Agenus (AGEN) 10-Q 9 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 03, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2023
Entity Registrant Name	AGENUS INC
Entity Central Index Key	0001098972
Entity Current Reporting Status	Yes
Trading Symbol	AGEN
Security Exchange Name	NASDAQ
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Title of 12(b) Security	Common stock, par value $0.01
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		381,495,471
Entity File Number	000-29089
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 Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
ASSETS
Cash and cash equivalents	$ 106,305	$ 178,674
Short-term investments		14,684
Accounts receivable	1,030	2,741
Prepaid expenses	15,886	13,829
Other current assets	2,329	3,194
Total current assets	125,550	213,122
Property, plant and equipment, net of accumulated amortization and depreciation of $60,750 and $54,075 at September 30, 2023 and December 31, 2022, respectively	139,679	133,017
Operating lease right-of-use assets	30,018	31,269
Goodwill	24,666	25,467
Acquired intangible assets, net of accumulated amortization of $17,444 and $16,148 at September 30, 2023 and December 31, 2022, respectively	4,497	6,228
Other long-term assets	11,062	4,453
Total assets	335,472	413,556
LIABILITIES AND STOCKHOLDERS' DEFICIT
Current portion, long-term debt	387	575
Current portion, liability related to sale of future royalties and milestones	98,500	83,510
Current portion, deferred revenue	4,994	12,269
Current portion, operating lease liabilities	2,559	1,943
Accounts payable	40,871	40,939
Accrued liabilities	37,629	38,259
Other current liabilities	13,416	11,457
Total current liabilities	198,356	188,952
Long-term debt, net of current portion	12,720	12,584
Liability related to sale of future royalties and milestones, net of current portion	167,070	187,753
Deferred revenue, net of current portion	1,143	1,143
Operating lease liabilities, net of current portion	63,166	63,326
Other long-term liabilities	8,309	14,700
Commitments and contingencies
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock, par value $0.01 per share; 800,000,000 shares authorized; 381,381,803 and 305,573,397 shares issued at September 30, 2023 and December 31, 2022, respectively	3,814	3,056
Additional paid-in capital	1,777,480	1,644,658
Accumulated other comprehensive income (loss)	(1,028)	915
Accumulated deficit	(1,909,378)	(1,709,907)
Total stockholders' deficit attributable to Agenus Inc.	(129,112)	(61,278)
Non-controlling interest	13,820	6,376
Total stockholders' deficit	(115,292)	(54,902)
Total liabilities and stockholders' deficit	335,472	413,556
Series A-1 convertible preferred stock [Member]
STOCKHOLDERS' (DEFICIT) EQUITY
Series A-1 convertible preferred stock; 31,620 shares designated, issued, and outstanding at September 30, 2023 and December 31, 2022; liquidation value of $33,833 at September 30, 2023	$ 0	$ 0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property plant and equipment, accumulated amortization and depreciation	$ 60,750	$ 54,075
Acquired intangible assets, accumulated amortization	$ 17,444	$ 16,148
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	381,381,803	305,573,397
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	$ 33,833

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue:
Total revenues	$ 24,314	$ 22,772	$ 72,513	$ 69,638
Operating expenses:
Cost of service revenue	(303)	(308)	(2,851)	(2,875)
Research and development	(51,443)	(46,011)	(167,846)	(133,412)
General and administrative	(18,909)	(18,105)	(57,562)	(55,971)
Contingent purchase price consideration fair value adjustment		7	398	950
Operating loss	(46,341)	(41,645)	(155,348)	(121,670)
Other income (expense):
Non-operating income	442	537	238	9,654
Interest expense, net	(18,633)	(15,607)	(53,745)	(44,538)
Net loss	(64,532)	(56,715)	(208,855)	(156,554)
Dividends on Series A-1 convertible preferred stock	(53)	(53)	(160)	(159)
Less: net loss attributable to non-controlling interest	(2,331)	(2,493)	(9,384)	(7,573)
Net loss attributable to Agenus Inc. common stockholders	$ (62,254)	$ (54,275)	$ (199,631)	$ (149,140)
Per common share data:
Basic net loss attributable to Agenus Inc. common stockholders	$ (0.16)	$ (0.19)	$ (0.57)	$ (0.54)
Diluted net loss attributable to Agenus Inc. common stockholders	$ (0.16)	$ (0.19)	$ (0.57)	$ (0.54)
Weighted average number of Agenus Inc. common shares outstanding:
Basic	378,152	286,854	349,167	274,170
Diluted	378,152	286,854	349,167	274,170
Other comprehensive loss:
Foreign currency translation loss	$ (311)	$ (1,505)	$ (1,943)	$ (848)
Other comprehensive loss	(311)	(1,505)	(1,943)	(848)
Comprehensive loss	(62,565)	(55,780)	(201,574)	(149,988)
Research and Development [Member]
Revenue:
Total revenues	3,414	4,573	8,515	13,220
Royalty Sales Milestone [Member]
Revenue:
Total revenues		7,934		25,250
Service Revenue [Member]
Revenue:
Total revenues	540	1,041	2,464	4,167
Non-Cash Royalty Revenue Related to the Sale of Future Royalties [Member]
Revenue:
Total revenues	$ 20,360	$ 9,224	$ 61,534	$ 27,001

