Agenus (AGEN) 10-K 16 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 15, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Entity Registrant Name	AGENUS INC
Entity Central Index Key	0001098972
Trading Symbol	AGEN
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		204,685,422
Entity Public Float			$ 670.5
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $.01 Par Value
Security Exchange Name	NASDAQ
Entity File Number	000-29089
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-1562417
Entity Address, Address Line One	3 Forbes Road
Entity Address, City or Town	Lexington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02421
City Area Code	781
Local Phone Number	674-4400
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference [Text Block]	Portions of the Registrant’s Definitive Proxy Statement relating to the 2021 Annual Meeting of Stockholders, which the registrant intends to file with the Securities and Exchange Commission pursuant to Regulation 14A within 120 days after the end of the registrant’s fiscal year ended December 31, 2020, are incorporated by reference into Part III of this Report.
ICFR Auditor Attestation Flag	true

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Cash and cash equivalents	$ 99,871	$ 61,808
Accounts Receivable	1,157	16,293
Prepaid expenses	10,746	7,420
Other current assets	2,009	1,015
Total current assets	113,783	86,536
Property, plant and equipment, net of accumulated amortization and depreciation of $47,201 and $42,861 at December 31, 2020 and 2019, respectively	26,790	26,326
Operating lease right-of-use assets	33,480	7,364
Goodwill	25,452	23,188
Acquired intangible assets, net of accumulated amortization of $11,841 and $9,431 at December 31, 2020 and 2019, respectively	10,886	10,504
Other long-term assets	4,123	1,417
Total assets	214,514	155,335
LIABILITIES, CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT
Current portion, long-term debt	833	646
Current portion, liability related to sale of future royalties and milestones	57,362	45,961
Current portion, deferred revenue	17,186	29,174
Current portion, operating lease liabilities	1,950	1,347
Accounts payable	17,015	13,564
Accrued liabilities	29,057	31,332
Other current liabilities	6,481	185
Total current liabilities	129,884	122,209
Long-term debt, net of current portion	18,879	13,380
Liability related to sale of future royalties and milestones, net of current portion	176,263	175,408
Deferred revenue, net of current portion	28,282	27,705
Operating lease liabilities, net of current portion	34,065	8,020
Contingent purchase price consideration	10,208	8,843
Other long-term liabilities	1,514	4,190
Commitments and contingencies (Note 20)
STOCKHOLDERS’ DEFICIT
Common stock, par value $0.01 per share; 400,000,000 shares authorized; 196,090,980 shares and 137,818,068 shares issued at December 31, 2020 and 2019, respectively	1,961	1,378
Additional paid-in capital	1,257,502	1,059,583
Accumulated other comprehensive income (loss)	2,772	(1,324)
Accumulated deficit	(1,465,907)	(1,284,993)
Total stockholders’ deficit attributable to Agenus Inc.	(203,672)	(225,356)
Non-controlling interest	(7,826)	(5,981)
Total stockholders’ deficit	(211,498)	(231,337)
Total liabilities, convertible preferred stock and stockholders’ deficit	214,514	155,335
Series C-1 Convertible Preferred Stock [Member]
CONVERTIBLE PREFERRED STOCK
Series C-1 convertible preferred stock; 12,459 shares designated, issued, and outstanding at December 31, 2020 and 2019	26,917	26,917
Series A-1 convertible preferred stock [Member]
STOCKHOLDERS’ DEFICIT
Series A-1 convertible preferred stock; 31,620 shares designated, issued, and outstanding at December 31, 2020 and 2019; liquidation value of $33,250 and $33,040 at December 31, 2020, and 2019, respectively	0	0
Total stockholders’ deficit	$ 0	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property plant and equipment, accumulated amortization and depreciation	$ 47,201	$ 42,861
Acquired intangible assets, accumulated amortization	$ 11,841	$ 9,431
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	400,000,000	400,000,000
Common stock, shares issued	196,090,980	137,818,068
Series C-1 Convertible Preferred Stock [Member]
Series C-1 convertible preferred stock, shares designated	12,459	12,459
Series C-1 convertible preferred stock, shares issued	12,459	12,459
Series C-1 convertible preferred stock, shares outstanding	12,459	12,459
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	$ 33,250	$ 33,040

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenues	$ 88,170	$ 150,048	$ 36,784
Operating expenses:
Cost of service revenue	(2,349)
Research and development	(142,617)	(168,339)	(124,600)
General and administrative	(59,218)	(46,041)	(37,340)
Contingent purchase price consideration fair value adjustment	(1,221)	(5,805)	1,335
Operating loss	(117,235)	(70,137)	(123,821)
Other income (expense):
Loss on modification of debt	(2,720)
Loss on early extinguishment of debt			(10,767)
Non-operating income (expense)	(1,858)	28	(2,183)
Interest expense, net	(61,078)	(41,451)	(25,273)
Net loss	(182,891)	(111,560)	(162,044)
Dividends on Series A-1 convertible preferred stock	(209)	(208)	(207)
Less: net loss attributable to non-controlling interest	(1,977)	(3,903)	(2,352)
Net loss attributable to Agenus Inc. common stockholders	$ (181,123)	$ (107,865)	$ (159,899)
Per common share data:
Basic and diluted net loss attributable to Agenus Inc. common stockholders	$ (1.05)	$ (0.80)	$ (1.44)
Weighted average number of Agenus Inc. common shares outstanding:
Basic and diluted	172,504	134,982	110,772
Other comprehensive income:
Foreign currency translation gain	$ 4,096	$ 215	$ 630
Other comprehensive income	4,096	215	630
Comprehensive loss	(177,027)	(107,650)	(159,269)
Service revenue [Member]
Revenue:
Total revenues	4,619
Royalty sales milestone [Member]
Revenue:
Total revenues		15,100
Other Revenues [Member]
Revenue:
Total revenues	91	4,679
Research and Development [Member]
Revenue:
Total revenues	35,915	99,845	19,475
Non Cash Royalty Revenue Related To The Sale Of Future Royalties And Milestone [Member]
Revenue:
Total revenues	$ 47,545	$ 30,424	$ 17,309

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Amendment to 2015 Warrants [Member]	Revision Of Prior Period Accounting Standards Update Adjustment [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Amendment to 2015 Warrants [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-controlling Interest [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]Revision Of Prior Period Accounting Standards Update Adjustment [Member]	Series C-1 Convertible Preferred Stock [Member]	Series A-1 convertible preferred stock [Member]
Stockholders' Equity, Beginning Balance at Dec. 31, 2017	$ (75,815)			$ 1,017	$ 951,812		$ (2,169)		$ (1,026,475)			$ 0
Balance, shares at Dec. 31, 2017				101,706,000								32,000
Net loss	(162,044)							$ (2,352)	(159,692)
Other comprehensive loss	630						630
AgenTus share distribution	274							274
Share-based compensation	7,351				7,351
Vesting of nonvested shares, value				$ 1	(1)
Vesting of nonvested shares, shares				53,000
Shares sold at the market, value	44,919			$ 178	44,741
Shares sold at the market, shares				17,799,000
Issuance of Series C-1 convertible preferred stock, net of issuance costs of $122											$ 39,879
Issuance of Series C-1 convertible preferred stock, net of issuance costs, shares											18,000
Payment of consultant in shares	50				50
Payment of consultant in shares, shares				26,000
Exercise of stock options and employee share purchases, value	1,234			$ 4	1,230
Exercise of stock options and employee share purchases, shares				413,000
Stockholders' Equity, Ending Balance at Dec. 31, 2018	(174,545)			$ 1,200	1,005,183		(1,539)	(2,078)	(1,177,311)			$ 0
Temporary Equity, shares at Dec. 31, 2018											18,000
Temporary Equity, Ending Balance at Dec. 31, 2018											$ 39,879
Balance, shares at Dec. 31, 2018				119,997,000								32,000
Accumulated deficit | ASC 606 [Member]			$ 8,856							$ 8,856
Net loss	(111,560)							(3,903)	(107,657)
Other comprehensive loss	215						215
Share-based compensation	9,892				9,892
Vesting of nonvested shares, value				$ 1	(1)
Vesting of nonvested shares, shares				130,000
Shares sold under Stock Purchase Agreement, values	30,000			$ 111	29,889
Shares sold under Stock Purchase Agreement, shares				11,111,000
Payment of consultant in shares	81				81
Payment of consultant in shares, shares				29,000
Conversion of Series C-1 convertible preferred stock	12,962			$ 60	12,902						$ (12,962)
Conversion of Series C-1 convertible preferred stock, shares				6,000,000							(6,000)
Exercise of stock options and employee share purchases, value	1,643			$ 6	1,637
Exercise of stock options and employee share purchases, shares				552,000
Stockholders' Equity, Ending Balance at Dec. 31, 2019	(231,337)			$ 1,378	1,059,583		(1,324)	(5,981)	(1,284,993)			$ 0
Temporary Equity, shares at Dec. 31, 2019											12,459
Temporary Equity, Ending Balance at Dec. 31, 2019											$ 26,917
Balance, shares at Dec. 31, 2019				137,819,000								32,000
Accumulated deficit	(1,284,993)
Accumulated deficit | ASC 842 [Member]			$ (25)							$ (25)
Net loss	(182,891)							(1,977)	(180,914)
Other comprehensive loss	4,096						4,096
Share-based compensation	10,121				10,121
Vesting of nonvested shares, value				$ 2	(2)
Vesting of nonvested shares, shares				166,000
Shares sold at the market, value	156,421			$ 509	155,912
Shares sold at the market, shares				50,947,000
Shares sold under Stock Purchase Agreement, values	20,000			$ 50	19,950
Shares sold under Stock Purchase Agreement, shares				4,963,000
Issuance of subsidiary shares to noncontrolling interest	2,374				2,242			132
Issuance of shares for business acquisition	900			$ 4	896
Shares Issued For Business Acquisition, shares				405,000
Amendment of 2015 warrants and issuance of 2020 warrants		$ 3,145				$ 3,145
Payment of CEO payroll in shares	296			$ 1	295
Payment of CEO payroll In shares, shares				86,000
Payment of consultant in shares	908			$ 2	906
Payment of consultant in shares, shares				208,000
Exercise of stock options and employee share purchases, value	4,469			$ 15	4,454
Exercise of stock options and employee share purchases, shares				1,499,000
Stockholders' Equity, Ending Balance at Dec. 31, 2020	(211,498)			$ 1,961	$ 1,257,502		$ 2,772	$ (7,826)	$ (1,465,907)			$ 0
Temporary Equity, shares at Dec. 31, 2020											12,459
Temporary Equity, Ending Balance at Dec. 31, 2020											$ 26,917
Balance, shares at Dec. 31, 2020				196,093,000								32,000
Accumulated deficit	$ (1,465,907)

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Series C-1 Convertible Preferred Stock [Member]
Issuance costs	$ 122

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (182,891)	$ (111,560)	$ (162,044)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	7,179	6,662	6,288
Share-based compensation	10,417	9,892	7,625
Non-cash royalty and milestone revenue	(47,545)	(30,424)	(17,309)
Non-cash interest expense	60,029	42,201	24,599
Donation of assets	622
Loss on disposal of assets	198	58	145
Change in fair value of contingent obligations	1,221	5,805	(1,335)
Loss on modification of debt	2,720
Loss on extinguishment of debt			10,767
Changes in operating assets and liabilities:
Accounts receivable	16,187	(15,355)	196
Inventories		55	24
Prepaid expenses	(187)	11,792	(8,210)
Accounts payable	2,767	(234)	5,366
Deferred revenue	(11,464)	53,900	(397)
Accrued liabilities and other current liabilities	3,826	7,097	3,303
Other operating assets and liabilities	(2,175)	1,429	(113)
Net cash used in operating activities	(139,096)	(18,682)	(131,095)
Cash flows from investing activities:
Proceeds from sale of plant and equipment			6
Purchases of plant and equipment	(3,466)	(4,657)	(3,597)
Cash paid for business acquisition, net	(975)
Net cash used in investing activities	(4,441)	(4,657)	(3,591)
Cash flows from financing activities:
Net proceeds from sale of equity	176,421	30,000	44,919
Proceeds from employee stock purchases and option exercises	4,469	1,643	1,234
Proceeds from issuance of long-term debt	6,197
Proceeds from sale of future royalties			204,878
Transaction costs from sale of future royalties and milestones			(494)
Repayments of debt	(1,462)		(161,847)
Payment of finance lease obligation	(1,770)	(320)	(283)
Net cash provided by financing activities	183,855	31,323	128,286
Effect of exchange rate changes on cash	379	770	(733)
Net increase (decrease) in cash, cash equivalents and restricted cash	40,697	8,754	(7,133)
Cash, cash equivalents and restricted cash, beginning of period	61,808	53,054	60,187
Cash, cash equivalents and restricted cash, end of period	102,505	61,808	53,054
Supplemental cash flow information:
Cash paid for interest	1,176	1,224	1,171
Supplemental disclosures - non-cash activities:
Purchases of plant and equipment in accounts payable and accrued liabilities	289	1,242	300
Issuance of common stock	900
Contingent purchase price consideration in connection with business acquisition	144
Issuance of subsidiary shares to noncontrolling interest	2,374
Lease right-of-use assets obtained in exchange for new operating lease liabilities	28,184	3,017
Lease right-of-use assets obtained in exchange for new finance lease liabilities	2,434
Payment to Consultant [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock	$ 908	$ 81	50
Series C-1 Convertible Preferred Stock [Member]
Cash flows from financing activities:
Net proceeds from sale of C-1 Preferred Stock			$ 39,879

