Form 10-Q - Quarterly report [Sections 13 or 15(d)]

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2024

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 000-29089

Agenus Inc.

(exact name of registrant as specified in its charter)

    Delaware

    06-1562417

    (State or other jurisdiction of
incorporation or organization)

    (I.R.S. Employer
Identification No.)

3 Forbes Road, Lexington, Massachusetts 02421

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code:

(781) 674-4400

Securities registered or to be registered pursuant to Section 12(b) of the Act.


Title of each class	Trading symbol(s)	Name of each exchange on which registered
Common stock, par value $0.01	AGEN	The Nasdaq Capital Market

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.


Large accelerated filer	☐	Accelerated filer	☒
Non-accelerated filer	☐	Smaller reporting company	☐
		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

Number of shares outstanding of the issuer’s Common Stock as of May 3, 2024: 20,999,261 shares.

Agenus Inc.

Three Months Ended March 31, 2024

Table of Contents


		Page
PART I
ITEM 1.	Financial Statements:	2
	Condensed Consolidated Balance Sheets as of March 31, 2024 (Unaudited) and December 31, 2023	2
	Condensed Consolidated Statements of Operations and Comprehensive Loss for the three months ended March 31, 2024 and 2023 (Unaudited)	3
	Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders’ Deficit for the three months ended March 31, 2024 and 2023 (Unaudited)	4
	Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2024 and 2023 (Unaudited)	6
	Notes to Unaudited Condensed Consolidated Financial Statements	7
ITEM 2.	Management's Discussion and Analysis of Financial Condition and Results of Operations	17
ITEM 3.	Quantitative and Qualitative Disclosures About Market Risk	22
ITEM 4.	Controls and Procedures	22

PART II
ITEM 1.	Legal Proceedings	24
ITEM 1A.	Risk Factors	24
ITEM 5.	Other Information	24
ITEM 6.	Exhibits	24
	Signatures	25

PART I - FINANCIAL INFORMATION

Item 1. Financial Statements

AGENUS INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

(Amounts in thousands, except share and per share amounts)


	March 31, 2024 (unaudited)			December 31, 2023
ASSETS
Cash and cash equivalents	$	52,856		$	76,110
Accounts receivable		476			25,836
Prepaid expenses		3,895			8,098
Other current assets		3,125			2,372
Total current assets		60,352			112,416
Property, plant and equipment, net of accumulated amortization and depreciation of $65,080 and $61,943 at March 31, 2024 and December 31, 2023, respectively		130,330			133,421
Operating lease right-of-use assets		29,340			29,606
Goodwill		24,698			24,723
Acquired intangible assets, net of accumulated amortization of $17,799 and $17,688 at March 31, 2024 and December 31, 2023, respectively		4,230			4,411
Other long-term assets		7,609			9,336
Total assets	$	256,559		$	313,913
LIABILITIES AND STOCKHOLDERS’ DEFICIT
Current portion, long-term debt	$	13,575		$	146
Current portion, liability related to sale of future royalties and milestones		133,588			132,502
Current portion, deferred revenue		13			18
Current portion, operating lease liabilities		2,811			2,587
Accounts payable		50,693			61,446
Accrued liabilities		41,291			45,283
Other current liabilities		14,031			13,915
Total current liabilities		256,002			255,897
Long-term debt, net of current portion		—			12,768
Liability related to sale of future royalties and milestones, net of current portion		125,249			124,556
Deferred revenue, net of current portion		1,143			1,143
Operating lease liabilities, net of current portion		61,756			62,511
Other long-term liabilities		2,732			5,420
Commitments and contingencies
STOCKHOLDERS’ DEFICIT
Series A-1 convertible preferred stock; 31,620 shares designated, issued, and outstanding at March 31, 2024 and December 31, 2023; liquidation value of $33,940 at March 31, 2024		0			0
Common stock, par value $0.01 per share; 800,000,000 shares authorized; 20,994,143 and 19,718,662 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively		210			197
Additional paid-in capital		1,816,985			1,796,095
Accumulated other comprehensive loss		(1,071	)		(955	)
Accumulated deficit		(2,017,554	)		(1,955,668	)
Total stockholders’ deficit attributable to Agenus Inc.		(201,430	)		(160,331	)
Non-controlling interest		11,107			11,949
Total stockholders’ deficit		(190,323	)		(148,382	)
Total liabilities and stockholders’ deficit	$	256,559		$	313,913

See accompanying notes to unaudited condensed consolidated financial statements.