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	MiNK Therapeutics, Inc.	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] MiNK Therapeutics, Inc.	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-controlling Interest [Member]	Non-controlling Interest [Member] MiNK Therapeutics, Inc.	Accumulated Deficit [Member]	Series A-1 convertible preferred stock [Member] Preferred Stock [Member]
Stockholders' Equity, Beginning Balance at Dec. 31, 2021	$ 47,909		$ 2,569	$ 1,520,212			$ 1,492	$ 13,469		$ (1,489,833)
Balance, shares at Dec. 31, 2021			256,899,000
Temporary Equity, Beginning Balance at Dec. 31, 2021											$ 0
Temporary Equity, shares at Dec. 31, 2021											32,000
Net loss	(50,604)							(2,279)		(48,325)
Other comprehensive income (loss)	(522)						(522)
Share-based compensation	4,947			4,205				742
Shares sold at the market	19,182		$ 70	19,112
Shares sold at the market, shares			7,039,000
Issuance of director deferred shares	19			19
Issuance of director deferred shares, shares			5,000
Issuance of shares for services	81		$ 1	80
Issuance of shares for services, shares			21,000
Vesting of nonvested shares			$ 1	(1)
Vesting of nonvested shares, shares			143,000
Exercise of stock options and employee share purchases	368		$ 1	367
Exercise of stock options and employee share purchases, shares			136,000
Issuance of shares for employee bonus	2,903		$ 38	6,245		$ (3,380)
Issuance of shares for employee bonus, Shares			3,845,000			(1,347,000)
Retirement of treasury shares	3,367		$ (13)			$ 3,380
Retirement of treasury shares, share			(1,347,000)			1,347,000
Stockholders' Equity, Ending Balance at Mar. 31, 2022	27,650		$ 2,667	1,550,239			970	11,932		(1,538,158)
Temporary Equity, Ending Balance at Mar. 31, 2022											$ 0
Balance, shares at Mar. 31, 2022			266,741,000
Temporary Equity, shares at Mar. 31, 2022											32,000
Stockholders' Equity, Beginning Balance at Dec. 31, 2021	47,909		$ 2,569	1,520,212			1,492	13,469		(1,489,833)
Balance, shares at Dec. 31, 2021			256,899,000
Temporary Equity, Beginning Balance at Dec. 31, 2021											$ 0
Temporary Equity, shares at Dec. 31, 2021											32,000
Net loss	(156,554)
Other comprehensive income (loss)	(848)
Stockholders' Equity, Ending Balance at Sep. 30, 2022	(11,836)		$ 2,949	1,614,836			644	8,549		(1,638,814)
Temporary Equity, Ending Balance at Sep. 30, 2022											$ 0
Balance, shares at Sep. 30, 2022			294,951,000
Temporary Equity, shares at Sep. 30, 2022											32,000
Stockholders' Equity, Beginning Balance at Dec. 31, 2021	47,909		$ 2,569	1,520,212			1,492	13,469		(1,489,833)
Balance, shares at Dec. 31, 2021			256,899,000
Temporary Equity, Beginning Balance at Dec. 31, 2021											$ 0
Temporary Equity, shares at Dec. 31, 2021											32,000
Share-based compensation								3,195
Stockholders' Equity, Ending Balance at Dec. 31, 2022	(54,902)		$ 3,056	1,644,658			915	6,376		(1,709,907)
Temporary Equity, Ending Balance at Dec. 31, 2022											$ 0
Balance, shares at Dec. 31, 2022			305,574,000
Temporary Equity, shares at Dec. 31, 2022											32,000
Stockholders' Equity, Beginning Balance at Mar. 31, 2022	27,650		$ 2,667	1,550,239			970	11,932		(1,538,158)
Balance, shares at Mar. 31, 2022			266,741,000
Temporary Equity, Beginning Balance at Mar. 31, 2022											$ 0
Temporary Equity, shares at Mar. 31, 2022											32,000
Net loss	(49,235)							(2,801)		(46,434)
Other comprehensive income (loss)	1,179						1,179
Share-based compensation	4,615			3,818				797
Shares sold at the market	28,237		$ 158	28,079
Shares sold at the market, shares			15,782,000
Issuance of shares for milestone achievement	500		$ 2	498
Issuance of shares for milestone achievement, shares			180,000
Issuance of shares for services	20		$ 1	19
Issuance of shares for services, shares			7,000
Exercise of stock options	14			14
Exercise of stock options, shares			6,000
Issuance of subsidiary shares to noncontrolling interest	294							294
Issuance of shares for employee bonus	114		$ 2	363		$ (251)
Issuance of shares for employee bonus, Shares			246,000			(100,000)
Retirement of treasury shares	250		$ (1)			$ 251
Retirement of treasury shares, share			(100,000)			100,000
Stockholders' Equity, Ending Balance at Jun. 30, 2022	13,638		$ 2,829	1,583,030			2,149	10,222		(1,584,592)
Temporary Equity, Ending Balance at Jun. 30, 2022											$ 0
Balance, shares at Jun. 30, 2022			282,862,000
Temporary Equity, shares at Jun. 30, 2022											32,000
Net loss	(56,715)							(2,493)		(54,222)
Other comprehensive income (loss)	(1,505)						(1,505)
Share-based compensation	4,434			3,614				820
Shares sold at the market	27,830		$ 117	27,713
Shares sold at the market, shares			11,753,000
Issuance of shares for services	19			19
Issuance of shares for services, shares			10,000
Vesting of nonvested shares, shares			67,000
Exercise of stock options and employee share purchases	463		$ 3	460
Exercise of stock options and employee share purchases, shares			259,000
Stockholders' Equity, Ending Balance at Sep. 30, 2022	(11,836)		$ 2,949	1,614,836			644	8,549		(1,638,814)
Temporary Equity, Ending Balance at Sep. 30, 2022											$ 0
Balance, shares at Sep. 30, 2022			294,951,000
Temporary Equity, shares at Sep. 30, 2022											32,000
Stockholders' Equity, Beginning Balance at Dec. 31, 2022	(54,902)		$ 3,056	1,644,658			915	6,376		(1,709,907)
Balance, shares at Dec. 31, 2022			305,574,000
Temporary Equity, Beginning Balance at Dec. 31, 2022											$ 0
Temporary Equity, shares at Dec. 31, 2022											32,000
Net loss	(70,893)							(2,639)		(68,254)
Other comprehensive income (loss)	2						2
Share-based compensation	5,485			4,566				919
Shares sold at the market	60,583		$ 338	60,245
Shares sold at the market, shares			33,785,000
Issuance of director deferred shares	983		$ 3	980
Issuance of director deferred shares, shares			250,000
Issuance of shares for services	318		$ 1	317
Issuance of shares for services, shares			132,000
Issuance of subsidiary shares to noncontrolling interest	726							726
Vesting of nonvested shares, shares			5,000
Exercise of stock options and employee share purchases	374		$ 2	327				45
Exercise of stock options and employee share purchases, shares			197,000
Issuance of shares for employee bonus	1,796		$ 27	4,198		$ (2,429)
Issuance of shares for employee bonus, Shares			2,716,000			(10,000)
Retirement of treasury shares	2,419		$ (10)			$ 2,429
Retirement of treasury shares, share			(996,000)			10,000
Stockholders' Equity, Ending Balance at Mar. 31, 2023	(53,109)		$ 3,417	1,715,291			917	5,427		(1,778,161)
Temporary Equity, Ending Balance at Mar. 31, 2023											$ 0
Balance, shares at Mar. 31, 2023			341,663,000
Temporary Equity, shares at Mar. 31, 2023											32,000
Stockholders' Equity, Beginning Balance at Dec. 31, 2022	(54,902)		$ 3,056	1,644,658			915	6,376		(1,709,907)
Balance, shares at Dec. 31, 2022			305,574,000
Temporary Equity, Beginning Balance at Dec. 31, 2022											$ 0
Temporary Equity, shares at Dec. 31, 2022											32,000
Net loss	(208,855)
Other comprehensive income (loss)	$ (1,943)
Share-based compensation								2,742
Exercise of stock options, shares	46,750
Stockholders' Equity, Ending Balance at Sep. 30, 2023	$ (115,292)		$ 3,814	1,777,480			(1,028)	13,820		(1,909,378)
Temporary Equity, Ending Balance at Sep. 30, 2023											$ 0
Balance, shares at Sep. 30, 2023			381,383,000
Temporary Equity, shares at Sep. 30, 2023											32,000
Stockholders' Equity, Beginning Balance at Mar. 31, 2023	(53,109)		$ 3,417	1,715,291			917	5,427		(1,778,161)
Balance, shares at Mar. 31, 2023			341,663,000
Temporary Equity, Beginning Balance at Mar. 31, 2023											$ 0
Temporary Equity, shares at Mar. 31, 2023											32,000
Net loss	(73,430)							(4,414)		(69,016)
Other comprehensive income (loss)	(1,634)						(1,634)
Share-based compensation	6,042			5,154				888
Shares sold at the market	42,247		$ 246	42,001
Shares sold at the market, shares			24,557,000
Issuance of subsidiary shares to noncontrolling interest	285							285
Vesting of nonvested shares, shares			17,000
MiNK stock dividend					$ (14,888)				$ 14,888
MiNK stock purchases		$ (235)			405				(640)
Issuance of shares for employee bonus	1,438		$ 19	3,061		$ (1,642)
Issuance of shares for employee bonus, Shares			1,928,000			(7,000)
Retirement of treasury shares	1,635		$ (7)			$ 1,642
Retirement of treasury shares, share			(673,000)			7,000
Stockholders' Equity, Ending Balance at Jun. 30, 2023	(76,761)		$ 3,675	1,751,024			(717)	16,434		(1,847,177)
Temporary Equity, Ending Balance at Jun. 30, 2023											$ 0
Balance, shares at Jun. 30, 2023			367,492,000
Temporary Equity, shares at Jun. 30, 2023											32,000
Net loss	(64,532)							(2,331)		(62,201)
Other comprehensive income (loss)	(311)						(311)
Share-based compensation	5,536			4,601				935
Shares sold at the market	20,350		$ 133	20,217
Shares sold at the market, shares			13,304,000
Payment of CEO payroll in shares	32			32
Payment of CEO payroll In shares, shares			27,000
Issuance of shares for services	312		$ 2	310
Issuance of shares for services, shares			198,000
Vesting of nonvested shares			$ 1	(1)
Vesting of nonvested shares, shares			63,000
Employee share purchases	410		$ 3	404				3
Employee share purchases, shares			299,000
MiNK stock purchases		$ (328)			$ 893				$ (1,221)
Stockholders' Equity, Ending Balance at Sep. 30, 2023	$ (115,292)		$ 3,814	$ 1,777,480			$ (1,028)	$ 13,820		$ (1,909,378)
Temporary Equity, Ending Balance at Sep. 30, 2023											$ 0
Balance, shares at Sep. 30, 2023			381,383,000
Temporary Equity, shares at Sep. 30, 2023											32,000

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (208,855)	$ (156,554)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	8,387	5,057
Share-based compensation	17,408	14,078
Non-cash royalty revenue	(61,534)	(27,001)
Non-cash interest expense	55,977	44,629
Loss (gain) on sale of assets	49	(6,601)
Gain on partial forgiveness of liability		(2,791)
Change in fair value of contingent obligations	(398)	(950)
Other, net	581
Changes in operating assets and liabilities:
Accounts receivable	1,308	(7,079)
Prepaid expenses	(1,765)	3,659
Accounts payable	915	1,339
Deferred revenue	(7,269)	(7,855)
Accrued liabilities and other current liabilities	12,518	(2,524)
Other operating assets and liabilities	(1,122)	14,558
Net cash used in operating activities	(183,800)	(128,035)
Cash flows from investing activities:
Purchases of plant and equipment	(9,731)	(38,716)
Proceeds from sale of property, plant and equipment	350	10,002
Purchase of long-term investment	(5,396)
Cash paid for business acquisition		(3,652)
Purchases of available-for-sale securities	(14,647)	(14,861)
Proceeds from sale of available-for-sale securities	30,000	20,000
Net cash provided by (used in) investing activities	576	(27,227)
Cash flows from financing activities:
Net proceeds from sale of equity	123,179	75,249
Proceeds from employee stock purchases and option exercises	807	845
Purchase of treasury shares to satisfy tax withholdings	(4,566)	(3,789)
Purchase of subsidiary shares	(564)
Payment of finance lease obligation	(6,305)	(248)
Net cash provided by financing activities	112,551	72,057
Effect of exchange rate changes on cash	(696)	(372)
Net decrease in cash, cash equivalents and restricted cash	(71,369)	(83,577)
Cash, cash equivalents and restricted cash, beginning of period	181,343	294,600
Cash, cash equivalents and restricted cash, end of period	109,974	211,023
Supplemental cash flow information:
Cash paid for interest	2,532	847
Supplemental disclosures - non-cash activities:
Purchases of plant and equipment in accounts payable and accrued liabilities		8,546
Insurance financing agreement	707	933
Issuance of subsidiary shares for employee bonus	1,011	294
Lease right-of-use assets obtained in exchange for new operating lease liabilities	318	9,148
Lease right-of-use assets obtained in exchange for new finance lease liabilities	4,812	648
Payment for Services [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock	630	120
Employee Bonus [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock	$ 7,288	6,634
Milestone Achievement [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		$ 500