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical)	Dec. 31, 2020$ / shares
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01
Payment to Consultant [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2020
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 (“I-O”) company advancing an extensive pipeline of immune checkpoint antibodies, adoptive cell therapies and neoantigen vaccines, to fight cancer and infections. Our business is designed to drive success in I-O through speed, innovation and effective combination therapies. We believe that combination therapies and a deep understanding of each patient’s cancer will drive substantial expansion of the patient population benefiting from current I-O therapies. In addition to a diverse pipeline, we have assembled fully integrated end-to-end capabilities including novel target discovery, antibody generation, cell line development and current good manufacturing practice manufacturing. We believe that these fully integrated capabilities enable us to produce novel candidates on timelines that are shorter than the industry standard. Leveraging our science and capabilities, we have forged important partnerships to advance our innovation. We are developing a comprehensive I-O portfolio driven by the following platforms and programs, which we intend to utilize individually and in combination: • our multiple antibody discovery platforms, including our proprietary display technologies, designed to drive the discovery of future CPM antibody candidates; • our antibody candidate programs, including our CPM programs; • our vaccine programs, including Prophage™, AutoSynVax™ and PhosPhoSynVax ™; • our saponin-based vaccine adjuvants, principally our QS-21 Stimulon™ adjuvant, or QS-21 Stimulon; and • our cell therapy subsidiary, AgenTus Therapeutics, Inc., which is designed to drive the discovery of future adoptive cell therapy, or “living drugs” programs. Our business activities include 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 and cash equivalents at December 31, 2020 were $99.9 million, an increase of $38.1 million from December 31, 2019. We have incurred significant losses since our inception. As of December 31, 2020, we had an accumulated deficit of $1.47 billion. Although we plan to launch our first commercial product in 2021, if approved, we do not expect to be profitable in 2021. During the past five years, we have successfully financed our operations through corporate partnerships, advance royalty sales and the sale of equity. Based on our current plans and projections, we believe that our cash resources of $99.9 million as of December 31, 2020, plus additional funding we anticipate from corporate events, will be sufficient to satisfy our liquidity requirements through the end of the year and into 2022. We are presently in financing, partnership, and out licensing discussions which, if consummated, could extend our cash resources further into and beyond 2022. Until we are successful in our efforts for capital infusion through these transactions or other financing options, and because the completion of such transactions is not entirely within our control, in accordance with accounting guidance we are required to disclose that substantial doubt exists about our ability to continue as a going concern for a period of one year after the date of filing of this Annual Report on Form 10-K. The financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the financial statements have been prepared on a basis that assumes we will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Management continues to address the Company’s liquidity position and has the flexibility to adjust spending as needed in order to preserve liquidity. In March 2020, in response to the COVID-19 pandemic, we streamlined our organization, which included a headcount reduction; our CEO, Dr. Garo Armen, elected to receive his base salary in stock rather than cash for the remainder of 2020 and through the first half of 2021. We continuously evaluate the likelihood of success of our programs. As such, our decisions to continue to fund or eliminate funding of each of our programs are predicated on these determinations, on an ongoing basis. We expect our potential sources of funding to include: (1) collaborations, out-licensing and/or partnering opportunities for our portfolio programs and product candidates with multiple parties (2) renegotiating third party agreements, (3) selling assets, (4) securing additional debt financing and/or (5) selling equity securities. 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 many of our antibody and neoantigen vaccine programs are early stage, and because any further development of HSP-based vaccines is dependent on clinical trial results, among other factors, we are unable to reliably estimate the cost of completing our research and development programs or the timing for bringing such programs to various markets or substantial partnering or out-licensing arrangements, and, therefore, when, if ever, material cash inflows 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, 2020
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 subsidiaries. All significant intercompany transactions and accounts have been eliminated in consolidation. Non-controlling interest in the consolidated financial statements represents the portion of two of our subsidiaries not 100% owned by Agenus. (b) Segment Information We are managed and currently operate as two segments. However, we have concluded that our two operating segments meet all three criteria required 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. (e) 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. (f) Accounts Receivable Accounts receivable are amounts due from our collaboration partners and customers as a result of research and development and other services provided, and milestones achieved. We considered the need for an allowance for doubtful accounts and have concluded that no allowance was needed as of December 31, 2020 and 2019, as the estimated risk of loss on our accounts receivable was determined to be minimal. (g) 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 $5.1 million, $4.8 million, and $4.3 million, for the years ended December 31, 2020, 2019, and 2018, respectively. (h) Fair Value of Financial Instruments The estimated fair values of all our financial instruments 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 $20.0 million and $14.1 million at December 31, 2020 and 2019, respectively. (i) Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes existing revenue recognition guidance. We adopted ASU 2014-09 and its related amendments (collectively known as “ASC 606”) on January 1, 2018 using the modified retrospective method- i.e., by recognizing the cumulative effect of initially applying ASC 606 as an adjustment to the opening balance of equity at January 1, 2018. The adoption of ASC 606 resulted in a cumulative adjustment to decrease our accumulated deficit by $ For the years ended December 31, 2020, 2019 and 2018, 16%, 60% and 43%, respectively, of our revenue was earned from one collaboration partner. In accordance with ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which we expect to be entitled to receive in exchange for these goods and services. To achieve this core principle, we apply the following five steps: 1) Identify the contract with the customer A contract with a customer exists when (i) the Company enters into an enforceable contract with a customer that defines each party’s rights regarding the goods or services to be transferred and identifies the related payment terms, (ii) the contract has commercial substance, and (iii) the Company determines that collection of substantially all consideration for goods and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. The Company applies judgment in determining the customer’s intent and ability to pay, which is based on a variety of factors including the customer’s historical payment experience, or in the case of a new customer, published credit and financial information pertaining to the customer. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the goods and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the good or service either on its own or together with other available resources, and are distinct in the context of the contract, whereby the transfer of the good or service is separately identifiable from other promises in the contract. To the extent a contract includes multiple promised goods and services, the Company must apply judgment to determine whether promised goods and services are capable of being distinct and are distinct in the context of the contract. If these criteria are not met, the promised goods and services are accounted for as a combined performance obligation. 3) Determine the transaction price The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring goods and services to the customer. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Any estimates, including the effect of the constraint on variable consideration, are evaluated at each reporting period for any changes. Determining the transaction price requires significant judgment, which is discussed in further detail for each of the Company’s contracts with customers in Note 1 4 . 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative stand-alone selling price basis unless the transaction price is variable and meets the criteria to be allocated entirely to a performance obligation or to a distinct service that forms part of a single performance obligation. The consideration to be received is allocated among the separate performance obligations based on relative stand-alone selling prices. Determining the amount of the transaction price to allocate to each separate performance obligation requires significant judgement, which is discussed in further detail for each of the Company’s contracts with customers in Note 14. 5) Recognize revenue when or as the Company satisfies a performance obligation The Company satisfies performance obligations either over time or at a point in time. Revenue is recognized over time if either 1) the customer simultaneously receives and consumes the benefits provided by the entity’s performance, 2) the entity’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or 3) the entity’s performance does not create an asset with an alternative use to the entity and the entity has an enforceable right to payment for performance completed to date. If the entity does not satisfy a performance obligation over time, the related performance obligation is satisfied at a point in time by transferring the control of a promised good or service to a customer. Examples of control are using the asset to produce goods or services, enhance the value of other assets, settle liabilities, and holding or selling the asset. ASC 606 requires the Company to select a single revenue recognition method for the performance obligation that faithfully depicts the Company’s performance in transferring control of the goods and services. The guidance allows entities to choose between two methods to measure progress toward complete satisfaction of a performance obligation: 1. Output methods - recognize revenue on the basis of direct measurements of the value to the customer of the goods or services transferred to date relative to the remaining goods or services promised under the contract (e.g. surveys of performance completed to date, appraisals of results achieved, milestones reached, time elapsed, and units of produced or units delivered); and 2. Input methods - recognize revenue on the basis of the entity’s efforts or inputs to the satisfaction of a performance obligation (e.g., resources consumed, labor hours expended, costs incurred, or time elapsed) relative to the total expected inputs to the satisfaction of that performance obligation. Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone payments: At the inception of each arrangement that includes development, regulatory or commercial milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. ASC 606 suggests two alternatives to use when estimating the amount of variable consideration: the expected value method and the most likely amount method. Under the expected value method, an entity considers the sum of probability-weighted amounts in a range of possible consideration amounts. Under the most likely amount method, an entity considers the single most likely amount in a range of possible consideration amounts. Whichever method is used, it should be consistently applied throughout the life of the contract; however, it is not necessary for the Company to use the same approach for all contracts. The Company uses the most likely amount method for development and regulatory milestone payments. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis. The Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re- evaluates the probability or achievement of each such milestone and any related constraint, and if necessary, adjusts its estimates of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). Up-front Fees: Depending on the nature of the agreement, up-front payments and fees may be recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. (j) 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 income (expense). We do not currently use derivative financial instruments to manage the risks associated with foreign currency fluctuations. We recorded a foreign currency loss of $3.1 million for the year ended December 31, 2020, a foreign currency gain of $0.1 million for the year ended December 31, 2019, and a foreign currency loss of $2.2 million for the year ended December 31, 2018. (k) 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. (l) Share-Based Compensation We account for share-based compensation in accordance with the provisions of ASC 718, Compensation—Stock Compensation. (m) 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. (n) Net Loss Per Share Basic income and loss per common share are 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, non-vested 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, 2020, 2019, and 2018, as they would be anti-dilutive: Year Ended 2020 2019 2018 Warrants 1,950 1,400 2,900 Stock options 28,916 27,164 18,614 Nonvested shares 887 2,120 2,214 Series A-1 convertible preferred stock 333 333 333 Series C-1 convertible preferred stock 12,459 12,459 18,459 (o) 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 the fair value of our reporting units to their net book value to determine if there is an indicator of impairment. We operate as two reporting units. ASC 350, Intangibles, Goodwill and Other (p) 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. (q) Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) (“ASC 842”) which supersedes Topic 840, Leases (“ASC 840”). We adopted ASC 842 on January 1, 2019 using the alternative transition method and recorded a cumulative effect adjustment to beginning retained earnings without restating prior periods. Accordingly, all financial information and disclosures for periods before January 1, 2019 continue to be presented under the requirements of ASC 840. We elected the package of practical expedients, which allowed us to carry forward our historical lease classification, our assessment of whether a contract is or contains a lease and our initial direct costs for any leases that existed prior to adoption of the new standard. At the inception of an agreement, we determine whether the contract contains a lease. If a lease is identified in such arrangement, we recognize a right-of-use asset and liability on our consolidated balance sheet and determine whether the lease should be classified as a finance or operating lease. We have elected not to recognize assets or liabilities for leases with lease terms of 12 months or less. A lease qualifies as a finance lease if any of the following criteria are met at the inception of the lease: (i) there is a transfer of ownership of the leased asset by the end of the lease term, (ii) we hold an option to purchase the leased asset that we are reasonably certain to exercise, (iii) the lease term is for a major part of the remaining economic life of the leased asset, (iv) the present value of the sum of lease payments equals or exceeds substantially all of the fair value of the leased asset, or (v) the nature of the leased asset is specialized to the point that it is expected to provide the lessor no alternative use at the end of the lease term. All other leases are recorded as operating leases. Our leases commence when the lessor makes the asset available for our use. Finance and operating lease right-of-use assets and liabilities are recognized at the lease commencement date. Lease liabilities are recognized as the present value of the lease payments over the lease term, net of any future lease incentives to be received, using the discount rate implicit in the lease. If the implicit rate is not readily determinable, as is the case with all our current leases, we utilize our incremental borrowing rate at the lease commencement date. Right-of-use assets are recognized based on the amount of the lease liability, adjusted for any advance lease payments paid, initial direct costs incurred, or lease incentives received prior to commencement. Right-of-use assets are subject to evaluation for impairment or disposal on a basis consistent with other long-lived assets. Operating lease payments are expensed using the straight-line method as an operating expense over the lease term, unless the right-of-use asset reflects impairment. We will then recognize the amortization of the right-of-use asset on a straight-line basis over the remaining lease term with rent expense still included in operating expense in our condensed consolidated statement of operations. Finance lease assets are amortized to depreciation expense using the straight-line method over the shorter of the useful life of the related asset or the lease term, unless the lease includes a provision that either (i) results in the transfer of ownership of the underlying asset at the end of the lease term or (ii) includes a purchase option whose exercise is reasonably certain. In either of these instances, the right-of-use asset is amortized over the useful life of the underlying asset. Finance lease payments are bifurcated into (i) a portion that is recorded as imputed interest expense and (ii) a portion that reduces the finance lease liability. We do not separate lease and non-lease components for any of our current asset classes when determining which lease payments to include in the calculation of its lease assets and liabilities. Variable lease payments are expensed in the period incurred. If a lease includes an option to extend or terminate the lease, we reflect the option in the lease term if it is reasonably certain the option will be exercised. Our right of use assets and lease liabilities generally exclude periods covered by renewal options and include periods covered by early termination options (based on our conclusion that it is not reasonably certain that we will exercise such options). We account for the sublease of space in our main Lexington, Massachusetts facility from the perspective of a lessor. Our sublease is classified as an operating lease. We record sublease income as a reduction of operating expense. Operating leases are recorded in “Operating lease right-of-use assets”, “Current portion, operating lease liabilities” and “Operating lease liabilities, net of current portion”, while finance leases are recorded in “Property, plant and equipment, net”, “Other current liabilities” and “Other long-term liabilities” on our condensed consolidated balance sheet. (r) Recent Accounting Pronouncements Recently Issued and Adopted In August 2018, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”). The amendments in ASU 2018-13 modify the disclosure requirements of fair value measurements. Certain disclosures are required to be applied on a retrospective basis and others on a prospective basis. We adopted the standard on January 1, 2020. The adoption did not have a material impact on our financial statement disclosures. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606, Revenue from Contracts with Customers, (“ASC 606”) (“ASU 2018-18”). ASU 2018-18 (1) clarifies that certain transactions between collaborative arrangement participants should be accounted for under ASC 606, when the collaborative arrangement participant is a customer in the context of a unit of account, (2) adds unit-of-account guidance in ASC 808 to align with ASC 606 when an entity is assessing whether the collaborative arrangement, or a part of the arrangement, is within the scope of ASC 606, and (3) precludes presenting transactions together with revenue when those transactions involve collaborative arrangement participants that are not directly related to third parties and are not customers. We adopted the standard on January 1, 2020. The adoption did not have a material impact on our consolidated financial statements. Recently Issued, Not Yet Adopted In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350) that will eliminate the requirement to calculate the implied fair value of goodwill to measure a goodwill impairment charge. Instead, an impairment charge will be based on the excess of a reporting unit’s carrying amount over its fair value. The guidance is effective for the Company in the first quarter of fiscal 2023. Early adoption is permitted. We do not anticipate the adoption of this guidance to have a material impact on our consolidated financial statements, absent any goodwill impairment. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 enhances and simplifies multiple aspects of the income tax accounting guidance in ASC 740. The standard will be effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years, with early adoption permitted. We are currently evaluating the impact of adoption of ASU 2019-12 on our consolidated financial statements. No other new accounting pronouncement issued or effective during the year ended December 31, 2020 had or is expected to have a material impact on our consolidated financial statements or disclosures.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Dec. 31, 2020
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”). 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. During January 2015, the first milestone noted above was achieved. 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. 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 (this milestone expired unachieved on December 23, 2020) 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.

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	(4) Goodwill and Acquired Intangible Assets The following table sets forth the changes in the carrying amount of goodwill for year ended December 31, 2020 (in thousands): Balance, December 31, 2019 $ 23,188 Effect of foreign currency 1,470 Addition of goodwill related to business acquisition 794 Balance, December 31, 2020 $ 25,452 Acquired intangible assets consisted of the following at December 31, 2020 and 2019 (in thousands): As of December 31, 2020 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 7-15 years $ 17,013 $ (10,112 ) $ 6,901 Trademarks 4-4.5 years 1,310 (980 ) 330 Other 2-7 years 2,272 (749 ) 1,523 In-process research and development Indefinite 2,132 — 2,132 Total $ 22,727 $ (11,841 ) $ 10,886 As of December 31, 2019 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 7-15 years $ 16,584 $ (8,044 ) $ 8,540 Trademarks 4.5 years 834 (834 ) — Other 2-6 years 572 (553 ) 19 In-process research and development Indefinite 1,945 — 1,945 Total $ 19,935 $ (9,431 ) $ 10,504 The weighted average amortization period of our finite-lived intangible assets is approximately 9 years. Amortization expense for the years ended December 31, 2020, 2019, and 2018 was $2.4 million, $2.0 million and $2.0 million, respectively. Amortization expense related to acquired intangibles is estimated at $2.2 million for each of 2021 and 2022, $1.7 million for 2023 and $0.6 The acquired IPR&D asset relates to the six pre-clinical 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, 2020
Cash And Cash Equivalents [Abstract]
Investments	(5) Investments Cash Equivalents Cash equivalents consisted of the following as of December 31, 2020 and 2019 (in thousands): December 31, 2020 December 31, 2019 Cost Estimated Fair Value Cost Estimated Fair Value Institutional Money Market Funds $ 64,256 $ 64,256 $ 55,258 $ 55,258 U.S. Treasury Bills 20,000 20,000 — — Total $ 84,256 $ 84,256 $ 55,258 $ 55,258 As a result of the short-term nature of our investments, there were minimal unrealized holding gains or losses as of December 31, 2020, 2019 and 2018. All the investments listed above have been classified as cash equivalents on our consolidated balance sheet as of December 31, 2020 and 2019, respectively.

Restricted Cash

Restricted Cash	12 Months Ended
	Dec. 31, 2020
Cash And Cash Equivalents [Abstract]
Restricted Cash	(6) Restricted Cash As of December 31, 2020, we maintained non-current restricted cash of $2.6 million. This amount is included within “Other long-term assets” in our consolidated balance sheets and is solely comprised of a letter of credit required under the lease of our facility in Emeryville, CA. We did not maintain restricted cash as of December 31, 2019 and 2018. The following table provides a reconciliation of cash, cash equivalents and restricted cash that agrees to the total of the aforementioned amounts shown in our consolidated statements of cash flows as of December 31, 2020, 2019 and 2018, respectively (in thousands): 2020 2019 2018 Cash and cash equivalents $ 99,871 $ 61,808 $ 53,054 Restricted cash 2,634 — — Cash, cash equivalents and restricted cash $ 102,505 $ 61,808 $ 53,054

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	(7) Property, Plant and Equipment Property, plant and equipment, net as of December 31, 2020 and 2019 consist of the following (in thousands): 2020 2019 Estimated Depreciable Lives Land $ 2,230 $ 2,230 Indefinite Building and building improvements 5,630 5,624 35 years Furniture, Fixtures, and other 5,866 6,394 3 to 10 years Laboratory, manufacturing and transportation equipment 22,855 20,880 4 to 10 years Leasehold improvements 28,390 25,350 2 to 12 years Software and computer equipment 9,020 8,709 3 years 73,991 69,187 Less accumulated depreciation and amortization (47,201 ) (42,861 ) Total $ 26,790 $ 26,326

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
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 2017 through 2020. 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 2016 and prior. However, net operating losses from the tax year 2016 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, 2020, we had available net operating loss carryforwards of $733.1 million and $237.0 million for Federal and state income tax purposes, respectively, which are available to offset future Federal and state taxable income, if any, $136.7 million of these Federal net operating loss carryforwards do not expire, while the remaining net operating loss carryforwards expire between 2021 and 2038. Our ability to use these net operating losses may be limited by change of control provisions under Internal Revenue Code Section 382 and may expire unused. In addition, we have $8.7 million and $6.7 million of Federal and state research and development credits, respectively, available to offset future taxable income. These Federal and state research and development credits expire between 2021 and 2033 and 2021 and 2029, respectively. Additionally, we have $394,000 of state investment tax credits, available to offset future taxable income and expire between 2021 and 2024. We also have foreign net operating loss carryforwards, which do not expire, available to offset future foreign taxable income of $9.6 million in the United Kingdom, $11.4 million in Belgium, $667,000 in Ireland, and $289,000 in Hong Kong. The potential impacts of such provisions are among the items considered and reflected in management’s assessment of our valuation allowance requirements. 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, 2020 and 2019 are presented below (in thousands). 2020 2019 Deferred tax assets: U.S. Federal and State net operating loss carryforwards $ 168,786 $ 143,126 Foreign net operating loss carryforwards 5,302 4,096 Research and development tax credits 14,314 16,364 Share-based compensation 4,846 4,774 Intangible Assets 39,477 38,710 Interest expense carryforward 7,114 3,893 Deferred Revenue 58,796 47,456 Lease Liability 8,389 2,002 Other 4,768 3,974 Total deferred tax assets 311,792 264,395 Less: valuation allowance (303,747 ) (262,228 ) Net deferred tax assets 8,045 2,167 Foreign intangible assets (1,052 ) (1,009 ) Right of use asset (7,852 ) (1,599 ) Other (192 ) (165 ) Deferred tax liabilities (9,096 ) (2,773 ) Net deferred tax liability $ (1,051 ) $ (606 ) In assessing the realizability 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 $41.5 million and $7.9 million during the years ended December 31, 2020 and 2019, respectively. Income tax benefit was nil for the years ended December 31, 2020, 2019 and 2018. Income taxes recorded differed from the amounts computed by applying the U.S. Federal income tax rate of 21% 2020 2019 2018 Computed “expected” Federal tax benefit $ (38,706 ) $ (23,413 ) $ (34,029 ) (Increase) reduction in income taxes benefit resulting from: Change in valuation allowance 41,519 7,913 24,233 (Decrease) increase due to uncertain tax positions (764 ) (64 ) 7 Foreign income inclusion 3,570 — 11,089 State and local income benefit, net of Federal income tax benefit (4,675 ) 4,144 (11,708 ) Equity based compensation 1,883 1,367 4,219 Foreign rate differential 629 (564 ) 956 Change in fair value contingent consideration 287 1,219 (280 ) Other, net (3,743 ) 9,398 5,513 Income tax benefit $ — $ — $ — A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): 2020 2019 2018 Balance, January 1 $ 4,292 $ 4,356 $ 4,349 Increase related to current year positions 88 122 — Increase (decrease) related to previously recognized positions (766 ) (186 ) 7 Balance, December 31 $ 3,614 $ 4,292 $ 4,356 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 Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Accrued Liabilities	(9) Accrued Liabilities Accrued liabilities consist of the following as of December 31, 2020 and 2019 (in thousands): December 31, 2020 December 31, 2019 Payroll $ 7,643 $ 9,575 Professional fees 4,457 4,314 Contract manufacturing costs 6,274 8,768 Research services 4,649 6,675 Other 6,034 2,000 Total $ 29,057 $ 31,332

Equity

Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Equity	(10) Equity Effective June 19, 2019, our certificate of incorporation was amended to increase the number of authorized shares of common stock from 240,000,000 to 400,000,000. 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. The Certificate of Designation does not contemplate a sinking fund. The Series A-1 Preferred Stock ranks senior to both our Series C-1 Convertible Preferred Stock and 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 $1.6 million or $51.54 per share, and $1.4 million, or $44.92 per share, at December 31, 2020 and 2019, respectively. In October 2017, we filed, and the SEC declared effective, a Registration Statement on Form S-3 (the “2017 Registration Statement”), covering the offering of up to $250 million of common stock, preferred stock, warrants, debt securities and units. The 2017 Registration Statement included a prospectus covering the offering, issuance and sale of up to 15 million shares of our common stock from time to time in “at-the-market offerings” pursuant to a Controlled Equity Offering SM In May 2018, we entered into an At Market Issuance Sales Agreement (the “Previous Sales Agreement”) with B. Riley FBR, Inc. (“BRFBR”) with respect to an at-the-market offering program under which we may offer and sell, from time to time at our sole discretion, up to 20 million shares of our common stock through BRFBR as our sales agent. The issuance and sale of the shares under the Agreement are made pursuant to our 2017 Registration Statement. In December 2018, we filed a prospectus supplement with the SEC in connection with the offer and sale of up to an additional 30 million shares from time to time pursuant to the Previous Sales Agreement . On July 22, 2020, we filed an Automatic Shelf Registration Statement on Form S-3ASR (file no. 333-240006) (the “Registration Statement”). The Registration Statement included both a base prospectus that covered the potential offering, issuance and sale from time to time of common stock, preferred stock, warrants, debt securities and units of Agenus and a prospectus covering the offering, issuance and sale of up to 100 million shares of our common stock from time to time in “at-the-market offerings” pursuant to a new At Market Issuance Sales Agreement (the “New Sales Agreement”) entered into with B. Riley on July 22, 2020. Pursuant to the New Sales Agreement, sales will be made only upon instructions by us to B. Riley. During the year ended December 31, 2020, we received net proceeds of approximately $156.4 million from the sale of approximately 50.1 million shares of our common stock at an average price per share of approximately $3.17, in at-the-market offerings under both the New Sales Agreement and the Previous Sales Agreement. On December 20, 2018, in connection of the Gilead Collaboration Agreement we also entered into the Stock Purchase Agreement (the “Gilead Stock Purchase Agreement”) with Gilead Sciences, Inc. (“Gilead”), pursuant to which Gilead purchased approximately 11.11 million shares of our common stock (the “Shares”) for an aggregate purchase price of $30.0 million, or $2.70 per Share. Gilead owned approximately 8.5% of the outstanding shares of our common stock after such purchase. Under the Stock Purchase Agreement, Gilead has agreed (i) not to dispose of any of the Shares for a period of 12 months, (ii) to certain standstill provisions that generally preclude it from acquiring more than 15% of our outstanding voting stock after taking into account the purchase of the Shares and (iii) to vote the Shares in accordance with the recommendations of our board of directors in connection with certain equity incentive plan or compensation matters for a period of 12 months. In the Gilead Stock Purchase Agreement, we agreed to register the Shares for resale under the Securities Act of 1933, and in October 2019 we filed a registration statement with the SEC accordingly. In June 2020, in connection with the Betta License Agreement, we entered into a stock purchase agreement with Betta and Betta HK, pursuant to which we agreed to sell to Betta HK approximately 5.0 million shares of our common stock for an aggregate purchase price of approximately $20.0 million, or $4.03 per share. The closing under the stock purchase agreement occurred in July 2020. Betta HK owned approximately 2.8% of the outstanding shares of our common stock after such purchase. Under the stock purchase agreement, Betta HK has 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 our board of directors for a period of 12 months. We have agreed to register the shares for resale under the Securities Act of 1933, as amended.