AGENUS INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

(Unaudited)

(Amounts in thousands, except per share amounts)


	Three Months Ended March 31,
	2024			2023
Revenue:
Research and development	$	—		$	2,612
Service revenue		238			1,184
Non-cash royalty revenue related to the sale of future royalties		27,767			19,106
Total revenues		28,005			22,902
Operating expenses:
Cost of service revenue		(107	)		(2,294	)
Research and development		(43,925	)		(57,118	)
General and administrative		(16,855	)		(18,237	)
Contingent purchase price consideration fair value adjustment		—			406
Operating loss		(32,882	)		(54,341	)
Other income (expense):
Non-operating income (expense)		(1,106	)		40
Interest expense, net		(29,466	)		(16,592	)
Net loss		(63,454	)		(70,893	)
Dividends on Series A-1 convertible preferred stock		(54	)		(53	)
Less: net loss attributable to non-controlling interest		(1,568	)		(2,639	)
Net loss attributable to Agenus Inc. common stockholders	$	(61,940	)	$	(68,307	)
Per common share data:
Basic and diluted net loss attributable to Agenus Inc. common stockholders	$	(3.04	)	$	(4.31	)
Weighted average number of Agenus Inc. common shares outstanding:
Basic and diluted		20,368			15,855

Other comprehensive income (loss):
Foreign currency translation income (loss)	$	(116	)	$	2
Other comprehensive income (loss)		(116	)		2
Comprehensive loss	$	(62,056	)	$	(68,305	)

See accompanying notes to unaudited condensed consolidated financial statements.

AGENUS INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT

(Unaudited)

(Amounts in thousands)


	Series A-1
	Convertible
	Preferred Stock				Common Stock						Treasury Stock
	Number of Shares		Par Value		Number of Shares		Par Value		Additional Paid-In Capital		Number of Shares		Amount		Accumulated Other Comprehensive Income (Loss)			Non-controlling Interest			Accumulated Deficit			Total
Balance at December 31, 2023		32	$	0		19,718	$	197	$	1,796,095		—	$	—	$	(955	)	$	11,949		$	(1,955,668	)		(148,382	)
Net loss		—		—		—		—		—		—		—		—			(1,568	)		(61,886	)		(63,454	)
Other comprehensive loss		—		—		—		—		—		—		—		(116	)		—			—			(116	)
Share-based compensation		—		—		—		—		3,477		—		—		—			719			—			4,196
Shares sold at the market		—		—		1,249		13		17,158		—		—		—			—			—			17,171
Payment of CEO payroll in shares		—		—		7		—		89		—		—		—			—			—			89
Vesting of nonvested shares		—		—		8		—		—		—		—		—			—			—			—
Exercise of stock options and employee share purchases		—		—		12		—		166		—		—		—			7			—			173
Balance at March 31, 2024		32	$	0		20,994	$	210	$	1,816,985		—	$	—	$	(1,071	)	$	11,107		$	(2,017,554	)	$	(190,323	)

See accompanying notes to unaudited condensed consolidated financial statements.

