based upon changes in the fair value of our common stock, expected volatility, and the risk-free interest rate, until the outside advisor completes his or her performance under the option agreement. Certain employees and consultants have been granted nonvested stock. The fair value of nonvested stock is calculated based on the closing sale price of our common stock on the date of issuance. A summary of nonvested stock activity for 2016 is presented below: Nonvested Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2015 1,730,604 $ 8.55 Granted 996,938 3.14 Vested (570,037 ) 8.52 Forfeited (215,029 ) 8.15 Outstanding at December 31, 2016 1,942,476 $ 6.45 As of December 31, 2016, there was $3.8 million of unrecognized share-based compensation expense related to these nonvested shares which pertained primarily to performance based awards for which, if all milestones are achieved, will be recognized over a period of 1.7 years. The total intrinsic value of shares vested during the years ended December 31, 2016, 2015, and 2014, was $2.4 million, $140,000, and $205,000, respectively. Cash received from option exercises and purchases under our 2009 ESPP for the years ended December 31, 2016, 2015, and 2014, was $1.2 million, $2.0 million, and $252,000, respectively. We issue new shares upon option exercises, purchases under our 2009 ESPP, vesting of nonvested stock, and under the Director’s Deferred Compensation Plan. During the years ended December 31, 2016, 2015, and 2014, 121,228 shares, 63,539 shares, and 46,025 shares, were issued under the 2009 ESPP, respectively. During the years ended December 31, 2016, 2015, and 2014, 570,037 shares, 35,332 shares, and 48,239 shares, respectively, were issued as a result of the vesting of nonvested stock. The impact on our results of operations from share-based compensation for the years ended December 31, 2016, 2015, and 2014, was as follows (in thousands). Year Ended 2016 2015 2014 Research and development $ 6,507 $ 2,654 $ 1,272 General and administrative 6,681 4,784 3,400 Total share-based compensation expense $ 13,188 $ 7,438 $ 4,672

License, Research and Other Agr

License, Research and Other Agreements	12 Months Ended
	Dec. 31, 2016
Research And Development [Abstract]
License, Research, and Other Agreements	(12) License, Research, and Other Agreements In May 2001, we entered into a license agreement with the University of Connecticut Health Center (“UConn”) which was amended in March 2003 and June 2009. Through the license agreement, we obtained an exclusive license to patent rights resulting from inventions discovered under a research agreement that was effective from February 1998 until December 2006. The term of the license agreement ends when the last of the licensed patents expires (2024) or becomes no longer valid. UConn may terminate the agreement: (1) if, after 30 days written notice for breach, we continue to fail to make any payments due under the license agreement, or (2) we cease to carry on our business related to the patent rights or if we initiate or conduct actions in order to declare bankruptcy. We may terminate the agreement upon 90 days written notice. We are still required to make royalty payments on any obligations created prior to the effective date of termination of the license agreement. Upon expiration or termination of the license agreement due to breach, we have the right to continue to manufacture and sell products covered under the license agreement which are considered to be works in progress for a period of 6 months. The license agreement contains aggregate milestone payments of $1.2 million for each product we develop covered by the licensed patent rights. These milestone payments are contingent upon regulatory filings, regulatory approvals and commercial sales of products. We have also agreed to pay UConn a royalty on the net sales of products covered by the license agreement as well as annual license maintenance fees beginning in May 2006. Royalties otherwise due on the net sales of products covered by the license agreement may be credited against the annual license maintenance fee obligations. As of December 31, 2016, we had paid $850,000 to UConn under the license agreement. The license agreement gives us complete discretion over the commercialization of products covered by the licensed patent rights, but also requires us to use commercially reasonable diligent efforts to introduce commercial products within and outside the United States. If we fail to meet these diligence requirements, UConn may be able to terminate the license agreement. In March 2003, we entered into an amendment agreement that amended certain provisions of the license agreement with UConn. The amendment agreement granted us a license to additional patent rights. In consideration for execution of the amendment agreement, we agreed to pay UConn an upfront payment and to make future payments for licensed patents or patent applications. Through December 31, 2016, we have paid approximately $100,000 to UConn under the license agreement, as amended. On December 5, 2014, Agenus Switzerland, entered into a license agreement with the Ludwig Institute for Cancer Research Ltd., or Ludwig, which replaced and superseded a prior agreement entered into between the parties in May 2011. Pursuant to the terms of the license agreement, Ludwig granted Agenus Switzerland an exclusive, worldwide license under certain intellectual property rights of Ludwig and Memorial Sloan Kettering Cancer Center arising from the prior agreement to further develop and commercialize GITR, OX40 and TIM-3 antibodies. On January 25, 2016, we and Agenus Switzerland entered into a second license agreement with Ludwig, on substantially similar terms, to develop CTLA-4 and PD-1 antibodies. Pursuant to the December 2014 license agreement, Agenus Switzerland made an upfront payment of $1.0 million to Ludwig. The December 2014 license agreement also obligates Agenus Switzerland to make potential milestone payments of up to $20.0 million for events prior to regulatory approval of licensed GITR, OX40 and TIM-3 products, and potential milestone payments in excess of $80.0 million if such licensed products are approved in multiple jurisdictions, in more than one indication, and certain sales milestones are achieved. Under the January 2016 license agreement, we are obligated to make potential milestone payments of up to $12.0 million for events prior to regulatory approval of CTLA-4 and PD-1 licensed products, and potential milestone payments of up to $32.0 million if certain sales milestones are achieved. Under each of these license agreements, we and/or Agenus Switzerland will also be obligated to pay low to mid-single digit royalties on all net sales of licensed products during the royalty period, and to pay Ludwig a percentage of any sublicensing income, ranging from a low to mid-double digit percentage depending on various factors. The license agreements may each be terminated as follows: (i) by either party if the other party commits a material, uncured breach; (ii) by either party if the other party initiates bankruptcy, liquidation or similar proceedings; or (iii) by Agenus Switzerland or us (as applicable) for convenience upon 90 days’ prior written notice. The license agreements also contain customary representations and warranties, mutual indemnification, confidentiality and arbitration provisions. In connection with the December 2015 acquisition of PhosImmune, we obtained exclusive rights to a portfolio of patent applications and one issued patent relating to phosphopeptide tumor targets (PTTs) under a patent license agreement with the University of Virginia (UVA). The UVA license gives us exclusive rights to develop and commercialize the PTT technology and an exclusive option to license any further PTT technology arising from ongoing research at UVA until December 2018. Under the license agreement, we will pay low to mid-single digit running royalties on net sales of PTT products, and a modest flat percentage of sublicensing income. In addition, we may be obligated to make milestone payments of up to $2.7 million for each indication of a licensed PTT product to complete clinical trials and achieve certain sales thresholds. If we fail to meet certain diligence milestones, we may also be required to pay penalties in excess of $150,000. The term of the UVA license agreement ends when the last of the licensed patents expires or becomes no longer valid. The term of the UVA license agreement ends when the last of the licensed patents expires or becomes no longer valid. The UVA license agreement may be terminated as follows: (i) by UVA in connection with our bankruptcy or cessation of business relating to the licensed technology, (ii) by UVA if we commit a material, uncured breach or (iii) by us for our convenience on 180 days written notice. We have entered into various agreements with contract manufacturers, institutions, and clinical research organizations (collectively "third party providers") to perform pre-clinical activities and to conduct and monitor our clinical studies. Under these agreements, subject to the enrollment of patients and performance by the applicable third party provider, we have estimated our total payments to be $128.7 million over the term of the studies. For the years ended December 31, 2016, 2015, and 2014, $23.1 million, $19.9 million, and $0.9 million, respectively, have been expensed in the accompanying consolidated statements of operations related to these third party providers. Through December 31, 2016, we have expensed $94.4 million as research and development expenses and $82.1 million of this estimate has been paid. The timing of expense recognition and future payments related to these agreements is subject to the enrollment of patients and performance by the applicable third party provider. We have various comprehensive agreements with collaborative partners that allow for the use of QS-21 Stimulon, an investigational adjuvant used in numerous vaccines under development for a variety of diseases including, but not limited to, hepatitis, HIV, influenza, cancer, Alzheimer’s disease, malaria, and tuberculosis. These agreements grant exclusive worldwide rights in some fields of use, and co-exclusive or non-exclusive rights in others. The agreements call for royalties to be paid to us by the collaborative partner on the future sales of licensed vaccines that include QS-21 Stimulon. In July 2006, we entered into a license agreement and a supply agreement with GlaxoSmithKline (“GSK”) for the use of QS-21 Stimulon (the “GSK License Agreement” and the “GSK Supply Agreement”, respectively). In January 2009, we entered into an Amended and Restated Manufacturing Technology Transfer and Supply Agreement (the “Amended GSK Supply Agreement”) under which GSK has the right to manufacture all of its requirements of commercial grade QS-21 Stimulon. GSK is obligated to supply us (or our affiliates, licensees, or customers) certain quantities of commercial grade QS-21 Stimulon for a stated period of time. In March 2012 we entered into a First Right to Negotiate and Amendment Agreement amending the GSK License Agreement and the Amended GSK Supply Agreement to clarify and include additional rights for the use of QS-21 Stimulon (the “GSK First Right to Negotiate Agreement”). In addition, we granted GSK the first right to negotiate for the purchase of the Company or certain of our assets. The first right to negotiate will expire after five years. As consideration for entering into the GSK First Right to Negotiate Agreement, GSK paid us an upfront, non-refundable payment of $9.0 million, $2.5 million of which is creditable toward future royalty payments. We sometimes refer to the GSK License Agreement, the Amended GSK Supply Agreement and the GSK First Right to Negotiate Agreement, the “GSK Agreements”. As of December 31, 2016, we had received $23.3 million of a potential $24.3 million in upfront and milestone payments related to the GSK Agreements. We are generally entitled to receive 2% royalties on net sales of prophylactic vaccines for a period of 10 years after the first commercial sale of a resulting GSK product, with some exceptions. The GSK License and Amended GSK Supply Agreements may be terminated by either party upon a material breach if the breach is not cured within the time specified in the respective agreement. The termination or expiration of the GSK License Agreement does not relieve either party from any obligation which accrued prior to the termination or expiration. Among other provisions, the milestone payment obligations survive termination or expiration of the GSK Agreements for any reason, and the license rights granted to GSK survive expiration of the GSK License Agreement. The license rights and payment obligations of GSK under the Amended GSK Supply Agreement survive termination or expiration, except that GSK's license rights and future royalty obligations do not survive if we terminate due to GSK's material breach unless we elect otherwise. For the years ended December 31, 2016, and 2015, no revenue was recognized under our GSK License and Amended GSK Supply Agreements. For the year ended December 31, 2014, we recognized revenue of $3.3 million, respectively, related to payments received under our GSK License and Amended GSK Supply Agreements. Deferred revenue of $2.5 million related to the GSK Agreements is included in deferred revenue on our consolidated balance sheet as of December 31, 2016.

Collaboration Agreement

Collaboration Agreement	12 Months Ended
	Dec. 31, 2016
Collaboration [Abstract]
Collaboration Agreements	(13) Collaboration Agreement Incyte Corporation On January 9, 2015 and effective February 19, 2015, we entered into a global license, development and commercialization agreement (the “Collaboration Agreement”) with Incyte Corporation pursuant to which the parties plan to develop and commercialize novel immuno-therapeutics using our antibody discovery platforms. The Collaboration Agreement was initially focused on four checkpoint modulator programs directed at GITR, OX40, LAG-3 and TIM-3. In addition to the four identified antibody programs, the parties have an option to jointly nominate and pursue the development and commercialization of antibodies against additional targets during a five year discovery period which, upon mutual agreement of the parties for no additional consideration, can be extended for an additional three years. In November 2015, we and Incyte jointly nominated and agreed to pursue the development and commercialization of three additional undisclosed CPM targets. On January 9, 2015, we also entered into the Stock Purchase Agreement with Incyte Corporation whereby, for an aggregate purchase price of $35.0 million, Incyte purchased approximately 7.76 million shares of our common stock; see Note 10 for more details. Agreement Structure Under the terms of the Collaboration Agreement, we received non-creditable, nonrefundable upfront payments totaling $25.0 million. In addition, the parties will share all costs and profits for the GITR, OX40 and two of the additional antibody programs on a 50:50 basis (profit-share products), and we are eligible to receive up to $20.0 million in future contingent development milestones under these programs. Incyte is obligated to reimburse us for all development costs that we incur in connection with the TIM-3, LAG-3 and one of the additional antibody programs (royalty-bearing products) and we are eligible to receive (i) up to $155.0 million in future contingent development, regulatory, and commercialization milestone payments and (ii) tiered royalties on global net sales at rates generally ranging from 6% to 12%. For each royalty-bearing product, we will also have the right to elect to co-fund 30% of development costs incurred following initiation of pivotal clinical trials in return for an increase in royalty rates. Additionally, we retain co-promotion participation rights in the United States on any profit-share product. Through the direction of a joint steering committee, the parties anticipate that, for each program, we will serve as the lead for pre-clinical development activities through investigational new drug application filing, and Incyte will serve as the lead for clinical development activities. The parties initiated the first clinical trials of antibodies arising from these programs in 2016. For each additional program beyond GITR, OX40, TIM-3 and LAG-3 that the parties elect to bring into the collaboration, we will have the option to designate it as a profit-share product or a royalty-bearing product. The Collaboration Agreement will continue as long as (i) any product is being developed or commercialized or (ii) the discovery period remains in effect. After the first anniversary of the effective date of the Collaboration Agreement, Incyte may terminate the Collaboration Agreement or any individual program for convenience upon 12 months’ notice. The Collaboration Agreement may also be terminated by either party upon the occurrence of an uncured material breach of the other party or by us if Incyte challenges patent rights controlled by us. In addition, either party may terminate the Collaboration Agreement as to any program if the other party is acquired and the acquiring party controls a competing program. Collaboration Revenue For the years ended December 31, 2016, and 2015, we recognized revenue of approximately $19.7 million, and $23.5 million, respectively, under the Collaboration Agreement, of which, $3.5 million and $9.1 million, respectively, was related to the amortization of the $25.0 million non-creditable, nonrefundable upfront payment. No revenue was recognized under the Collaboration Agreement for the year ended December 31, 2014. As of December 31, 2016, we had deferred revenue remaining under the Collaboration Agreement of approximately $12.4 million, of which approximately $2.6 million and $9.8 million are classified as current and long-term, respectively, on our consolidated balance sheet. As of December 31, 2015, we had deferred revenue remaining under the Collaboration Agreement of approximately $15.8 million, of which approximately $3.6 million and $12.2 million are classified as current and long-term, respectively, on our consolidated balance sheet. On February 14, 2017, the parties amended the Collaboration Agreement by entering into a First Amendment to License, Development and Commercialization Agreement (the “Amendment”). On February 14, 2017, the parties also entered into an additional Stock Purchase Agreement pursuant to which Incyte purchased 10 million shares of our common stock at a price of $6.00 per share. See Note 22 for further details.