Series C-1 Convertible Preferre

Series C-1 Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
Series C-1 Convertible Preferred Stock	(11) Series C-1 Convertible Preferred Stock In October 2018, we entered into a Stock Purchase Agreement with certain institutional investors (the “Purchasers”), pursuant to which we issued and sold an aggregate of 18,459 shares of Series C-1 Convertible Preferred Stock (the “C-1 Preferred Shares”), at a purchase price of $2,167 per share. Each C-1 Preferred Share is convertible into 1,000 shares of our common stock at an initial conversion price of $2.167 per share of common stock, which represents a 10% premium over the prior day’s closing price on Nasdaq. The aggregate purchase price paid by the Purchasers C-1 Preferred Shares was approximately $40,000,000. We received net proceeds of $39.9 million after offering expenses. The Stock Purchase Agreement requires us to register the resale of the Common Stock underlying the C-1 Preferred Shares (the “Conversion Shares”), which occurred in the fourth quarter of 2018. The C-1 Preferred Shares have been classified as temporary or mezzanine equity on our Consolidated Balance Sheets in accordance with U.S. GAAP as the C-1 Convertible Preferred Shares contain deemed liquidation rights that are a contingent redemption feature not solely in the Company’s control. Conversion The C-1 Preferred Shares are convertible at the option of the stockholder into the number of shares of Common Stock determined by dividing the stated value of the C-1 Preferred Shares being converted by the conversion price of $2.167, subject to adjustment for stock splits, reverse stock splits and similar recapitalization events. We will not effect any conversion of the C-1 Preferred Shares, and a stockholder shall not have the right to convert any portion of the C-1 Preferred Shares, to the extent that, after giving effect to the conversion such stockholder would beneficially own in excess of 9.99% of the number of shares of the Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock pursuant to a notice of conversion (the “Beneficial Ownership Limitation”). By written notice to us, a Purchaser may from time to time increase or decrease the Beneficial Ownership Limitation percentage not in excess of 19.99% of the number of shares of Common Stock outstanding immediately after giving effect to the issuance of the shares of Common Stock pursuant to a notice of conversion; provided that any such increase will not be effective until the sixty-first (61st) day after such notice is delivered to the us. In the year ended December 31, 2019, holders of shares of Series C-1 Preferred Stock converted a portion of such shares into 6.0 million shares of our common stock. As of December 31, 2020, 12,459 shares of Series C-1 Convertible Preferred Stock remained outstanding. Voting The C-1 Preferred Shares do not have voting rights. However, as long as any Preferred Shares are outstanding, we may not, without the affirmative vote of the holders of a majority of the then-outstanding C-1 Preferred Shares, (i) alter or change adversely the powers, preferences or rights given to the C-1 Preferred Shares or alter or amend the Certificate of Designation, amend or repeal any provision of, or add any provision to, our Certificate of Incorporation or bylaws, or file any articles of amendment, certificate of designations, preferences, limitations and relative rights of any series of preferred stock, if such action would adversely alter or change the preferences, rights, privileges or powers of, or restrictions provided for the benefit of the C-1 Preferred Shares, regardless of whether any of the foregoing actions shall be by means of amendment to the Certificate of Incorporation or by merger, consolidation or otherwise, (ii) issue further C-1 Preferred Shares or increase or decrease (other than by conversion) the number of authorized C-1 Preferred Shares, or (iii) enter into any agreement with respect to any of the foregoing. Dividends The C-1 Preferred Shares are entitled to receive dividends equal (on an as-if-converted-to-Common-Stock-basis, without regard to the Beneficial Ownership Limitation) to and in the same form, and in the same manner, as dividends (other than dividends in the form of Common Stock) actually paid on shares of Common Stock when, and if paid. Liquidation In any liquidation or dissolution of the Company, the C-1 Preferred Shares are entitled to participate in the distribution of assets, to the extent legally available for distribution, on a pari passu basis with the Common Stock. Redemption If at any time while the C-1 Preferred Shares are outstanding, a) the Company effects any merger, consolidation, stock sale or other business combination (other than such a transaction in which the Company is the surviving or continuing entity and its common stock is not exchanged for or converted into other securities, cash or property), b) the Company effects any sale of all or substantially all of its assets in one transaction or a series of related transactions, c) any tender offer or exchange offer (whether by the Company or another person) is completed pursuant to which more than 50% of the common stock not held by the Company or is exchanged for or converted into other securities, cash or property, or d) the Company effects any reclassification of the common stock or any compulsory share exchange pursuant (other than as a result of a dividend, subdivision or combination covered above) to which the common stock is effectively converted into or exchanged for other securities, cash or property, (in any such case, a “Fundamental Transaction”) then, upon any subsequent conversion of the C-1 Preferred Shares, the holder shall have the right to receive, in lieu of the right to receive shares of common stock, for each share of common stock that would have been issued upon such conversion immediately prior to the occurrence of such Fundamental Transaction, the same kind and amount of securities, cash or property as it would have been entitled to receive upon the occurrence of such Fundamental Transaction if it had been, immediately prior to such Fundamental Transaction, the holder of the equivalent amount of common stock. Registration Payment Arrangement We were required to file a registration statement covering the resale of the full number of shares no later than 30 days after the closing of the agreement and must use commercially reasonable efforts to cause the registration statement to be declared effective no later than 90 days after the closing date (no review by the SEC) or in the event of a review by the SEC, 120 days after the closing date. We filed, and the SEC declared effective this registration statement during 2018. If the registration statement is not maintained we must pay to each holder 1.0% of the holder’s ratable interest in the aggregate purchase price on the day of the filing/maintenance failure and on every thirtieth day thereafter until the filing/maintenance failure is cured, up to a maximum of 6% (six months). We currently deem the likelihood that we will ever be required to make payments under this arrangement to be remote, and as such no contingent liability has been recorded in our Consolidated Balance Sheets.

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 31, 2020
Share Based Compensation [Abstract]
Share-Based Compensation Plans	(12) 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, non-vested (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, non-vested (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, for up to 29.2 million shares of our common stock (subject to adjustment in the event of stock splits and other similar events). As of December 31, 2020, no shares remain available for issuance under the 2009 EIP. On April 10, 2019, our Board of Directors adopted, and on June 19, 2019, our stockholders approved, our 2019 Equity Incentive Plan (the “2019 EIP”). The 2019 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 40.2 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, the 2009 EIP and the 2019 EIP. No awards will be granted under the 2019 EIP after June 19, 2029. 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 were 166,666 shares of common stock reserved for issuance under the 2009 ESPP. Rights to purchase common stock under the 2009 ESPP were granted at the discretion of the Compensation Committee, which determined the frequency and duration of individual offerings under the plan and the dates when stock may have been purchased. Eligible employees participated voluntarily and may have withdrawn from any offering at any time before the stock is purchased. Participation terminated automatically upon termination of employment. The purchase price per share of common stock in an offering was 85% of the lesser of its fair value at the beginning of the offering period or on the applicable exercise date and may have been 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 have acquired more than 3,333 shares of stock in any offering period. No participant was allowed to purchase shares under the 2009 ESPP if such employee would own or would have been deemed to own stock possessing 5% or more of the total combined voting power or value of the Company. The 2009 ESPP plan terminated on June 10, 2019. In the second quarter of 2019, our Board of Directors adopted, and on June 16, 2020, our stockholders approved the 2019 Employee Stock Purchase Plan (the “2019 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 500,000 shares reserved for issuance under the 2019 ESPP. Our Directors’ 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 575,000 shares of our common stock reserved for issuance under this plan. As of December 31, 2020, 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 475,192 units, each representing a share of our common stock at a weighted average common stock price of $4.38, had been credited to participants’ stock accounts as of December 31, 2020. 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 primarily 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 fair value of each option granted during the periods was estimated on the date of grant using the following weighted average assumptions: 2020 2019 2018 Expected volatility 66 % 64 % 64 % Expected term in years 6 5 6 Risk-free interest rate 0.8 % 1.8 % 2.8 % 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 2020 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2019 27,164,147 $ 3.67 Granted 7,330,377 3.82 Exercised (1,161,757 ) 3.05 Forfeited (2,974,728 ) 3.30 Expired (1,441,638 ) 4.52 Outstanding at December 31, 2020 28,916,401 3.70 7.47 $ 7,088,129 Vested or expected to vest at December 31, 2020 28,916,401 3.70 7.47 $ 7,088,129 Exercisable at December 31, 2020 14,997,220 $ 3.98 6.13 $ 3,232,022 The weighted average grant-date fair values of options granted during the years ended December 31, 2020, 2019, and 2018, was $2.04, $1.77, and $1.23, respectively. The aggregate intrinsic value in the table above represents the difference between our closing stock price on the last trading day of fiscal 2020 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, 2020 (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, 2020, 2019, and 2018, determined on the dates of exercise, was $1.2 million, $385,000, and $399,000, respectively. During 2020, 2019, and 2018, 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 certain awards dated March 2, 2018, August 6, 2018, December 31, 2018 and December 24, 2019. In March 2018, our Board of Directors approved certain awards subject to forfeiture in the event stockholder approval was not obtained to increase the shares available under our 2009 EIP. This approval was obtained in June 2018. Accordingly, these awards have a grant date of June 2018, with an exercise price as of the date the Board of Director's approved the awards in March 2018. In August 2018, our Board of Directors approved certain awards. However, the awards were not communicated until October 2018. Accordingly, these awards have a grant date of October 2018 with an exercise price as of the date the Board of Director's approved the awards in August 2018. In December 2018, our Board of Directors approved certain awards subject to forfeiture in the event stockholder approval was not obtained for our 2019 EIP. This approval was obtained in June 2019. Accordingly, these awards have a grant date of June 2019, with an exercise price as of the date the Board of Director's approved the awards in December 2018. In December 2019, our Board of Directors approved certain awards. However, the awards were not communicated until February 2020. Accordingly, these awards have a grant date of February 2020 with an exercise price as of the date the Board of Director's approved the awards in December 2019. As of December 31, 2020, there was $22.3 million of unrecognized share-based compensation expense related to stock options granted to employees, consultants and directors for which, if all milestones are achieved, will be recognized over a weighted average period of 2.2 years. Certain employees and consultants have been granted non-vested stock. The fair value of non-vested market-based awards is calculated based on a Monte Carlo simulation as of the date of issuance. The fair value of other non-vested stock is calculated based on the closing sale price of our common stock on the date of issuance. A summary of non-vested stock activity for 2020 is presented below: Nonvested Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2019 2,207,943 $ 2.85 Granted 179,816 3.60 Vested (165,632 ) 2.75 Forfeited (1,335,311 ) 3.43 Outstanding at December 31, 2020 886,816 $ 2.14 As of December 31, 2020, there was $0.8 million of unrecognized share-based compensation expense related to these non-vested shares 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, 2020, 2019, and 2018, was $621,000, $357,000, and $242,000, respectively. Cash received from option exercises and purchases under our 2009 ESPP for the years ended December 31, 2020, 2019, and 2018, was $4.5 million, $1.6 million, and $1.2 million, respectively. We issue new shares upon option exercises, purchases under our 2009 ESPP and 2019 ESPP, vesting of non-vested stock and under the Directors’ Deferred Compensation Plan. During the years ended December 31, 2020, 2019, and 2018, 236,855 shares, 84,703 shares, and 140,313 shares, were issued under 2009 ESPP and 2019 ESPP, respectively. During the years ended December 31, 2020, 2019, and 2018, 165,632 shares, 129,675 shares, and 53,050 shares, respectively, were issued as a result of the vesting of non-vested stock. The impact on our results of operations from share-based compensation for the years ended December 31, 2020, 2019, and 2018, was as follows (in thousands). Year Ended 2020 2019 2018 Research and development $ 3,758 $ 3,873 $ 3,498 General and administrative 6,363 6,019 4,127 Total share-based compensation expense $ 10,121 $ 9,892 $ 7,625