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical)	Sep. 30, 2023 $ / shares
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01
Payment for Services [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	0.01
Employee Bonus [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	0.01
Milestone Achievement [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01

Insider Trading Arrangements

Insider Trading Arrangements	9 Months Ended
	Sep. 30, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Business, Liquidity and Basis o

Business, Liquidity and Basis of Presentation	9 Months Ended
	Sep. 30, 2023
Description Of Business [Abstract]
Business, Liquidity and Basis of Presentation	Note A - Business, Liquidity and Basis of Presentation Agenus Inc. (including its subsidiaries, collectively referred to as “Agenus,” the “Company,” “we,” “us,” and “our”) is a leading clinical-stage biotechnology company developing therapies targeting cancer with a robust pipeline of immunological agents. Our mission is to expand patient populations benefiting from cancer immunotherapy through combination approaches, using a broad repertoire of antibody therapeutics, adoptive cell therapies (through our subsidiary MiNK Therapeutics, Inc. (“MiNK”)), and vaccine adjuvants (through our subsidiary SaponiQx, Inc. (“SaponiQx”)). We believe that combination therapies and a deep understanding of each patient’s cancer will significantly expand the patient population benefiting from immuno-oncology (“I-O”) treatments. In addition to our diverse pipeline, we have established fully integrated capabilities encompassing novel target discovery, antibody generation, cell line development, and good manufacturing practice (GMP) manufacturing. We believe these integrated capabilities enable us to develop and, if approved, commercialize novel candidates on accelerated timelines compared to industry standards. Through independent development and strategic partnerships, we leverage our scientific expertise and capabilities to drive innovation in the I-O field. Our I-O portfolio is driven by several platforms and programs, which we plan to utilize individually and in combination: • Multiple antibody discovery platforms, including proprietary display technologies, to identify future antibody candidates. • Antibody candidate programs, including our lead asset, botensilimab, an Fc-enhanced CTLA-4 antibody. At a corporate update at the European Society for Medical Oncology in October 2023, we presented updated data based on a total of 70 efficacy evaluable refractory microsatellite stable metastatic colorectal cancer patients with no active liver metastases from the Phase 1 study. These patients received the combination of botensilimab (either 1 or 2 mg/kg every 6 weeks) and balstilimab (3 mg/kg every 2 weeks). The results showed a survival and efficacy benefit compared to what has been reported for standard of care in a comparable patient population. The 12-month overall survival (“OS”) was 74 % with a median OS not yet reached, after a median follow up of 12.3 months, compared to a median OS of 12.9 months reported for standard of care. The confirmed overall response rate based on RECIST 1.1 was 24 % compared to 2.8 % reported with standard of care. • Our saponin-based vaccine adjuvant platform, primarily centered around our STIMULON cultured plant cell (“cpc”) QS-21 adjuvant (“STIMULON cpc QS-21”). • A pipeline of novel allogeneic invariant natural killer T cell therapies for treating cancer and other immune-mediated diseases, controlled by MiNK. Our business activities encompass various areas such as product research, preclinical and clinical development, intellectual property prosecution, manufacturing, regulatory and clinical affairs, corporate finance and development activities, and support of collaborations. Our strategy includes developing and commercializing product candidates through existing and new collaborations. Our cash, cash equivalents and short-term investments at September 30, 2023 were $ 106.3 million, a decrease of $ 87.1 million from December 31, 2022 . Cash and cash equivalents of our subsidiary, MiNK, at June 30, 2023, were $ 10.6 million. MiNK cash can only be accessed by Agenus through a declaration of a dividend by the MiNK Board of Directors or through settlement of intercompany balances. We have incurred losses since our inception. As of September 30, 2023, we had an accumulated deficit of $ 1.9 billion. We have financed our operations through income and revenues generated from corporate partnerships, advance royalty sales and proceeds from equity issuances. Based on our current plans and projections, we believe that our cash resources of $ 106.3 million at September 30, 2023, plus additional funding we anticipate from the achievement of a milestone under an existing partnership, will be sufficient to satisfy our liquidity requirements for at least one year from when these financial statements were issued. This milestone will be triggered upon dosing the first patient in a clinical trial which is currently screening patients and is expected to occur by end of 2023. However, until this event occurs, in accordance with the relevant 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 Quarterly Report on Form 10-Q. In addition to the expected milestone payment by end of 2023, we are in active discussions to sell two non-strategic assets expected to close in the first half of 2024 with an estimated aggregate value of approximately $ 65.0 million. These transactions could extend our cash resources well beyond 2024 . We are also in advanced discussions for a potential structured financing for botensilimab/balstilimab, as well as a potential corporate collaboration with a large pharma or biotech company. None of these sources of cash involve equity or debt issuance. Management continues to address the Company’s liquidity position and has the flexibility to adjust spending as needed in order to preserve liquidity. In August 2023, we prioritized and focused our resources to accelerate the development, registration, and commercialization of our lead asset postponing all preclinical and other clinical programs and reducing our workforce by approximately 25 %. Our CEO, Dr. Garo Armen has elected to receive his base salary and any potential bonus payments in stock rather than cash. 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 sources of funding to include payments from current collaborations which include milestones and royalty payments from companies, including Bristol-Myers Squibb Company, UroGen Pharma Ltd., Gilead Sciences, Inc., Incyte Corporation, and Merck Sharpe & Dohme; out-licensing and/or partnering opportunities for our portfolio programs and product candidates with multiple parties; additional third-party agreements; asset sales; royalty monetization; project financing, and/or sales of equity securities . The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete annual consolidated financial statements. In the opinion of our management, the condensed consolidated financial statements include all normal and recurring adjustments considered necessary for a fair presentation of our financial position and operating results. All significant intercompany transactions and accounts have been eliminated in consolidation. Operating results for the nine months ended September 30, 2023, are not necessarily indicative of the results that may be expected for the year ending December 31, 2023. For further information, refer to our consolidated financial statements and footnotes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission (“SEC”). The preparation of consolidated financial statements in conformity with U.S. GAAP requires management 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual results could differ materially from those estimates. For our foreign subsidiaries, the local currency is the functional currency. Assets and liabilities of our foreign subsidiaries are translated into U.S. dollars using rates in effect at the balance sheet date while revenues and expenses are translated into U.S. dollars using average exchange rates during the period. The cumulative translation adjustment resulting from changes in exchange rates are included in the consolidated balance sheets as a component of accumulated other comprehensive income in total stockholders’ equity (deficit). In 2023, we deconsolidated certain foreign subsidiaries and recognized a gain of $ 132,000 , included in "Other income (expense)" on our condensed consolidated statements of operations and comprehensive loss.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	Note B - Net Loss Per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding (including common shares issuable under our Amended and Restated Directors’ Deferred Compensation Plan, or “DDCP”). Diluted loss per common share is calculated by dividing loss attributable to common stockholders by the weighted average number of common shares outstanding (including common shares issuable under our DDCP) plus the dilutive effect of outstanding instruments such as warrants, stock options, non-vested shares and convertible preferred stock. 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. The following securities (listed on an as-if-converted-to-Common-Stock basis) have been excluded from the computation of diluted weighted average shares outstanding as of September 30, 2023 and 2022, as they would be anti-dilutive (in thousands): Three and Nine Months Ended September 30, 2023 2022 Warrants 1,980 1,980 Stock options 44,034 36,207 Non-vested shares 697 403 Series A-1 convertible preferred stock 333 333

Investments

Investments	9 Months Ended
	Sep. 30, 2023
Cash and Cash Equivalents [Abstract]
Investments	Note C - Investments Cash equivalents and short-term investments consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 December 31, 2022 Cost Estimated Cost Estimated Institutional money market funds $ 71,605 $ 71,605 $ 149,856 $ 149,856 U.S. Treasury Bills 24,877 24,877 29,522 29,522 Total $ 96,482 $ 96,482 $ 179,378 $ 179,378 As a result of the short-term nature of these investments, there were minimal unrealized holding gains or losses for the three and nine months ended September 30, 2023 and 2022. Of the investments listed above, all were classified as cash equivalents on our condensed consolidated balance sheets as of September 30, 2023. As of December 31, 2022, $ 164.7 million were classified as cash equivalents and $ 14.7 million as short-term investments on our condensed consolidated balance sheets.