Certain Related Party Transacti

Certain Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Certain Related Party Transactions	(14) Certain Related Party Transactions Effective February 12, 2014, in connection with our acquisition of the capital stock of 4-Antibody and pursuant to the Share Exchange Agreement, our Board of Directors elected Shahzad Malik, M.D. as a director. Dr. Malik is a General Partner of Advent Venture Partners LLP (“Advent”). Advent, through its affiliated entities, was Agenus Switzerland’s largest shareholder prior to the completion of the acquisition. Upon completion of the acquisition, Advent and its affiliates received 996,088 shares of our common stock, having a value of approximately $3.0 million. In connection with the achievement of the first milestone in January 2015 under the Share Exchange Agreement, Advent and its affiliates received consideration of approximately $6.2 million. The above listed consideration was received by Advent and its affiliated entities, not Dr. Malik in his individual capacity. In May 2015, we issued and sold 12,650,000 shares of our common stock in an underwritten public offering for net proceeds of approximately $75.0 million. Of the 12,650,000 shares of our common stock issued and sold, 1,587,302 of these shares of common stock were issued and sold to Advent. Our Audit and Finance Committee approved a charitable contribution to the Children of Armenia Fund (“COAF”) totaling $100,000 for 2016. Dr. Garo H. Armen, our CEO, is the founder and chairman of COAF. The 2016 charitable contribution was comprised of a cash component and a non-cash component. The cash component was $50,000, which we paid in quarterly installments. The non-cash component was $50,000, which was the estimated value of a portion of office space made available to COAF employees. We also consider our transactions with Incyte, as disclosed in Footnote 13 and Footnote 22, to be related party transactions.

Leases

Leases	12 Months Ended
	Dec. 31, 2016
Leases [Abstract]
Leases	(15) Leases We lease manufacturing, research and development, and office facilities under various lease arrangements. Rent expense (before sublease income) was $3.3 million, $2.3 million, and $2.1 million, for the years ended December 31, 2016, 2015, and 2014, respectively. We lease a facility in Lexington, Massachusetts for our manufacturing, research and development, and corporate offices. During December 2012 we entered into a commercial lease for approximately 5,600 square feet of office space in New York, New York for use as corporate offices. Through our acquisition of Agenus Switzerland, we lease facilities Basel, Switzerland for manufacturing, research and development and corporate offices. In December 2015, in connection with the XOMA antibody manufacturing facility asset acquisition, we executed lease agreements in Berkeley, California for manufacturing and corporate offices. In December 2015, we additionally executed a lease for research and development, and corporate offices in Cambridge, United Kingdom. In February 2016, we executed a lease agreement in Charlottesville, Virginia for research and development and corporate offices. The future minimum rental payments under our facility lease agreements, which expire at various times between 2017 and 2025, are as follows (in thousands): Year ending December 31, 2017 $ 3,530 2018 3,226 2019 2,492 2020 2,133 2021 1,762 Thereafter 3,865 Total $ 17,008 In connection with the Lexington facility, we maintain a fully collateralized letter of credit of $1.0 million. No amounts had been drawn on the letter of credit as of December 31, 2016. In addition, for our properties, we are required to have an aggregate deposit of $270,000 with the landlords as interest-bearing security deposits pursuant to our obligation under the leases. We sublet a portion of our facilities and received rental payments of $733,000, $780,000, and $365,000 for the years ended December 31, 2016, 2015, and 2014, respectively. We are contractually entitled to receive rental payments of $529,000 in 2017. During 2016, we entered into an agreement which is classified as a capital lease for a piece of laboratory equipment. No such agreement existed during 2015. It is included in our property and equipment as follows (in thousands): 2016 Estimated Depreciable Lives Laboratory and manufacturing equipment $ 1,021 4 years Less accumulated depreciation and amortization (51 ) Total $ 970 Under the terms of the capital lease agreement, we will remit payments to the lessor of $288,000 for each of the years 2017 through 2019 and $144,000 for the year ending December 31, 2020.

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt	(16) Debt Debt obligations consisted of the following as of December 31, 2016 and 2015 (in thousands): Debt instrument Principal at December 31, 2016 Non-cash Interest Unamortized Debt Issuance Costs Unamortized Debt Discount Balance at December 31, 2016 Current Portion: Debentures $ 146 $ — $ — $ — $ 146 Long-term Portion: 2015 Subordinated Notes 14,000 — — (1,311 ) 12,689 Note Purchase Agreement 100,000 19,421 (1,345 ) (222 ) 117,853 Total long-term $ 114,000 $ 19,421 $ (1,345 ) $ (1,533 ) $ 130,542 Total $ 114,146 $ 19,421 $ (1,345 ) $ (1,533 ) $ 130,688 Debt instrument Principal at December 31, 2015 Non-cash Interest Unamortized Debt Issuance Costs Unamortized Debt Discount Balance at December 31, 2015 Current Portion: Debentures $ 146 $ — $ — $ — $ 146 Long-term Portion: 2015 Subordinated Notes 14,000 — — (2,292 ) 11,708 Note Purchase Agreement 100,000 4,342 (1,481 ) (243 ) 102,619 Total long-term $ 114,000 $ 4,342 $ (1,481 ) $ (2,535 ) $ 114,326 Total $ 114,146 $ 4,342 $ (1,481 ) $ (2,535 ) $ 114,473 Subordinated Notes On February 20, 2015, we, certain existing investors and certain additional investors entered into an Amended and Restated Note Purchase Agreement, pursuant to which we (i) canceled our senior subordinated promissory notes issued in April 2013 (the “2013 Notes”) in exchange for new senior subordinated promissory notes (the “2015 Subordinated Notes”) in the aggregate principal amount of $5.0 million, (ii) issued additional 2015 Subordinated Notes in the aggregate principal amount of $9.0 million and (iii) issued five year warrants (the “2013 Warrants”) to purchase 1,400,000 shares of our common stock at an exercise price of $5.10 per share. The 2015 Subordinated Notes bear interest at a rate of 8% per annum, payable in cash on the first day of each month in arrears. Among other default and acceleration terms customary for indebtedness of this type, the 2015 Subordinated Notes include default provisions which allow for the noteholders to accelerate the principal payment of the 2015 Subordinated Notes in the event we become involved in certain bankruptcy proceedings, become insolvent, fail to make a payment of principal or (after a grace period) interest on the 2015 Subordinated Notes, default on other indebtedness with an aggregate principal balance of $13.5 million or more if such default has the effect of accelerating the maturity of such indebtedness, or become subject to a legal judgment or similar order for the payment of money in an amount greater than $13.5 million if such amount will not be covered by third-party insurance. The 2015 Subordinated Notes are not convertible into shares of our common stock and will mature on February 20, 2018, at which point we must repay the outstanding balance in cash. The Company may prepay the 2015 Subordinated Notes at any time, in part or in full, without premium or penalty. The exchange of the 2013 Notes for the 2015 Subordinated Notes was accounted for as a debt extinguishment under the guidance of ASC 470 Debt The warrants to purchase 500,000 shares of the Company’s common stock issued in connection with the 2013 Notes (the “2013 Warrants”) have an exercise price of $4.41 per share, and are scheduled to expire on April 15, 2017. In March 2017, we and the holders of the 2015 Subordinated Notes entered into an Amendment to Notes and Warrants, pursuant to which we (i) extended the term of the 2013 Warrants by two years from April 15, 2017 to April 15, 2019 and (ii) extended the maturity date of the 2015 Notes by two years from February 20, 2018 to February 20, 2020. The 2013 Warrants and 2015 Notes are otherwise unchanged. See Note 22 for further details. Note Purchase Agreement Related to Future Royalties On September 4, 2015, we and our wholly-owned subsidiaries, Antigenics LLC (“Antigenics”) and Aronex Pharmaceuticals, Inc. (“Aronex”), entered into a Note Purchase Agreement (the “NPA”) with Oberland Capital SA Zermatt LLC, as collateral agent (“Oberland”), an affiliate of Oberland as the lead purchaser and other purchasers. Pursuant to the terms of the NPA, on September 8, 2015 (the “Closing Date”), Antigenics issued $100.0 million aggregate principal amount of limited recourse notes (the “Notes”) to the purchasers. Antigenics has the option to issue an additional $15.0 million aggregate principal amount of Notes (the “Additional Notes”) to the purchasers within 15 days after approval of GSK’s shingles vaccine, HZ/su, by the Food and Drug Administration, provided such approval occurs on or before June 30, 2018. The Notes accrue interest at a rate of 13.5% per annum, compounded quarterly, from and after the Closing Date computed on the basis of a 360-day year and the actual number of days elapsed. Principal and interest payments are due on each of March 15, June 15, September 15 and December 15, and shall be made solely from the royalties paid from GSK to Antigenics on sales of GSK’s shingles and malaria vaccines. The Notes are limited recourse and secured solely by a first priority security interest in the royalties and accounts and payment intangibles relating thereto plus various rights of Antigenics related to the royalties under its contracts with GSK (the “Collateral”). GSK will send all royalty payments to a segregated bank account, and to the extent there are insufficient royalties deposited into the account to fund a quarterly interest payment, the interest will be capitalized and added to the aggregate principal balance of the loan. As of December 31, 2016 we have capitalized interest of $19.4 million. The final legal maturity date of the Notes is the earlier of (i) the 10th anniversary of the first commercial sale of GSK’s shingles or malaria vaccines and (ii) September 8, 2030 (the “Maturity Date”). Antigenics’ obligation to repay all principal and accrued and unpaid interest by the Maturity Date is secured only by the Collateral. At our option, we may redeem all, but not less than all, of the Notes at any time prior to the Maturity Date. The redemption price is equal to the outstanding principal amount of the Notes, plus all accrued and unpaid interest thereon, plus a premium payment that would yield an aggregate internal rate of return (“IRR”) for the purchasers as follows: (i) an IRR of 20% if the redemption occurs within 24 months of the Closing Date, (ii) an IRR of 17.5% if the redemption occurs after 24 months but within 48 months of the Closing Date, and (iii) an IRR of 15% if the redemption occurs more than 48 months after the Closing Date (the “Redemption Payment”). On September 8, 2018, each purchaser has the option to require Antigenics to repurchase up to 15% of the Notes issued to such purchaser on the Closing Date (the “Put Notes”) at a purchase price equal to the principal amount thereof plus accrued and unpaid interest thereon (the “Put Payment”). Antigenics is required to complete any such repurchase within 90 days after September 8, 2018. On the earlier of (i) September 8, 2027 and (ii) the Maturity Date, Antigenics is required to pay the purchasers an amount equal to the following (the “Make-Whole Payment”): $100.0 million (or $115.0 million if the Additional Notes are sold) minus the aggregate amount of all payments made in respect of the Notes (regardless of whether characterized as principal or interest at the time of payment), including the original principal amount of any repaid Put Notes. The NPA specifies a number of events of default (some of which are subject to applicable cure periods), including (i) failure to cause royalty payments to be deposited into the segregated bank account, (ii) payment defaults, (iii) breaches of representations and warranties made at the time the Notes were issued, (iv) covenant defaults, (v) a final and unappealable judgment against Antigenics for the payment of money in excess of $1.0 million, (vi) bankruptcy or insolvency defaults, (vii) the failure to maintain a first-priority perfected security interest in the Collateral in favor of the collateral agent and (viii) the occurrence of a change of control of Agenus. Upon the occurrence of an event of default, subject to cure periods in certain circumstance and some limited exceptions, Oberland may declare the Notes immediately due and payable, in which case Antigenics would owe a payment equal to the Redemption Payment (the “Accelerated Default Payment”). Upon the occurrence and during the continuance of any event of default, interest on the Notes also increases by 2.5% per annum. Agenus and Aronex (together, the “Guarantors”), are parties to the NPA as guarantors of certain of Antigenics’ obligations under the NPA. The Guarantors generally guarantee the Put Payment, the Make-Whole Payment, the Redemption Payment and the Accelerated Default Payment. In accordance with the guidance of ASC 470 Debt We will periodically assess the expected royalties using a combination of historical results, internal projections and forecasts from external sources. To the extent such payments are greater or less than our initial estimates or the timing of such payments is materially different than our original estimates, we will prospectively adjust the estimated time period over which the debt and interest will be repaid. There are a number of factors that could materially affect the amount and timing of royalty payments from GSK, all of which are not within our control. Such factors include, but are not limited to, changing standards of care, the introduction of competing products, manufacturing or other delays, biosimilar competition, patent protection, adverse events that result in governmental health authority imposed restrictions on the use of the drug products, significant changes in foreign exchange rates, and other events or circumstances that could result in reduced royalty payments from GSK, all of which would result in a reduction of royalty revenues and the interest expense over the life of the NPA. As royalties are remitted to the purchasers, we will record non-cash royalty revenues and non-cash interest expense within our consolidated statements of operations and comprehensive loss over the term of the NPA as interest accrues and royalties are generated. We have not recognized any royalty revenue to date, and recorded $15.1 million and $4.3 million in non-cash interest expense for the years ended December 31, 2016 and 2015, respectively, within our consolidated statement of operations and comprehensive loss. In connection with the execution of the NPA, we reimbursed the purchasers for legal fees of $250,000 and incurred debt issuance costs of approximately $1.5 million. Under the relevant accounting guidance, legal fees and debt issuance costs have been recorded as a reduction to the gross proceeds. These amounts are being amortized over 12 years, the expected term of the Notes, using the effective interest rate method. Other In June 2016, we executed a capital lease agreement that expires in June 2020 for equipment with a carrying value of approximately $1.0 million, which is included in property, plant and equipment, net on our consolidated balance sheets as of December 31, 2016. As of December 31, 2016, our remaining obligations under the capital lease agreement are approximately $0.9 million, of which $289,000 and $599,000 are classified as other current and other long-term liabilities, respectively, on our condensed consolidated balance sheets. At December 31, 2016, approximately $146,000 of debentures we assumed in our merger with Aquila Biopharmaceuticals are outstanding. These debentures carry interest at 7% and are callable by the holders. Accordingly, they are classified as short-term debt. Revenue Interest Assignment Termination On April 15, 2013, we and Antigenics entered into a Revenue Interests Assignment Agreement (the “Original Agreement”) with Ingalls & Snyder Value Partners, L.P. and Arthur Koenig (together, “Ingalls”), pursuant to which we and Antigenics sold to Ingalls 20% of all the royalties Antigenics was entitled to receive from GSK and Janssen Sciences Ireland Uc on products associated with Agenus’s QS-21 Stimulon (collectively, the “Assigned Interests”). On September 4, 2015, we and Antigenics entered into a Revenue Interest Assignment and Termination Agreement (the “Assignment and Termination Agreement”) with Ingalls, pursuant to which we terminated the Original Agreement and repurchased the Assigned Interests in exchange for (i) $20.0 million in cash and (ii) 300,000 shares of Agenus common stock for total consideration of approximately $22.1 million. The closing under the Assignment and Termination Agreement took place on September 8, 2015 immediately prior to the closing under the NPA. Effective September 8, 2015, we have no further obligations under the Original Agreement. During the year ended December 31, 2015, we recorded a fair value adjustment of approximately $6.9 million recorded within non-operating (expense) income in our consolidated statement of operations and comprehensive loss.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Measurements [Abstract]
Fair Value Measurements	(17) Fair Value Measurements We measure our cash equivalents and short-term investments, contingent purchase price considerations and in the past, our contingent royalty obligation, at fair value. Our cash equivalents and short-term investments are comprised solely of U.S. Treasury Bills that are valued using quoted market prices with no valuation adjustments applied. Accordingly, these securities are categorized as Level 1 assets. We measure our contingent purchase price consideration at fair value. The fair values of our Agenus Switzerland and PhosImmune contingent purchase price consideration, $3.9 million and $3.6 million, respectively, are based on significant inputs not observable in the market, which require them to be reported as Level 3 liabilities within the fair value hierarchy. The valuation of the liabilities uses assumptions we believe would be made by a market participant. The fair value of our Agenus Switzerland and PhosImmune contingent purchase price consideration is based on estimates from a Monte Carlo simulation of our market capitalization and share price, respectively, and other factors impacting the probability of triggering the milestone payments. Market capitalization and share price were evolved using a geometric brownian motion, calculated daily for the life of the contingent purchase price consideration. Assets and liabilities measured at fair value are summarized below (in thousands): Description December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash equivalents $ 9,990 $ 9,990 $ — $ — Short-term investments 4,988 4,988 — — Total $ 14,978 $ 14,978 $ — $ — Liabilities: Contingent purchase price consideration 7,561 — — 7,561 Total $ 7,561 $ — $ — $ 7,561 Description December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash equivalents $ 19,996 $ 19,996 Short-term investments 34,965 34,965 — — Total $ 54,961 $ 54,961 $ — $ — Liabilities: Contingent purchase price consideration 5,608 — — 5,608 Total $ 5,608 $ — $ — $ 5,608 The following table presents our liabilities measured at fair value using significant unobservable inputs (Level 3), as of December 31, 2016 (amounts in thousands): Balance, December 31, 2015 $ 5,608 Change in fair value of contingent purchase price consideration during the period 1,953 Balance, December 31, 2016 $ 7,561 There were no changes in the valuation techniques during the period and there were no transfers into or out of Levels 1 and 2. The fair value of our outstanding debt balance at December 31, 2016 and 2015 was $129.2 million and $115.9 million, respectively, based on the Level 2 valuation hierarchy of the fair value measurements standard using a present value methodology which was derived by evaluating the nature and terms of each note and considering the prevailing economic and market conditions at the balance sheet date. The principal amount of our outstanding debt balance at both December 31, 2016 and 2015 was $114.1 million.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2016
Contingencies Disclosure [Abstract]
Contingencies	(18) Contingencies We may currently be, or may become, a party to legal proceedings. While we currently believe that the ultimate outcome of any of these proceedings will not have a material adverse effect on our financial position, results of operations, or liquidity, litigation is subject to inherent uncertainty. Furthermore, litigation consumes both cash and management attention.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2016
Compensation And Retirement Disclosure [Abstract]
Benefit Plans	(19) Benefit Plans We sponsor a defined contribution 401(k) savings plan for all eligible employees, as defined in the savings plan. Participants may contribute up to 60% of their compensation, as defined in the savings plan, with a maximum annual contribution of $18,000 for individuals under 50 years old and $24,000 for individuals 50 years old and older in 2016. Each participant is fully vested in his or her contributions and related earnings and losses. During the years ended December 31, 2016 and 2015, we made discretionary contributions of $302,000 and $307,000, respectively; no discretionary contributions or expense was recorded for the year ended December 31, 2014. For the years ended December 31, 2016, and 2015, we expensed $302,000 and $307,000, respectively, related to the discretionary contribution. No expense was recorded for the year ended December 31, 2014. We also have a multiple employer benefit plan that covers certain international employees. The annual measurement date for this plan is December 31. Benefits are based upon years of service and compensation. We are required to recognize the funded status (the difference between the fair value of plan assets and the projected benefit obligations) of our multiple employer plan in our consolidated balance sheets which, for the years ended December 31, 2016, and 2015 amounted to a liability of approximately $1.2 million and $944,000, respectively, with a corresponding adjustment to accumulated other comprehensive loss of $154,000 and $245,000 for the years ended December 31, 2016 and 2015, respectively. During the years ended December 31, 2016, and 2015, we contributed approximately $153,000 and $119,000, respectively, to our international benefit plan and we expect to contribute approximately $162,000 to that plan during 2017. As of December 31, 2016, the benefits expected to be paid under this plan in the next five years and in the aggregate for the five years thereafter are as follows, $136,000 in 2017, $125,000 in 2018, $116,000 in 2019, $107,000 in 2020, $100,000 in 2021 and $452,000 for the years 2022-2026.