License, Research and Other Agr

License, Research and Other Agreements	12 Months Ended
	Dec. 31, 2020
Research And Development [Abstract]
License, Research, and Other Agreements	(13) License, Research, and Other Agreements 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. As of March 2021, the last granted patent that is licensed to us by UVA will expire in late 2033, and there are currently pending patent applications that, if granted, will not expire until mid-2037. 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 $385.5 million over the term of the studies. For the years ended December 31, 2020, 2019, and 2018, $64.7 million, $87.7 million, and $41.5 million, respectively, have been expensed in the accompanying consolidated statements of operations related to these third-party providers. Through December 31, 2020, we have expensed $318.7 million as research and development expenses and $308.1 million of this amount 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.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2020
Collaboration [Abstract]
Revenue from Contracts with Customers	(14) Revenue from Contracts with Customers Gilead Collaboration Agreement On December 20, 2018, we entered into a series of agreements with Gilead focused on the development and commercialization of up to five novel immuno-oncology therapies. Pursuant to the terms of the license agreement, the option and license agreements and the stock purchase agreement we entered into with Gilead (each defined below and, collectively, the “Gilead Collaboration Agreements”), at the closing of the transaction on January 23, 2019 (the “Effective Date”), we received an upfront cash payment from Gilead of $120.0 million and Gilead made a $30.0 million equity investment in Agenus. We are also eligible to receive up to $1.1 billion in aggregate potential milestones. License Agreement Pursuant to the terms of a On November 6, 2020, we received notice from Gilead that it is returning GS-1423 back to us and voluntarily terminating the License Agreement, effective as of February 4, 2021. The Option and License Agreements and the Stock Purchase Agreement (described below) remain in full force and effect. Option and License Agreements Pursuant to the terms of two separate option and license agreements between the parties (each, an “Option and License Agreement” and together, the “Option and License Agreements”), we granted Gilead exclusive options to license exclusively (“License Option”) our bispecific antibody, AGEN1223, and our monospecific antibody, AGEN2373 (together, the “Option Programs”), during the respective Option Periods (defined below). Pursuant to the terms of the Option and License Agreements, we agreed to grant Gilead an exclusive, worldwide license under our intellectual property rights to develop, manufacture and commercialize AGEN1223 or AGEN2373, as applicable, in all fields of use upon Gilead’s exercise of the applicable License Option. Gilead is entitled to exercise its License Option for either or both Option Programs at any time up until ninety (90) days following Gilead’s receipt of a data package with respect to the first complete Phase 1b clinical trial for each Option Program (the “Option Period”). During the Option Period, we are responsible for the costs and expenses related to the development of the Option Programs. After Gilead’s exercise of a License Option, if at all, Gilead would be responsible for all development, manufacturing and commercialization activities relating to the relevant Option Program at Gilead’s cost and expense. During the Option Period, we are eligible to receive milestones of up to $30.0 million in the aggregate. If Gilead exercises a License Option, it would be required to pay an upfront license exercise fee of $50.0 million for each License Option that is exercised. Following any exercise of a License Option, we would be eligible to receive additional development and commercial milestones of up to $520.0 million in the aggregate for each such Option Program, as well as tiered royalty payments on aggregate net sales. For either, but not both, of the Option Programs, we will have the right to opt-in to share Gilead’s development and commercialization costs in the United States for such Option Program in exchange for a profit (loss) share on a 50:50 basis and revised milestone payments. If we opt-in under one Option and License Agreement, our right to opt-in under the other Option and License Agreement automatically terminates. We filed INDs for each of AGEN1223 and AGEN2373 in 2019, and both assets are now in clinical development. Unless earlier terminated, each Option and License Agreement will continue until the earlier of (i) the expiration of the Option Period, without Gilead’s exercise of the License Option; and (ii) the date all of Gilead’s applicable payment obligations under the Option and License Agreement have been performed or have expired. Under the terms of each Option and License Agreement, we and Gilead each have the right to terminate the agreement for material breach by, or insolvency of, the other party. Gilead may also terminate an Option License Agreement in its entirety, or on a product-by-product or country-by-country basis for convenience upon ninety (90) days’ notice. Stock Purchase Agreement Pursuant to the terms of a stock purchase agreement between the parties (the “Stock Purchase Agreement”), Gilead purchased 11,111,111 shares of Agenus common stock (the “Shares”) for an aggregate purchase price of $30.0 million, or $2.70 per share. Gilead owned approximately 8.5% of the outstanding shares of Agenus common stock after such purchase. Under the Stock Purchase Agreement, Gilead has agreed (i) not to dispose of any of the Shares for a period of 12 months, (ii) to certain standstill provisions that generally preclude it from acquiring more than 15% of Agenus’ outstanding voting stock after taking into account the purchase of the Shares and (iii) 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 12 months. In the Stock Purchase Agreement we agreed to register the Shares for resale under the Securities Act of 1933, and in October 2019 we filed a registration statement with the SEC accordingly. Collaboration Revenue We identified the following performance obligations under the Gilead Collaboration Agreements: (1) the license that we granted to Gilead pursuant to the License Agreement (the “AGEN1423 License”), (2) our obligation to complete manufacturing and know-how tech transfer activities to Gilead pursuant to the License Agreement to enable Gilead or its third party contract manufacturing organization to manufacture the licensed antibody (the “AGEN1423 Technology Transfer”), (3) our obligation to advance development of AGEN1223 to the option exercise point pursuant to the AGEN1223 Option and License Agreement (such development activities, the “AGEN1223 R&D Services”), and (4) our obligation to advance development of AGEN2373 to the option exercise point pursuant to the AGEN2373 Option and License Agreement (such development activities, the “AGEN2373 R&D Services”). We determined that the AGEN1423 License was both capable of being distinct and distinct within the context of the contract given both the advanced stage of development and that the IND was anticipated to be accepted within a short period of time after the Effective Date. Gilead can begin deriving benefit from the license prior to the AGEN1423 Technology Transfer being completed. The technology transfer plan includes an extensive list of items to be transferred over time and is separate from the transfer of the AGEN1423 License which occurred at contract inception. As a result, we concluded that the AGEN1423 License and AGEN1423 Technology Transfer are separate performance obligations. We considered whether the AGEN1223 R&D Services and AGEN2373 R&D Services were distinct from one another and from the performance obligations related to AGEN1423. We determined that the research and development services related to each antibody were both capable of being distinct and distinct within the context of the contract given that each program is governed by a separate option agreement with a separate development plan. The services performed to develop each program are independent of one another, and the antibodies are in different stages of development. We concluded that the AGEN1223 R&D Services and AGEN2373 R&D Services are separate performance obligations. We determined that there were no significant financing components, noncash consideration, or amounts that may be refunded to the customer, and as such the total upfront fixed consideration of license and research and development fees totaling $120.0 million would be included in the total transaction price. In addition to the fixed consideration, the variable consideration milestones related to IND acceptance for each of the three antibodies was also included in the transaction price. We determined that based on the likelihood of the triggering event occurring for the acceptance of each IND filling, the most likely amount for each of the three milestones was the stated value, totaling $22.5 million. The variable consideration related to each performance obligation will be allocated entirely to that specific performance obligation. The remaining fixed consideration will be allocated using the relative standalone selling price method. We determined the estimated standalone selling price of the AGEN1423 License by applying a risk adjusted, net present value, estimate of future cash flow approach. We determined the estimated standalone selling price of the AGEN1423 Technology Transfer, and AGEN1223 R&D Services and AGEN2373 R&D Services by using the estimated costs of satisfying these performance obligations, plus an appropriate margin for such services. Revenue attributable to the AGEN1423 License was recognized at a point-in-time, upon delivery of the license to Gilead at the Effective Date. The AGEN1423 Technology Transfer, AGEN1223 R&D Services and AGEN2373 R&D Services are satisfied over time and revenue attributable to these performance obligations will be recognized as the related services are being performed using the input of costs incurred over total costs expected to be incurred. We believe this is the best measure of progress because other measures do not reflect how we transfer our performance obligations to Gilead. A cost-based input method of revenue recognition requires management to make estimates of costs to complete our performance obligations. In making such estimates, significant judgment is required to evaluate assumptions related to cost estimates. The cumulative effect of revisions to estimated costs to complete our performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated. A significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods. For the year ended December 31, 2020, we recognized $12.3 million of research and development revenue related to the Gilead Collaboration Agreements based on the partial satisfaction of the over time performance obligations as of period end. For the year ended December 31, 2019, we recognized $86.1 million of research and development revenue related to the Gilead Collaboration Agreements. This amount included $20.6 million of the transaction price recognized based on the partial satisfaction of the over time performance obligations as of period end. We expect to recognize deferred research and development revenue of $ 17.0 27.1 Betta License Agreement In June 2020, we entered into a license and collaboration agreement (the “Betta License Agreement”) with Betta Pharmaceuticals Co., Ltd. (“Betta”), pursuant to which we granted Betta an exclusive license to develop, manufacture and commercialize balstilimab and zalifrelimab in Greater China. Under the terms of the Betta License Agreement, we received $15.0 million upfront in July 2020 and are eligible to receive up to $100.0 million in milestone payments plus royalties on any future sales in Greater China. We also entered into a stock purchase agreement with Betta and a wholly-owned subsidiary of Betta (“Betta HK”). Refer to Note 10 – Equity for additional detail. We identified the following performance obligations under the Betta License Agreement: (1) the license of balstilimab and zalifrelimab and (2) our obligation to complete manufacturing technology transfer activities to Betta (the “Technology Transfer”) for We determined that the license of balstilimab and zalifrelimab was both capable of being distinct and distinct within the context of the contract as the license has significant stand-alone functionality as of contract inception based on the advanced development stage of balstilimab and zalifrelimab. Betta can begin deriving benefit from the license prior to the Technology Transfer being completed. The Technology Transfer is completed over time and is separate from the transfer of the license, which occurred at contract inception. As a result, we concluded that the license and Technology Transfer are separate performance obligations. We determined that there were no significant financing components, noncash consideration, or amounts that may be refunded to the customer, and as such the total upfront fixed consideration of $15.0 million would be included in the total transaction price and be allocated to the identified performance obligations using the relative standalone selling price method. We determined the estimated standalone selling price of the balstilimab and zalifrelimab Revenue attributable to the balstilimab and zalifrelimab license was recognized at a point-in-time, upon delivery of the license to Betta at contract inception. The Technology Transfer is satisfied over time and revenue attributable to this performance obligation will be recognized as the related services are being performed using the input of costs incurred over total costs expected to be incurred. We believe this is the best measure of progress because other measures do not reflect how we transfer the performance obligation to Betta. For the year ended December 31, 2020, we recognized $13.9 million of research and development revenue related to the Betta License Agreement. UroGen License Agreement In November 2019, we entered into a License Agreement with UroGen Pharma Ltd. (the “UroGen License Agreement”) in which we granted a license of AGEN1884 for use with UroGen's sustained release technology for intravesical delivery in patients with urinary tract cancers. Pursuant to the terms of the UroGen License Agreement, we received an upfront cash payment from UroGen of $10.0 million. We are eligible to receive up to $200.0 million in potential development, regulatory and commercial milestones, as well as 14-20% royalties on net sales of the products containing AGEN1884. We identified the following performance obligations under the UroGen License Agreement: (1) the license of AGEN1884 that we granted UroGen, and (2) the clinical supply of AGEN1884 that we agreed to supply to UroGen. We determined that the license of AGEN1884 was both capable of being distinct and distinct within the context of the contract as the license has significant stand-alone functionality as of contract inception based on the advanced development stage of AGEN1884. We also determined that the clinical supply of AGEN1884 was both capable of being distinct and distinct within the context of the contract as it was considered a readily available resource in the market. We determined that there were no significant financing components, noncash consideration, or amounts that may be refunded to the customer, and as such the total upfront fixed consideration of the license totaling $10.0 million would be included in the total transaction price. We concluded that the combined standalone selling price of the license approximated the $10.0 million upfront fee and as such the full amount will be recognized at a point-in-time, upon delivery of the license to UroGen at contract inception. We will not estimate the transaction price in order to recognize the revenue related to the AGEN1884 supply due to the “as invoiced” practical expedient. For the year ended December 31, 2020, we recognized approximately $63,000 of research and development revenue related to the UroGen License Agreement. For the year ended December 31, 2019, we recognized $10.0 million of research and development revenue related to the UroGen License Agreement. GSK License and Amended GSK Supply Agreements In July 2006, we entered into a license agreement and a supply agreement with 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. Under these agreements, GSK paid an upfront license fee of $3.0 million and agreed to pay aggregate milestones of $5.0 million. In July 2007, the Amended GSK Supply Agreement was further amended, and we were paid an additional fixed fee of $7.3 million. 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 our 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, which such rights expired in March 2017. 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. As of December 31, 2017, we had received all of the potential $24.3 million in upfront and milestone payments related to the GSK Agreements. We were also 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, but we sold these royalty rights to HCR in January 2018 pursuant to the HCR Royalty Purchase Agreement (See Note 18). 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 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. We assessed this arrangement in accordance with ASC 606 and concluded that the contract counterparty, GSK, is a customer. We identified the following performance obligations under the contract: (1) an exclusive license to QS-21 in the specified field and related technology transfer; and (2) and exclusive license to QS-21 in an additional field. We determined that the fixed payments of $19.3 million constituted all of the consideration to be included in the transaction price and to be allocated to the performance obligations based on their relative stand-alone selling prices. The fixed upfront consideration is recognized under ASC 606 based on when control of the combined performance obligation is transferred to the customer, which corresponds with the service period (through December 2014). At contract inception, the milestones of $5.0 million had been excluded from the transaction price, as we could not conclude that it was probable a significant reversal would not occur. Event driven milestones are a form of variable consideration as the payments are variable based on the occurrence of future events. As part of its estimation of the amount, we considered numerous factors, including that receipt of the milestones is outside of our control and contingent upon success in future clinical trials and the licensee’s efforts. Recognition of event driven milestones should be recognized when the variable consideration is able to be estimated. As of December 31, 2017, all milestones had been received, and therefore recognized. Any consideration related to royalties will be recognized when the related sales occur as they were determined to relate predominantly to the license granted to GSK and therefore have also been excluded from the transaction price. For the year ended December 31, 2020, we recognized $46.5 million in non-cash royalty revenue. For the year ended December 31, 2019, we recognized $15.1 million in royalty sales milestone revenue and $30.4 million in non-cash royalty revenue. For the year ended December 31, 2018, we recognized $17.3 million in non-cash royalty revenue. The cumulative impact of changing the timing of revenue recognition for the GSK License and Amended GSK Supply Agreements as of January 1, 2018 was a decrease to stockholders' deficit of approximately $2.5 million and a corresponding decrease in deferred revenue of $2.5 million for the portion of the upfront fee creditable toward future royalties, as described above. This amount was included in the transition adjustment, as under ASC 606 it would have been recognized as revenue in March 2012, at the time of the amendment. Merck Collaboration and License Agreement During the quarter ended June 30, 2014, we entered into a collaboration and license agreement with Merck to discover and optimize fully-human antibodies against two undisclosed cancer targets using the Retrocyte Display ® For the year ended December 31, 2020, we recognized $9.0 million in research and development revenue and $1.0 million in non-cash milestone revenue related to the achievement of a milestone. For the year ended December 31, 2019, no revenue was recognized. For each of the year ended December 31, 2018, we recognized $4.0 million in research and development revenue related to the achievement of a milestone. The adoption of ASC 606 did not have an impact on the Merck collaboration and license agreement. Incyte Collaboration Agreement On January 9, 2015 and effective February 19, 2015, we entered into a global license, development and commercialization agreement (the “Collaboration Agreement”) with Incyte 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 amended the Collaboration Agreement by entering into a Second Amendment to License, Development and Commercialization Agreement (the “Second Amendment”). See “Amendments” section below. Pursuant to the XOMA Royalty Purchase Agreement, we sold to XOMA 33% of the future royalties and 10% of the future milestones that we were entitled to receive from Incyte, excluding the $5.0 million milestone that we recognized in the three months ended September 30, 2018. As of December 31, 2020, we remain eligible to receive up to $450.0 million in future potential development, regulatory and commercial milestones across all programs in the collaboration, as well as 67% of all future royalties on worldwide product sales. Agreement Structure Under the terms of the Collaboration Agreement, we received non-creditable, nonrefundable upfront payments totaling $25.0 million. In addition, until the Amendment, the parties shared all costs and profits for the GITR, OX40 and two of the additional antibody programs on a 50:50 The Collaboration Agreement will continue as long as (i) any product is being developed or commercialized or (ii) the discovery period remains in effect. 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. Amendments Pursuant to the terms of the First Amendment, the GITR and OX40 programs immediately converted from profit-share programs to royalty-bearing programs and we became 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 TIGIT and one undisclosed target were removed from the collaboration, with the undisclosed target reverting to Incyte and TIGIT 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 First Amendment, Incyte paid us $20.0 million in accelerated milestones related to the clinical development of the antibody candidates targeting GITR and OX40. Pursuant to the terms of the Second Amendment, we transitioned preclinical development and IND preparation of the undisclosed target to Incyte. Collaboration Revenue For the year ended December 31, 2020, we recognized approximately $0.7 million of research and development revenue for research and development services provided. For the year ended December 31, 2019, we recognized approximately $3.7 million of research and development revenue. This amount included $2.0 million of the transaction price for the Incyte Collaboration Agreement recognized based on proportional performance and $1.7 million for research and development services. For the year ended December 31, 2018, we recognized approximately $15.5 million of research and development revenue. This amount included $1.3 million of the transaction price for the Incyte Collaboration Agreement recognized based on proportional performance, $10.0 million for the achievement of milestones and $4.2 million for research and development services. The cumulative impact of the adoption of ASC 606 for the Incyte Collaboration Agreement as of January 1, 2018 was a decrease to stockholders' deficit of approximately $6.4 million and a corresponding decrease in deferred revenue of $6.4 million. Disaggregation of Revenue The following table presents revenue (in thousands) for years ended December 31, 2020, 2019 and 2018, disaggregated by geographic region and revenue type. Revenue by geographic region is allocated based on the domicile of our respective business operations. Year ended December 31, 2020 United States Rest of World Total Revenue Type Research and development services $ 754 $ — $ 754 License fees and milestones 22,857 — 22,857 Other services — 4,619 4,619 Recognition of deferred research and development revenue 12,304 — 12,304 Recognition of deferred grant revenue 91 — 91 Non-cash royalties and milestones 47,545 — 47,545 $ 83,551 $ 4,619 $ 88,170 Year ended December 31, 2019 Revenue Type Research and development services $ 1,707 $ — $ 1,707 License fees 75,500 — 75,500 Royalty sales milestone 15,100 — 15,100 Manufacturing services 3,337 — 3,337 Recognition of deferred research and development revenue 22,638 — 22,638 Recognition of deferred grant revenue 652 690 1,342 Non-cash royalties 30,424 — 30,424 $ 149,358 $ 690 $ 150,048 Year ended December 31, 2018 Revenue Type Research and development services $ 4,150 $ — $ 4,150 License and collaboration milestones 10,000 4,000 14,000 Recognition of deferred research and development revenue 1,325 — 1,325 Non-cash royalties 17,309 — 17,309 $ 32,784 $ 4,000 $ 36,784 Contract Balances Contract assets primarily relate to our rights to consideration for work completed in relation to our research and development services performed but not billed at the reporting date. The contract assets are transferred to receivables when the rights become unconditional. Currently, we do not have any contract assets which have not transferred to a receivable. We had no asset impairment charges related to contract assets in the period. The contract liabilities primarily relate to contracts where we received payments but have not yet satisfied the related performance obligations. The advance consideration received from customers for research and development services or licenses bundled with other promises is a contract liability until the underlying performance obligations are transferred to the customer. The following table provides information about contract assets and contract liabilities from contracts with customers (in thousands): Year ended December 31, 2020 Balance at beginning of period Additions Deductions Balance at end of period Contract assets: Unbilled receivables from collaboration partners $ - $ - $ - $ - Contract liabilities: Deferred revenue $ 56,414 $ 1,400 $ (12,530 ) $ 45,284 The change in contract liabilities is primarily related to the recognition of $12.3 million of revenue related to the Gilead Collaboration Agreements and the addition of $1.1 million of deferred revenue from the Betta License Agreement during the year ended December 31, 2020. Deferred revenue related to the Gilead Collaboration Agreements of $44.1 million as of December 31, 2020, which was comprised of the $142.5 million initial transaction price, less $98.4 million of research and development revenue recognized from the effective date of the contract, will be recognized as the combined performance obligation is satisfied. We also recorded a $1.2 million receivable as of December 31, 2020 for research and development and other services provided In the year ended December 31, 2020, we did not recognize any revenue from amounts included in the contract asset or the contract liability balances from performance obligations satisfied in previous periods. None of the costs to obtain or fulfill a contract were capitalized.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	(15) Related Party Transactions Our Audit and Finance Committee approved a charitable contribution to the Children of Armenia Fund (“COAF”) of up to $125,000 for 2020. Dr. Garo H. Armen, our CEO, is the founder and chairman of COAF. The 2020 charitable contribution was comprised of a cash component and a non-cash component. The cash component was $59,000, 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 and Gilead, as disclosed in Note 14, to be related party transactions.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	(16) Leases The majority of our operating lease agreements are for the office, research and development and manufacturing space we use to conduct our operations. We lease space in Lexington, Massachusetts for our manufacturing, research and development, and corporate offices, office space in New York, New York for use as corporate offices, facilities in Berkeley, California, for manufacturing and corporate offices, a facility in Emeryville, California for the development of a cGMP manufacturing facility We also have a finance lease agreement for transportation equipment that expires in 2022. The components of lease cost recorded in our condensed consolidated statement of operations were as follows (in thousands): Year ended December 31, 2020 Year ended December 31, 2019 Operating lease cost $ 4,698 $ 2,551 Finance lease cost 375 221 Variable lease cost 1,887 1,414 Sublease income (578 ) (561 ) Net lease cost $ 6,382 $ 3,625 Variable lease cost for the years ended December 31, 2020 and 2019, primarily related to common area maintenance, taxes, utilities and insurance associated with our operating leases. Short-term lease cost for the years ended December 31, 2020 and 2019 was immaterial. Cash paid for amounts included in the measurement of operating lease liabilities for the years ended December 31, 2020 and 2019 was approximately $1.6 million and $1.4 million, respectively. Cash paid for amounts included in the measurement of finance lease liabilities for the year ended December 31, 2020 was approximately $1.8 million. The following table presents supplemental balance sheet information related to our leases as of December 31, 2020 and 2019 (in thousands): As of December 31, 2020 As of December 31, 2019 Operating Leases Operating lease right-of-use assets $ 33,480 $ 7,364 Total operating lease right-of-use assets 33,480 7,364 Current portion, operating lease liabilities 1,950 1,347 Operating lease liabilities, net of current portion 34,065 8,020 Total operating lease liabilities 36,015 9,367 Finance Leases Property, plant and equipment, net 2,231 796 Total finance lease right-of-use assets 2,231 796 Other current liabilities 746 148 Other long-term liabilities 66 — Total finance lease liabilities $ 812 $ 148 Maturities of our operating lease liabilities as of December 31, 2020 were as follows (in thousands): Year Operating Leases Finance leases Expected sublease receipts Net future lease commitments 2021 $ (14,813 ) $ 804 $ (595 ) $ (14,604 ) 2022 5,007 67 (613 ) 4,461 2023 9,486 — — 9,486 2024 8,279 — — 8,279 2025 8,473 — — 8,473 Thereafter 85,638 — — 85,638 Total $ 102,070 $ 871 $ (1,208 ) $ 101,733 Less imputed interest (66,055 ) (59 ) Present value of lease liabilities $ 36,015 $ 812 In the above table, expected operating lease payments for the years ending December 31, 2021 and 2022, include $19.2 million and $2.1 million, respectively in lease incentives expected to be received from the lessor of our Emeryville, CA facility related to the construction of tenant improvements. The weighted-average remaining lease terms and discount rates related to our operating leases were as follows: December 31, 2020 Operating Finance Weighted average remaining lease term (in years) 11.9 1.1 Weighted average discount rate 12.0 % 12.3 %

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	(17) Debt Debt obligations consisted of the following as of December 31, 2020 and 2019 (in thousands): Debt instrument Balance at December 31, 2020 Current Portion: Debentures $ 146 Other 687 Long-term Portion: 2015 Subordinated Notes 12,682 Other 6,197 Total $ 19,712 As of December 31, 2020, the principal amount of our outstanding debt balance was $20.0 million. Debt instrument Principal at December 31, 2019 Unamortized Debt Discount Balance at December 31, 2019 Current Portion: Debentures $ 146 $ — $ 146 2015 Subordinated Notes $ 500 $ — $ 500 Long-term Portion: 2015 Subordinated Notes 13,500 (120 ) 13,380 Total $ 14,146 $ (120 ) $ 14,026 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 are set to mature on February 23, 2023, at which point we would be required to repay the full outstanding balance in cash. We may prepay the 2015 Subordinated Notes at any time, in part or in full, without premium or penalty. The warrants to purchase 500,000 shares of the Company’s common stock issued in connection with the 2013 Notes (the “2013 Warrants”) had an exercise price of $4.41 per share; and expired on April 15, 2019. On February 18, 2020, we entered into an amendment to the 2015 Subordinated Notes (the “Amendment”) pursuant to which we: • extended the maturity date of $ 13.5 million of the 2015 Subordinated Notes by three years from February 20, 2020 to February 20, 2023 ; • repaid $0.5 million of the 2015 Subordinated Notes; • extended the exercise period of the warrants to purchase 1,350,000 shares of the Company’s common stock previously issued in 2015 by three years from February 20, 2020 to February 20, 2023; and • issued new warrants to purchase 675,000 shares of the Company’s common stock with a term of five years and an exercise price of $4.48 per share, which represented a 20% premium over the 30-day average trailing closing price of the Company’s common stock as of the date of the Amendment. The Amendment was accounted for as a debt extinguishment under the guidance of ASU 470: Debt which primarily represents the fair value of the new and extended warrants Payroll Protection Program In May 2020, we entered into promissory notes with Bank of America, NA for aggregate loan proceeds of approximately $6.2 million (collectively, the “Loan”) under the Small Business Administration (the “SBA”) Paycheck Protection Program of the Coronavirus Aid, Relief and Economic Security Act of 2020 (the “CARES Act”). Though we have not yet finalized our forgiveness submission, we believe we used at least 60% of the Loan proceeds for covered payroll costs and no more than 40% of the Loan proceeds for rent and utilities in accordance with the relevant terms and conditions of the CARES Act, as amended by the Paycheck Protection Program Flexibility Act. Each Loan has a two-year The Loan may be forgiven partially or fully if the Loan proceeds are used for covered payroll costs, rent and utilities, provided that such amounts are incurred during the twenty-four week period commencing on receipt of the Loan proceeds, and at least 60% of any forgiven amount has been used for covered payroll costs. Any forgiveness of the Loan will be subject to approval by the SBA and will require us to apply for such treatment in the future. As we have not yet finalized our forgiveness submission, we cannot yet determine if the Loan will be partially or fully forgiven. Therefore, we have classified the Loan proceeds as debt in our condensed consolidated balance sheet. Note Purchase Agreement Related to Future Royalties In January 2018, we through our wholly-owned subsidiary, Antigenics, entered into a Royalty Purchase Agreement (the “HCR Royalty Purchase Agreement”) with Healthcare Royalty Partners III, L.P., and certain of its affiliates (collectively “HCR”), and we used $161.9 million of the upfront proceeds from HCR to redeem all of our limited recourse notes (the “Notes”) dated September 8, 2015, accordingly, the related note purchase agreement and the Notes issued thereunder were redeemed in full and terminated. In connection with this redemption, we recorded a $10.8 million loss on early extinguishment of debt which primarily reflects the payment of premiums to fully redeem the notes and the write-off of unamortized debt issuance costs and discounts. See Note 18 for additional information on the Royalty Purchase Agreement. The Notes accrued interest at a rate of 13.5% per annum, compounded quarterly, computed on the basis of a 360-day year and the actual number of days elapsed. The Notes had limited recourse and were 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 redemption price was 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 of 17.5% in accordance with the terms of the NPA. No non-cash interest expense related to the Notes was recorded for the years ended December 31, 2020 and 2019. We recorded $849,000 in non-cash interest expense related to the Notes for the year ended, December 31, 2018, within our consolidated statement of operations and comprehensive loss. Other At December 31, 2020, 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.