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	9 Months Ended
	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	Note D - Goodwill and Acquired Intangible Assets The following table sets forth the changes in the carrying amount of goodwill for the nine months ended September 30, 2023 (in thousands): Balance, December 31, 2022 $ 25,467 Disposals ( 805 ) Foreign currency translation adjustment 4 Balance, September 30, 2023 $ 24,666 Acquired intangible assets consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): As of September 30, 2023 Amortization Gross carrying Accumulated Net carrying Intellectual property 7 - 15 years $ 16,841 $ ( 15,099 ) $ 1,742 Trademarks 4 - 4.5 years 1,182 ( 1,139 ) 43 Other 2 - 7 years 1,860 ( 1,206 ) 654 In-process research and development Indefinite 2,058 — 2,058 Total $ 21,941 $ ( 17,444 ) $ 4,497 As of December 31, 2022 Amortization Gross carrying Accumulated Net carrying Intellectual property 7 - 15 years $ 16,790 $ ( 13,782 ) $ 3,008 Trademarks 4 - 4.5 years 1,272 ( 1,139 ) 133 Other 2 - 6 years 2,278 ( 1,227 ) 1,051 In-process research and development Indefinite 2,036 — 2,036 Total $ 22,376 $ ( 16,148 ) $ 6,228 The weighted average amortization period of our finite-lived intangible assets is 9 years. Amortization expense related to acquired intangibles is estimated at $ 0.1 million for the remainder of 2023, $ 0.5 million for the years ending December 31, 2024, 2025 and 2026 and $ 0.4 million for the year ending December 31, 2027.

Debt

Debt	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Debt	Note E - Debt Debt obligations consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): Debt instrument Balance at Current Portion: Debentures $ 146 Other 241 Long-term Portion: 2015 Subordinated Notes 12,720 Total $ 13,107 Debt instrument Balance at Current Portion: Debentures $ 146 Other 429 Long-term Portion: 2015 Subordinated Notes 12,584 Total $ 13,159 As of September 30, 2023 and December 31, 2022, the principal amount of our outstanding debt balance was $ 13.4 million and $ 13.6 million, respectively.

Liability Related to the Sale o

Liability Related to the Sale of Future Royalties and Milestones	9 Months Ended
	Sep. 30, 2023
Liability Related To Sale Of Future Royalties And Milestones [Abstract]
Liability Related to the Sale of Future Royalties and Milestones	Note F – Liability Related to the Sale of Future Royalties and Milestones The following table shows the activity within the liability account in the nine months ended September 30, 2023 (in thousands): Period from Liability related to sale of future royalties and milestones - beginning balance $ 271,560 Non-cash royalty revenue ( 61,534 ) Non-cash interest expense recognized 55,797 Liability related to sale of future royalties and milestones - ending balance 265,823 Less: unamortized transaction costs ( 253 ) Liability related to sale of future royalties and milestones, net $ 265,570 Healthcare Royalty Partners In January 2018, we, through our wholly-owned subsidiary Antigenics, LLC (“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”). Pursuant to the terms of the HCR Royalty Purchase Agreement, we sold to HCR 100 % of Antigenics’ worldwide rights to receive royalties from GlaxoSmithKline (“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. Although we sold all of our rights to receive royalties on sales of GSK’s vaccines containing QS-21, as a result of our obligation to HCR, we are required to account for the $ 190.0 million in proceeds from this transaction as a liability on our condensed consolidated balance sheet that will be recognized into revenue in proportion to the royalty payments from GSK to HCR 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 condensed consolidated balance sheets based on the estimated royalty payments to be received by HCR in the next 12 months from the financial statement reporting date. During the nine months ended September 30, 2023 , we recognized $ 61.5 million of non-cash royalty revenue, and we recorded $ 55.8 million 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, and the related recognition of interest expense. During the nine months ended September 30, 2023 , our estimate of the effective annual interest rate over the life of the agreement increased to 29.4 %, which results in a life of contract interest rate of 23.4 %.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	9 Months Ended
	Sep. 30, 2023
Other Liabilities Disclosure [Abstract]
Accrued and Other Current Liabilities	Note G - Accrued and Other Current Liabilities Accrued liabilities consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 December 31, 2022 Payroll $ 10,853 $ 15,872 Professional fees 6,250 6,946 Contract manufacturing costs 3,822 1,848 Research services 11,387 7,074 Other 5,317 6,519 Total $ 37,629 $ 38,259 Other current liabilities consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 December 31, 2022 Finance lease liabilities $ 10,190 $ 7,952 Other 3,226 3,505 Total $ 13,416 $ 11,457

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Measurements [Abstract]
Fair Value Measurements	Note H - Fair Value Measurements Assets and liabilities measured at fair value are summarized below (in thousands): Description September 30, 2023 Quoted Prices in Significant Significant Assets: Cash equivalents (Note C) $ 96,482 $ 96,482 $ — $ — Long-term investments 4,682 4,682 — — Total $ 101,164 $ 101,164 $ — $ — Liabilities: Contingent purchase price considerations $ 476 $ — $ — $ 476 Total $ 476 $ — $ — $ 476 Description December 31, 2022 Quoted Prices in Significant Significant Assets: Cash equivalents (Note C) $ 164,694 $ — $ — $ — Short-term investments (Note C) 14,689 — — — Total $ 179,383 $ — $ — $ — Liabilities: Contingent purchase price consideration $ 874 $ — $ — $ 874 Total $ 874 $ — $ — $ 874 Long-term investments are included in "Other long-term assets" in our condensed consolidated balance sheets. We measure our contingent purchase price considerations at fair value. The fair values of our contingent purchase price considerations at September 30, 2023 and December 31, 2022, of $ 0.5 million and $ 0.9 million, respectively, included in "Other long-term liabilities" in our condensed consolidated balance sheets, 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 share price, as well as other factors impacting the probability of triggering the milestone payments. Share price was evolved using a geometric Brownian motion, calculated daily for the life of the contingent purchase price considerations. The fair value of our outstanding debt balance at September 30, 2023 and December 31, 2022 was $ 13.1 million and $ 13.2 million, respectively, based on the Level 2 valuation hierarchy of the fair value measurements standard using a present value methodology that 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 September 30, 2023 and December 31, 2022 was $ 13.4 million and $ 13.6 million, respectively.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2023
Collaboration [Abstract]
Revenue from Contracts with Customers	Note I - Revenue from Contracts with Customers Gilead Collaboration Agreement On December 20, 2018, we entered into a series of agreements with Gilead Sciences, Inc. (“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 (collectively, the “Gilead Collaboration Agreements”), at the closing of the transaction on January 23, 2019, we received an upfront cash payment from Gilead of $ 120.0 million and Gilead made a $ 30.0 million equity investment in Agenus. On November 6, 2020, we received notice from Gilead that it was returning AGEN1423 to us and voluntarily terminating the applicable license agreement. The termination was effective as of February 4, 2021. In the third quarter of 2021 we ceased development of AGEN1223 and in October 2021 the AGEN1223 option and license agreement was formally terminated. The AGEN2373 option and license agreement and the stock purchase agreement remain in full force and effect. We remain eligible to receive a $ 50.0 million exercise fee and, if exercised, up to $ 520.0 million in aggregate potential milestones. Collaboration Revenue For the three months ended September 30, 2023 and 2022, we recognized approximately $ 2.9 million and $ 4.5 million, respectively, of research and development revenue based on the partial satisfaction of the over time performance obligations as of quarter end. For the nine months ended September 30, 2023, we recognized approximately $ 7.2 million of research and development revenue based on the partial satisfaction of the over time performance obligations as of period end. For the nine months ended September 30, 2022, we recognized research and development revenue of $ 5.0 million related to the achievement of a milestone and $ 7.1 million 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 $ 5.0 million for the remainder of 2023 related to performance obligations that are unsatisfied or partially unsatisfied as of September 30, 2023. Disaggregation of Revenue The following table presents revenue (in thousands) for the three and nine months ended September 30, 2023 and 2022, disaggregated by geographic region and revenue type. Revenue by geographic region is allocated based on the domicile of our respective business operations. Three months ended September 30, 2023 United States Rest of World Total Revenue Type Research and development services $ 447 $ — $ 447 Other services — 540 540 Clinical product revenue 116 — 116 Recognition of deferred revenue 2,851 — 2,851 Non-cash royalties 20,360 — 20,360 $ 23,774 $ 540 $ 24,314 Three months ended September 30, 2022 Revenue Type Royalty sales milestone $ 7,934 $ — $ 7,934 Research and development services 121 — 121 Other services — 1,041 1,041 Recognition of deferred revenue 4,452 — 4,452 Non-cash royalties 9,224 — 9,224 $ 21,731 $ 1,041 $ 22,772 Nine months ended September 30, 2023 United States Rest of World Total Revenue Type Research and development services $ 1,158 $ — $ 1,158 Other services — 2,464 2,464 Clinical product revenue 116 — 116 Recognition of deferred revenue 7,241 — 7,241 Non-cash royalties 61,534 — 61,534 $ 70,049 $ 2,464 $ 72,513 Nine months ended September 30, 2022 Revenue Type License fees and milestones $ 5,000 $ — $ 5,000 Royalty sales milestone 25,250 — 25,250 Research and development services 1,154 — 1,154 Other services — 4,167 4,167 Recognition of deferred revenue 7,066 — 7,066 Non-cash royalties 27,001 — 27,001 $ 65,471 $ 4,167 $ 69,638 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. 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 liabilities from contracts with customers (in thousands): Nine months ended September 30, 2023 Balance at beginning of period Additions Deductions Balance at end of period Contract liabilities: Deferred revenue $ 13,412 $ 22 $ ( 7,297 ) $ 6,137 The change in contract liabilities is primarily related to the recognition of $ 7.2 million of revenue related to the Gilead Collaboration Agreements during the nine months ended September 30, 2023 . Deferred revenue related to the Gilead Collaboration Agreements of $ 5.0 million as of September 30, 2023 , which was comprised of the $ 142.5 million initial transaction price, less $ 137.5 million of license and collaboration revenue recognized from the effective date of the contract, will be recognized as the combined performance obligation is satisfied. We also recorded a $ 1.0 million receivable as of September 30, 2023, for research and development and other services provided. During the nine months ended September 30, 2023 , 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. No ne of the costs to obtain or fulfill a contract were capitalized.