Geographical Information

Geographical Information	12 Months Ended
	Dec. 31, 2016
Geographic Information [Abstract]
Geographical Information	(20) Geographic Information The following is geographical information regarding our revenues for the years ended December 31, 2016, 2015 and 2014 and our long-lived assets as of December 31, 2016 and 2015 (in thousands): 2016 2015 2014 Revenue: United States $ 20,332 $ 23,668 $ 3,664 Europe 2,242 1,149 3,313 $ 22,573 $ 24,817 $ 6,977 Revenue by geographic region is allocated based on the domicile of our respective business operations. 2016 2015 Long-lived Assets: United States $ 22,360 $ 14,434 Europe 4,557 2,147 Total $ 26,917 $ 16,581 Long-lived assets include “Property, plant and equipment, net” and “Other long-term assets” from the consolidated balance sheets, by the geographic location where the asset resides.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Data Unaudited [Abstract]
Quarterly Financial Data (Unaudited)	(21) Quarterly Financial Data (Unaudited) Quarter Ended March 31, June 30, September 30, December 31, 2016 Revenue $ 5,959 $ 6,592 $ 4,446 $ 5,576 Net loss (31,779 ) (28,320 ) (40,774 ) (26,122 ) Net loss attributable to common shareholders (31,829 ) (28,371 ) (40,825 ) (26,174 ) Per common share, basic and diluted: Basic and diluted net loss attributable to common stockholders (0.37 ) (0.33 ) (0.47 ) (0.30 ) 2015 Revenue $ 3,953 $ 6,377 $ 6,848 $ 7,639 Net loss (18,741 ) (40,410 ) (13,122 ) (15,607 ) Net loss attributable to common shareholders (18,792 ) (40,461 ) (13,173 ) (15,658 ) Per common share, basic and diluted: Basic and diluted net loss attributable to common stockholders (0.28 ) (0.53 ) (0.16 ) (0.18 ) Net loss attributable to common stockholders per share is calculated independently for each of the quarters presented. Therefore, the sum of the quarterly net loss per share amounts will not necessarily equal the total for the full fiscal year.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	(22) Subsequent Events On February 14, 2017, the Agenus and Incyte amended the Collaboration Agreement by entering into a First Amendment to License, Development and Commercialization Agreement (the “Amendment”). Pursuant to the terms of the Amendment, the GITR and OX40 programs immediately converted from profit-share programs to royalty-bearing programs with Agenus now eligible to receive a flat 15% royalty on global net sales should any candidates from either of these two programs be approved. Incyte is now responsible for global development and commercialization and all associated costs for these programs. In addition, the profit-share programs relating to the two undisclosed targets were removed from the collaboration, with one reverting to Incyte and one to Agenus. Should any of those programs be successfully developed by a party, the other party will be eligible to receive the same milestone payments as the royalty-bearing programs and royalties at a 15% rate on global net sales. The terms for the remaining three royalty-bearing programs targeting TIM-3, LAG-3 and one undisclosed target remain unchanged, with Incyte being responsible for global development and commercialization and all associated costs. The Amendment gives Incyte exclusive rights and all decision-making authority for manufacturing, development, and commercialization with respect to all royalty-bearing programs. In connection with the Amendment, Incyte paid Agenus $20.0 million in accelerated milestones related to the clinical development of the antibody candidates targeting GITR and OX40. Agenus is now eligible to receive up to an additional $510.0 million in future potential development, regulatory and commercial milestones across all programs in the collaboration. On February 14, 2017, Agenus and Incyte also entered into a Stock Purchase Agreement (the “Stock Purchase Agreement” and together with the Amendment, the “Agreements”), pursuant to which Incyte purchased 10 million shares of Agenus’ common stock (the “Shares”) at a purchase price of $6.00 per share. Immediately following the transaction, Incyte owned approximately 18.1% of the outstanding shares of Agenus. Under the Stock Purchase Agreement, Incyte agreed not to dispose of any of the Shares for a period of 12 months and to vote the Shares in accordance with the recommendations of the Agenus board of directors in connection with certain equity incentive plan or compensation matters for a period of 18 months, and Agenus has agreed to certain registration rights with respect to the Shares. Under the Amendment, the parties also revised the existing standstill provision to permit Incyte’s acquisition of the Shares, but Incyte is precluded from acquiring any additional shares of Agenus’ voting stock until December 31, 2019. In March 2017, Agenus and the holders of the 2015 Subordinated Notes entered into an Amendment to Notes and Warrants, pursuant to which the parties (i) extended the term of the 2013 Warrants by two years from April 15, 2017 to April 15, 2019 and (ii) extended the maturity date of the 2015 Notes by two years from February 20, 2018 to February 20, 2020. The 2013 Warrants and 2015 Notes are otherwise unchanged.