Liability Related to the Sale o

Liability Related to the Sale of Future Royalties and Milestones	12 Months Ended
	Dec. 31, 2020
Liability Related To Sale Of Future Royalties And Milestones [Abstract]
Liability Related to the Sale of Future Royalties and Milestones	(18) Liability Related to the Sale of Future Royalties and Milestones The following table shows the activity within the liability account in the year ended December 31, 2020 and for the period from the inception of the royalty transactions to December 31, 2020 (in thousands): Year ended December 31, 2020 Period from inception to December 31, 2020 Liability related to sale of future royalties and milestones - beginning balance $ 221,845 $ — Proceeds from sale of future royalties and milestones — 205,000 Non-cash royalty and milestone revenue (47,545 ) (95,279 ) Non-cash interest expense recognized 59,741 124,320 Liability related to sale of future royalties and milestones - ending balance 234,041 234,041 Less: unamortized transaction costs (416 ) (416 ) Liability related to sale of future royalties and milestones, net $ 233,625 $ 233,625 Healthcare Royalty Partners On January 6, 2018, we, through Antigenics, entered into the HCR Royalty Purchase Agreement with HCR, which closed on January 19, 2018. Pursuant to the terms of the HCR Royalty Purchase Agreement, we sold to HCR 100% of Antigenics’ worldwide rights to receive royalties GSK on sales of GSK’s vaccines containing our QS-21 Stimulon adjuvant. At closing, we received gross proceeds of $190.0 million from HCR. As part of the transaction, we reimbursed HCR for transaction costs of $100,000 and incurred approximately $500,000 in transaction costs of our own, which are presented net of the liability in the consolidated balance sheet and will be amortized to interest expense over the estimated life of the HCR Royalty Purchase Agreement. Although we sold all of our rights to receive royalties on sales of GSK’s vaccines containing QS-21, we are required to account for these royalties as revenue when earned, and we recorded the $190.0 million in proceeds from this transaction as a liability on our consolidated balance sheet that will be amortized using the interest method over the estimated life of the HCR Royalty Purchase Agreement. The liability is classified between the current and non-current portion of liability related to sale of future royalties and milestones in the consolidated balance sheets based on the estimated recognition of the royalty payments to be received by HCR in the next 12 months from the financial statement reporting date. In the years ended December 31, 2020, 2019 and 2018, we recognized $46.5 million, $30.4 million and $17.3 million, respectively, of non-cash royalty revenue and we recorded $59.7, $41.5 million and $23.1 million, respectively, of related non-cash interest expense related to the HCR Royalty Purchase Agreement. As royalties are remitted to HCR from GSK, the balance of the recorded liability will be effectively repaid over the life of the HCR Royalty Purchase Agreement. To determine the amortization of the recorded liability, we are required to estimate the total amount of future royalty payments to be received by HCR. The sum of these amounts less the $190.0 million proceeds we received will be recorded as interest expense over the life of the HCR Royalty Purchase Agreement. Periodically, we assess the estimated royalty payments to be paid to HCR from GSK, and to the extent the amount or timing of the payments is materially different from our original estimates, we will prospectively adjust the amortization of the liability. Since the inception of the HCR Royalty Purchase Agreement our estimate of the effective annual interest rate over the life of the agreement increased to 28.2%, which results in a retrospective interest rate of 23.4%. 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 non-cash royalty revenues and the non-cash interest expense over the life of the HCR Royalty Purchase Agreement. Conversely, if sales of GSK’s vaccines containing QS-21 are more than expected, the non-cash royalty revenues and the non-cash interest expense recorded by us would be greater over the life of the HCR Royalty Purchase Agreement. Pursuant to the HCR Royalty Purchase Agreement, we were also entitled to receive up to $40.4 million in milestone payments from HCR (through the royalty payments from GSK) based on sales of GSK’s vaccines as follows: (i) $15.1 million upon reaching $2.0 billion last-twelve-months net sales any time prior to 2024 and (ii) $25.3 million upon reaching $2.75 billion last-twelve-months net sales any time prior to 2026. In the fourth quarter of 2019, the $15.1 million milestone was achieved, as sales for the year ended December 31, 2019 exceeded $2.0 billion. As such, we recognized $15.1 million in royalty sales milestone revenue in the year ended December 31, 2019. We remain eligible to receive the $25.3 million milestone. Additionally, pursuant to the HCR Royalty Purchase Agreement, we were obligated to pay HCR approximately $25.9 million in 2021 (the “Rebate Payment”) if neither of the following sales milestones are achieved: (i) 2019 sales exceed $1.0 billion or (ii) 2020 sales exceed $1.75 billion. However, we were released from this obligation in the fourth quarter of 2019 when GSK announced that Shingrix sales for the first nine months of 2019 reached 1.28 billion pounds (or approximately $1.6 billion). XOMA On September 20, 2018, we, through our wholly-owned subsidiary, Agenus Royalty Fund, LLC, entered into a Royalty Purchase Agreement (the “XOMA Royalty Purchase Agreement”) with XOMA (US) LLC (“XOMA”). Pursuant to the terms of the XOMA Royalty Purchase Agreement, XOMA paid us $15.0 million at closing in exchange for the right to receive 33% of the future royalties and 10% of the future milestones that we are entitled to receive from Incyte Corporation (“Incyte”) and Merck Sharpe & Dohme (“Merck”) under our agreements with each party (see Note 14), net of certain of our obligations to a third party and excluding the $5.0 million milestone from Incyte that we recognized in the quarter ended September 30, 2018. We retained 90% of the future milestones and 67% of the future royalties under our agreements with Incyte and Merck. Although we sold our rights to receive 33% of future royalties and 10% of future milestones, as a result of our significant continued involvement in the generation of the potential royalties and milestones, we are required to account for the full amount of these royalties and milestones as revenue when earned, and we recorded the $15.0 million in proceeds from this transaction as a liability on our consolidated balance sheet. Under the terms of the XOMA Royalty Purchase Agreement, should the percentage of milestones and royalties ultimately received by XOMA fail to repay the amount received by us at closing we would have no further obligation to XOMA. In the fourth quarter of 2020, we achieved a $10.0 million milestone under the Merck agreement. As such, we recorded $1.0 million in non-cash milestone revenue related to the XOMA Royalty Purchase Agreement for the year ended December 31, 2020 and reduced the XOMA liability by $1.0 million.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Measurements [Abstract]
Fair Value Measurements	(19) Fair Value Measurements We measure our contingent purchase price consideration at fair value. The fair values of our Agenus Switzerland, PhosImmune and other contingent purchase price consideration, $8.3 million, $1.6 million and $0.3 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 these liabilities use assumptions we believe would be made by a market participant and are mainly based on estimates from a Monte Carlo simulation of our market capitalization and share price, as well as 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 considerations The significant unobservable inputs include the anticipated timelines to achieve the contingent purchase milestones and our estimated credit spread, the weighted average values of which (weighted based on the value of each contingent liability), as of December 31, 2020, are shown in the table below. December 31, 2020 December 31, 2019 Period of time to achieve milestones (in years) 1.3 1.7 Credit spread 5.5 % 16.4 % Liabilities measured at fair value are summarized below (in thousands): Description December 31, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities: Contingent purchase price consideration 10,208 — — 10,208 Total $ 10,208 $ — $ — $ 10,208 Description December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities: Contingent purchase price consideration 8,843 — — 8,843 Total $ 8,843 $ — $ — $ 8,843 The following table presents our liabilities measured at fair value using significant unobservable inputs (Level 3), as of December 31, 2020 (amounts in thousands): Balance, December 31, 2019 $ 8,843 Change in fair value of contingent purchase price consideration during the period 1,221 Addition of contingent purchase price consideration related to business acquisition 144 Balance, December 31, 2020 $ 10,208 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, 2020 and 2019 was $19.9 million and $14.2 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 December 31, 2020 and 2019 was $20.0 million and $14.1, respectively.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Contingencies	(20) 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, 2020
Compensation And Retirement Disclosure [Abstract]
Benefit Plans	(21) Benefit Plans We sponsor a defined contribution 401(k) Savings Plan in the US and a defined contribution Group Personal Pension Plan in the UK (the “Plans”) for all eligible employees, as defined in the Plans. Participants may contribute a portion of their compensation, subject to a maximum annual amount, as established by the applicable taxing authority. Each participant is fully vested in his or her contributions and related earnings and losses. During the years ended December 31, 2020, 2019, and 2018 we made discretionary contributions to the Plans of $1.1 million, $922,000, and $617,000, respectively. For the years ended December 31, 2020, 2019, and 2018, we expensed $1.1 million, $922,000, and $617,000, respectively, related to the discretionary contribution to the Plans.

Geographical Information

Geographical Information	12 Months Ended
	Dec. 31, 2020
Geographic Information [Abstract]
Geographical Information	(22) Geographic Information The following is geographical information regarding our revenues for the years ended December 31, 2020, 2019 and 2018 and our long-lived assets as of December 31, 2020 and 2019 (in thousands): 2020 2019 2018 Revenue: United States $ 83,551 $ 149,358 $ 32,784 Rest of world 4,619 690 4,000 $ 88,170 $ 150,048 $ 36,784 In the table above, revenue by geographic region is allocated based on the domicile of our respective business operations. 2020 2019 Long-lived Assets: United States $ 27,611 $ 23,822 Rest of world 3,302 3,921 Total $ 30,913 $ 27,743 In the table above, 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, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	(23) Quarterly Financial Data (Unaudited) Quarter Ended March 31, June 30, September 30, December 31, 2020 Revenue $ 15,128 $ 26,945 $ 14,832 $ 31,265 Net income (loss) (45,271 ) (48,244 ) (51,646 ) (37,730 ) Net income (loss) attributable to Agenus Inc. common shareholders (44,726 ) (47,532 ) (51,205 ) (37,660 ) Per common share, basic and diluted: Basic and diluted net loss attributable to Agenus Inc. common stockholders (0.31 ) (0.28 ) (0.28 ) (0.20 ) 2019 Revenue $ 79,891 $ 15,715 $ 19,940 $ 34,502 Net income (loss) 17,435 (51,867 ) (46,277 ) (30,851 ) Net income (loss) attributable to Agenus Inc. common shareholders 18,454 (50,686 ) (45,526 ) (30,107 ) Per common share, basic and diluted: Basic net income (loss) attributable to Agenus Inc. common stockholders 0.14 (0.38 ) (0.33 ) (0.22 ) Diluted net income (loss) attributable to Agenus Inc. common stockholders 0.12 (0.38 ) (0.33 ) (0.22 ) 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, 2020
Subsequent Events [Abstract]
Subsequent Events	(24) Subsequent Events At the Market Offerings During the period of January 1, 2021 through March 12, 2021, we sold approximately 9.1 million shares of our common stock under the New Sales Agreement .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
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 subsidiaries. All significant intercompany transactions and accounts have been eliminated in consolidation. Non-controlling interest in the consolidated financial statements represents the portion of two of our subsidiaries not 100% owned by Agenus.
Segment Information	(b) Segment Information We are managed and currently operate as two segments. However, we have concluded that our two operating segments meet all three criteria required 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.
Concentrations of Credit Risk	(e) 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.
Accounts Receivable	(f) Accounts Receivable Accounts receivable are amounts due from our collaboration partners and customers as a result of research and development and other services provided, and milestones achieved. We considered the need for an allowance for doubtful accounts and have concluded that no allowance was needed as of December 31, 2020 and 2019, as the estimated risk of loss on our accounts receivable was determined to be minimal.
Property, Plant and Equipment	(g) 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 $5.1 million, $4.8 million, and $4.3 million, for the years ended December 31, 2020, 2019, and 2018, respectively.
Fair Value of Financial Instruments	(h) Fair Value of Financial Instruments The estimated fair values of all our financial instruments 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 $20.0 million and $14.1 million at December 31, 2020 and 2019, respectively.
Revenue Recognition	(i) Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes existing revenue recognition guidance. We adopted ASU 2014-09 and its related amendments (collectively known as “ASC 606”) on January 1, 2018 using the modified retrospective method- i.e., by recognizing the cumulative effect of initially applying ASC 606 as an adjustment to the opening balance of equity at January 1, 2018. The adoption of ASC 606 resulted in a cumulative adjustment to decrease our accumulated deficit by $ For the years ended December 31, 2020, 2019 and 2018, 16%, 60% and 43%, respectively, of our revenue was earned from one collaboration partner. In accordance with ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which we expect to be entitled to receive in exchange for these goods and services. To achieve this core principle, we apply the following five steps: 1) Identify the contract with the customer A contract with a customer exists when (i) the Company enters into an enforceable contract with a customer that defines each party’s rights regarding the goods or services to be transferred and identifies the related payment terms, (ii) the contract has commercial substance, and (iii) the Company determines that collection of substantially all consideration for goods and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. The Company applies judgment in determining the customer’s intent and ability to pay, which is based on a variety of factors including the customer’s historical payment experience, or in the case of a new customer, published credit and financial information pertaining to the customer. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the goods and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the good or service either on its own or together with other available resources, and are distinct in the context of the contract, whereby the transfer of the good or service is separately identifiable from other promises in the contract. To the extent a contract includes multiple promised goods and services, the Company must apply judgment to determine whether promised goods and services are capable of being distinct and are distinct in the context of the contract. If these criteria are not met, the promised goods and services are accounted for as a combined performance obligation. 3) Determine the transaction price The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring goods and services to the customer. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Any estimates, including the effect of the constraint on variable consideration, are evaluated at each reporting period for any changes. Determining the transaction price requires significant judgment, which is discussed in further detail for each of the Company’s contracts with customers in Note 1 4 . 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative stand-alone selling price basis unless the transaction price is variable and meets the criteria to be allocated entirely to a performance obligation or to a distinct service that forms part of a single performance obligation. The consideration to be received is allocated among the separate performance obligations based on relative stand-alone selling prices. Determining the amount of the transaction price to allocate to each separate performance obligation requires significant judgement, which is discussed in further detail for each of the Company’s contracts with customers in Note 14. 5) Recognize revenue when or as the Company satisfies a performance obligation The Company satisfies performance obligations either over time or at a point in time. Revenue is recognized over time if either 1) the customer simultaneously receives and consumes the benefits provided by the entity’s performance, 2) the entity’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or 3) the entity’s performance does not create an asset with an alternative use to the entity and the entity has an enforceable right to payment for performance completed to date. If the entity does not satisfy a performance obligation over time, the related performance obligation is satisfied at a point in time by transferring the control of a promised good or service to a customer. Examples of control are using the asset to produce goods or services, enhance the value of other assets, settle liabilities, and holding or selling the asset. ASC 606 requires the Company to select a single revenue recognition method for the performance obligation that faithfully depicts the Company’s performance in transferring control of the goods and services. The guidance allows entities to choose between two methods to measure progress toward complete satisfaction of a performance obligation: 1. Output methods - recognize revenue on the basis of direct measurements of the value to the customer of the goods or services transferred to date relative to the remaining goods or services promised under the contract (e.g. surveys of performance completed to date, appraisals of results achieved, milestones reached, time elapsed, and units of produced or units delivered); and 2. Input methods - recognize revenue on the basis of the entity’s efforts or inputs to the satisfaction of a performance obligation (e.g., resources consumed, labor hours expended, costs incurred, or time elapsed) relative to the total expected inputs to the satisfaction of that performance obligation. Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone payments: At the inception of each arrangement that includes development, regulatory or commercial milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. ASC 606 suggests two alternatives to use when estimating the amount of variable consideration: the expected value method and the most likely amount method. Under the expected value method, an entity considers the sum of probability-weighted amounts in a range of possible consideration amounts. Under the most likely amount method, an entity considers the single most likely amount in a range of possible consideration amounts. Whichever method is used, it should be consistently applied throughout the life of the contract; however, it is not necessary for the Company to use the same approach for all contracts. The Company uses the most likely amount method for development and regulatory milestone payments. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis. The Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re- evaluates the probability or achievement of each such milestone and any related constraint, and if necessary, adjusts its estimates of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). Up-front Fees: Depending on the nature of the agreement, up-front payments and fees may be recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less.
Foreign Currency Transactions	(j) 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 income (expense). We do not currently use derivative financial instruments to manage the risks associated with foreign currency fluctuations. We recorded a foreign currency loss of $3.1 million for the year ended December 31, 2020, a foreign currency gain of $0.1 million for the year ended December 31, 2019, and a foreign currency loss of $2.2 million for the year ended December 31, 2018.
Research and Development	(k) 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	(l) Share-Based Compensation We account for share-based compensation in accordance with the provisions of ASC 718, Compensation—Stock Compensation.
Income Taxes	(m) 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	(n) Net Loss Per Share Basic income and loss per common share are 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, non-vested 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, 2020, 2019, and 2018, as they would be anti-dilutive: Year Ended 2020 2019 2018 Warrants 1,950 1,400 2,900 Stock options 28,916 27,164 18,614 Nonvested shares 887 2,120 2,214 Series A-1 convertible preferred stock 333 333 333 Series C-1 convertible preferred stock 12,459 12,459 18,459
Goodwill	(o) 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 the fair value of our reporting units to their net book value to determine if there is an indicator of impairment. We operate as two reporting units. ASC 350, Intangibles, Goodwill and Other
Long-lived Assets	(p) 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.
Leases	(q) Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) (“ASC 842”) which supersedes Topic 840, Leases (“ASC 840”). We adopted ASC 842 on January 1, 2019 using the alternative transition method and recorded a cumulative effect adjustment to beginning retained earnings without restating prior periods. Accordingly, all financial information and disclosures for periods before January 1, 2019 continue to be presented under the requirements of ASC 840. We elected the package of practical expedients, which allowed us to carry forward our historical lease classification, our assessment of whether a contract is or contains a lease and our initial direct costs for any leases that existed prior to adoption of the new standard. At the inception of an agreement, we determine whether the contract contains a lease. If a lease is identified in such arrangement, we recognize a right-of-use asset and liability on our consolidated balance sheet and determine whether the lease should be classified as a finance or operating lease. We have elected not to recognize assets or liabilities for leases with lease terms of 12 months or less. A lease qualifies as a finance lease if any of the following criteria are met at the inception of the lease: (i) there is a transfer of ownership of the leased asset by the end of the lease term, (ii) we hold an option to purchase the leased asset that we are reasonably certain to exercise, (iii) the lease term is for a major part of the remaining economic life of the leased asset, (iv) the present value of the sum of lease payments equals or exceeds substantially all of the fair value of the leased asset, or (v) the nature of the leased asset is specialized to the point that it is expected to provide the lessor no alternative use at the end of the lease term. All other leases are recorded as operating leases. Our leases commence when the lessor makes the asset available for our use. Finance and operating lease right-of-use assets and liabilities are recognized at the lease commencement date. Lease liabilities are recognized as the present value of the lease payments over the lease term, net of any future lease incentives to be received, using the discount rate implicit in the lease. If the implicit rate is not readily determinable, as is the case with all our current leases, we utilize our incremental borrowing rate at the lease commencement date. Right-of-use assets are recognized based on the amount of the lease liability, adjusted for any advance lease payments paid, initial direct costs incurred, or lease incentives received prior to commencement. Right-of-use assets are subject to evaluation for impairment or disposal on a basis consistent with other long-lived assets. Operating lease payments are expensed using the straight-line method as an operating expense over the lease term, unless the right-of-use asset reflects impairment. We will then recognize the amortization of the right-of-use asset on a straight-line basis over the remaining lease term with rent expense still included in operating expense in our condensed consolidated statement of operations. Finance lease assets are amortized to depreciation expense using the straight-line method over the shorter of the useful life of the related asset or the lease term, unless the lease includes a provision that either (i) results in the transfer of ownership of the underlying asset at the end of the lease term or (ii) includes a purchase option whose exercise is reasonably certain. In either of these instances, the right-of-use asset is amortized over the useful life of the underlying asset. Finance lease payments are bifurcated into (i) a portion that is recorded as imputed interest expense and (ii) a portion that reduces the finance lease liability. We do not separate lease and non-lease components for any of our current asset classes when determining which lease payments to include in the calculation of its lease assets and liabilities. Variable lease payments are expensed in the period incurred. If a lease includes an option to extend or terminate the lease, we reflect the option in the lease term if it is reasonably certain the option will be exercised. Our right of use assets and lease liabilities generally exclude periods covered by renewal options and include periods covered by early termination options (based on our conclusion that it is not reasonably certain that we will exercise such options). We account for the sublease of space in our main Lexington, Massachusetts facility from the perspective of a lessor. Our sublease is classified as an operating lease. We record sublease income as a reduction of operating expense. Operating leases are recorded in “Operating lease right-of-use assets”, “Current portion, operating lease liabilities” and “Operating lease liabilities, net of current portion”, while finance leases are recorded in “Property, plant and equipment, net”, “Other current liabilities” and “Other long-term liabilities” on our condensed consolidated balance sheet.
Recent Accounting Pronouncements	(r) Recent Accounting Pronouncements Recently Issued and Adopted In August 2018, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”). The amendments in ASU 2018-13 modify the disclosure requirements of fair value measurements. Certain disclosures are required to be applied on a retrospective basis and others on a prospective basis. We adopted the standard on January 1, 2020. The adoption did not have a material impact on our financial statement disclosures. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606, Revenue from Contracts with Customers, (“ASC 606”) (“ASU 2018-18”). ASU 2018-18 (1) clarifies that certain transactions between collaborative arrangement participants should be accounted for under ASC 606, when the collaborative arrangement participant is a customer in the context of a unit of account, (2) adds unit-of-account guidance in ASC 808 to align with ASC 606 when an entity is assessing whether the collaborative arrangement, or a part of the arrangement, is within the scope of ASC 606, and (3) precludes presenting transactions together with revenue when those transactions involve collaborative arrangement participants that are not directly related to third parties and are not customers. We adopted the standard on January 1, 2020. The adoption did not have a material impact on our consolidated financial statements. Recently Issued, Not Yet Adopted In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350) that will eliminate the requirement to calculate the implied fair value of goodwill to measure a goodwill impairment charge. Instead, an impairment charge will be based on the excess of a reporting unit’s carrying amount over its fair value. The guidance is effective for the Company in the first quarter of fiscal 2023. Early adoption is permitted. We do not anticipate the adoption of this guidance to have a material impact on our consolidated financial statements, absent any goodwill impairment. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 enhances and simplifies multiple aspects of the income tax accounting guidance in ASC 740. The standard will be effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years, with early adoption permitted. We are currently evaluating the impact of adoption of ASU 2019-12 on our consolidated financial statements. No other new accounting pronouncement issued or effective during the year ended December 31, 2020 had or is expected to have a material impact on our consolidated financial statements or disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [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, 2020, 2019, and 2018, as they would be anti-dilutive: Year Ended 2020 2019 2018 Warrants 1,950 1,400 2,900 Stock options 28,916 27,164 18,614 Nonvested shares 887 2,120 2,214 Series A-1 convertible preferred stock 333 333 333 Series C-1 convertible preferred stock 12,459 12,459 18,459

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 (in thousands): Balance, December 31, 2019 $ 23,188 Effect of foreign currency 1,470 Addition of goodwill related to business acquisition 794 Balance, December 31, 2020 $ 25,452
Schedule of Acquired Intangible Assets	Acquired intangible assets consisted of the following at December 31, 2020 and 2019 (in thousands): As of December 31, 2020 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 7-15 years $ 17,013 $ (10,112 ) $ 6,901 Trademarks 4-4.5 years 1,310 (980 ) 330 Other 2-7 years 2,272 (749 ) 1,523 In-process research and development Indefinite 2,132 — 2,132 Total $ 22,727 $ (11,841 ) $ 10,886 As of December 31, 2019 Amortization period (years) Gross carrying amount Accumulated amortization Net carrying amount Intellectual Property 7-15 years $ 16,584 $ (8,044 ) $ 8,540 Trademarks 4.5 years 834 (834 ) — Other 2-6 years 572 (553 ) 19 In-process research and development Indefinite 1,945 — 1,945 Total $ 19,935 $ (9,431 ) $ 10,504

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Cash And Cash Equivalents [Abstract]
Schedule of Cash Equivalents	Cash equivalents consisted of the following as of December 31, 2020 and 2019 (in thousands): December 31, 2020 December 31, 2019 Cost Estimated Fair Value Cost Estimated Fair Value Institutional Money Market Funds $ 64,256 $ 64,256 $ 55,258 $ 55,258 U.S. Treasury Bills 20,000 20,000 — — Total $ 84,256 $ 84,256 $ 55,258 $ 55,258