Share-Based Compensation Plans

Share-Based Compensation Plans	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Share-Based Compensation Plans	Note J - Share-based Compensation Plans We primarily use the Black-Scholes option pricing model to value stock options granted to employees and non-employees, including stock options granted to members of our Board of Directors. However, the fair value of stock option market-based awards is calculated based on a Monte Carlo simulation as of the date of issuance. All stock options have 10-year terms and generally vest ratably over a 3 or 4 -year period. A summary of option activity for the nine months ended September 30, 2023 is presented below: Options Weighted Weighted Aggregate Outstanding at December 31, 2022 35,984,967 $ 3.51 Granted 10,440,674 2.26 Exercised ( 46,750 ) 1.68 Forfeited ( 1,438,712 ) 2.50 Expired ( 906,590 ) 3.50 Outstanding at September 30, 2023 44,033,589 $ 3.25 6.76 $ — Vested or expected to vest at September 30, 2023 44,033,589 $ 3.25 6.76 $ — Exercisable at September 30, 2023 27,981,624 $ 3.59 5.84 $ — The weighted average grant-date fair values of stock options granted during the nine months ended September 30, 2023 and 2022 were $ 1.44 and $ 1.77 , respectively. As of September 30, 2023 , there was approximately $ 27.3 million of total unrecognized share-based compensation expense related to these stock options and stock options granted under subsidiary plans which, if all milestones are achieved, will be recognized over a weighted average period of 1.9 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 the nine months ended September 30, 2023 is presented below: Non-vested Weighted Outstanding at December 31, 2022 355,802 $ 2.50 Granted 5,304,201 2.35 Vested ( 4,728,222 ) 2.45 Forfeited ( 235,000 ) 2.11 Outstanding at September 30, 2023 696,781 $ 1.85 As of September 30, 2023 , there was approximately $ 1.1 million of unrecognized share-based compensation expense related to these non-vested shares and non-vested shares granted under subsidiary plans which will be recognized over a period of 2.3 years. During the nine months ended September 30, 2023 , 449,391 shares were issued under the 2019 Employee Stock Purchase Plan, 46,750 shares were issued as a result of stock option exercises and 84,414 shares were issued as a result of the vesting of non-vested stock. Additionally, 4,643,808 shares were issued as payment for certain employee bonuses, with 1,668,767 of those shares being withheld to cover taxes, resulting in a net share issuance of 2,975,041 . The impact on our results of operations from share-based compensation for the three and nine months ended September 30, 2023 and 2022, was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 1,464 $ 1,200 $ 4,853 $ 3,731 General and administrative 4,072 3,234 12,210 10,265 Total share-based compensation expense $ 5,536 $ 4,434 $ 17,063 $ 13,996

Restricted Cash

Restricted Cash	9 Months Ended
	Sep. 30, 2023
Cash and Cash Equivalents [Abstract]
Restricted Cash	Note K – Restricted Cash As of September 30, 2023, and December 31, 2022 , we maintained non-current restricted cash of $ 3.7 million and $ 2.7 million, respectively. This amount is included within “Other long-term assets” in our condensed consolidated balance sheets and is comprised of letters of credit required under our facility leases. The following table provides a reconciliation of cash, cash equivalents and restricted cash that sums to the total of the same such amounts shown in the condensed consolidated statements of cash flows (in thousands): Nine Months Ended September 30, 2023 Nine Months Ended September 30, 2022 Beginning of Period End of Period Beginning of Period End of Period Cash and cash equivalents $ 178,674 $ 106,305 $ 291,931 $ 208,354 Restricted cash 2,669 3,669 2,669 2,669 Cash, cash equivalents and restricted cash $ 181,343 $ 109,974 $ 294,600 $ 211,023

Equity

Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Equity	Note L – Equity On June 23, 2023, we filed an Automatic Shelf Registration Statement on Form S-3ASR (file no. 333-272911) (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 supplement for the potential offer and sale of up to 184,638,269 shares of common stock (the “Placement Shares”) in “at the market” offerings pursuant to an At Market Issuance Sales Agreement by and between Agenus and B. Riley Securities, Inc. (the “Sales Agent”), dated as of July 22, 2020 (the “Sales Agreement”). Sales pursuant to the Sales Agreement will be made only upon our instruction to the Sales Agent, and we cannot provide assurances that we will issue any additional Placement Shares pursuant to the Sales Agreement. During the three and nine months ended September 30, 2023 , we received net proceeds of approximately $ 20.4 million and $ 123.2 million from the sale of approximately 13.3 million and 71.6 million shares of our common stock, respectively, in at-the-market offerings under the Sales Agreement.

Non-controlling Interest

Non-controlling Interest	9 Months Ended
	Sep. 30, 2023
Noncontrolling Interest [Abstract]
Non-controlling Interest	Note M – Non-controlling Interest Non-controlling interest recorded in our condensed consolidated financial statements as of September 30, 2023 and December 31, 2022, relates to the following approximate interests in certain consolidated subsidiaries, which we do not own. September 30, 2023 December 31, 2022 MiNK Therapeutics, Inc. 37 % 22 % SaponiQx, Inc. 30 % 30 % Changes in non-controlling interest for the periods ended September 30, 2023 and December 31, 2022, were as follows (in thousands): September 30, 2023 December 31, 2022 Beginning balance $ 6,376 $ 13,469 Net loss attributable to non-controlling interest ( 9,384 ) ( 10,582 ) Other items: Distribution of subsidiary shares to Agenus stockholders 14,888 — Purchase of subsidiary shares ( 1,861 ) — Issuance of subsidiary shares for employee bonus 1,011 294 Issuance of subsidiary shares under employee stock purchase plan 48 — Subsidiary share-based compensation 2,742 3,195 Total other items 16,828 3,489 Ending balance $ 13,820 $ 6,376 Distribution of subsidiary shares to Agenus stockholders On March 29, 2023 , our Board of Directors declared a stock dividend (the "Dividend") consisting of an aggregate of 5.0 million shares (the "Dividend Stock") of common stock, par value $ 0.00001 per share, of MiNK held by Agenus to record holders of Agenus' common stock, par value $ 0.01 per share as of the close of business on April 17, 2023 (the "Record Date"). On May 1, 2023 , we paid the Dividend and distributed 0.0146 of a share of the Dividend Stock for each share of Agenus Common Stock outstanding as of the close of business on the Record Date. No fractional shares were issued in connection with the Dividend and the shareholders of Agenus who were entitled to receive fractional shares of the Dividend Stock received cash (without interest) in lieu of such fractional shares. Subsequent to the distribution of the Dividend Stock, we maintained a controlling voting interest in MiNK. Purchase of subsidiary shares During the nine months ended September 30, 2023, we purchased 408,518 shares of MiNK common stock in multiple open market transactions.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Note N – Related Party Transactions In 2023, our Audit and Finance Committee approved a contract between Avillion Life Sciences LTD ("Avillion") and Agenus for the performance of up to $ 450,000 of clinical consulting services. Allison Jeynes, a member of our Board of Directors, is chief executive officer of Avillion. For the nine months ended September 30, 2023, approximately $ 450,000 related to these services is included in “Research and development” expense in our condensed consolidated statements of operations. During the nine months ended September 30, 2023, our Audit and Finance Committee approved, and we performed research and development manufacturing services totaling $ 256,000 for Protagenic Therapeutics, Inc ("Protagenic"). We will be reimbursed for these services on an actual time and materials basis. Dr. Garo H. Armen, our CEO, is Executive Chairman of and has a greater than 10 % equity interest in Protagenic.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recent Accounting Pronouncements	Note O - Recent Accounting Pronouncements Recently Issued and Adopted In January 2017, the Financial Accounting Standards Board 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. We adopted the standard on January 1, 2023 . The adoption did no t have a material impact on our consolidated financial statements . No other new accounting pronouncement issued or effective during the nine months ended September 30, 2023 had or is expected to have a material impact on our consolidated financial statements or disclosures.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding	The following securities Three and Nine Months Ended September 30, 2023 2022 Warrants 1,980 1,980 Stock options 44,034 36,207 Non-vested shares 697 403 Series A-1 convertible preferred stock 333 333