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	(a) Basis of Presentation and Principles of Consolidation The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles and include the accounts of Agenus and our wholly-owned subsidiaries. All significant intercompany transactions and accounts have been eliminated in consolidation. Certain reclassifications have been made to previously reported amounts to conform to the current presentation.
Segment Information	(b) Segment Information We are managed and operated as one business segment. The entire business is managed by a single executive operating committee that reports to the chief executive officer. We do not operate separate lines of business with respect to any of our product candidates or geographic locations. Accordingly, we do not prepare discrete financial information with respect to separate product areas or by location and do not have separately reportable segments as defined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 280, Segment Reporting.
Use of Estimates	(c) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We base those estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates.
Cash and Cash Equivalents	(d) Cash and Cash Equivalents We consider all highly liquid investments purchased with maturities at acquisition of three months or less to be cash equivalents. Cash equivalents consist primarily of money market funds and U.S. Treasury Bills.
Investments	(e) Investments We classify investments in marketable securities at the time of purchase. At December 31, 2016 and 2015, all marketable securities are classified as available for sale and as such, the investments are recorded at fair value. Gains and losses on the sale of marketable securities are recognized in operations based on the specific identification method. At December 31, 2016 and 2015, our investments consisted of institutional money market funds and U.S. Treasury Bills.
Concentrations of Credit Risk	(f) Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk are primarily cash equivalents, investments, and accounts receivable. We invest our cash, cash equivalents and short-term investments in accordance with our investment policy, which specifies high credit quality standards and limits the amount of credit exposure from any single issue, issuer, or type of investment. We carry balances in excess of federally insured levels, however, we have not experienced any losses to date from this practice.
Inventories	(g) Inventories Inventories are stated at the lower of cost or market. Cost has been determined using standard costs that approximate the first-in, first-out method. Inventory as of December 31, 2016 and 2015 consisted solely of finished goods.
Accounts Receivable	(h) Accounts Receivable Accounts receivable are primarily amounts due from our collaboration partner as a result of research and development services provided and reimbursements under co-funded research and development programs. We considered the need for an allowance for doubtful accounts and have concluded that no allowance was needed as of December 31, 2016 and 2015, as the estimated risk of loss on our accounts receivable was determined to be minimal.
Property, Plant and Equipment	(i) Property, Plant and Equipment Property, plant and equipment, including software developed for internal use, are carried at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Amortization of leasehold improvements is computed over the shorter of the lease term or estimated useful life of the asset. Additions and improvements are capitalized, while repairs and maintenance are charged to expense as incurred. Amortization and depreciation of plant and equipment was $2.7 million, $1.4 million, and $1.1 million, for the years ended December 31, 2016, 2015, and 2014, respectively.
Fair Value of Financial Instruments	(j) Fair Value of Financial Instruments The estimated fair values of all of our financial instruments, excluding debt, approximate their carrying amounts in the consolidated balance sheets. The fair value of our outstanding debt is based on a present value methodology. The outstanding principal amount of our debt, including the current portion, was $114.1 million and $114.1 million at December 31, 2016 and 2015, respectively.
Revenue Recognition	(k) Revenue Recognition Revenue for services under research and development contracts are recognized as the services are performed, or as clinical trial materials are provided. Non-refundable milestone payments that represent the completion of a separate earnings process are recognized as revenue when earned. License fees and royalties are recognized as they are earned. Grant revenue is recognized when the related expense is recorded. Revenue recognized from collaborative agreements is based upon the provisions of ASC 605-25, Revenue Recognition – Multiple-Element Arrangements
Foreign Currency Transactions	(l) Foreign Currency Transactions Gains and losses from our foreign currency based accounts and transactions, such as those resulting from the translation and settlement of receivables and payables denominated in foreign currencies, are included in the consolidated statements of operations within other (expense) income. We do not currently use derivative financial instruments to manage the risks associated with foreign currency fluctuations. We recorded foreign currency losses of $2.1 million, $866,000, and $773,000, for the years ended December 31, 2016, 2015, and 2014, respectively.
Research and Development	(m) Research and Development Research and development expenses include the costs associated with our internal research and development activities, including salaries and benefits, share-based compensation, occupancy costs, clinical manufacturing costs, related administrative costs, and research and development conducted for us by outside advisors, such as sponsored university-based research partners and clinical study partners. We account for our clinical study costs by estimating the total cost to treat a patient in each clinical trial and recognizing this cost based on estimates of when the patient receives treatment, beginning when the patient enrolls in the trial. Research and development expenses also include the cost of clinical trial materials shipped to our research partners. Research and development costs are expensed as incurred.
Share-based Compensation	(n) Share-Based Compensation We account for share-based compensation in accordance with the provisions of ASC 718, Compensation—Stock Compensation Equity-Based Payments to Non-Employees.
Income Taxes	(o) Income Taxes Income taxes are accounted for under the asset and liability method with deferred tax assets and liabilities recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which such items are expected to be reversed or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations in the period that includes the enactment date. Deferred tax assets are recognized when they are more likely than not expected to be realized.
Net Loss Per Share	(p) Net Loss Per Share Basic income and loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding (including common shares issuable under our Directors’ Deferred Compensation Plan). Diluted income per common share is calculated by dividing net income attributable to common stockholders by the weighted average number of common shares outstanding (including common shares issuable under our Directors’ Deferred Compensation Plan) plus the dilutive effect of outstanding instruments such as warrants, stock options, nonvested shares, convertible preferred stock, and convertible notes. Because we reported a net loss attributable to common stockholders for all periods presented, diluted loss per common share is the same as basic loss per common share, as the effect of utilizing the fully diluted share count would have reduced the net loss per common share. Therefore, the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as of December 31, 2016, 2015, and 2014, as they would be anti-dilutive: Year Ended 2016 2015 2014 Warrants 4,351,450 4,351,450 2,951,450 Stock options 11,693,400 8,345,835 6,525,724 Nonvested shares 1,942,476 1,730,604 78,828 Convertible preferred stock 333,333 333,333 333,333
Goodwill	(q) Goodwill Goodwill represents the excess of cost over the fair value of net assets of businesses acquired. Goodwill is not amortized, but instead tested for impairment at least annually. Annually we assess whether there is an indication that goodwill is impaired, or more frequently if events and circumstances indicate that the asset might be impaired during the year. We perform our annual impairment test as of October 31 of each year. The first step of our impairment analysis compares our fair value to our net book value to determine if there is an indicator of impairment. We operate as a single operating segment and single reporting unit and our fair value is based on our quoted market price of our common stock to derive the market capitalization as of the date of the impairment test. ASC 350, Intangibles, Goodwill and Other
In-process Research and Development	(r) In-process Research and Development Acquired in-process research and development (“IPR&D”) represents the fair value assigned to research and development assets that have not reached technological feasibility. The value assigned to acquired IPR&D is determined by estimating the costs to develop the acquired technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the net cash flows to present value. The revenue and costs projections used to value acquired IPR&D are, as applicable, reduced based on the probability of success of developing a new drug. Additionally, the projections consider the relevant market sizes and growth factors, expected trends in technology, and the nature and expected timing of new product introductions by us and our competitors. The rates utilized to discount the net cash flows to their present value are commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections. Upon the acquisition of IPR&D, we complete an assessment of whether our acquisition constitutes the purchase of a single asset or a group of assets. We consider multiple factors in this assessment, including the nature of the technology acquired, the presence or absence of separate cash flows, the development process and stage of completion, quantitative significance and our rationale for entering into the transaction. If we acquire an asset or group of assets that do not meet the definition of a business under applicable accounting standards, then the acquired IPR&D is expensed on its acquisition date. Future costs to develop these assets are recorded to research and development expense as they are incurred. We review amounts capitalized as acquired IPR&D for impairment at least annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of the assets might not be recoverable. When performing our impairment assessment, we have the option to first assess qualitative factors to determine whether it is necessary to recalculate the fair value of our acquired IPR&D. If we elect this option and believe, as a result of the qualitative assessment, that it is more-likely-than-not that the fair value of our acquired IPR&D is less than its carrying amount, we calculate the fair value using the same methodology as described above. If the carrying value of our acquired IPR&D exceeds its fair value, then the intangible asset is written-down to its fair value. Alternatively, we may elect to not first assess qualitative factors and immediately recalculate the fair value of our acquired IPR&D. No IPR&D impairments were recognized for the years presented.
Accounting for Asset Retirement Obligations	(s) Accounting for Asset Retirement Obligations We record the fair value of an asset retirement obligation as a liability in the period in which we incur a legal obligation associated with the retirement of tangible long-lived assets that result from the acquisition, construction, development, and/or normal use of the assets. A legal obligation is a liability that a party is required to settle as a result of an existing or enacted law, statute, ordinance, or contract. We are also required to record a corresponding asset that is depreciated over the life of the asset. Subsequent to the initial measurement of the asset retirement obligation, the obligation will be adjusted at the end of each period to reflect the passage of time (accretion) and changes in the estimated future cash flows underlying the obligation. Changes in the liability due to accretion are charged to the consolidated statement of operations, whereas changes due to the timing or amount of cash flows are an adjustment to the carrying amount of the related asset. Our asset retirement obligations primarily relate to the expiration of our facility lease and anticipated costs to be incurred based on our lease terms.
Long-lived Assets	(t) Long-lived Assets If required based on certain events and circumstances, recoverability of assets to be held and used, other than goodwill and intangible assets not being amortized, is measured by a comparison of the carrying amount of an asset to the undiscounted future net cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset exceeds its estimated future undiscounted cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Authoritative guidance requires companies to separately report discontinued operations and extends that reporting to a component of an entity that either has been disposed of (by sale, abandonment, or in a distribution to owners) or is classified as held for sale. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.
Recent Accounting Pronouncements	(u) Recent Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 requires management to evaluate, at each annual or interim reporting period, whether there are conditions or events that exist that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. ASU 2014-15 is effective for annual periods ending after December 15, 2016 and earlier application is permitted. The adoption of ASU 2014-15 did not have an effect on the Company’s consolidated financial statements or disclosures as the Company concluded there were no conditions or events that existed at the time these consolidated financial statements were issued that raise substantial doubt about the Company’s ability to continue as a going concern. In April 2015, the FASB issued ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, ). In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) requires lessees to recognize a right-of-use asset and a lease liability on their balance sheets for all leases with terms greater than twelve months. Based on certain criteria, leases will be classified as either financing or operating, with classification affecting the pattern of expense recognition in the income statement. for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted In March 2016, the FASB issued ASU 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, (“ASU 2016-09”). ASU 2016-09 provides for the simplification of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 applies to all entities and is effective for the annual effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted for any entity in any interim or annual period. We do not expect the impact of ASU 2016-09 to be material to our financial position and results of operations. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, which provides guidance regarding the definition of a business, with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 is effective for the Company in the first quarter of 2018, with early adoption permitted, and prospective application required. We will apply the provisions of ASU 2016-09 to any relevant transactions no later than the first quarter of 2018 and may consider earlier adoption for relevant transactions which occur in 2017.

Description of Business (Table

Description of Business (Tables)	12 Months Ended
	Dec. 31, 2016
Description Of Business [Abstract]
Schedule of Cash, Cash Equivalents and Short-Term Investments	Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Cash, cash equivalents and short-term investments $ 148.2 $ 123.3 $ 95.4 $ 76.4 Decrease in cash, cash equivalents and short-term investments $ 23.5 $ 24.9 $ 27.9 $ 19.0 Cash used in operating activities $ 21.5 $ 18.5 $ 23.8 $ 16.0 Reported net loss $ 31.8 $ 28.3 $ 40.8 $ 26.1

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding	the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as of December 31, 2016, 2015, and 2014, as they would be anti-dilutive: Year Ended 2016 2015 2014 Warrants 4,351,450 4,351,450 2,951,450 Stock options 11,693,400 8,345,835 6,525,724 Nonvested shares 1,942,476 1,730,604 78,828 Convertible preferred stock 333,333 333,333 333,333

Goodwill and Acquired Intangi34

Goodwill and Acquired Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill	The following table sets forth the changes in the carrying amount of goodwill for year ended December 31, 2016 (in thousands): Balance, December 31, 2015 $ 22,793 Effect of foreign currency (401 ) Balance, December 31, 2016 $ 22,392
Schedule of Acquired Intangible Assets	Acquired intangible assets consisted of the following at December 31, 2016 and 2015 (in thousands): As of December 31, 2016 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 7-15 years $ 16,358 $ (2,384 ) $ 13,973 Trademarks 4.5 years 791 (505 ) 286 Other 2-6 years 563 (303 ) 260 In-process research and development Indefinite 1,846 — 1,846 Total $ 19,558 $ (3,193 ) $ 16,365 As of December 31, 2015 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 15 years $ 16,472 $ (542 ) $ 15,931 Trademarks 4.5 years 812 (339 ) 473 Other 3 years 567 (107 ) 460 In-process research and development Indefinite 1,896 — 1,896 Total $ 19,747 $ (987 ) $ 18,760

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2016
Cash And Cash Equivalents [Abstract]
Schedule of Cash Equivalents and Short-term Investments	Cash equivalents and short-term investments consisted of the following as of December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Cost Estimated Fair Value Cost Estimated Fair Value Institutional Money Market Funds $ 38,913 $ 38,913 $ 106,370 $ 106,370 U.S. Treasury Bills 14,978 14,978 54,945 54,961 Total $ 53,891 $ 53,891 $ 161,315 $ 161,331

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment, net as of December 31, 2016 and 2015 consist of the following (in thousands): 2016 2015 Estimated Depreciable Lives Land $ 2,230 $ 2,230 Indefinite Building and building improvements 4,605 2,900 35 years Furniture, Fixtures, and other 3,993 2,168 3 to 10 years Laboratory and manufacturing equipment 16,107 12,241 4 to 10 years Leasehold improvements 23,154 18,938 2 to 12 years Software and computer equipment 6,789 6,323 3 years 56,878 44,800 Less accumulated depreciation and amortization (31,244 ) (29,489 ) Total $ 25,634 $ 15,311

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities	The tax effect of temporary differences and net operating loss and tax credit carryforwards that give rise to significant portions of the deferred tax assets and deferred tax liabilities as of December 31, 2016 and 2015 are presented below (in thousands). 2016 2015 Deferred tax assets: U.S. Federal and State net operating loss carryforwards $ 241,572 $ 221,139 Foreign net operating loss carryforwards 13,075 8,412 Research and development tax credits 17,723 19,475 Share-based compensation 13,165 10,339 Other 15,513 7,123 Total deferred tax assets 301,048 266,488 Less: valuation allowance (295,502 ) (260,057 ) Net deferred tax assets 5,546 6,431 Deferred tax liabilities (6,197 ) (7,093 ) Net deferred tax liability $ (651 ) $ (662 )
Schedule of Effective Income Tax Rate Reconciliation	Income tax benefit was $5.4 million for the year ended December 31, 2015 and nil for each of the years ended December 31, 2016 and 2014, respectively. The income tax benefit of $5.4 million for the year ended December 31, 2015 was entirely related to a deferred tax benefit recognized as a result of deferred tax liabilities recorded in connection with our acquisitions of PhosImmune and certain assets from XOMA. Income taxes recorded differed from the amounts computed by applying the U.S. Federal income tax rate of 34% to loss before income taxes as a result of the following (in thousands). 2016 2015 2014 Computed “expected” Federal tax benefit $ (42,781 ) $ (31,669 ) $ (14,445 ) (Increase) reduction in income taxes benefit resulting from: Change in valuation allowance 35,471 25,908 14,043 (Decrease) increase due to uncertain tax positions (203 ) 203 117 State and local income benefit, net of Federal income tax benefit (3,452 ) (3,869 ) (642 ) Net operating loss expirations — — 996 Foreign rate differential 4,398 (314 ) 726 Other, net 6,567 4,354 (795 ) Income tax benefit $ — $ (5,387 ) $ —
Summary of Income Tax Contingencies	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): 2016 2015 2014 Balance, January 1 $ 5,481 $ 5,778 $ 5,649 Increase related to current year positions — 203 90 (Decrease) increase related to previously recognized positions (203 ) (500 ) 39 Balance, December 31 $ 5,278 $ 5,481 $ 5,778