Restricted Cash (Tables)

Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2020
Cash And Cash Equivalents [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash that agrees to the total of the aforementioned amounts shown in our consolidated statements of cash flows as of December 31, 2020, 2019 and 2018, respectively (in thousands): 2020 2019 2018 Cash and cash equivalents $ 99,871 $ 61,808 $ 53,054 Restricted cash 2,634 — — Cash, cash equivalents and restricted cash $ 102,505 $ 61,808 $ 53,054

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Schedule of Property, Plant and Equipment, net	Property, plant and equipment, net as of December 31, 2020 and 2019 consist of the following (in thousands): 2020 2019 Estimated Depreciable Lives Land $ 2,230 $ 2,230 Indefinite Building and building improvements 5,630 5,624 35 years Furniture, Fixtures, and other 5,866 6,394 3 to 10 years Laboratory, manufacturing and transportation equipment 22,855 20,880 4 to 10 years Leasehold improvements 28,390 25,350 2 to 12 years Software and computer equipment 9,020 8,709 3 years 73,991 69,187 Less accumulated depreciation and amortization (47,201 ) (42,861 ) Total $ 26,790 $ 26,326

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 and 2019 are presented below (in thousands). 2020 2019 Deferred tax assets: U.S. Federal and State net operating loss carryforwards $ 168,786 $ 143,126 Foreign net operating loss carryforwards 5,302 4,096 Research and development tax credits 14,314 16,364 Share-based compensation 4,846 4,774 Intangible Assets 39,477 38,710 Interest expense carryforward 7,114 3,893 Deferred Revenue 58,796 47,456 Lease Liability 8,389 2,002 Other 4,768 3,974 Total deferred tax assets 311,792 264,395 Less: valuation allowance (303,747 ) (262,228 ) Net deferred tax assets 8,045 2,167 Foreign intangible assets (1,052 ) (1,009 ) Right of use asset (7,852 ) (1,599 ) Other (192 ) (165 ) Deferred tax liabilities (9,096 ) (2,773 ) Net deferred tax liability $ (1,051 ) $ (606 )
Schedule of Effective Income Tax Rate Reconciliation	Income tax benefit was nil for the years ended December 31, 2020, 2019 and 2018. Income taxes recorded differed from the amounts computed by applying the U.S. Federal income tax rate of 21% 2020 2019 2018 Computed “expected” Federal tax benefit $ (38,706 ) $ (23,413 ) $ (34,029 ) (Increase) reduction in income taxes benefit resulting from: Change in valuation allowance 41,519 7,913 24,233 (Decrease) increase due to uncertain tax positions (764 ) (64 ) 7 Foreign income inclusion 3,570 — 11,089 State and local income benefit, net of Federal income tax benefit (4,675 ) 4,144 (11,708 ) Equity based compensation 1,883 1,367 4,219 Foreign rate differential 629 (564 ) 956 Change in fair value contingent consideration 287 1,219 (280 ) Other, net (3,743 ) 9,398 5,513 Income tax benefit $ — $ — $ —
Summary of Income Tax Contingencies	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): 2020 2019 2018 Balance, January 1 $ 4,292 $ 4,356 $ 4,349 Increase related to current year positions 88 122 — Increase (decrease) related to previously recognized positions (766 ) (186 ) 7 Balance, December 31 $ 3,614 $ 4,292 $ 4,356

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following as of December 31, 2020 and 2019 (in thousands): December 31, 2020 December 31, 2019 Payroll $ 7,643 $ 9,575 Professional fees 4,457 4,314 Contract manufacturing costs 6,274 8,768 Research services 4,649 6,675 Other 6,034 2,000 Total $ 29,057 $ 31,332

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2020
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: 2020 2019 2018 Expected volatility 66 % 64 % 64 % Expected term in years 6 5 6 Risk-free interest rate 0.8 % 1.8 % 2.8 % Dividend yield 0 % 0 % 0 %
Schedule of Stock Option Activity	A summary of option activity for 2020 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2019 27,164,147 $ 3.67 Granted 7,330,377 3.82 Exercised (1,161,757 ) 3.05 Forfeited (2,974,728 ) 3.30 Expired (1,441,638 ) 4.52 Outstanding at December 31, 2020 28,916,401 3.70 7.47 $ 7,088,129 Vested or expected to vest at December 31, 2020 28,916,401 3.70 7.47 $ 7,088,129 Exercisable at December 31, 2020 14,997,220 $ 3.98 6.13 $ 3,232,022
Summary of Non-vested Stock Activity	A summary of non-vested stock activity for 2020 is presented below: Nonvested Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2019 2,207,943 $ 2.85 Granted 179,816 3.60 Vested (165,632 ) 2.75 Forfeited (1,335,311 ) 3.43 Outstanding at December 31, 2020 886,816 $ 2.14
Schedule of Share-Based Compensation Expense	The impact on our results of operations from share-based compensation for the years ended December 31, 2020, 2019, and 2018, was as follows (in thousands). Year Ended 2020 2019 2018 Research and development $ 3,758 $ 3,873 $ 3,498 General and administrative 6,363 6,019 4,127 Total share-based compensation expense $ 10,121 $ 9,892 $ 7,625

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2020
Collaboration [Abstract]
Summary of Disaggregation of Revenue	The following table presents revenue (in thousands) for years ended December 31, 2020, 2019 and 2018, disaggregated by geographic region and revenue type. Revenue by geographic region is allocated based on the domicile of our respective business operations. Year ended December 31, 2020 United States Rest of World Total Revenue Type Research and development services $ 754 $ — $ 754 License fees and milestones 22,857 — 22,857 Other services — 4,619 4,619 Recognition of deferred research and development revenue 12,304 — 12,304 Recognition of deferred grant revenue 91 — 91 Non-cash royalties and milestones 47,545 — 47,545 $ 83,551 $ 4,619 $ 88,170 Year ended December 31, 2019 Revenue Type Research and development services $ 1,707 $ — $ 1,707 License fees 75,500 — 75,500 Royalty sales milestone 15,100 — 15,100 Manufacturing services 3,337 — 3,337 Recognition of deferred research and development revenue 22,638 — 22,638 Recognition of deferred grant revenue 652 690 1,342 Non-cash royalties 30,424 — 30,424 $ 149,358 $ 690 $ 150,048 Year ended December 31, 2018 Revenue Type Research and development services $ 4,150 $ — $ 4,150 License and collaboration milestones 10,000 4,000 14,000 Recognition of deferred research and development revenue 1,325 — 1,325 Non-cash royalties 17,309 — 17,309 $ 32,784 $ 4,000 $ 36,784
Schedule of Information about Contract Assets and Contract Liabilities from Contracts with Customers	The following table provides information about contract assets and contract liabilities from contracts with customers (in thousands): Year ended December 31, 2020 Balance at beginning of period Additions Deductions Balance at end of period Contract assets: Unbilled receivables from collaboration partners $ - $ - $ - $ - Contract liabilities: Deferred revenue $ 56,414 $ 1,400 $ (12,530 ) $ 45,284

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Components of Lease Cost Recorded in Condensed Consolidated Statement of Operations	The components of lease cost recorded in our condensed consolidated statement of operations were as follows (in thousands): Year ended December 31, 2020 Year ended December 31, 2019 Operating lease cost $ 4,698 $ 2,551 Finance lease cost 375 221 Variable lease cost 1,887 1,414 Sublease income (578 ) (561 ) Net lease cost $ 6,382 $ 3,625
Schedule of Supplemental Balance Sheet Information Related to Lease	The following table presents supplemental balance sheet information related to our leases as of December 31, 2020 and 2019 (in thousands): As of December 31, 2020 As of December 31, 2019 Operating Leases Operating lease right-of-use assets $ 33,480 $ 7,364 Total operating lease right-of-use assets 33,480 7,364 Current portion, operating lease liabilities 1,950 1,347 Operating lease liabilities, net of current portion 34,065 8,020 Total operating lease liabilities 36,015 9,367 Finance Leases Property, plant and equipment, net 2,231 796 Total finance lease right-of-use assets 2,231 796 Other current liabilities 746 148 Other long-term liabilities 66 — Total finance lease liabilities $ 812 $ 148
Schedule of Maturities of Operating Lease Liabilities in Accordance With ASC 842	Maturities of our operating lease liabilities as of December 31, 2020 were as follows (in thousands): Year Operating Leases Finance leases Expected sublease receipts Net future lease commitments 2021 $ (14,813 ) $ 804 $ (595 ) $ (14,604 ) 2022 5,007 67 (613 ) 4,461 2023 9,486 — — 9,486 2024 8,279 — — 8,279 2025 8,473 — — 8,473 Thereafter 85,638 — — 85,638 Total $ 102,070 $ 871 $ (1,208 ) $ 101,733 Less imputed interest (66,055 ) (59 ) Present value of lease liabilities $ 36,015 $ 812
Schedule of Weighted-Average Remaining Lease Terms and Discount Rates Related to Operating Leases	The weighted-average remaining lease terms and discount rates related to our operating leases were as follows: December 31, 2020 Operating Finance Weighted average remaining lease term (in years) 11.9 1.1 Weighted average discount rate 12.0 % 12.3 %

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Debt Obligations	Debt obligations consisted of the following as of December 31, 2020 and 2019 (in thousands): Debt instrument Balance at December 31, 2020 Current Portion: Debentures $ 146 Other 687 Long-term Portion: 2015 Subordinated Notes 12,682 Other 6,197 Total $ 19,712 As of December 31, 2020, the principal amount of our outstanding debt balance was $20.0 million. Debt instrument Principal at December 31, 2019 Unamortized Debt Discount Balance at December 31, 2019 Current Portion: Debentures $ 146 $ — $ 146 2015 Subordinated Notes $ 500 $ — $ 500 Long-term Portion: 2015 Subordinated Notes 13,500 (120 ) 13,380 Total $ 14,146 $ (120 ) $ 14,026

Liability Related to the Sale_2

Liability Related to the Sale of Future Royalties and Milestones (Tables)	12 Months Ended
	Dec. 31, 2020
Liability Related To Sale Of Future Royalties And Milestones [Abstract]
Schedule of Liability Account	The following table shows the activity within the liability account in the year ended December 31, 2020 and for the period from the inception of the royalty transactions to December 31, 2020 (in thousands): Year ended December 31, 2020 Period from inception to December 31, 2020 Liability related to sale of future royalties and milestones - beginning balance $ 221,845 $ — Proceeds from sale of future royalties and milestones — 205,000 Non-cash royalty and milestone revenue (47,545 ) (95,279 ) Non-cash interest expense recognized 59,741 124,320 Liability related to sale of future royalties and milestones - ending balance 234,041 234,041 Less: unamortized transaction costs (416 ) (416 ) Liability related to sale of future royalties and milestones, net $ 233,625 $ 233,625

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Weighted Average Values of Contingent Purchase Milestones and Credit Spread	The significant unobservable inputs include the anticipated timelines to achieve the contingent purchase milestones and our estimated credit spread, the weighted average values of which (weighted based on the value of each contingent liability), as of December 31, 2020, are shown in the table below. December 31, 2020 December 31, 2019 Period of time to achieve milestones (in years) 1.3 1.7 Credit spread 5.5 % 16.4 %
Schedule of Liabilities Measured at Fair Value	Liabilities measured at fair value are summarized below (in thousands): Description December 31, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities: Contingent purchase price consideration 10,208 — — 10,208 Total $ 10,208 $ — $ — $ 10,208 Description December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities: Contingent purchase price consideration 8,843 — — 8,843 Total $ 8,843 $ — $ — $ 8,843
Schedule of Liabilities Measured at Fair Value Using Significant Unobservable Inputs	The following table presents our liabilities measured at fair value using significant unobservable inputs (Level 3), as of December 31, 2020 (amounts in thousands): Balance, December 31, 2019 $ 8,843 Change in fair value of contingent purchase price consideration during the period 1,221 Addition of contingent purchase price consideration related to business acquisition 144 Balance, December 31, 2020 $ 10,208

Geographical Information (Table

Geographical Information (Tables)	12 Months Ended
	Dec. 31, 2020
Geographic Information [Abstract]
Revenue by Geographic Areas	The following is geographical information regarding our revenues for the years ended December 31, 2020, 2019 and 2018 and our long-lived assets as of December 31, 2020 and 2019 (in thousands): 2020 2019 2018 Revenue: United States $ 83,551 $ 149,358 $ 32,784 Rest of world 4,619 690 4,000 $ 88,170 $ 150,048 $ 36,784
Long-lived Assets by Geographic Areas	In the table above, revenue by geographic region is allocated based on the domicile of our respective business operations. 2020 2019 Long-lived Assets: United States $ 27,611 $ 23,822 Rest of world 3,302 3,921 Total $ 30,913 $ 27,743

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Quarter Ended March 31, June 30, September 30, December 31, 2020 Revenue $ 15,128 $ 26,945 $ 14,832 $ 31,265 Net income (loss) (45,271 ) (48,244 ) (51,646 ) (37,730 ) Net income (loss) attributable to Agenus Inc. common shareholders (44,726 ) (47,532 ) (51,205 ) (37,660 ) Per common share, basic and diluted: Basic and diluted net loss attributable to Agenus Inc. common stockholders (0.31 ) (0.28 ) (0.28 ) (0.20 ) 2019 Revenue $ 79,891 $ 15,715 $ 19,940 $ 34,502 Net income (loss) 17,435 (51,867 ) (46,277 ) (30,851 ) Net income (loss) attributable to Agenus Inc. common shareholders 18,454 (50,686 ) (45,526 ) (30,107 ) Per common share, basic and diluted: Basic net income (loss) attributable to Agenus Inc. common stockholders 0.14 (0.38 ) (0.33 ) (0.22 ) Diluted net income (loss) attributable to Agenus Inc. common stockholders 0.12 (0.38 ) (0.33 ) (0.22 )

Description of Business (Narrat

Description of Business (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Description Of Business [Abstract]
Cash and cash equivalents	$ 99,871	$ 61,808	$ 53,054
Increase in cash and cash equivalents	38,100
Accumulated deficit	$ 1,465,907	$ 1,284,993

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Basis of Presentation and Principles of Consolidation) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020Subsidiary
Accounting Policies [Abstract]
Number of subsidiaries not 100% owned	2
Percentage of subsidiaries not owned	100.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Segment Information) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020Segment
Accounting Policies [Abstract]
Number of operating segments	2
Number of reportable segment	1

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Accounts Receivable) (Narrative) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Allowance for doubtful accounts receivable	$ 0	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies (Property, Plant and Equipment) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Depreciation	$ 5.1	$ 4.8	$ 4.3

Summary of Significant Accoun_8

Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Long-term Debt, Gross	$ 20,000	$ 14,146

Summary of Significant Accoun_9

Summary of Significant Accounting Policies (Revenue Recognition) (Narrative) (Details) - USD ($) $ in Millions	Jan. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
One collaboration partner [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage		16.00%	60.00%	43.00%
ASC 606 [Member]
Concentration Risk [Line Items]
Decrease in accumulated deficit	$ (8.9)			$ (5.7)
Deferred revenue, Period increase (decrease), current portion	(3)			(1)
Deferred revenue, Period increase (decrease), net of portion	$ (5.9)			(4.7)
Decrease in research and development revenue				$ 3.2

Summary of Significant Accou_10

Summary of Significant Accounting Policies (Foreign Currency Transactions) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Foreign Currency [Abstract]
Foreign Currency Transaction Gain (Loss), before Tax	$ (3.1)	$ 0.1	$ (2.2)

Summary of Significant Accou_11

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,950	1,400	2,900
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	28,916	27,164	18,614
Non-vested Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	887	2,120	2,214
Series A-1 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
Series C-1 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	12,459	12,459	18,459

Summary of Significant Accou_12

Summary of Significant Accounting Policies (Goodwill) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020USD ($)
Accounting Policies [Abstract]
Impairment of goodwill	$ 0

Business Acquisitions (Narrativ

Business Acquisitions (Narrative) (Details) - USD ($)	Dec. 23, 2015	Feb. 12, 2014
4-antibody acquisition [Member]
Business Acquisition [Line Items]
Contingent Consideration		$ 40,000,000
PhosImmune Inc. [Member]
Business Acquisition [Line Items]
Contingent Consideration	$ 35,000,000
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
Business combination, milestone expiration unachieved period	Dec. 23, 2020
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

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangible Assets (Schedule of Changes in Goodwill) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 23,188
Effect of foreign currency	1,470
Addition of goodwill related to business acquisition	794
Ending balance	$ 25,452

Goodwill and Acquired Intangi_4

Goodwill and Acquired Intangible Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 22,727	$ 19,935
Accumulated amortization	(11,841)	(9,431)
Net carrying amount	10,886	10,504
Indefinite-lived Intangible Assets Acquired	2,132	1,945
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	17,013	16,584
Accumulated amortization	(10,112)	(8,044)
Net carrying amount	$ 6,901	$ 8,540
Intellectual Property [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	7 years	7 years
Intellectual Property [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	15 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	$ 1,310	$ 834
Accumulated amortization	(980)	(834)
Net carrying amount	330
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,272	572
Accumulated amortization	(749)	(553)
Net carrying amount	$ 1,523	$ 19
Other [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	2 years	2 years
Other [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	6 years	6 years

Goodwill and Acquired Intangi_5

Goodwill and Acquired Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years
Amortization expense	$ 2.4	$ 2	$ 2
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2020		2.2
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2021		2.2
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2022	2.2
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2023	1.7
Finite-Lived Intangible Assets, Estimated Amortization Expense, 2024		$ 0.6
Finite-Lived Intangible Asset, Expected Amortization Expense, 2025	$ 0.6

Investments (Schedule of Cash E

Investments (Schedule of Cash Equivalents) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents	$ 84,256	$ 55,258
Cost [Member] | Institutional Money Market Funds [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents	64,256	55,258
Cost [Member] | U.S. Treasury Bills [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents	20,000
Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents	84,256	55,258
Estimated Fair Value [Member] | Institutional Money Market Funds [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents	64,256	$ 55,258
Estimated Fair Value [Member] | U.S. Treasury Bills [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents	$ 20,000

Restricted Cash (Narrative) (De

Restricted Cash (Narrative) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash And Cash Equivalents [Abstract]
Restricted cash	$ 2,634,000	$ 0	$ 0

Restricted Cash (Schedule of Re

Restricted Cash (Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash And Cash Equivalents [Abstract]
Cash and cash equivalents	$ 99,871,000	$ 61,808,000	$ 53,054,000
Restricted cash	2,634,000	0	0
Cash, cash equivalents and restricted cash	$ 102,505,000	$ 61,808,000	$ 53,054,000	$ 60,187,000

Property, Plant and Equipment_2

Property, Plant and Equipment (Schedule of Property, Plant and Equipment, net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 73,991	$ 69,187
Plant and equipment, accumulated amortization and depreciation	(47,201)	(42,861)
Property, Plant and Equipment, Net	26,790	26,326
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,230	2,230
Property, Plant and Equipment, Useful Life	Indefinite
Building and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 5,630	5,624
Property, Plant and Equipment, Useful Life	35 years
Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 5,866	6,394
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, manufacturing and transportation equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 22,855	20,880
Laboratory, manufacturing and transportation equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	4 years
Laboratory, manufacturing and transportation 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	$ 28,390	25,350
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	$ 9,020	$ 8,709
Property, Plant and Equipment, Useful Life	3 years

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Research and development tax credits	$ 14,314,000	$ 16,364,000
Valuation Allowance, Deferred Tax Asset, Change in Amount	41,519,000	7,913,000	$ 24,233,000
Income tax benefit	$ 0	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 733,100,000
Operating loss carryforwards that do not expire	136,700,000
Research and development tax credits	$ 8,700,000
Internal Revenue Service (IRS) [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2021
Internal Revenue Service (IRS) [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2033
Federal and State [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2021
Federal and State [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2038
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 237,000,000
Research and development tax credits	6,700,000
Investment tax credit	$ 394,000
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2021
Investment tax credit expiration year	2021
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Research and development tax credits expiration year	2029
Investment tax credit expiration year	2024
Foreign Tax Authority [Member] | United Kingdom [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 9,600,000
Foreign Tax Authority [Member] | Belgium [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	11,400,000
Foreign Tax Authority [Member] | Ireland [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	667,000
Foreign Tax Authority [Member] | Hong Kong [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	289,000
Worldwide [Member]
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Change in Amount	$ 41,500,000	$ 7,900,000

Income Taxes Deferred tax asset

Income Taxes Deferred tax assets and deferred tax liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
U.S. Federal and State net operating loss carryforwards	$ 168,786	$ 143,126
Foreign net operating loss carryforwards	5,302	4,096
Research and development tax credits	14,314	16,364
Share-based compensation	4,846	4,774
Intangible Assets	39,477	38,710
Interest expense carryforward	7,114	3,893
Deferred Revenue	58,796	47,456
Lease Liability	8,389	2,002
Other	4,768	3,974
Total deferred tax assets	311,792	264,395
Less: valuation allowance	(303,747)	(262,228)
Net deferred tax assets	8,045	2,167
Foreign intangible assets	(1,052)	(1,009)
Right of use asset	(7,852)	(1,599)
Other	(192)	(165)
Deferred tax liabilities	(9,096)	(2,773)
Net deferred tax liability	$ (1,051)	$ (606)