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2023
Cash and Cash Equivalents [Abstract]
Schedule of Cash Equivalents	Cash equivalents and short-term investments consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 December 31, 2022 Cost Estimated Cost Estimated Institutional money market funds $ 71,605 $ 71,605 $ 149,856 $ 149,856 U.S. Treasury Bills 24,877 24,877 29,522 29,522 Total $ 96,482 $ 96,482 $ 179,378 $ 179,378

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2023
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 the nine months ended September 30, 2023 (in thousands): Balance, December 31, 2022 $ 25,467 Disposals ( 805 ) Foreign currency translation adjustment 4 Balance, September 30, 2023 $ 24,666
Schedule of Acquired Intangible Assets	Acquired intangible assets consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): As of September 30, 2023 Amortization Gross carrying Accumulated Net carrying Intellectual property 7 - 15 years $ 16,841 $ ( 15,099 ) $ 1,742 Trademarks 4 - 4.5 years 1,182 ( 1,139 ) 43 Other 2 - 7 years 1,860 ( 1,206 ) 654 In-process research and development Indefinite 2,058 — 2,058 Total $ 21,941 $ ( 17,444 ) $ 4,497 As of December 31, 2022 Amortization Gross carrying Accumulated Net carrying Intellectual property 7 - 15 years $ 16,790 $ ( 13,782 ) $ 3,008 Trademarks 4 - 4.5 years 1,272 ( 1,139 ) 133 Other 2 - 6 years 2,278 ( 1,227 ) 1,051 In-process research and development Indefinite 2,036 — 2,036 Total $ 22,376 $ ( 16,148 ) $ 6,228

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Schedule of Debt Obligations	Debt obligations consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): Debt instrument Balance at Current Portion: Debentures $ 146 Other 241 Long-term Portion: 2015 Subordinated Notes 12,720 Total $ 13,107 Debt instrument Balance at Current Portion: Debentures $ 146 Other 429 Long-term Portion: 2015 Subordinated Notes 12,584 Total $ 13,159

Liability Related to the Sale_2

Liability Related to the Sale of Future Royalties and Milestones (Tables)	9 Months Ended
	Sep. 30, 2023
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 nine months ended September 30, 2023 (in thousands): Period from Liability related to sale of future royalties and milestones - beginning balance $ 271,560 Non-cash royalty revenue ( 61,534 ) Non-cash interest expense recognized 55,797 Liability related to sale of future royalties and milestones - ending balance 265,823 Less: unamortized transaction costs ( 253 ) Liability related to sale of future royalties and milestones, net $ 265,570

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2023
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 December 31, 2022 Payroll $ 10,853 $ 15,872 Professional fees 6,250 6,946 Contract manufacturing costs 3,822 1,848 Research services 11,387 7,074 Other 5,317 6,519 Total $ 37,629 $ 38,259
Schedule of Other Current Liabilities	Other current liabilities consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 December 31, 2022 Finance lease liabilities $ 10,190 $ 7,952 Other 3,226 3,505 Total $ 13,416 $ 11,457

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities measured at Fair Value	Assets and liabilities measured at fair value are summarized below (in thousands): Description September 30, 2023 Quoted Prices in Significant Significant Assets: Cash equivalents (Note C) $ 96,482 $ 96,482 $ — $ — Long-term investments 4,682 4,682 — — Total $ 101,164 $ 101,164 $ — $ — Liabilities: Contingent purchase price considerations $ 476 $ — $ — $ 476 Total $ 476 $ — $ — $ 476 Description December 31, 2022 Quoted Prices in Significant Significant Assets: Cash equivalents (Note C) $ 164,694 $ — $ — $ — Short-term investments (Note C) 14,689 — — — Total $ 179,383 $ — $ — $ — Liabilities: Contingent purchase price consideration $ 874 $ — $ — $ 874 Total $ 874 $ — $ — $ 874 Long-term investments are included in "Other long-term assets" in our condensed consolidated balance sheets.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2023
Collaboration [Abstract]
Summary of Disaggregation of Revenue	The following table presents revenue (in thousands) for the three and nine months ended September 30, 2023 and 2022, disaggregated by geographic region and revenue type. Revenue by geographic region is allocated based on the domicile of our respective business operations. Three months ended September 30, 2023 United States Rest of World Total Revenue Type Research and development services $ 447 $ — $ 447 Other services — 540 540 Clinical product revenue 116 — 116 Recognition of deferred revenue 2,851 — 2,851 Non-cash royalties 20,360 — 20,360 $ 23,774 $ 540 $ 24,314 Three months ended September 30, 2022 Revenue Type Royalty sales milestone $ 7,934 $ — $ 7,934 Research and development services 121 — 121 Other services — 1,041 1,041 Recognition of deferred revenue 4,452 — 4,452 Non-cash royalties 9,224 — 9,224 $ 21,731 $ 1,041 $ 22,772 Nine months ended September 30, 2023 United States Rest of World Total Revenue Type Research and development services $ 1,158 $ — $ 1,158 Other services — 2,464 2,464 Clinical product revenue 116 — 116 Recognition of deferred revenue 7,241 — 7,241 Non-cash royalties 61,534 — 61,534 $ 70,049 $ 2,464 $ 72,513 Nine months ended September 30, 2022 Revenue Type License fees and milestones $ 5,000 $ — $ 5,000 Royalty sales milestone 25,250 — 25,250 Research and development services 1,154 — 1,154 Other services — 4,167 4,167 Recognition of deferred revenue 7,066 — 7,066 Non-cash royalties 27,001 — 27,001 $ 65,471 $ 4,167 $ 69,638
Schedule of Information about Contract Assets and Contract Liabilities from Contracts with Customers	The following table provides information about contract liabilities from contracts with customers (in thousands): Nine months ended September 30, 2023 Balance at beginning of period Additions Deductions Balance at end of period Contract liabilities: Deferred revenue $ 13,412 $ 22 $ ( 7,297 ) $ 6,137

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Schedule of Stock Option Activity	A summary of option activity for the nine months ended September 30, 2023 is presented below: Options Weighted Weighted Aggregate Outstanding at December 31, 2022 35,984,967 $ 3.51 Granted 10,440,674 2.26 Exercised ( 46,750 ) 1.68 Forfeited ( 1,438,712 ) 2.50 Expired ( 906,590 ) 3.50 Outstanding at September 30, 2023 44,033,589 $ 3.25 6.76 $ — Vested or expected to vest at September 30, 2023 44,033,589 $ 3.25 6.76 $ — Exercisable at September 30, 2023 27,981,624 $ 3.59 5.84 $ —
Summary of Non-vested Stock Activity	A summary of non-vested stock activity for the nine months ended September 30, 2023 is presented below: Non-vested Weighted Outstanding at December 31, 2022 355,802 $ 2.50 Granted 5,304,201 2.35 Vested ( 4,728,222 ) 2.45 Forfeited ( 235,000 ) 2.11 Outstanding at September 30, 2023 696,781 $ 1.85
Schedule of Share-Based Compensation Expense	The impact on our results of operations from share-based compensation for the three and nine months ended September 30, 2023 and 2022, was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 1,464 $ 1,200 $ 4,853 $ 3,731 General and administrative 4,072 3,234 12,210 10,265 Total share-based compensation expense $ 5,536 $ 4,434 $ 17,063 $ 13,996

Restricted Cash (Tables)

Restricted Cash (Tables)	9 Months Ended
	Sep. 30, 2023
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 sums to the total of the same such amounts shown in the condensed consolidated statements of cash flows (in thousands): Nine Months Ended September 30, 2023 Nine Months Ended September 30, 2022 Beginning of Period End of Period Beginning of Period End of Period Cash and cash equivalents $ 178,674 $ 106,305 $ 291,931 $ 208,354 Restricted cash 2,669 3,669 2,669 2,669 Cash, cash equivalents and restricted cash $ 181,343 $ 109,974 $ 294,600 $ 211,023

Non-controlling Interest (Table

Non-controlling Interest (Tables)	9 Months Ended
	Sep. 30, 2023
Noncontrolling Interest [Abstract]
Schedule Of Approximate Interests In Certain Consolidated Subsidiaries	Non-controlling interest recorded in our condensed consolidated financial statements as of September 30, 2023 and December 31, 2022, relates to the following approximate interests in certain consolidated subsidiaries, which we do not own. September 30, 2023 December 31, 2022 MiNK Therapeutics, Inc. 37 % 22 % SaponiQx, Inc. 30 % 30 %
Schedule Of Changes In Non-controlling Interest	Changes in non-controlling interest for the periods ended September 30, 2023 and December 31, 2022, were as follows (in thousands): September 30, 2023 December 31, 2022 Beginning balance $ 6,376 $ 13,469 Net loss attributable to non-controlling interest ( 9,384 ) ( 10,582 ) Other items: Distribution of subsidiary shares to Agenus stockholders 14,888 — Purchase of subsidiary shares ( 1,861 ) — Issuance of subsidiary shares for employee bonus 1,011 294 Issuance of subsidiary shares under employee stock purchase plan 48 — Subsidiary share-based compensation 2,742 3,195 Total other items 16,828 3,489 Ending balance $ 13,820 $ 6,376