Accrued and Other Current Lia38

Accrued and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following as of December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Payroll $ 6,504 $ 4,600 Professional fees 2,373 3,343 Contract manufacturing costs 10,492 3,886 Research services 5,639 1,698 Leasehold improvements 1,280 — Other 1,587 638 Total $ 27,875 $ 14,166
Other Current Liabilities	Other current liabilities consisted of the following as of December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Current portion of deferred purchase price (Note 4) $ 3,948 $ 5,906 Other 843 398 Total $ 4,791 $ 6,304

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Share Based Compensation [Abstract]
Weighted Average Assumptions used to Estimate Fair Value of Options Granted	The fair value of each option granted during the periods was estimated on the date of grant using the following weighted average assumptions: 2016 2015 2014 Expected volatility 65 % 77 % 84 % Expected term in years 4 6 6 Risk-free interest rate 1.0 % 1.6 % 1.7 % Dividend yield 0 % 0 % 0 %
Schedule Of Stock Option Activity	A summary of option activity for 2016 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2015 8,345,835 $ 4.40 Granted 4,572,489 4.28 Exercised (224,012 ) 3.32 Forfeited (206,426 ) 5.99 Expired (794,486 ) 5.99 Outstanding at December 31, 2016 11,693,400 $ 4.51 7.52 $ 3,750,615 Vested or expected to vest at December 31, 2016 10,837,540 $ 4.53 7.38 $ 3,637,128 Exercisable at December 31, 2016 5,835,130 $ 4.64 6.02 $ 2,950,330
Schedule Of Nonvested Shares	A summary of nonvested stock activity for 2016 is presented below: Nonvested Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2015 1,730,604 $ 8.55 Granted 996,938 3.14 Vested (570,037 ) 8.52 Forfeited (215,029 ) 8.15 Outstanding at December 31, 2016 1,942,476 $ 6.45
Schedule Of Share-Based Compensation Expense	The impact on our results of operations from share-based compensation for the years ended December 31, 2016, 2015, and 2014, was as follows (in thousands). Year Ended 2016 2015 2014 Research and development $ 6,507 $ 2,654 $ 1,272 General and administrative 6,681 4,784 3,400 Total share-based compensation expense $ 13,188 $ 7,438 $ 4,672

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2016
Leases [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The future minimum rental payments under our facility lease agreements, which expire at various times between 2017 and 2025, are as follows (in thousands): Year ending December 31, 2017 $ 3,530 2018 3,226 2019 2,492 2020 2,133 2021 1,762 Thereafter 3,865 Total $ 17,008
Schedule of Capital Lease for Piece of Laboratory Equipment	During 2016, we entered into an agreement which is classified as a capital lease for a piece of laboratory equipment. No such agreement existed during 2015. It is included in our property and equipment as follows (in thousands): 2016 Estimated Depreciable Lives Laboratory and manufacturing equipment $ 1,021 4 years Less accumulated depreciation and amortization (51 ) Total $ 970

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of Debt Obligations	Debt obligations consisted of the following as of December 31, 2016 and 2015 (in thousands): Debt instrument Principal at December 31, 2016 Non-cash Interest Unamortized Debt Issuance Costs Unamortized Debt Discount Balance at December 31, 2016 Current Portion: Debentures $ 146 $ — $ — $ — $ 146 Long-term Portion: 2015 Subordinated Notes 14,000 — — (1,311 ) 12,689 Note Purchase Agreement 100,000 19,421 (1,345 ) (222 ) 117,853 Total long-term $ 114,000 $ 19,421 $ (1,345 ) $ (1,533 ) $ 130,542 Total $ 114,146 $ 19,421 $ (1,345 ) $ (1,533 ) $ 130,688 Debt instrument Principal at December 31, 2015 Non-cash Interest Unamortized Debt Issuance Costs Unamortized Debt Discount Balance at December 31, 2015 Current Portion: Debentures $ 146 $ — $ — $ — $ 146 Long-term Portion: 2015 Subordinated Notes 14,000 — — (2,292 ) 11,708 Note Purchase Agreement 100,000 4,342 (1,481 ) (243 ) 102,619 Total long-term $ 114,000 $ 4,342 $ (1,481 ) $ (2,535 ) $ 114,326 Total $ 114,146 $ 4,342 $ (1,481 ) $ (2,535 ) $ 114,473

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Assets and liabilities measured at fair value are summarized below (in thousands): Description December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash equivalents $ 9,990 $ 9,990 $ — $ — Short-term investments 4,988 4,988 — — Total $ 14,978 $ 14,978 $ — $ — Liabilities: Contingent purchase price consideration 7,561 — — 7,561 Total $ 7,561 $ — $ — $ 7,561 Description December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash equivalents $ 19,996 $ 19,996 Short-term investments 34,965 34,965 — — Total $ 54,961 $ 54,961 $ — $ — Liabilities: Contingent purchase price consideration 5,608 — — 5,608 Total $ 5,608 $ — $ — $ 5,608
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents our liabilities measured at fair value using significant unobservable inputs (Level 3), as of December 31, 2016 (amounts in thousands): Balance, December 31, 2015 $ 5,608 Change in fair value of contingent purchase price consideration during the period 1,953 Balance, December 31, 2016 $ 7,561

Geographical Information (Table

Geographical Information (Tables)	12 Months Ended
	Dec. 31, 2016
Geographic Information [Abstract]
Revenue by Geographic Areas	The following is geographical information regarding our revenues for the years ended December 31, 2016, 2015 and 2014 and our long-lived assets as of December 31, 2016 and 2015 (in thousands): 2016 2015 2014 Revenue: United States $ 20,332 $ 23,668 $ 3,664 Europe 2,242 1,149 3,313 $ 22,573 $ 24,817 $ 6,977
Long-lived Assets by Geographic Areas	Revenue by geographic region is allocated based on the domicile of our respective business operations. 2016 2015 Long-lived Assets: United States $ 22,360 $ 14,434 Europe 4,557 2,147 Total $ 26,917 $ 16,581

Quarterly Financial Data (Una44

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Data Unaudited [Abstract]
Schedule of Quarterly Financial Information	Quarter Ended March 31, June 30, September 30, December 31, 2016 Revenue $ 5,959 $ 6,592 $ 4,446 $ 5,576 Net loss (31,779 ) (28,320 ) (40,774 ) (26,122 ) Net loss attributable to common shareholders (31,829 ) (28,371 ) (40,825 ) (26,174 ) Per common share, basic and diluted: Basic and diluted net loss attributable to common stockholders (0.37 ) (0.33 ) (0.47 ) (0.30 ) 2015 Revenue $ 3,953 $ 6,377 $ 6,848 $ 7,639 Net loss (18,741 ) (40,410 ) (13,122 ) (15,607 ) Net loss attributable to common shareholders (18,792 ) (40,461 ) (13,173 ) (15,658 ) Per common share, basic and diluted: Basic and diluted net loss attributable to common stockholders (0.28 ) (0.53 ) (0.16 ) (0.18 )

Description of Business (Narrat

Description of Business (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended				12 Months Ended
	Feb. 28, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Description Of Business [Line Items]
Cash, cash equivalents, and short-term investments		$ 76,400,000	$ 95,400,000	$ 123,300,000	$ 148,200,000	$ 76,400,000
Decrease in cash cash equivalents and short term investments		19,000,000	$ 27,900,000	$ 24,900,000	$ 23,500,000	95,300,000
Accumulated deficit		$ (905,329,320)				$ (905,329,320)	$ (779,187,464)
Subsequent Event [Member] | Incyte Corporation [Member]
Description Of Business [Line Items]
Proceeds from collaborators	$ 80,000,000

Description of Business - Sched

Description of Business - Schedule of Cash, Cash Equivalents and Short-Term Investments (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Description Of Business [Abstract]
Cash, cash equivalents and short-term investments	$ 76,400,000	$ 95,400,000	$ 123,300,000	$ 148,200,000					$ 76,400,000
Decrease in cash, cash equivalents and short-term investments	19,000,000	27,900,000	24,900,000	23,500,000					95,300,000
Cash used in operating activities	16,000,000	23,800,000	18,500,000	21,500,000					(79,960,811)	$ (47,175,441)	$ (38,234,585)
Reported net loss	$ 26,122,000	$ 40,774,000	$ 28,320,000	$ 31,779,000	$ 15,607,000	$ 13,122,000	$ 40,410,000	$ 18,741,000	$ 126,995,175	$ 87,881,121	$ 42,486,174

Summary of Significant Accoun47

Summary of Significant Accounting Policies (Segment Information) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016Segment
Accounting Policies [Abstract]
Number of operating business segment	1

Summary of Significant Accoun48

Summary of Significant Accounting Policies (Accounts Receivable) (Narrative) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Allowance for doubtful accounts receivable	$ 0	$ 0

Summary of Significant Accoun49

Summary of Significant Accounting Policies (Property, Plant and Equipment) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Depreciation	$ 2.7	$ 1.4	$ 1.1

Summary of Significant Accoun50

Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Long-term Debt, Gross	$ 114,146	$ 114,146

Summary of Significant Accoun51

Summary of Significant Accounting Policies (Revenue Recognition) (Narrative) (Details) - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
One collaboration partner [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	87.00%	95.00%
One research partner [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			48.00%

Summary of Significant Accoun52

Summary of Significant Accounting Policies (Foreign Currency Transactions) (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Foreign Currency [Abstract]
Foreign Currency Transaction Gain (Loss), before Tax	$ (2,100,000)	$ (866,000)	$ (773,000)

Summary of Significant Accoun53

Summary of Significant Accounting Policies (Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,351,450	4,351,450	2,951,450
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	11,693,400	8,345,835	6,525,724
Nonvested shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,942,476	1,730,604	78,828
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	333,333	333,333	333,333

Summary of Significant Accoun54

Summary of Significant Accounting Policies (Goodwill) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)
Accounting Policies [Abstract]
Impairment of goodwill	$ 0

Summary of Significant Accoun55

Summary of Significant Accounting Policies (In-process Research and Development) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)
In-process Research and Development [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Impairment of IPR&D	$ 0

Summary of Significant Accoun56

Summary of Significant Accounting Policies (Recent Accounting Pronouncements) (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2015
ASU 2015-03 [Member]
New Accounting Pronouncement Early Adoption [Line Items]
Debt issuance costs	$ 0	$ 1,500,000
Amortization of the debt issuance costs	135,000
ASU 2016-02 [Member]
New Accounting Pronouncement Early Adoption [Line Items]
Operating leases expect to recognize assets and liabilities	$ 13,800,000

Business Acquisitions (Narrativ

Business Acquisitions (Narrative) (Details) - USD ($)	Dec. 31, 2015	Dec. 23, 2015	Feb. 12, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Non-operating (expense) income				$ (2,202,336)	$ (5,968,170)	$ 2,096,334
4-antibody acquisition [Member]
Business Acquisition [Line Items]
Issuance of stock for acquisition, share			3,334,079
Issuance of stock for acquisition, value			$ 10,100,000			$ 10,102,259
Contingent Consideration			40,000,000
Business Combination, Contingent Consideration, Liability			9,700,000
PhosImmune Inc. [Member]
Business Acquisition [Line Items]
Issuance of stock for acquisition, share		1,631,521
Issuance of stock for acquisition, value		$ 7,400,000			7,400,000
Contingent Consideration		35,000,000
Business Combination, Contingent Consideration, Liability		2,500,000
Amount Received by Stock Holders Cash		2,500,000
Antibody Manufacturing Facility Acquisition [Member]
Business Acquisition [Line Items]
Issuance of stock for acquisition, value	$ 500,000				500,000
Cash consideration for purchased assets	$ 4,700,000
Shares issued for purchased assets	109,211
Additional Shares to be Issued	109,211
Non-operating (expense) income					$ 1,500,000
Contingent Milestone 1 [Member] | 4-antibody acquisition [Member]
Business Acquisition [Line Items]
Contingent Consideration			20,000,000
Market Capitalization			$ 300,000,000
Debt Instrument, Redemption, Threshold Trading Days			10 days
Contingent Milestone 1 [Member] | PhosImmune Inc. [Member]
Business Acquisition [Line Items]
Contingent Consideration		$ 5,000,000
Debt Instrument, Redemption, Threshold Trading Days		60 days
Trading Price of our Common Stock		$ 8
Contingent Milestone 2 [Member] | 4-antibody acquisition [Member]
Business Acquisition [Line Items]
Contingent Consideration			$ 10,000,000
Market Capitalization			$ 750,000,000
Debt Instrument, Redemption, Threshold Trading Days			30 days
Contingent Milestone 2 [Member] | PhosImmune Inc. [Member]
Business Acquisition [Line Items]
Contingent Consideration		$ 15,000,000
Debt Instrument, Redemption, Threshold Trading Days		60 days
Trading Price of our Common Stock		$ 13
Contingent Milestone 3 [Member] | 4-antibody acquisition [Member]
Business Acquisition [Line Items]
Contingent Consideration			$ 10,000,000
Market Capitalization			$ 1,000,000,000
Debt Instrument, Redemption, Threshold Trading Days			30 days
Contingent Milestone 3 [Member] | PhosImmune Inc. [Member]
Business Acquisition [Line Items]
Contingent Consideration		$ 15,000,000
Debt Instrument, Redemption, Threshold Trading Days		60 days
Trading Price of our Common Stock		$ 19