Income Taxes Tax rate reconcili

Income Taxes Tax rate reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Computed “expected” Federal tax benefit	$ (38,706,000)	$ (23,413,000)	$ (34,029,000)
Change in valuation allowance	41,519,000	7,913,000	24,233,000
(Decrease) increase due to uncertain tax positions	(764,000)	(64,000)	7,000
Foreign income inclusion	3,570,000		11,089,000
State and local income benefit, net of Federal income tax benefit	(4,675,000)	4,144,000	(11,708,000)
Equity based compensation	1,883,000	1,367,000	4,219,000
Foreign rate differential	629,000	(564,000)	956,000
Change in fair value contingent consideration	287,000	1,219,000	(280,000)
Other, net	(3,743,000)	9,398,000	5,513,000
Income tax benefit	$ 0	$ 0	$ 0

Income Taxes Unrecognized tax b

Income Taxes Unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits, Beginning balance	$ 4,292	$ 4,356	$ 4,349
Increase related to current year positions	88	122
Increase (decrease) related to previously recognized positions	(766)	(186)	7
Unrecognized Tax Benefits, Ending balance	$ 3,614	$ 4,292	$ 4,356

Accrued Liabilities (Schedule o

Accrued Liabilities (Schedule of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities Current [Abstract]
Payroll	$ 7,643	$ 9,575
Professional fees	4,457	4,314
Contract manufacturing costs	6,274	8,768
Research services	4,649	6,675
Other	6,034	2,000
Total	$ 29,057	$ 31,332

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($)	Dec. 20, 2018	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jul. 22, 2020	Jun. 19, 2019	May 31, 2018	Oct. 31, 2017	Dec. 31, 2013
Class Of Stock [Line Items]
Common stock, shares authorized			400,000,000	400,000,000			240,000,000
Shares sold at the market, value			$ 156,421,000		$ 44,919,000
At Market Issuance Sales Agreement [Member] | B. Riley FBR, Inc. [Member] | New Sales Agreement [Member]
Class Of Stock [Line Items]
Common shares available for sale through sales agent						100,000,000
Net proceeds from issuance of common stock			$ 156,400,000
Shares sold at the market, shares			50,100,000
Shares sold price per share			$ 3.17
Stock Purchase Agreement [Member]
Class Of Stock [Line Items]
Shares sold at the market, shares	11,111,111
Shares sold at the market, value	$ 30,000,000
Number of shares purchased, price per share	$ 2.70
Percentage of common stock outstanding shares	8.50%
Stock purchase agreement, additional shares indisposable period	12 months
Maximum percentage of voting stock allowed to acquire	15.00%
Stock purchase agreement, additional shares, favorable voting period	12 months
Stock Purchase Agreement [Member] | Gilead Sciences Incorporation [Member]
Class Of Stock [Line Items]
Shares sold at the market, shares	11,110,000
Shares sold at the market, value	$ 30,000,000
Number of shares purchased, price per share	$ 2.70
Percentage of common stock outstanding shares	8.50%
Stock purchase agreement, additional shares indisposable period	12 months
Maximum percentage of voting stock allowed to acquire	15.00%
Stock purchase agreement, additional shares, favorable voting period	12 months
Stock Purchase Agreement [Member] | Betta HK [Member]
Class Of Stock [Line Items]
Shares sold at the market, shares		5,000,000
Shares sold at the market, value		$ 20,000,000
Percentage of common stock outstanding shares		2.80%
Stock purchase agreement, additional shares indisposable period		12 months
Stock purchase agreement, additional shares, favorable voting period		12 months
Number of shares purchased, price per share		$ 4.03
Maximum [Member]
Class Of Stock [Line Items]
Common stock, preferred stock, warrants, debt securities and units issuable amount									$ 250,000,000
Maximum [Member] | At Market Issuance Sales Agreement [Member] | B. Riley FBR, Inc. [Member]
Class Of Stock [Line Items]
Common shares available for sale through sales agent								20,000,000
Common stock, additional shares reserved for sale					30,000,000
At-The-Market Offerings [Member] | Sales Agreement [Member]
Class Of Stock [Line Items]
Common stock, shares authorized									15,000,000
Series A convertible preferred stock [Member]
Class Of Stock [Line Items]
Preferred Stock, Redemption Price Per Share										$ 94.86
Preferred Stock, Redemption Amount										$ 31,600,000
Preferred Stock, Liquidation Preference Per Share										$ 1,000
Preferred Stock, Amount of Preferred Dividends in Arrears			$ 1,600,000	$ 1,400,000
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears			$ 51.54	$ 44.92

Series C-1 Preferred Stock (Nar

Series C-1 Preferred Stock (Narrative) (Details) - USD ($)	Dec. 20, 2018	Oct. 31, 2018	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2019
Class Of Stock [Line Items]
Contingent liability
Series C-1 Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Common stock issued upon conversion of each convertible preferred stock					6,000,000
Aggregate proceeds from issuance of convertible prederred stock				$ 39,879,000
Series C-1 Convertible Preferred Stock remained outstanding			12,459	18,000	12,459
Stock Purchase Agreement [Member]
Class Of Stock [Line Items]
Shares sold at the market, shares	11,111,111
Number of shares purchased, price per share	$ 2.70
Stock Purchase Agreement [Member] | Certain Institutional Investors [Member] | Series C-1 Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Shares sold at the market, shares		18,459
Number of shares purchased, price per share		$ 2,167
Common stock issued upon conversion of each convertible preferred stock		1,000
Preferred Stock, Redemption Price Per Share		$ 2.167
Price per share premium to closing price percentage		10.00%
Aggregate proceeds from issuance of convertible prederred stock		$ 40,000,000
Net proceeds from issuance of convertible preferred stock		$ 39,900,000
Percentage of beneficial ownership limitation of common stock outstanding		9.99%
Notice period of increase beneficial ownership limitation		61 days
Convertible peferred stock, redemption description			If at any time while the C-1 Preferred Shares are outstanding, a) the Company effects any merger, consolidation, stock sale or other business combination (other than such a transaction in which the Company is the surviving or continuing entity and its common stock is not exchanged for or converted into other securities, cash or property), b) the Company effects any sale of all or substantially all of its assets in one transaction or a series of related transactions, c) any tender offer or exchange offer (whether by the Company or another person) is completed pursuant to which more than 50% of the common stock not held by the Company or is exchanged for or converted into other securities, cash or property, or d) the Company effects any reclassification of the common stock or any compulsory share exchange pursuant (other than as a result of a dividend, subdivision or combination covered above) to which the common stock is effectively converted into or exchanged for other securities, cash or property, (in any such case, a “Fundamental Transaction”) then, upon any subsequent conversion of the C-1 Preferred Shares, the holder shall have the right to receive, in lieu of the right to receive shares of common stock, for each share of common stock that would have been issued upon such conversion immediately prior to the occurrence of such Fundamental Transaction, the same kind and amount of securities, cash or property as it would have been entitled to receive upon the occurrence of such Fundamental Transaction if it had been, immediately prior to such Fundamental Transaction, the holder of the equivalent amount of common stock.
Stock Purchase Agreement [Member] | Certain Institutional Investors [Member] | Series C-1 Convertible Preferred Stock [Member] | Maximum [Member]
Class Of Stock [Line Items]
Percentage of beneficial ownership limitation of common stock outstanding		19.99%
Percentage of redemption of common stock included in tender offer			50.00%
Registration Payment Arrangement [Member]
Class Of Stock [Line Items]
Period to file registration statement, declared effective on SEC review			120 days
Penalty percentage for not meeting the registration agreement			1.00%
Penalty period			6 months
Contingent liability			$ 0
Registration payment arrangement, term			We were required to file a registration statement covering the resale of the full number of shares no later than 30 days after the closing of the agreement and must use commercially reasonable efforts to cause the registration statement to be declared effective no later than 90 days after the closing date (no review by the SEC) or in the event of a review by the SEC, 120 days after the closing date. We filed, and the SEC declared effective this registration statement during 2018.
Registration Payment Arrangement [Member] | Maximum [Member]
Class Of Stock [Line Items]
Period to file registration statement			30 days
Period to file registration statement, declared effective			90 days
Penalty percentage for not meeting the registration agreement			6.00%

Share-Based Compensation Plan_2

Share-Based Compensation Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019	Jun. 19, 2019	Jun. 10, 2009
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value of options granted	$ 2.04	$ 1.77	$ 1.23
Total intrinsic value of options exercised	$ 1,200,000	$ 385,000	$ 399,000
Intrinsic value of shares vested	$ 621,000	$ 357,000	$ 242,000
Vesting of nonvested shares, shares	165,632	129,675	53,050
Stock Options [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense, weighted average period	2 years 2 months 12 days
Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense	$ 800,000
Performance Based Award [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense, weighted average period	1 year 8 months 12 days
Employees and directors [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense	$ 22,300,000
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	0					29,200,000
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
2019 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					40,200,000
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	$ 4,500,000	$ 1,600,000	$ 1,200,000
Shares issued under ESPP	236,855	84,703	140,313
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
2019 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	575,000			500,000
Shares issued under Director Deferred Compensation Plan	72,081
Shares credited under Director Deferred Compensation Plan	475,192
Weighted average stock price of shares credited under Director Deferred Compensation Plan	$ 4.38
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 Plan_3

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation [Abstract]
Expected volatility	66.00%	64.00%	64.00%
Expected term in years	6 years	5 years	6 years
Risk-free interest rate	0.80%	1.80%	2.80%
Dividend yield	0.00%	0.00%	0.00%

Share-Based Compensation Plan_4

Share-Based Compensation Plans (Schedule Of Stock Option Activity) (Details)	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share Based Compensation [Abstract]
Options Outstanding, Beginning Balance | shares	27,164,147
Options Granted | shares	7,330,377
Options Exercised | shares	(1,161,757)
Options Forfeited | shares	(2,974,728)
Options Expired | shares	(1,441,638)
Options Outstanding, Ending Balance | shares	28,916,401
Options Vested or expected to vest | shares	28,916,401
Options Exercisable | shares	14,997,220
Options Outstanding, Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 3.67
Options Granted, Weighted Average Exercise Price | $ / shares	3.82
Options Exercised, Weighted Average Exercise Price | $ / shares	3.05
Options Forfeited, Weighted Average Exercise Price | $ / shares	3.30
Options Expired, Weighted Average Exercise Price | $ / shares	4.52
Options Outstanding, Weighted Average Exercise Price, Ending Balance | $ / shares	3.70
Options Vested or expected to vest, Weighted Average Exercise Price | $ / shares	3.70
Options Exercisable, Weighted Average Exercise Price | $ / shares	$ 3.98
Options Outstanding, Weighted Average Remaining Contractual Term	7 years 5 months 19 days
Options Vested or expected to vest, Weighted Average Remaining Contractual Term	7 years 5 months 19 days
Options Exercisable, Weighted Average Remaining Contractual Term	6 years 1 month 17 days
Options Outstanding, Aggregate Intrinsic Value | $	$ 7,088,129
Options Vested or expected to vest, Aggregate Intrinsic Value | $	7,088,129
Options Exercisable, Aggregate Intrinsic Value | $	$ 3,232,022

Share-Based Compensation Plan_5

Share-Based Compensation Plans (Summary Of Non-vested Stock Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation [Abstract]
Non-vested Shares Outstanding, Beginning Balance	2,207,943
Non-vested Shares Granted	179,816
Non-vested Shares Vested	(165,632)	(129,675)	(53,050)
Non-vested Shares Forfeited	(1,335,311)
Non-vested Shares Outstanding, Ending Balance	886,816	2,207,943
Non-vested Shares Outstanding, Weighted Average Grant Date Fair Value, Beginning Balance	$ 2.85
Non-vested Shares Granted, Weighted Average Grant Date Fair Value	3.60
Non-vested Shares Vested, Weighted Average Grant Date Fair Value	2.75
Non-vested Shares Forfeited, Weighted Average Grant Date Fair Value	3.43
Non-vested Shares Outstanding, Weighted Average Grant Date Fair Value, Ending Balance	$ 2.14	$ 2.85

Share-Based Compensation Plan_6

Share-Based Compensation Plans (Schedule Of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 10,121	$ 9,892	$ 7,625
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	3,758	3,873	3,498
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 6,363	$ 6,019	$ 4,127

License, Research and Other A_2

License, Research and Other Agreements (Narrative) (Details) - USD ($)	Jan. 25, 2016	Dec. 05, 2014	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Revenue Arrangement [Line Items]
Estimate of total payments for clinical trials			$ 385,500,000
Clinical trials expense			64,700,000	$ 87,700,000	$ 41,500,000
Cumulative payments for clinical trials			308,100,000
Research and Development Expense [Member]
Deferred Revenue Arrangement [Line Items]
Clinical trials expense			318,700,000
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
LICR [Member]
Deferred Revenue Arrangement [Line Items]
License costs		$ 1,000,000
Type of Cost, Good or Service [Extensible List]		us-gaap:LicenseMember
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

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Narrative) (Details)

Jan. 23, 2019USD ($)

Dec. 20, 2018USD ($)AgreementProgramOption$ / sharesshares

Sep. 20, 2018

Jan. 02, 2018USD ($)

Feb. 14, 2017

Nov. 30, 2015Program

Feb. 19, 2015USD ($)Program

Jan. 09, 2015USD ($)Program

Jul. 31, 2020USD ($)

Nov. 30, 2019USD ($)

Mar. 31, 2012USD ($)

Jul. 31, 2007USD ($)

Jul. 31, 2006USD ($)

Dec. 31, 2020USD ($)

Sep. 30, 2020USD ($)

Jun. 30, 2020USD ($)

Mar. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Sep. 30, 2019USD ($)

Jun. 30, 2019USD ($)

Mar. 31, 2019USD ($)

Sep. 30, 2018USD ($)

Sep. 30, 2019USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Revenue From Contract With Customer [Line Items]

Shares sold at the market, value

$ 156,421,000

$ 44,919,000

Revenue recognized

$ 31,265,000

$ 14,832,000

$ 26,945,000

$ 15,128,000

$ 34,502,000

$ 19,940,000

$ 15,715,000

$ 79,891,000

88,170,000

$ 150,048,000

36,784,000

Decrease in deferred revenue

(11,464,000)

53,900,000

(397,000)

Contract with customer, liability, revenue recognized

12,530,000

Asset impairment charges

0

Deferred revenue, Additions

1,400,000

Capitalized contract , cost

0

0

GSK Supply Agreement [Member]

Revenue From Contract With Customer [Line Items]

Milestone payments for license costs

$ 5,000,000

5,000,000

Additional fixed fee for license costs

$ 7,300,000

Negotiation right expiry date

2017-03

Proceeds from negotiation right

$ 9,000,000

Proceeds from negotiation right creditable against future royalty payments

$ 2,500,000

Revenue fixed payments

19,300,000

UroGen License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Proceeds from collaborators

$ 10,000,000

Revenue recognized

63,000

10,000,000

Transaction price recognized

10,000,000

GSK Agreements [Member]

Revenue From Contract With Customer [Line Items]

Royalty payments on net sales (as a percent)

2.00%

Total potential proceeds from license

$ 24,300,000

Period to receive license fees

10 years

Milestone method revenue recognized

15,100,000

Non-cash royalty revenue recognized

46,500,000

30,400,000

17,300,000

Decrease to stockholders' deficit

2,500,000

Decrease in deferred revenue

2,500,000

Merck Collaboration and License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Potential Payments

76,500,000

Percentage of future royalties on worldwide product sales

67.00%

Upfront License Fee [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

75,500,000

Upfront License Fee [Member] | GSK Supply Agreement [Member]

Revenue From Contract With Customer [Line Items]

Proceeds from collaborators

$ 3,000,000

Upfront License Fee [Member] | UroGen License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Upfront cash payment

$ 10,000,000

Research and Development Revenue [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

35,915,000

99,845,000

19,475,000

Research and Development Revenue [Member] | Merck Collaboration and License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Aggregate potential milestones receivable

1,000,000

Revenue recognized

$ 0

9,000,000

4,000,000

Profit-share Products [Member]

Revenue From Contract With Customer [Line Items]

Milestone payments for license costs

$ 20,000,000

Number of collaboration agreement programs | Program

2

Royalty-bearing Products [Member]

Revenue From Contract With Customer [Line Items]

Milestone payments for license costs

$ 155,000,000

Number of collaboration agreement programs | Program

1

Research and development services [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

754,000

1,707,000

4,150,000

Collaborative Arrangement [Member]

Revenue From Contract With Customer [Line Items]

Percentage of profit and costs sharing ratio

50.00%

License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Number of license agreement | Agreement

1

Number of license agreement programs | Program

2

License agreement termination notice period

90 days

Option And License Agreements [Member]

Revenue From Contract With Customer [Line Items]

Number of separate option and license agreements | Option

2

Upfront license exercise fee

$ 50,000,000

Number of option and license agreement | Option

1

Collaboration Agreement Termination Notice Period

90 days

Option And License Agreements [Member] | Development Regulatory and Commercialization Milestones [Member]

Revenue From Contract With Customer [Line Items]

Milestone payments receivable

$ 520,000,000

Stock Purchase Agreement [Member]

Revenue From Contract With Customer [Line Items]

Shares sold at the market, value

$ 30,000,000

Shares sold at the market, shares | shares

11,111,111

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

$ 2.70

Percentage of common stock outstanding shares

8.50%

Stock purchase agreement, additional shares indisposable period

12 months

Maximum percentage of voting stock allowed to acquire

15.00%

Stock purchase agreement, additional shares, favorable voting period

12 months

Betta Pharmaceuticals Collaboration Agreement [Member]

Revenue From Contract With Customer [Line Items]

Deferred revenue, Additions

1,100,000

Royalty Purchase Agreement [Member] | Merck Collaboration and License Agreement [Member] | XOMA [Member]

Revenue From Contract With Customer [Line Items]

Percentage of sold future royalties right to receive

33.00%

Percentage of sold future milestones right to receive

10.00%

Development Regulatory and Commercialization Milestones [Member]

Revenue From Contract With Customer [Line Items]

Reserved right to elect to co-fund of development costs (as a percent)

30.00%

Gilead Collaboration Agreement [Member]

Revenue From Contract With Customer [Line Items]

Contract with customer, liability, revenue recognized

12,300,000

Contract with customer, net asset liability

44,100,000

44,100,000

Initial transaction price

142,500,000

Gilead Collaboration Agreement [Member] | Research and Development Revenue [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

98,400,000

Maximum [Member] | UroGen License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Royalty payments on net sales (as a percent)

20.00%

Maximum [Member] | Development Regulatory and Commercialization Milestones [Member] | UroGen License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Potential milestone payments receivable

$ 200,000,000

Maximum [Member] | License Agreement [Member] | Development Regulatory and Commercialization Milestones [Member]

Revenue From Contract With Customer [Line Items]

Potential milestone payments receivable

$ 552,500,000

Maximum [Member] | Option And License Agreements [Member]

Revenue From Contract With Customer [Line Items]

Milestone payments receivable

30,000,000

Maximum [Member] | Development Regulatory and Commercialization Milestones [Member]

Revenue From Contract With Customer [Line Items]

Royalty payments on net sales (as a percent)

12.00%

Minimum [Member] | UroGen License Agreement [Member]

Revenue From Contract With Customer [Line Items]

Royalty payments on net sales (as a percent)

14.00%

Minimum [Member] | Development Regulatory and Commercialization Milestones [Member]

Revenue From Contract With Customer [Line Items]

Royalty payments on net sales (as a percent)

6.00%

Gilead Sciences Incorporation [Member]

Revenue From Contract With Customer [Line Items]

Milestones stated value

22,500,000

Gilead Sciences Incorporation [Member] | License and Research and Development Fees [Member]

Revenue From Contract With Customer [Line Items]

Proceeds from collaborators

120,000,000

Gilead Sciences Incorporation [Member] | Collaborative Arrangement [Member]

Revenue From Contract With Customer [Line Items]

Upfront cash payment

$ 120,000,000

Shares sold at the market, value

$ 30,000,000

Transaction price recognized

20,600,000

Gilead Sciences Incorporation [Member] | Collaborative Arrangement [Member] | Research and Development Revenue [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

12,300,000

86,100,000

Gilead Sciences Incorporation [Member] | Stock Purchase Agreement [Member]

Revenue From Contract With Customer [Line Items]

Shares sold at the market, value

$ 30,000,000

Shares sold at the market, shares | shares

11,110,000

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

$ 2.70

Percentage of common stock outstanding shares

8.50%

Stock purchase agreement, additional shares indisposable period

12 months

Maximum percentage of voting stock allowed to acquire

15.00%

Stock purchase agreement, additional shares, favorable voting period

12 months

Gilead Sciences Incorporation [Member] | Maximum [Member] | Collaborative Arrangement [Member]