Business, Liquidity and Basis_2

Business, Liquidity and Basis of Presentation (Narrative) (Details)		1 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Oct. 22, 2023 Refractory	Aug. 31, 2023	Jun. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Product Information [Line Items]
Cash, cash equivalents and short term investment				$ 106,300,000
Decrease cash, cash equivalents and short term investment					$ 87,100,000
Accumulated deficit				1,909,378,000	1,709,907,000
Cash and cash equivalents				$ 106,305,000	$ 178,674,000		$ 208,354,000	$ 291,931,000
Number Of Efficacy Evaluable Refractory | Refractory	70
Percentage of overall survival not yet reached	74%
Percentage of overall response rate based on RECIST 1.1	24%
Percentage of standard rate of care	2.80%
Sale of non-strategic assets, description				we are in active discussions to sell two non-strategic assets expected to close in the first half of 2024 with an estimated aggregate value of approximately $65.0 million. These transactions could extend our cash resources well beyond 2024
Percentage of reduced workforce		25%
Forecast
Product Information [Line Items]
Aggregated value for sale of non-strategic assets			$ 65,000,000
Other income (expense)
Product Information [Line Items]
Gain on deconsolidation of certain foreign subsidiaries				$ 132,000
MiNK Therapeutics, Inc.
Product Information [Line Items]
Cash and cash equivalents						$ 10,600,000

Net Loss Per Share (Schedule of

Net Loss Per Share (Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,980,000	1,980,000	1,980,000	1,980,000
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	44,034,000	36,207,000	44,034,000	36,207,000
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	697,000	403,000	697,000	403,000
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	333,000	333,000	333,000	333,000

Investments (Schedule of Cash E

Investments (Schedule of Cash Equivalents and Short Term Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	$ 106,300
Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	96,482	$ 179,378
Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	96,482	179,378
Institutional Money Market Funds [Member] | Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	71,605	149,856
Institutional Money Market Funds [Member] | Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	71,605	149,856
U.S. Treasury Bills [Member] | Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	24,877	29,522
U.S. Treasury Bills [Member] | Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	$ 24,877	$ 29,522

Investments Additional Informat

Investments Additional Informations (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Cash And Cash Equivalents [Line Items]
Cash equivalents	$ 164,700
Short-term investments	14,684
Short Term Investments [Member]
Cash And Cash Equivalents [Line Items]
Short-term investments	$ 14,700

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangible Assets (Schedule of Changes in Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 25,467
Disposals	(805)
Foreign currency translation adjustment	4
Ending balance	$ 24,666

Goodwill and Acquired Intangi_4

Goodwill and Acquired Intangible Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 21,941	$ 22,376
Accumulated amortization	(17,444)	(16,148)
Net carrying amount	4,497	6,228
Indefinite-lived Intangible Assets Acquired	2,058	2,036
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	16,841	16,790
Accumulated amortization	(15,099)	(13,782)
Net carrying amount	$ 1,742	$ 3,008
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]
Gross carrying amount	$ 1,182	$ 1,272
Accumulated amortization	(1,139)	(1,139)
Net carrying amount	$ 43	$ 133
Trademarks [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	4 years	4 years
Trademarks [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period (years)	4 years 6 months	4 years 6 months
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,860	$ 2,278
Accumulated amortization	(1,206)	(1,227)
Net carrying amount	$ 654	$ 1,051
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)	7 years	6 years

Goodwill and Acquired Intangi_5

Goodwill and Acquired Intangible Assets (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years
Finite-Lived Intangible Assets, Estimated Amortization Expense, Remainder of 2023	$ 0.1
Finite-Lived Intangible Assets, Estimated Amortization Expense, December 31, 2024	0.5
Finite-Lived Intangible Assets, Estimated Amortization Expense, December 31, 2025	0.5
Finite-Lived Intangible Assets, Estimated Amortization Expense, December 31, 2026	0.5
Finite-Lived Intangible Assets, Estimated Amortization Expense, December 31, 2027	$ 0.4

Debt - Schedule of Debt Obligat

Debt - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Other	$ 241	$ 429
Total	13,107	13,159
2015 Subordinated Notes [Member]
Debt Instrument [Line Items]
2015 Subordinated Notes	12,720	12,584
Debentures [Member]
Debt Instrument [Line Items]
Debentures	$ 146	$ 146

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Principal amount of outstanding debt	$ 13.4	$ 13.6

Liability Related to the Sale_3

Liability Related to the Sale of Future Royalties and Milestones (Schedule of Liability Account) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Liability Related To Sale Of Future Royalties And Milestones [Abstract]
Liability related to sale of future royalties and milestones - beginning balance	$ 271,560
Non-cash royalty revenue	(61,534)
Non-cash interest expense recognized	55,797
Liability related to sale of future royalties and milestones - ending balance	265,823
Less: unamortized transaction costs	(253)
Liability related to sale of future royalties and milestones, net	$ 265,570

Liability Related to the Sale_4

Liability Related to the Sale of Future Royalties and Milestones (Narrative) (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 19, 2018	Sep. 30, 2023
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Non-cash royalty revenue recognized		$ 61,534
Non-cash interest expense		55,797
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%
Gross proceeds received for royalty rights	$ 190,000
Non-cash royalty revenue recognized		61,500
Non-cash interest expense		$ 55,800
Effective annual interest rate		29.40%
Prospective effective annual interest rate		23.40%

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities (Schedule of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Payroll	$ 10,853	$ 15,872
Professional fees	6,250	6,946
Contract manufacturing costs	3,822	1,848
Research services	11,387	7,074
Other	5,317	6,519
Total	$ 37,629	$ 38,259

Accrued and Other Current Lia_4

Accrued and Other Current Liabilities (Schedule of Other Current Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Other Liabilities, Current [Abstract]
Finance lease liabilities	$ 10,190	$ 7,952
Other	3,226	3,505
Total	$ 13,416	$ 11,457

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price considerations	$ 476	$ 874
Long-term Debt, Gross	13,400	13,600
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price considerations	0	0
Debt Instrument, Fair Value Disclosure	$ 13,100	$ 13,200

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents	$ 96,482	$ 164,694
Short-term investments		14,689
Long-term investments	4,682
Total	101,164	179,383
Contingent purchase price considerations	476	874
Total	476	874
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents	96,482	0
Short-term investments		0
Long-term investments	4,682
Total	101,164	0
Contingent purchase price considerations	0	0
Total	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents	0	0
Short-term investments		0
Long-term investments	0
Total	0	0
Contingent purchase price considerations	0	0
Total	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents	0	0
Short-term investments		0
Long-term investments	0
Total	0	0
Contingent purchase price considerations	476	874
Total	$ 476	$ 874

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Narrative) (Details) - USD ($)		3 Months Ended						9 Months Ended
	Jan. 23, 2019	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 20, 2018
Revenue From Contract With Customer [Line Items]
Shares sold at the market		$ 20,350,000	$ 42,247,000	$ 60,583,000	$ 27,830,000	$ 28,237,000	$ 19,182,000
Revenue		24,314,000			22,772,000			$ 72,513,000	$ 69,638,000
Asset impairment charges								0
Contract with customer, liability, revenue recognized								7,297,000
Receivables for R & D services		1,000,000						1,000,000
Capitalized contract , cost		0						0
Research and Development Revenue [Member]
Revenue From Contract With Customer [Line Items]
Revenue		3,414,000			4,573,000			8,515,000	13,220,000
Gilead Collaboration Agreement [Member]
Revenue From Contract With Customer [Line Items]
Contract with customer, liability, revenue recognized								7,200,000
Contract with customer, net asset liability		5,000,000						5,000,000
Initial transaction price								142,500,000
Gilead Collaboration Agreement [Member] | License and Collaboration Revenue [Member]
Revenue From Contract With Customer [Line Items]
Revenue				$ 137,500,000
Gilead Sciences, Inc. [Member] | Collaborative Arrangement [Member]
Revenue From Contract With Customer [Line Items]
Fee received	$ 120,000,000
Shares sold at the market	30,000,000
Upfront license exercise fee	$ 50,000,000
Milestone Payments Receivable										$ 520,000,000
Transaction price recognized									7,100,000
Gilead Sciences, Inc. [Member] | Collaborative Arrangement [Member] | Research and Development Revenue [Member]
Revenue From Contract With Customer [Line Items]
Revenue		$ 2,900,000			$ 4,500,000			$ 7,200,000	$ 5,000,000