Asset Purchase Agreement (Narra

Asset Purchase Agreement (Narrative) (Details) - USD ($)	Apr. 07, 2015	May 31, 2015	Sep. 30, 2007	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Shares issued for purchased assets (in US$ per share)			$ 18.48
Research and development expense				$ 94,971,379	$ 70,444,259	$ 22,349,327
Celexion, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Cash consideration for purchased assets	$ 1,000,000
Shares issued for purchased assets	574,140	574,140
Shares issued for purchased assets (in US$ per share)	$ 5.23
Research and development expense					$ 13,200,000
Asset Purchase Agreement Payable On Nine Month Anniversaries | Celexion, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Contractual cash payment	$ 1,000,000
Asset Purchase Agreement Payable On Eighteen Month Anniversaries | Celexion, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Contractual cash payment	1,000,000
Asset Purchase Agreement Payable On Twelve Month Anniversaries | Celexion, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Contractual cash payment	4,000,000
Asset Purchase Agreement Payable On Twenty Four Month Anniversaries | Celexion, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Contractual cash payment	$ 4,000,000

Goodwill and Acquired Intangi59

Goodwill and Acquired Intangible Assets (Schedule of Changes in Goodwill) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 22,792,778
Effect of foreign currency	(401,000)
Ending balance	$ 22,392,411

Goodwill and Acquired Intangi60

Goodwill and Acquired Intangible Assets (Acquired Intangible Assets) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 19,558,000	$ 19,747,000
Accumulated amortization	(3,193,092)	(987,394)
Net carrying amount	16,364,726	18,759,662
Indefinite-lived Intangible Assets Acquired	1,846,000	$ 1,896,000
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)		15 years
Gross carrying amount	16,358,000	$ 16,472,000
Accumulated amortization	(2,384,000)	(542,000)
Net carrying amount	$ 13,973,000	$ 15,931,000
Intellectual Property [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	7 years
Intellectual Property [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	15 years
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	4 years 6 months	4 years 6 months
Gross carrying amount	$ 791,000	$ 812,000
Accumulated amortization	(505,000)	(339,000)
Net carrying amount	286,000	$ 473,000
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)		3 years
Gross carrying amount	563,000	$ 567,000
Accumulated amortization	(303,000)	(107,000)
Net carrying amount	$ 260,000	$ 460,000
Other [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	2 years
Other [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	6 years

Goodwill and Acquired Intangi61

Goodwill and Acquired Intangible Assets (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years
Amortization expense	$ 2,200,000	$ 525,000	$ 462,000
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2017	2,200,000
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2018	2,000,000
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2019	1,900,000
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2020	1,900,000
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2021	$ 1,900,000

Schedule of Cash Equivalents an

Schedule of Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short-term investments	$ 53,891	$ 161,315
Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short-term investments	53,891	161,331
Institutional Money Market Funds [Member] | Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short-term investments	38,913	106,370
Institutional Money Market Funds [Member] | Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short-term investments	38,913	106,370
U.S. Treasury Bills [Member] | Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short-term investments	14,978	54,945
U.S. Treasury Bills [Member] | Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short-term investments	$ 14,978	$ 54,961

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Line Items]
Available-for-sale securities sold before maturity	$ 0
Cash equivalents	48,900,000	$ 126,400,000
Short-term investments	4,988,751	34,964,730
U.S. Treasury Bills [Member]
Cash And Cash Equivalents [Line Items]
Proceeds from sale of short-term investments	$ 85,000,000	$ 14,500,000	$ 0

Property, Plant and Equipment64

Property, Plant and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 56,878,000	$ 44,800,000
Plant and equipment, accumulated amortization and depreciation	(31,243,967)	(29,488,793)
Property, Plant and Equipment, Net	25,633,985	15,310,623
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,230,000	2,230,000
Property, Plant and Equipment, Useful Life	Indefinite
Building and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 4,605,000	2,900,000
Property, Plant and Equipment, Useful Life	35 years
Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 3,993,000	2,168,000
Furniture, fixtures and other [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Furniture, fixtures and other [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Laboratory and manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 16,107,000	12,241,000
Property, Plant and Equipment, Useful Life	4 years
Laboratory and manufacturing equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	4 years
Laboratory and manufacturing equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 23,154,000	18,938,000
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	12 years
Software and computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 6,789,000	$ 6,323,000
Property, Plant and Equipment, Useful Life	3 years

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Research and development tax credits	$ 17,723,000	$ 19,475,000
Stock based compensation tax benefits	13,165,000	10,339,000
Valuation Allowance, Deferred Tax Asset, Change in Amount	(35,471,000)	(25,908,000)	$ (14,043,000)
Income tax benefit	$ 0	(5,387,067)	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	34.00%
Worldwide [Member]
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Change in Amount	$ 35,300,000	$ 25,900,000
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	682,200,000
Research and development tax credits	$ 8,900,000
Internal Revenue Service (IRS) [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2,018
Internal Revenue Service (IRS) [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2,033
Federal and State [Member]
Operating Loss Carryforwards [Line Items]
Stock based compensation tax benefits	$ 900,000
Federal and State [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2,017
Federal and State [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2,036
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 178,100,000
Research and development tax credits	$ 13,400,000
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2,017
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2,029
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 58,700,000
Foreign Tax Authority [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2,017
Foreign Tax Authority [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2,023

Income Taxes Deferred tax asset

Income Taxes Deferred tax assets and deferred tax liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. Federal and State net operating loss carryforwards	$ 241,572	$ 221,139
Foreign net operating loss carryforwards	13,075	8,412
Research and development tax credits	17,723	19,475
Share-based compensation	13,165	10,339
Other	15,513	7,123
Total deferred tax assets	301,048	266,488
Less: valuation allowance	(295,502)	(260,057)
Net deferred tax assets	5,546	6,431
Deferred tax liabilities	(6,197)	(7,093)
Net deferred tax liability	$ (651)	$ (662)

Income Taxes Tax rate reconcili

Income Taxes Tax rate reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Computed “expected” Federal tax benefit	$ (42,781,000)	$ (31,669,000)	$ (14,445,000)
Change in valuation allowance	35,471,000	25,908,000	14,043,000
(Decrease) increase due to uncertain tax positions	(203,000)	203,000	117,000
State and local income benefit, net of Federal income tax benefit	(3,452,000)	(3,869,000)	(642,000)
Net operating loss expirations			996,000
Foreign rate differential	4,398,000	(314,000)	726,000
Other, net	6,567,000	4,354,000	(795,000)
Income tax benefit	$ 0	$ (5,387,067)	$ 0

Income Taxes Unrecognized tax b

Income Taxes Unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits, Beginning balance	$ 5,481	$ 5,778	$ 5,649
Increase related to current year positions		203	90
(Decrease) increase related to previously recognized positions	(203)	(500)	39
Unrecognized Tax Benefits, Ending balance	$ 5,278	$ 5,481	$ 5,778

Accrued and Other Current Lia69

Accrued and Other Current Liabilities (Schedule of Accrued Liabilities) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Accrued Liabilities Current [Abstract]
Payroll	$ 6,504,000	$ 4,600,000
Professional fees	2,373,000	3,343,000
Contract manufacturing costs	10,492,000	3,886,000
Research services	5,639,000	1,698,000
Leasehold improvements	1,280,000
Other	1,587,000	638,000
Total	$ 27,874,703	$ 14,165,816

Accrued and Other Current Lia70

Accrued and Other Current Liabilities (Other Current Liabilities) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Current portion of deferred purchase price	$ 3,948,000	$ 5,906,000
Other	843,000	398,000
Total	$ 4,791,265	$ 6,304,281

Equity (Narrative) (Details)

Equity (Narrative) (Details)

Feb. 14, 2017$ / sharesshares

Jan. 09, 2015USD ($)$ / sharesshares

Jan. 09, 2015USD ($)$ / sharesshares

Sep. 07, 2014USD ($)

Jul. 09, 2008

May 31, 2015USD ($)shares

Feb. 28, 2014USD ($)shares

Aug. 31, 2009USD ($)$ / sharesshares

Apr. 30, 2009shares

Jan. 31, 2008$ / sharesshares

Sep. 30, 2007$ / sharesshares

Sep. 30, 2013USD ($)$ / sharesshares

Dec. 31, 2016USD ($)$ / sharesshares

Dec. 31, 2015USD ($)$ / sharesshares

Dec. 31, 2014USD ($)shares

Sep. 30, 2016USD ($)shares

Jun. 14, 2016shares

Sep. 30, 2015USD ($)shares

Oct. 31, 2014USD ($)shares

Dec. 31, 2013USD ($)$ / shares

Dec. 31, 2012shares

Class Of Stock [Line Items]

Common stock, shares authorized

240,000,000

140,000,000

Common stock, shares issued

270,562

87,794,933

86,390,697

Stock Issued During Period, Price Per Share | $ / shares

$ 18.48

Shares sold in registered direct offering, shares

730,994

1,451,450

Sale of Stock, Price Per Share | $ / shares

$ 13.68

$ 18

Class of Warrant or Right, Term

10 years

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

694,441

Class of Warrant or Right, Exercisable Term

9 years 6 months

Warrants issued

1,451,450

Proceeds from Issuance of Private Placement | $

$ 10,000,000

Stock Issued During Period, Shares, New Issues

12,650,000

Net proceeds from issuance of common stock | $

$ 75,000,000

Stock Issued During Period, Value, New Issues | $

$ 2,167,070

$ 74,669,980

$ 600,659

Total shares issued for contingent milestone payment

80,493

Shares issued for contingent milestone payment, value | $

$ 345,000

Common stock, value | $

$ 877,949

$ 863,907

Registered direct offering [Member]

Class Of Stock [Line Items]

Shares sold in registered direct offering, shares

3,333,000

Class of Warrant or Right, Term

5 years

Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares

$ 3.75

Class of Warrant or Right, Exercisable Term

6 months

Warrants issued

1,000,000

Net proceeds from issuance of common stock | $

$ 9,500,000

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

0.3

Stock Issued During Period, Value, New Issues | $

$ 56,000,000

2012 ATM Program [Member]

Class Of Stock [Line Items]

Shares available for sale through sales agent

10,000,000

Stock Issued During Period, Shares, New Issues

215,000

Net proceeds from issuance of common stock | $

$ 601,000

Payments of stock issuance costs | $

$ 20,000

2014 ATM Program [Member]

Class Of Stock [Line Items]

Shares available for sale through sales agent

10,000,000

Stock Issued During Period, Shares, New Issues

497,000

Net proceeds from issuance of common stock | $

$ 2,200,000

Payments of stock issuance costs | $

$ 67,000

Stock Purchase Agreement [Member]

Class Of Stock [Line Items]

Shares sold in registered direct offering, shares

7,760,000

Stock Issued During Period, Shares, New Issues

7,760,000

7,760,000

Net proceeds from issuance of common stock | $

$ 35,000,000

$ 35,000,000

Share Price | $ / shares

$ 4.51

$ 4.51

Stock Purchase Agreement [Member] | Incyte Corporation [Member] | Subsequent Event [Member]

Class Of Stock [Line Items]

Stock Issued During Period, Shares, New Issues

10,000,000

Number of shares purchased, price per share | $ / shares

$ 6

Revenue Interest Assignment and Termination Agreement [Member]

Class Of Stock [Line Items]

Common stock, shares issued

300,000

Common stock, value | $

$ 2,100,000

Technology Transfer and License Agreement [Member]

Class Of Stock [Line Items]

Common stock, shares issued

157,313

Common stock, value | $

$ 887,000

Maximum [Member]

Class Of Stock [Line Items]

Aggregate gross proceeds available | $

$ 150,000,000

Chief Executive Officer [Member]

Class Of Stock [Line Items]

Warrants issued

284,785

10-year warrants [Member]

Class Of Stock [Line Items]

Class of Warrant or Right, Term

10 years

Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares

$ 18

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

1,451,450

10-year Unit warrants [Member]

Class Of Stock [Line Items]

Class of Warrant or Right, Term

10 years

Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares

$ 18

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

1,451,450

Unit warrants [Member]

Class Of Stock [Line Items]

Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares

$ 18

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

1,451,450

Class of Warrant or Right, Exercisable Term

18 months

August 2009 6-month warrants [Member]

Class Of Stock [Line Items]

Class of Warrant or Right, Term

6 months

Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares

$ 13.86

August 2009 6-month warrants [Member] | Maximum [Member]

Class Of Stock [Line Items]

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

365,495

August 2009 4-year warrants [Member]

Class Of Stock [Line Items]

Class of Warrant or Right, Term

4 years

Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares

$ 15

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

328,946

Common Stock [Member]

Class Of Stock [Line Items]

Common shares issued upon conversion

988,202

Stock Issued During Period, Shares, New Issues

496,520

12,650,000

215,489

Stock Issued During Period, Value, New Issues | $

$ 4,965

$ 126,500

$ 2,155

Treasury Stock, Shares, Retired

43,490

188,184

43,490

Common Stock [Member] | Registered direct offering [Member]

Class Of Stock [Line Items]

Shares sold in registered direct offering, shares

22,236,000

Stock Issued During Period, Shares, New Issues

22,236,000

Series A convertible preferred stock [Member]

Class Of Stock [Line Items]