Revenue From Contract With Customer [Line Items]

Aggregate potential milestones receivable

$ 1,100,000,000

Betta Pharmaceuticals Co., Ltd [Member] | Betta Pharmaceuticals Collaboration Agreement [Member]

Revenue From Contract With Customer [Line Items]

Upfront payment received

$ 15,000,000

Betta Pharmaceuticals Co., Ltd [Member] | Betta Pharmaceuticals Collaboration Agreement [Member] | Fixed Consideration [Member]

Revenue From Contract With Customer [Line Items]

Upfront payment received

15,000,000

Betta Pharmaceuticals Co., Ltd [Member] | Betta Pharmaceuticals Collaboration Agreement [Member] | Research and Development Revenue [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

$ 13,900,000

Betta Pharmaceuticals Co., Ltd [Member] | Maximum [Member] | Betta Pharmaceuticals Collaboration Agreement [Member]

Revenue From Contract With Customer [Line Items]

Aggregate potential milestones receivable

$ 100,000,000

Incyte Corporation [Member]

Revenue From Contract With Customer [Line Items]

Collaboration Agreement Termination Notice Period

12 months

Transaction price recognized

2,000,000

Percentage of future royalties on worldwide product sales

67.00%

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

Receivables for R & D services

1,200,000

$ 1,200,000

Incyte Corporation [Member] | Adjusted Balance Under ASC 605 [Member]

Revenue From Contract With Customer [Line Items]

Transaction price recognized

1,300,000

Incyte Corporation [Member] | Agenus Inc [Member]

Revenue From Contract With Customer [Line Items]

Number of collaboration agreement programs | Program

3

Incyte Corporation [Member] | Research and Development Revenue [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

700,000

Incyte Corporation [Member] | License and Service

Revenue From Contract With Customer [Line Items]

Revenue recognized

3,700,000

Incyte Corporation [Member] | License and Service | Adjusted Balance Under ASC 605 [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

15,500,000

Incyte Corporation [Member] | Research and development services [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

$ 1,700,000

Incyte Corporation [Member] | Research and development services [Member] | Adjusted Balance Under ASC 605 [Member]

Revenue From Contract With Customer [Line Items]

Revenue recognized

4,200,000

Incyte Corporation [Member] | Collaborative Arrangement [Member]

Revenue From Contract With Customer [Line Items]

Proceeds from collaborators

$ 25,000,000

Royalty payments on net sales (as a percent)

15.00%

Proceeds from milestones recognized

$ 5,000,000

Upfront payment received related to clinical development

$ 20,000,000

Incyte Corporation [Member] | Collaborative Arrangement [Member] | ASC 606 [Member]

Revenue From Contract With Customer [Line Items]

Decrease to stockholders' deficit

$ 6,400,000

Decrease in deferred revenue

$ 6,400,000

Incyte Corporation [Member] | Collaborative Arrangement [Member] | Adjusted Balance Under ASC 605 [Member]

Revenue From Contract With Customer [Line Items]

Contract with customer, liability, revenue recognized

$ 10,000,000

Incyte Corporation [Member] | Royalty Purchase Agreement [Member] | XOMA [Member]

Revenue From Contract With Customer [Line Items]

Percentage of sold future royalties right to receive

33.00%

Percentage of sold future milestones right to receive

10.00%

Proceeds from milestones recognized

$ 5,000,000

Incyte Corporation [Member] | Maximum [Member] | Collaborative Arrangement [Member]

Revenue From Contract With Customer [Line Items]

Potential milestone payments receivable

$ 450,000,000

$ 450,000,000

Revenue from Contracts with C_4

Revenue from Contracts with Customers (Narrative) (Details 1) - Gilead Sciences Incorporation [Member] $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Expect to recognize deferred research and development revenue	$ 17
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Expect to recognize deferred research and development revenue	$ 27.1
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year

Revenue from Contracts with C_5

Revenue from Contracts with Customers (Summary of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Revenue	$ 31,265	$ 14,832	$ 26,945	$ 15,128	$ 34,502	$ 19,940	$ 15,715	$ 79,891	$ 88,170	$ 150,048	$ 36,784
Research and development services [Member]
Disaggregation Of Revenue [Line Items]
Revenue									754	1,707	4,150
License fees and milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue									22,857
License Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue										75,500
Other services [Member]
Disaggregation Of Revenue [Line Items]
Revenue									4,619
Royalty sales milestone [Member]
Disaggregation Of Revenue [Line Items]
Revenue										15,100
Manufacturing services [Member]
Disaggregation Of Revenue [Line Items]
Revenue										3,337
Recognition of Deferred Research and Development Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue									12,304	22,638	1,325
Recognition of Deferred Grant Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue									91	1,342
Non-cash royalties and milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue									47,545
Non-cash royalties [Member]
Disaggregation Of Revenue [Line Items]
Revenue									47,545	30,424	17,309
License and collaboration milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue											14,000
United States [Member]
Disaggregation Of Revenue [Line Items]
Revenue									83,551	149,358	32,784
United States [Member] | Research and development services [Member]
Disaggregation Of Revenue [Line Items]
Revenue									754	1,707	4,150
United States [Member] | License fees and milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue									22,857
United States [Member] | License Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue										75,500
United States [Member] | Royalty sales milestone [Member]
Disaggregation Of Revenue [Line Items]
Revenue										15,100
United States [Member] | Manufacturing services [Member]
Disaggregation Of Revenue [Line Items]
Revenue										3,337
United States [Member] | Recognition of Deferred Research and Development Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue									12,304	22,638	1,325
United States [Member] | Recognition of Deferred Grant Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue									91	652
United States [Member] | Non-cash royalties and milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue									47,545
United States [Member] | Non-cash royalties [Member]
Disaggregation Of Revenue [Line Items]
Revenue										30,424	17,309
United States [Member] | License and collaboration milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue											10,000
Rest of World [Member]
Disaggregation Of Revenue [Line Items]
Revenue									4,619	690	4,000
Rest of World [Member] | Other services [Member]
Disaggregation Of Revenue [Line Items]
Revenue									$ 4,619
Rest of World [Member] | Recognition of Deferred Grant Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue										$ 690
Rest of World [Member] | License and collaboration milestones [Member]
Disaggregation Of Revenue [Line Items]
Revenue											$ 4,000

Revenue from Contracts with C_6

Revenue from Contracts with Customers (Schedule of Information about Contract Assets and Contract Liabilities from Contracts with Customers) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Contract With Customer Asset And Liability [Abstract]
Deferred revenue, Beginning Balance	$ 56,414
Deferred revenue, Additions	1,400
Deferred revenue, Deductions	(12,530)
Deferred revenue, Ending Balance	$ 45,284

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - Children of Armenia Fund ("COAF") [Member]	12 Months Ended
	Dec. 31, 2020USD ($)
Related Party Transaction [Line Items]
Cash charitable contribution	$ 59,000
Cash installments payment	Quarterly
Non-cash charitable contribution	$ 50,000
Maximum [Member]
Related Party Transaction [Line Items]
Charitable contribution	$ 125,000

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Finance lease, expiration period	2022
Cash payments for operating lease liabilities	$ 1.6	$ 1.4
Cash payments for finance lease liabilities	1.8
Expected lease incentives to be received, 2021	19.2
Expected lease incentives to be received, 2022	$ 2.1
Minimum [Member]
Lessee Lease Description [Line Items]
Operating lease, expiration period	2022
Maximum [Member]
Lessee Lease Description [Line Items]
Operating lease, expiration period	2036

Leases (Schedule of Components

Leases (Schedule of Components of Lease Cost Recorded in Condensed Consolidated Statement of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 4,698	$ 2,551
Finance lease cost	375	221
Variable lease cost	1,887	1,414
Sublease income	(578)	(561)
Net lease cost	$ 6,382	$ 3,625

Leases (Schedule of Supplementa

Leases (Schedule of Supplemental Balance Sheet Information Related to Lease) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Total operating lease right-of-use assets	$ 33,480	$ 7,364
Current portion, operating lease liabilities	1,950	1,347
Operating lease liabilities, net of current portion	34,065	8,020
Total operating lease liabilities	36,015	9,367
Property, plant and equipment, net	2,231	796
Other current liabilities	746	148
Other long-term liabilities	66
Total finance lease liabilities	812	148
Property, plant and equipment, net [Member]
Lessee Lease Description [Line Items]
Property, plant and equipment, net	$ 2,231	$ 796

Leases (Schedule of Maturities

Leases (Schedule of Maturities of Operating Lease Liabilities in Accordance With ASC 842) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating Leases, 2021	$ (14,813)
Operating Leases, 2022	5,007
Operating Leases, 2023	9,486
Operating Leases, 2024	8,279
Operating Leases, 2025	8,473
Operating Leases, Thereafter	85,638
Operating Leases, Total	102,070
Operating Leases, Less imputed interest	(66,055)
Operating Leases, Present value of lease liabilities	36,015	$ 9,367
Finance leases, 2021	804
Finance leases, 2022	67
Finance leases, Total	871
Finance leases, Less imputed interest	(59)
Finance leases, Present value of lease liabilities	812	$ 148
Expected sublease receipts, 2021	(595)
Expected sublease receipts, 2022	(613)
Expected sublease receipts, Total	(1,208)
Net future lease commitments, 2021	(14,604)
Net future lease commitments, 2022	4,461
Net future lease commitments, 2023	9,486
Net future lease commitments, 2024	8,279
Net future lease commitments, 2025	8,473
Net future lease commitments, Thereafter	85,638
Net future lease commitments, Total	$ 101,733

Leases (Schedule of Weighted-Av

Leases (Schedule of Weighted-Average Remaining Lease Terms and Discount Rates Related to Operating Leases) (Details)	Dec. 31, 2020
Leases [Abstract]
Operating lease, weighted average remaining lease term (in years)	11 years 10 months 24 days
Operating lease, weighted average discount rate	12.00%
Finance lease, weighted average remaining lease term (in years)	1 year 1 month 6 days
Finance lease, weighted average discount rate	12.30%

Debt - Schedule of Debt Obligat

Debt - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Other	$ 687
Total	19,712	$ 14,026
Debt instrument, Long-term Portion
Long-term Debt, Gross	20,000	14,146
Unamortized Debt Discount Total		(120)
Other services [Member]
Debt Instrument [Line Items]
Other	6,197
2015 Subordinated Notes [Member]
Debt Instrument [Line Items]
2015 Subordinated Notes	12,682	13,380
Debt instrument, Long-term Portion
Principal Balance, Long-term Portion		13,500
Unamortized Debt Discount, Long-term Portion		(120)
Debentures [Member]
Debt Instrument [Line Items]
Debentures	$ 146	146
Debt instrument, Current Portion
Principal Balance, Short-term Portion		146
2015 Subordinated Notes [Member]
Debt Instrument [Line Items]
Debentures		500
Debt instrument, Current Portion
Principal Balance, Short-term Portion		$ 500

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	Feb. 17, 2020	May 31, 2020	Apr. 30, 2020	Feb. 18, 2020	Jan. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 20, 2015
Debt Instrument [Line Items]
Principal amount of outstanding debt						$ 20,000,000	$ 14,146,000
Warrants issued				675,000
Class of warrant or right, exercise price of warrants or rights				$ 4.48
Remaining debt payment						1,462,000		$ 161,847,000
Warrants issued				675,000
Warrants outstanding, Term				5 years
Premium over warrants exercise price				20.00%
Loss on other expense								(10,767,000)
Loss on extinguishment of debt								10,767,000
Long-term Debt, Gross						$ 20,000,000	14,146,000
Antigenics LLC [Member]
Debt Instrument [Line Items]
Debt instrument redemption price percentage						17.50%
Paycheck Protection Program [Member] | COVID 19 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		1.00%
Loan term		2 years
Percentage of loan proceeds to be used for payroll costs		60.00%
Percentage of loan proceeds to be used for rent and utilities		40.00%
Paycheck Protection Program [Member] | Promissory notes with Bank of America [Member] | COVID 19 [Member]
Debt Instrument [Line Items]
Aggregate loan proceeds		$ 6,200,000
Notes 2015 [Member]
Debt Instrument [Line Items]
Debt discount amortization period	3 years
Notes 2015 [Member] | Common Stock [Member]
Debt Instrument [Line Items]
Warrants issued				1,350,000
Warrants issued				1,350,000
Warrants exercise period date	Feb. 20, 2020			Feb. 20, 2023
2013 Warrants [Member]
Debt Instrument [Line Items]
Class of warrant or right, exercise price of warrants or rights						$ 4.41			$ 5.10
2013 Warrants [Member] | Common Stock [Member]
Debt Instrument [Line Items]
Warrants issued						500,000			1,400,000
Warrants issued						500,000			1,400,000
Limited Recourse Notes [Member] | Oberland Capital SA Zermatt LLC [Member] | Antigenics LLC [Member]
Debt Instrument [Line Items]
Debt instrument accrued interest rate percentage						13.50%
Debt instrument period for computation of interest rate						360 days
Aquila Debentures [Member]
Debt Instrument [Line Items]
Principal amount of outstanding debt						$ 146,000
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					$ 13,500,000
Debt instrument, maturity date	Feb. 20, 2020			Feb. 20, 2023		Feb. 23, 2023
Remaining debt payment			$ 500,000	$ 500,000
Loss on other expense						$ 2,700,000
Loss on extinguishment of debt						(2,700,000)
Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Noncash interest expenses						$ 0	$ 0	$ 849,000
Note Purchase Agreement [Member] | Oberland Capital SA Zermatt LLC [Member]
Debt Instrument [Line Items]
Remaining debt payment					$ 161,900,000
Loss on other expense					(10,800,000)
Loss on extinguishment of debt					$ 10,800,000

Liability Related to the Sale_3

Liability Related to the Sale of Future Royalties and Milestones (Schedule of Liability Account) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Liability related to sale of future royalties and milestones - beginning balance	$ 221,845
Non-cash royalty and milestone revenue	(47,545)
Non-cash interest expense recognized	59,741
Liability related to sale of future royalties and milestones - ending balance	234,041
Less: unamortized transaction costs	(416)
Liability related to sale of future royalties and milestones, net	233,625
Period from Inception [Member]
Proceeds from sale of future royalties and milestones	205,000
Non-cash royalty and milestone revenue	(95,279)
Non-cash interest expense recognized	124,320
Liability related to sale of future royalties and milestones - ending balance	234,041
Less: unamortized transaction costs	(416)
Liability related to sale of future royalties and milestones, net	$ 233,625

Liability Related to the Sale_4

Liability Related to the Sale of Future Royalties and Milestones (Narrative) (Details) - USD ($)	Sep. 20, 2018	Jan. 19, 2018	Jan. 06, 2018	Dec. 31, 2020	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Non-cash interest expense							$ 59,741,000
Incyte Corporation and Merck Sharpe & Dohme [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Percentage of future milestones retained	90.00%
Percentage of future royalties retained	67.00%
GSK Agreements [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Non-cash royalty revenue recognized							46,500,000	$ 30,400,000	$ 17,300,000
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Percentage of purchase of worldwide rights to receive royalties			100.00%
Gross proceeds received for royalty rights		$ 190,000,000
Reimbursed HCR for transaction costs		100,000
Transaction costs incurred		500,000
Non-cash royalty revenue recognized							46,500,000	30,400,000	17,300,000
Non-cash interest expense							$ 59,700,000	41,500,000	$ 23,100,000
Effective annual interest rate							28.20%
Prospective effective annual interest rate							23.40%
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member] | Maximum [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Potential milestone payments receivable		40,400,000						15,100,000
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member] | Prior to 2024 [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Potential milestone payments receivable		15,100,000						15,100,000
Sales milestones target			$ 2,000,000,000					$ 2,000,000,000
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member] | Prior to 2026 [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Potential milestone payments receivable		$ 25,300,000		$ 25,300,000			$ 25,300,000
Sales milestones target			2,750,000,000
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member] | 2021 [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Payables upon not achieving sales milestones			25,900,000
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member] | 2019 [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Sales milestones target			1,000,000,000			$ 1,600,000,000
HCR [Member] | GSK Agreements [Member] | Royalty Purchase Agreement [Member] | 2020 [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Sales milestones target			$ 1,750,000,000
XOMA [Member] | Royalty Purchase Agreement [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Proceeds from royalties and milestones payment	$ 15,000,000
Liability related to sale of future royalties and milestones	$ 15,000,000
XOMA [Member] | Royalty Purchase Agreement [Member] | Incyte Corporation and Merck Sharpe & Dohme [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Percentage of sold future royalties right to receive	33.00%
Percentage of sold future milestones right to receive	10.00%
XOMA [Member] | Royalty Purchase Agreement [Member] | Incyte Corporation [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Percentage of sold future royalties right to receive	33.00%
Percentage of sold future milestones right to receive	10.00%
Proceeds from milestones recognized					$ 5,000,000
XOMA [Member] | Merck Collaboration and License Agreement [Member] | Royalty Purchase Agreement [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Percentage of sold future royalties right to receive	33.00%
Percentage of sold future milestones right to receive	10.00%
Sales milestone target achieved				10,000,000
Non-cash milestone revenue recognized							1,000,000
Increase (decrease) in liability related to sale of future royalties and milestones				$ (1,000,000)			$ (1,000,000)

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	$ 10,208,000	$ 8,843,000
Fair value of transfers into or out of Levels 1 and 2	0
Long-term Debt, Gross	20,000,000	14,146,000
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	19,900,000	$ 14,200,000
4-antibody acquisition [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	8,300,000
PhosImmune Inc. [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	1,600,000
Other Contingent
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price consideration	$ 300,000

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Weighted Average Values of Contingent Purchase Milestones and Credit Spread) (Details) - Weighted Average	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Period of time to achieve milestones (in years)	1 year 3 months 18 days	1 year 8 months 12 days
Credit spread	5.50%	16.40%

Fair Value Measurements (Sche_2

Fair Value Measurements (Schedule of Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Contingent purchase price consideration, Fair Value Disclosure	$ 10,208	$ 8,843
Total	10,208	8,843
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Contingent purchase price consideration, 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]
Contingent purchase price consideration, Fair Value Disclosure	0	0
Total	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Contingent purchase price consideration, Fair Value Disclosure	10,208	8,843
Total	$ 10,208	$ 8,843

Fair Value Measurements (Sche_3

Fair Value Measurements (Schedule of Liabilities Measured at Fair Value Using Significant Unobservable Inputs) (Details) - Significant Unobservable Inputs (Level 3) [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Balance, beginning of period	$ 8,843
Balance, end of period	10,208
Contingent Purchase Price
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Change in fair value of consideration during the period	1,221
Addition of contingent purchase price consideration related to business acquisition	$ 144

Benefit Plans (Narrative) (Deta

Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 1,100,000	$ 922,000	$ 617,000
Expensed plan contributions	$ 1,100,000	$ 922,000	$ 617,000

Geographical Information (Detai

Geographical Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 31,265	$ 14,832	$ 26,945	$ 15,128	$ 34,502	$ 19,940	$ 15,715	$ 79,891	$ 88,170	$ 150,048	$ 36,784
Long-Lived Assets	30,913				27,743				30,913	27,743
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									83,551	149,358	32,784
Long-Lived Assets	27,611				23,822				27,611	23,822
Rest Of World [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									4,619	690	$ 4,000
Long-Lived Assets	$ 3,302				$ 3,921				$ 3,302	$ 3,921

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Revenue	$ 31,265	$ 14,832	$ 26,945	$ 15,128	$ 34,502	$ 19,940	$ 15,715	$ 79,891	$ 88,170	$ 150,048	$ 36,784
Net income (loss)	(37,730)	(51,646)	(48,244)	(45,271)	(30,851)	(46,277)	(51,867)	17,435
Net income (loss) attributable to Agenus Inc. common shareholders	$ (37,660)	$ (51,205)	$ (47,532)	$ (44,726)	$ (30,107)	$ (45,526)	$ (50,686)	$ 18,454	$ (181,123)	$ (107,865)	$ (159,899)
Basic and diluted net loss attributable to Agenus Inc. common stockholders	$ (0.20)	$ (0.28)	$ (0.28)	$ (0.31)					$ (1.05)	$ (0.80)	$ (1.44)
Basic net income (loss) attributable to Agenus Inc. common stockholders					$ (0.22)	$ (0.33)	$ (0.38)	$ 0.14
Diluted net income (loss) attributable to Agenus Inc. common stockholders					$ (0.22)	$ (0.33)	$ (0.38)	$ 0.12

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - B. Riley FBR, Inc. [Member] - Subsequent Event [Member] $ in Millions	2 Months Ended
	Mar. 12, 2021USD ($)shares
Subsequent Event [Line Items]
Net proceeds from issuance of common stock | $	$ 31.8
Shares sold at the market, shares | shares	9,100,000