Revenue from Contracts with C_4

Revenue from Contracts with Customers (Narrative) (Details 1) - Gilead Sciences, Inc. [Member] $ in Millions	Sep. 30, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-10-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Expect to recognize deferred research and development revenue	$ 5
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation Of Revenue [Line Items]
Revenue	$ 24,314	$ 22,772	$ 72,513	$ 69,638
License Fee Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue				5,000
Royalty Sales Milestone [Member]
Disaggregation Of Revenue [Line Items]
Revenue		7,934		25,250
Clinical Product Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	116		116
Research and development services [Member]
Disaggregation Of Revenue [Line Items]
Revenue	447	121	1,158	1,154
Other services [Member]
Disaggregation Of Revenue [Line Items]
Revenue	540	1,041	2,464	4,167
Recognition of deferred revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	2,851	4,452	7,241	7,066
Non-cash royalty revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	20,360	9,224	61,534	27,001
Non-Cash Royalty Revenue Related to the Sale of Future Royalties [Member]
Disaggregation Of Revenue [Line Items]
Revenue	20,360	9,224	61,534	27,001
United States [Member]
Disaggregation Of Revenue [Line Items]
Revenue	23,774	21,731	70,049	65,471
United States [Member] | License Fee Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue				5,000
United States [Member] | Royalty Sales Milestone [Member]
Disaggregation Of Revenue [Line Items]
Revenue		7,934		25,250
United States [Member] | Clinical Product Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	116		116
United States [Member] | Research and development services [Member]
Disaggregation Of Revenue [Line Items]
Revenue	447	121	1,158	1,154
United States [Member] | Recognition of deferred revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	2,851	4,452	7,241	7,066
United States [Member] | Non-cash royalty revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	20,360	9,224	61,534	27,001
Rest of World [Member]
Disaggregation Of Revenue [Line Items]
Revenue	540	1,041	2,464	4,167
Rest of World [Member] | Other services [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 540	$ 1,041	$ 2,464	$ 4,167

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	9 Months Ended
	Sep. 30, 2023 USD ($)
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Deferred revenue, Beginning Balance	$ 13,412
Additions	22
Deferred revenue, Deductions	(7,297)
Deferred revenue, Ending Balance	$ 6,137

Share-Based Compensation Plan_2

Share-Based Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value of options granted	$ 1.44	$ 1.77
Shares issued from exercise of options	46,750
Shares issued from vesting of non vested stock	$ 2.45
Employee Stock Option
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense	$ 27.3
Unrecognized share-based compensation expense, weighted average period	1 year 10 months 24 days
Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense, Other than option	$ 1.1
Unrecognized share-based compensation expense, weighted average period	2 years 3 months 18 days
2009 EIP [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
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	3 years
2009 EIP [Member] | Maximum [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	4 years
2019 ESPP [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares issued under ESPP	449,391
Shares issued from exercise of options	46,750
Shares issued from vesting of non vested stock	$ 84,414
A2020 Employee Bonus
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Additional share issued for employee bonus	4,643,808
Share withheld to cover taxes	1,668,767
Share issued net	2,975,041

Share-Based Compensation Plan_3

Share-Based Compensation Plans (Schedule of Stock Option Activity) (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Options Outstanding, Beginning Balance | shares	35,984,967
Options Granted | shares	10,440,674
Options Exercised | shares	(46,750)
Options Forfeited | shares	(1,438,712)
Options Expired | shares	(906,590)
Options Outstanding, Ending Balance | shares	44,033,589
Options Vested or expected to vest | shares	44,033,589
Options Exercisable | shares	27,981,624
Options Outstanding, Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 3.51
Options Granted, Weighted Average Exercise Price | $ / shares	2.26
Options Exercised, Weighted Average Exercise Price | $ / shares	1.68
Options Forfeited, Weighted Average Exercise Price | $ / shares	2.5
Options Expired, Weighted Average Exercise Price | $ / shares	3.5
Options Outstanding, Weighted Average Exercise Price, Ending Balance | $ / shares	3.25
Options Vested or expected to vest, Weighted Average Exercise Price | $ / shares	3.25
Options Exercisable, Weighted Average Exercise Price | $ / shares	$ 3.59
Options Outstanding, Weighted Average Remaining Contractual Term	6 years 9 months 3 days
Options Vested or expected to vest, Weighted Average Remaining Contractual Term	6 years 9 months 3 days
Options Exercisable, Weighted Average Remaining Contractual Term	5 years 10 months 2 days

Share-Based Compensation Plan_4

Share-Based Compensation Plans (Summary of Non-vested Stock Activity) (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Non-vested Shares Outstanding, Beginning Balance | shares	355,802
Non-vested Shares Granted | shares	5,304,201
Non-vested Shares Vested | shares	(4,728,222)
Non-vested Shares Forfeited | shares	(235,000)
Non-vested Shares Outstanding, Ending Balance | shares	696,781
Non-vested Shares Outstanding, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 2.50
Non-vested Shares Granted, Weighted Average Grant Date Fair Value | $ / shares	2.35
Non-vested Shares Vested, Weighted Average Grant Date Fair Value | $ / shares	2.45
Non-vested Shares Forfeited, Weighted Average Grant Date Fair Value | $ / shares	2.11
Non-vested Shares Outstanding, Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 1.85

Share-Based Compensation Plan_5

Share-Based Compensation Plans (Schedule of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 5,536	$ 4,434	$ 17,063	$ 13,996
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	1,464	1,200	4,853	3,731
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 4,072	$ 3,234	$ 12,210	$ 10,265

Restricted Cash (Narrative) (De

Restricted Cash (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Non-current restricted cash	$ 3.7	$ 2.7

Restricted Cash (Schedule of Re

Restricted Cash (Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 106,305	$ 178,674	$ 208,354	$ 291,931
Restricted cash	3,669	2,669	2,669	2,669
Cash, cash equivalents and restricted cash	$ 109,974	$ 181,343	$ 211,023	$ 294,600

Equity (Narrative) (Details)

Equity (Narrative) (Details) - At Market Issuance Sales Agreement [Member] - B. Riley FBR, Inc. [Member] - New Sales Agreement [Member] $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023 USD ($) shares	Sep. 30, 2023 USD ($) shares
Class Of Stock [Line Items]
Shares sold at the market, shares	184,638,269	184,638,269
Net proceeds from issuance of common stock | $	$ 20.4	$ 123.2
Shares sold at the market, shares	13,300,000	71,600,000

Non-controlling Interest - Sche

Non-controlling Interest - Schedule Of Approximate Interests In Certain Consolidated Subsidiaries (Details)	Sep. 30, 2023	Dec. 31, 2022
MiNK Therapeutics, Inc.
Minority Interest [Line Items]
Percentage of Non-controlling interest	37%	22%
SaponiQx, Inc.
Minority Interest [Line Items]
Percentage of Non-controlling interest	30%	30%

Non-controlling Interest - Sc_2

Non-controlling Interest - Schedule Of Changes In Non-controlling Interest (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Minority Interest [Line Items]
Beginning balance			$ 6,376				$ 6,376
Less: net loss attributable to non-controlling interest	$ (2,331)			$ (2,493)			(9,384)	$ (7,573)
Issuance of subsidiary shares for employee bonus							1,011	294
Share-based compensation	5,536	$ 6,042	5,485	4,434	$ 4,615	$ 4,947
Ending balance	13,820						13,820		$ 6,376
Non-controlling Interest [Member]
Minority Interest [Line Items]
Beginning balance			6,376			13,469	6,376	$ 13,469	13,469
Less: net loss attributable to non-controlling interest							(9,384)		(10,582)
Distribution of subsidiary shares to Agenus stockholders							14,888
Purchase of subsidiary shares							(1,861)
Issuance of subsidiary shares for employee bonus							1,011		294
Issuance of subsidiary shares under employee stock purchase plan							48
Share-based compensation	935	$ 888	$ 919	$ 820	$ 797	$ 742	2,742		3,195
Total other items							16,828		3,489
Ending balance	$ 13,820						$ 13,820		$ 6,376

Non-controlling Interest - Addi

Non-controlling Interest - Additional Information (Details) - USD ($)			3 Months Ended			9 Months Ended
	May 01, 2023	Mar. 29, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Minority Interest [Line Items]
Issuance of subsidiary shares to noncontrolling interest			$ 285,000	$ 726,000	$ 294,000
Date of declared stock dividend		Mar. 29, 2023
Dividends common stock, shares		5,000,000
Common stock, par value		$ 0.01				$ 0.01	$ 0.01
Close of business, date of record		Apr. 17, 2023
Dividend Paid [Member]
Minority Interest [Line Items]
Dividends, date to be paid	May 01, 2023
Dividend distribution price per share	$ 0.0146
Number of fractional shares issued	0
MiNK Therapeutics, Inc.
Minority Interest [Line Items]
Common stock, par value		$ 0.00001
Purchase of common stock in multiple open market transactions						$ 408,518

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details)	9 Months Ended
	Sep. 30, 2023 USD ($)
Research and Development Manufacturing Services [Member]
Related Party Transaction [Line Items]
Total expenses	$ 450,000
Research and Development Manufacturing Services [Member] | Protagenic Therapeutics, Inc [Member]
Related Party Transaction [Line Items]
Total expenses	256,000
Clinical Research Services [Member]
Related Party Transaction [Line Items]
Total expenses	$ 450,000
Dr. Garo H. Armen [Member] | Protagenic Therapeutics, Inc [Member]
Related Party Transaction [Line Items]
Percentage of equity interest in related party entity by related party	10%

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2023
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
Accounting Standards Update [Extensible Enumeration]	us-gaap:AccountingStandardsUpdate201704Member