Preferred Stock, Redemption Price Per Share | $ / shares

$ 94.86

Preferred Stock, Redemption Amount | $

$ 31,600,000

Preferred Stock, Liquidation Preference Per Share | $ / shares

$ 1,000

Series A-1 convertible preferred stock [Member]

Class Of Stock [Line Items]

Preferred Stock, Amount of Preferred Dividends in Arrears | $

$ 800,000

$ 595,000

Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears | $ / shares

$ 25.29

$ 18.82

Preferred stock, shares issued, Series A

31,620

31,620

Preferred stock, shares outstanding, Series A-1

31,620

31,620

Series B-1 convertible preferred stock [Member]

Class Of Stock [Line Items]

Preferred stock, shares issued, Series A

10,000

Convertible Preferred Stock, Right to Purchase Common Share, Price per Share, Maximum | $ / shares

$ 24.96

Series B-2 convertible preferred stock [Member]

Class Of Stock [Line Items]

Preferred stock, shares issued, Series A

5,250

Stock, Convertible, Conversion Price is Equal to a Stated Percentage of the Total Dollar Amount Previously Invested , Stated Percentage

35.00%

Series B conversion right term

7 years

Conversion of Stock, Shares Converted

2,145

Preferred stock, shares outstanding, Series A-1

3,105

Stock, Convertible, Total Number of Shares of Common Stock Issued or Issuable Cannot Exceed a Stated Percentage of Outstanding Common Stock, Stated Percentage

19.90%

Series B2 convertible preferred stock cancelled and extinguished | $

$ 3,105

Series B2 convertible preferred stock [Member]

Class Of Stock [Line Items]

Dividends paid | $

$ 0

Liquidation preference | $

$ 0

Series B2 convertible preferred stock cancelled and extinguished | $

$ 3,105

Share-Based Compensation Plan72

Share-Based Compensation Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 10, 2009
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average stock price of shares credited under Director Deferred Compensation Plan	$ 5.45
Weighted average grant-date fair value of options granted	$ 4.65	$ 3.55	$ 1.87
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 445,000	$ 1,200,000	$ 45,000
Intrinsic value of shares vested	$ 2,400,000	$ 140,000	$ 205,000
Vesting of nonvested shares, shares	570,037	35,332	48,239
Stock Options [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost, weighted average period	2 years 3 months 18 days
Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost	$ 3,800,000
Performance Based Award [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost, weighted average period	1 year 8 months 12 days
Employees and directors [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost, options	$ 10,000,000
Outside Advisors [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost, options	$ 243,000
1999 EIP [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	2,000,000
2009 EIP [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized				20,200,000
Deferred Compensation Arrangement with Individual, Maximum Contractual Term	10 years
2009 EIP [Member] | Minimum [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period, minimum	3 years
2009 EIP [Member] | Maximum [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period, minimum	4 years
2009 ESPP [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	166,666
Share-Based compensation award by Share-based payment award, purchase price as percent of fair value	85.00%
Employee stock purchase threshold as a percentage of the total combined voting power of the Company	5.00%
Share-based compensation awards expiration date	Jun. 10, 2019
Proceeds from Stock Plans	$ 1,200,000	$ 2,000,000	$ 252,000
Shares issued under ESPP	121,228	63,539	46,025
2009 ESPP [Member] | Employees and directors [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Maximum number of shares allowed to be purchased by employees	3,333
Director deferred compensation plan [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	325,000
Shares issued under Director Deferred Compensation Plan	72,081
Shares credited under Director Deferred Compensation Plan	246,627
2015 IEP [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,500,000

Share-Based Compensation Plan73

Share-Based Compensation Plans (Schedule of Fair Value of Option Granted Estimated on Date of Grant Using Weighted Average Assumptions) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation [Abstract]
Expected volatility	65.00%	77.00%	84.00%
Expected term in years	4 years	6 years	6 years
Risk-free interest rate	1.00%	1.60%	1.70%
Dividend yield	0.00%	0.00%	0.00%

Share-Based Compensation Plan74

Share-Based Compensation Plans (Schedule Of Stock Option Activity) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation [Abstract]
Options Outstanding, Beginning Balance	8,345,835
Options Granted	4,572,489
Options Exercised	(224,012)
Options Forfeited	(206,426)
Options Expired	(794,486)
Options Outstanding, Ending Balance	11,693,400	8,345,835
Options Vested or expected to vest	10,837,540
Options Exercisable	5,835,130
Options Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 4.40
Options Granted, Weighted Average Exercise Price	4.28
Options Exercised, Weighted Average Exercise Price	3.32
Options Forfeited, Weighted Average Exercise Price	5.99
Options Expired, Weighted Average Exercise Price	5.99
Options Outstanding, Weighted Average Exercise Price, Ending Balance	4.51	$ 4.40
Options Vested or expected to vest, Weighted Average Exercise Price		$ 4.53
Options Exercisable, Weighted Average Exercise Price	$ 4.64
Options Outstanding, Weighted Average Remaining Contractual Term	7 years 6 months 7 days
Options Vested or expected to vest, Weighted Average Remaining Contractual Term		7 years 4 months 17 days
Options Exercisable, Weighted Average Remaining Contractual Term	6 years 7 days
Options Outstanding, Aggregate Intrinsic Value	$ 3,750,615
Options Vested or expected to vest, Aggregate Intrinsic Value		$ 3,637,128
Options Exercisable, Aggregate Intrinsic Value	$ 2,950,330

Share-Based Compensation Plan75

Share-Based Compensation Plans (Summary Of Nonvested Stock Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation [Abstract]
Nonvested Shares Outstanding, Beginning Balance	1,730,604
Nonvested Shares Granted	996,938
Nonvested Shares Vested	(570,037)	(35,332)	(48,239)
Nonvested Shares Forfeited	(215,029)
Nonvested Shares Outstanding, Ending Balance	1,942,476	1,730,604
Nonvested Shares Outstanding, Weighted Average Grant Date Fair Value, Beginning Balance	$ 8.55
Nonvested Shares Granted, Weighted Average Grant Date Fair Value	3.14
Nonvested Shares Vested, Weighted Average Grant Date Fair Value	8.52
Nonvested Shares Forfeited in Period, Weighted Average Grant Date Fair Value	8.15
Nonvested Shares Outstanding, Weighted Average Grant Date Fair Value, Ending Balance	$ 6.45	$ 8.55

Share-Based Compensation Plan76

Share-Based Compensation Plans (Schedule Of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 13,188	$ 7,438	$ 4,672
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	6,507	2,654	1,272
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 6,681	$ 4,784	$ 3,400

License, Research and Other A77

License, Research and Other Agreements (Narrative) (Details) - USD ($)	Jan. 25, 2016	Dec. 05, 2014	Mar. 31, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Revenue Arrangement [Line Items]
Estimate of total payments for clinical trials				$ 128,700,000
Clinical trials expense				23,100,000	$ 19,900,000	$ 900,000
Cumulative payments for clinical trials				82,100,000
GSK Supply Agreement [Member]
Deferred Revenue Arrangement [Line Items]
Negotiation right expiration period			5 years
Proceeds from negotiation right			$ 9,000,000
Proceeds from negotiation right creditable against future royalty payments			$ 2,500,000
Research and Development Expense [Member]
Deferred Revenue Arrangement [Line Items]
Clinical trials expense				94,400,000
UVA license agreement [Member] | Maximum [Member]
Deferred Revenue Arrangement [Line Items]
Milestone payments for license costs				2,700,000
UVA license agreement [Member] | Minimum [Member]
Deferred Revenue Arrangement [Line Items]
Penalties for Milestone Payment				$ 150,000
UConn Agreement [Member]
Deferred Revenue Arrangement [Line Items]
Period for which failure to pay royalties may result in contract termination				30 days
Period for which company may terminate the contract				90 days
Period the Company may continue to manufacture and sell products, after contract breach				6 months
Milestone payments for license costs				$ 1,200,000
License costs				850,000
UConn Agreement, as amended [Member]
Deferred Revenue Arrangement [Line Items]
License costs				100,000
LICR [Member]
Deferred Revenue Arrangement [Line Items]
License costs		$ 1,000,000
Milestone payments for license costs pre-regulatory approval	$ 12,000,000	20,000,000
Milestone payments for license costs post-regulatory approval	$ 32,000,000	$ 80,000,000
GSK Agreements [Member]
Deferred Revenue Arrangement [Line Items]
Proceeds from license fees received				23,300,000
Total potential proceeds from license				$ 24,300,000
Royalty payments on net sales (as a percent)				2.00%
License and services revenue				$ 0	$ 0	$ 3,300,000
Deferred revenue				$ 2,500,000
GSK Agreements [Member] | Maximum [Member]
Deferred Revenue Arrangement [Line Items]
Period to receive license fees			10 years
GSK Agreements [Member] | Minimum [Member]
Deferred Revenue Arrangement [Line Items]
Period to receive license fees			7 years

Collaboration Agreement (Narrat

Collaboration Agreement (Narrative) (Details)	Feb. 14, 2017$ / sharesshares	Nov. 30, 2015Program	Sep. 04, 2015shares	Feb. 19, 2015Program	Jan. 09, 2015USD ($)Programshares	Jan. 09, 2015USD ($)shares	Feb. 28, 2017USD ($)	May 31, 2015USD ($)shares	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from issuance of common stock								$ 75,000,000
Stock issued to repurchase the Assigned Interest | shares								12,650,000
Revenues									$ 5,576,000	$ 4,446,000	$ 6,592,000	$ 5,959,000	$ 7,639,000	$ 6,848,000	$ 6,377,000	$ 3,953,000	$ 22,573,303	$ 24,817,025	$ 6,977,455
Current portion, deferred revenue									2,610,719				3,829,371				2,610,719	3,829,371
Deferred Revenue, Noncurrent									12,344,782				15,065,754				12,344,782	15,065,754
Profit-share products [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of collaboration agreement programs | Program					2
Milestone payments for license costs					$ 20,000,000
Royalty-bearing products [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of collaboration agreement programs | Program					1
Milestone payments for license costs					$ 155,000,000
Stock Purchase Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from issuance of common stock					$ 35,000,000	$ 35,000,000
Stock issued to repurchase the Assigned Interest | shares					7,760,000	7,760,000
Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Stock issued to repurchase the Assigned Interest | shares			300,000
Percentage of profit and costs sharing ratio					50.00%
Revenues																	19,700,000	23,500,000	$ 0
Revenue, amortization																	$ 3,500,000	9,100,000
Development Regulatory and Commercialization Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Reserved right to elect to co-fund of development costs (as a percent)					30.00%
Development Regulatory and Commercialization Milestones [Member] | Minimum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Range of royalty payments on future global net sales (as a percent)					6.00%
Development Regulatory and Commercialization Milestones [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Range of royalty payments on future global net sales (as a percent)					12.00%
Incyte Corporation [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of collaboration agreement programs | Program				4
Discovery period of antibodies development and commercialization period				5 years
Extended discovery period of antibodies development and commercialization period				3 years
Collaboration agreement termination notice period																	12 months
Deferred revenue									12,400,000				15,800,000				$ 12,400,000	15,800,000
Current portion, deferred revenue									2,600,000				3,600,000				2,600,000	3,600,000
Deferred Revenue, Noncurrent									$ 9,800,000				$ 12,200,000				$ 9,800,000	$ 12,200,000
Incyte Corporation [Member] | Subsequent Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from collaborators							$ 80,000,000
Incyte Corporation [Member] | Stock Purchase Agreement [Member] | Subsequent Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Stock issued to repurchase the Assigned Interest | shares	10,000,000
Number of shares purchased, price per share | $ / shares	$ 6
Incyte Corporation [Member] | Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from collaborators					$ 25,000,000
Incyte Corporation [Member] | Collaborative Arrangement [Member] | Subsequent Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Range of royalty payments on future global net sales (as a percent)	15.00%
Incyte Corporation [Member] | Agenus Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of collaboration agreement programs | Program		3

Certain Related Party Transac79

Certain Related Party Transactions (Narrative) (Details) - USD ($)	Feb. 12, 2014	May 31, 2015	Dec. 31, 2016	Dec. 31, 2014	Jan. 31, 2015
Related Party Transaction [Line Items]
Shares sold at the market, shares		12,650,000
Net proceeds from issuance of common stock		$ 75,000,000
4-antibody acquisition [Member]
Related Party Transaction [Line Items]
Stock Issued During Period, Shares, Acquisitions	3,334,079
Issuance of common stock in connection with acquisitions	$ 10,100,000			$ 10,102,259
Contingent Consideration	40,000,000
4-antibody acquisition [Member] | Contingent Milestone 1 [Member]
Related Party Transaction [Line Items]
Contingent Consideration	$ 20,000,000
Advent Venture Partners LLP [Member]
Related Party Transaction [Line Items]
Stock Issued During Period, Shares, Acquisitions	996,088
Issuance of common stock in connection with acquisitions	$ 3,000,000
Shares sold at the market, shares		1,587,302
Advent Venture Partners LLP [Member] | 4-antibody acquisition [Member] | Contingent Milestone 1 [Member]
Related Party Transaction [Line Items]
Contingent Consideration					$ 6,200,000
Children of Armenia Fund (“COAF”) [Member]
Related Party Transaction [Line Items]
Charitable contribution			$ 100,000
Cash charitable contribution			$ 50,000
Cash installments payment			Quarterly
Non-cash charitable contribution			$ 50,000

Leases Narrative (Details)

Leases Narrative (Details)	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2012ft²
Operating Leased Assets [Line Items]
Operating leases, rent expense		$ 3,300,000	$ 2,300,000	$ 2,100,000
Letters of credit outstanding, amount		1,000,000
Amounts drawn on letter of credit		0
Security deposit		270,000
Rental income, non-operating		733,000	$ 780,000	$ 365,000
Capital lease payments for 2017		288,000
Capital lease payments for 2018		288,000
Capital lease payments for 2019		288,000
Capital lease payments for 2020		$ 144,000
Scenario Forecast [Member]
Operating Leased Assets [Line Items]
Rental income, non-operating	$ 529,000
Minimum [Member]
Operating Leased Assets [Line Items]
Lease expiration year		2,017
Maximum [Member]
Operating Leased Assets [Line Items]
Lease expiration year		2,025
New York [Member]
Operating Leased Assets [Line Items]
Square footage of real estate property | ft²					5,600

Leases (Details)

Leases (Details) $ in Thousands	Dec. 31, 2016USD ($)
Leases [Abstract]
2,017	$ 3,530
2,018	3,226
2,019	2,492
2,020	2,133
2,021	1,762
Thereafter	3,865
Total	$ 17,008

Leases - (Schedule of Capital L

Leases - (Schedule of Capital Lease for Piece of Laboratory Equipment) (Details) - Laboratory Equipment [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Capital Leased Assets [Line Items]
Laboratory and manufacturing equipment	$ 1,021
Less accumulated depreciation and amortization	(51)
Total	$ 970
Estimated Depreciable Lives	4 years

Debt - Schedule of Debt Obligat

Debt - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Feb. 20, 2015
Debt instrument, Long-term Portion
Principal Balance, Long-term Portion	$ 114,000	$ 114,000
Non-cash Interest, Long-term Portion	19,421	4,342
Unamortized Debt Issuance Costs, Long-term Portion	(1,345)	(1,481)
Unamortized Debt Discount, Long-term Portion	(1,533)	(2,535)
Balance, Long-term Portion	130,542	114,326
Principal, Balance Total	114,146	114,146
Non-cash Interest Total	19,421	4,342
Unamortized Debt Issuance Costs Total	(1,345)	(1,481)
Unamortized Debt Discount Total	(1,533)	(2,535)	$ (3,000)
Balance, Long-Term Debt Total	130,688	114,473
2015 Subordinated Notes [Member]
Debt instrument, Long-term Portion
Principal Balance, Long-term Portion	14,000	14,000
Unamortized Debt Discount, Long-term Portion	(1,311)	(2,292)
Balance, Long-term Portion	12,689	11,708
Note Purchase Agreement [Member]
Debt instrument, Long-term Portion
Principal Balance, Long-term Portion	100,000	100,000
Non-cash Interest, Long-term Portion	19,421	4,342
Unamortized Debt Issuance Costs, Long-term Portion	(1,345)	(1,481)
Unamortized Debt Discount, Long-term Portion	(222)	(243)
Balance, Long-term Portion	117,853	102,619
Debentures [Member]
Debt instrument, Current Portion
Principal Balance, Short-term Portion	146	146
Balance, Short-term Portion	$ 146	$ 146

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	Sep. 08, 2015	Sep. 04, 2015	Feb. 20, 2015	Mar. 16, 2017	May 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 15, 2015	Aug. 31, 2009
Debt Instrument [Line Items]
warrants issued										694,441
Loss on extinguishment of debt							$ (154,117)
Debt Instrument, Unamortized Discount			$ 3,000,000			$ 1,533,000	2,535,000
Debt Instrument, Convertible, Remaining Discount Amortization Period			3 years
Carrying value of capital lease included in property, plant and equipment, net						25,633,985	15,310,623
Long-term Debt, Gross						$ 114,146,000	114,146,000
Stock issued to repurchase the Assigned Interest					12,650,000
Assignment and Termination Agreement [Member]
Debt Instrument [Line Items]
Percent of royalties sold under repurchase agreement									20.00%
Cash payment to repurchase the Assigned Interest		$ 20,000,000
Stock issued to repurchase the Assigned Interest		300,000
Total consideration amount to repurchase the Assigned Interest		$ 22,100,000
Fair value adjustment settlement amount of contingent royalty							$ 6,900,000
Equipment [Member]
Debt Instrument [Line Items]
Capital lease expiration period						2020-06
Capital lease obligations						$ 900,000
Equipment [Member] | Other Current Liabilities [Member]
Debt Instrument [Line Items]
Capital lease obligations included in other current liabilities						289,000
Equipment [Member] | Other Long-term Liabilities [Member]
Debt Instrument [Line Items]
Capital lease obligations included in other long-term liabilities						$ 599,000
Antigenics LLC [Member]
Debt Instrument [Line Items]
Maximum repurchase percentage of notes						15.00%
Maximum period for repurchase of notes						90 days
Amounts payable to purchasers on maturity date						$ 100,000,000
Additional amount payable in issuance of excess of notes on maturity date						115,000,000
Notes default payment amount						$ 1,000,000
Increase in interest rate on notes in event of default						2.50%
Antigenics LLC [Member] | Within 24 Months of the Closing Date [Member]
Debt Instrument [Line Items]
Debt instrument redemption price percentage						20.00%
Antigenics LLC [Member] | After 24 Months but Within 48 Months of the Closing Date [Member]
Debt Instrument [Line Items]
Debt instrument redemption price percentage						17.50%
Antigenics LLC [Member] | More than 48 Months After the Closing Date [Member]
Debt Instrument [Line Items]
Debt instrument redemption price percentage						15.00%
Common Stock [Member]
Debt Instrument [Line Items]
Stock issued to repurchase the Assigned Interest						496,520	12,650,000	215,489
2013 Warrants [Member]
Debt Instrument [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights			$ 5.10			$ 4.41
Warrant expiration date						Apr. 15, 2017
2013 Warrants [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Warrant expiration date				Apr. 15, 2019
2013 Warrants [Member] | Common Stock [Member]
Debt Instrument [Line Items]
warrants issued			1,400,000			500,000
Limited Recourse Notes [Member] | Antigenics LLC [Member] | Oberland Capital SA Zermatt LLC [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 100,000,000
Additional notes maximum issuance period	15 days
Debt instrument accrued interest rate percentage						13.50%
Debt instrument period for computation of interest rate						360 days
Limited Recourse Notes [Member] | Glaxo Smith Kline [Member] | Oberland Capital SA Zermatt LLC [Member]
Debt Instrument [Line Items]
Capitalized interest amount						$ 19,400,000
Additional Notes [Member] | Antigenics LLC [Member] | Oberland Capital SA Zermatt LLC [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 15,000,000
Aquila Debentures [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage						7.00%
Long-term Debt, Gross						$ 146,000
Senior Subordinated Notes [Member] | Notes 2013 Exchanged To Notes 2015 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 5,000,000
Senior Subordinated Notes [Member] | Notes 2015 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 9,000,000
Debt Instrument, Interest Rate, Stated Percentage			8.00%
Debt Instrument, Debt Default Provisions, Face Amount			$ 13,500,000
Debt Instrument, Maturity Date						Feb. 20, 2018
Senior Subordinated Notes [Member] | Notes 2015 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				Feb. 20, 2020
Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Remaining Discount Amortization Period						12 years
Noncash interest expenses						$ 15,100,000	$ 4,300,000
Royalty revenue recognized						0	$ 0
Reimbursed purchaser for legal fees						250,000
Debt issuance costs						1,500,000
Capital Lease [Member] | Equipment [Member]
Debt Instrument [Line Items]
Carrying value of capital lease included in property, plant and equipment, net						$ 1,000,000

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	$ 7,561,000	$ 5,608,000
Fair value of transfers into or out of Levels 1 and 2	0
Long-term Debt, Gross	114,146,000	114,146,000
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	0	0
Debt Instrument, Fair Value Disclosure	129,200,000	$ 115,900,000
4-antibody acquisition [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	3,900,000
PhosImmune Inc. [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	$ 3,600,000

Fair Value Measurements Asset a

Fair Value Measurements Asset and Liabilities Measured at Fair Value (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value Disclosure	$ 9,990,000	$ 19,996,000
Short-term investments, Fair Value Disclosure	4,988,000	34,965,000
Total	14,978,000	54,961,000
Contingent purchase price considerations, Fair Value Disclosure	7,561,000	5,608,000
Total	7,561,000	5,608,000
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value Disclosure	9,990,000	19,996,000
Short-term investments, Fair Value Disclosure	4,988,000	34,965,000
Total	14,978,000	54,961,000
Contingent purchase price considerations, Fair Value Disclosure	0	0
Total	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value Disclosure	0	0
Short-term investments, Fair Value Disclosure	0	0
Total	0	0
Contingent purchase price considerations, Fair Value Disclosure	0	0
Total	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value Disclosure	0	0
Short-term investments, Fair Value Disclosure	0	0
Total	0	0
Contingent purchase price considerations, Fair Value Disclosure	7,561,000	5,608,000
Total	$ 7,561,000	$ 5,608,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Significant Unobservable Inputs (Level 3) [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Balance, beginning of period	$ 5,608
Balance, end of period	7,561
Contingent purchase price [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Change in fair value of considerations during the period	$ 1,953

Benefit Plans (Narrative) (Deta

Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contributions per employee	60.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 302,000	$ 307,000	$ 0
Expensed plan contributions	302,000	307,000	$ 0
Maximum contribution, Under 50 [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contributions per employee, Amount	18,000
Maximum contribution, Over 50 [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contributions per employee, Amount	24,000
Foreign Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status	(1,200,000)	(944,000)
Accumulated other comprehensive loss	(154,000)	(245,000)
Defined benefit plan, contributions by employer	153,000	$ 119,000
Defined benefit plans, estimated future employer contributions during 2017	162,000
Benefits expected to be paid, 2017	136,000
Benefits expected to be paid, 2018	125,000
Benefits expected to be paid, 2019	116,000
Benefits expected to be paid, 2020	107,000
Benefits expected to be paid, 2021	100,000
Benefits expected to be paid, 2022-2026	$ 452,000

Geographical Information (Detai

Geographical Information (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	$ 5,576,000	$ 4,446,000	$ 6,592,000	$ 5,959,000	$ 7,639,000	$ 6,848,000	$ 6,377,000	$ 3,953,000	$ 22,573,303	$ 24,817,025	$ 6,977,455
Long-Lived Assets	26,917,000				16,581,000				26,917,000	16,581,000
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues									20,332,000	23,668,000	3,664,000
Long-Lived Assets	22,360,000				14,434,000				22,360,000	14,434,000
Europe [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues									2,242,000	1,149,000	$ 3,313,000
Long-Lived Assets	$ 4,557,000				$ 2,147,000				$ 4,557,000	$ 2,147,000

Quarterly Financial Data (Una90

Quarterly Financial Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Revenues	$ 5,576,000	$ 4,446,000	$ 6,592,000	$ 5,959,000	$ 7,639,000	$ 6,848,000	$ 6,377,000	$ 3,953,000	$ 22,573,303	$ 24,817,025	$ 6,977,455
Net loss	(26,122,000)	(40,774,000)	(28,320,000)	(31,779,000)	(15,607,000)	(13,122,000)	(40,410,000)	(18,741,000)	(126,995,175)	(87,881,121)	(42,486,174)
Net loss attributable to common shareholders	$ (26,174,000)	$ (40,825,000)	$ (28,371,000)	$ (31,829,000)	$ (15,658,000)	$ (13,173,000)	$ (40,461,000)	$ (18,792,000)	$ (127,199,421)	$ (88,084,081)	$ (42,690,006)
Basic and diluted net income (loss) attributable to common stockholders	$ (0.30)	$ (0.47)	$ (0.33)	$ (0.37)	$ (0.18)	$ (0.16)	$ (0.53)	$ (0.28)	$ (1.46)	$ (1.13)	$ (0.71)

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - USD ($)	Feb. 14, 2017	Sep. 04, 2015	Jan. 09, 2015	Jan. 09, 2015	Mar. 16, 2017	May 31, 2015	Dec. 31, 2016
Subsequent Event [Line Items]
Shares sold at the market, shares						12,650,000
2013 Warrants [Member]
Subsequent Event [Line Items]
Warrant expiration date							Apr. 15, 2017
Notes 2015 [Member] | Senior Subordinated Notes [Member]
Subsequent Event [Line Items]
Debt instrument, maturity date							Feb. 20, 2018
Subsequent Event [Member] | 2013 Warrants [Member]
Subsequent Event [Line Items]
Warrant expiration date					Apr. 15, 2019
Subsequent Event [Member] | Notes 2015 [Member] | Senior Subordinated Notes [Member]
Subsequent Event [Line Items]
Debt instrument, maturity date					Feb. 20, 2020
Collaborative Arrangement [Member]
Subsequent Event [Line Items]
Shares sold at the market, shares		300,000
Stock Purchase Agreement [Member]
Subsequent Event [Line Items]
Shares sold at the market, shares			7,760,000	7,760,000
Incyte Corporation [Member] | Collaborative Arrangement [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Amended collaboration agreement, description	Incyte is now responsible for global development and commercialization and all associated costs for these programs. In addition, the profit-share programs relating to the two undisclosed targets were removed from the collaboration, with one reverting to Incyte and one to Agenus. Should any of those programs be successfully developed by a party, the other party will be eligible to receive the same milestone payments as the royalty-bearing programs and royalties at a 15% rate on global net sales.
Royalty payments on net sales (as a percent)	15.00%
Accelerated milestone payments received	$ 20,000,000
Incyte Corporation [Member] | Collaborative Arrangement [Member] | Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Potential milestone payments receivable	$ 510,000,000
Incyte Corporation [Member] | Stock Purchase Agreement [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Shares sold at the market, shares	10,000,000
Number of shares purchased, price per share	$ 6
Percentage of shares owned	18.10%
Stock purchase agreement amendment description	Under the Amendment, the parties also revised the existing standstill provision to permit Incyte’s acquisition of the Shares, but Incyte is precluded from acquiring any additional shares of Agenus’ voting stock until December 31, 2019.