AGENUS INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT

(Unaudited)

(Amounts in thousands)


	Series A-1
	Convertible
	Preferred Stock				Common Stock									Treasury Stock
	Number of Shares		Par Value		Number of Shares			Par Value			Additional Paid-In Capital			Number of Shares			Amount			Accumulated Other Comprehensive Income (Loss)		Non-controlling Interest			Accumulated Deficit			Total
Balance at December 31, 2022		32	$	0		15,278		$	153		$	1,647,561			—		$	—		$	915	$	6,376		$	(1,709,907	)	$	(54,902	)
Net loss		—		—		—			—			—			—			—			—		(2,639	)		(68,254	)		(70,893	)
Other comprehensive income		—		—		—			—			—			—			—			2		—			—			2
Share-based compensation		—		—		—			—			4,566			—			—			—		919			—			5,485
Shares sold at the market		—		—		1,689			17			60,566			—			—			—		—			—			60,583
Issuance of director deferred shares		—		—		13			1			982			—			—			—		—			—			983
Issuance of shares for services		—		—		7			—			318			—			—			—		—			—			318
Vesting of nonvested shares		—		—		—			—			—			—			—			—		—			—			—
Exercise of stock options and employee share purchases		—		—		10			—			329			—			—			—		45			—			374
Issuance of subsidiary shares for employee bonus		—		—		—			—			—			—			—			—		726			—			726
Issuance of shares for employee bonus		—		—		136			1			4,224			(1	)		(2,429	)		—		—			—			1,796
Retirement of treasury shares		—		—		(50	)		(1	)		(9	)		1			2,429			—		—			—			2,419
Balance at March 31, 2023		32	$	0		17,083		$	171		$	1,718,537			—		$	—		$	917	$	5,427		$	(1,778,161	)	$	(53,109	)

See accompanying notes to unaudited condensed consolidated financial statements.

AGENUS INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)

(Amounts in thousands, except per share amounts)


	Three Months Ended March 31,
	2024			2023
Cash flows from operating activities:
Net loss	$	(63,454	)	$	(70,893	)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization		3,374			2,562
Share-based compensation		4,152			5,485
Non-cash royalty revenue		(27,767	)		(19,106	)
Non-cash interest expense		29,595			17,273
Loss disposal of assets, net		9			21
Other, net		1,125			(406	)
Changes in operating assets and liabilities:
Accounts receivable		25,341			1,291
Prepaid expenses		4,202			2,965
Accounts payable		(10,733	)		2,032
Deferred revenue		(4	)		(2,382	)
Accrued liabilities and other current liabilities		(3,622	)		5,158
Other operating assets and liabilities		(409	)		(2,526	)
Net cash used in operating activities		(38,191	)		(58,526	)
Cash flows from investing activities:
Purchases of plant and equipment		(35	)		(1,842	)
Sale of long-term investment		264			—
Purchases of available-for-sale securities		—			(14,647	)
Proceeds from sale of available-for-sale securities		—			5,000
Net cash provided by (used in) investing activities		229			(11,489	)
Cash flows from financing activities:
Net proceeds from sale of equity		17,171			60,583
Proceeds from employee stock purchases and option exercises		173			374
Purchase of treasury shares to satisfy tax withholdings		—			(2,819	)
Payment of finance lease obligation		(2,514	)		(1,888	)
Net cash provided by financing activities		14,830			56,250
Effect of exchange rate changes on cash		(122	)		(90	)
Net decrease in cash, cash equivalents and restricted cash		(23,254	)		(13,855	)
Cash, cash equivalents and restricted cash, beginning of period		79,779			181,343
Cash, cash equivalents and restricted cash, end of period	$	56,525		$	167,488
Supplemental cash flow information:
Cash paid for interest	$	667		$	830
Supplemental disclosures - non-cash activities:
Purchases of plant and equipment in accounts payable and accrued liabilities	$	—		$	3,893
Issuance of common stock, $0.01 par value, in connection with payment for services		—			318
Insurance financing agreement		612			707
Issuance of common stock, $0.01 par value, for payment of certain employee bonuses		—			4,215
Issuance of subsidiary options for payment of certain employee bonuses		133			—
Issuance of subsidiary shares for certain employee bonuses		—			726
Lease right-of-use assets obtained in exchange for new operating lease liabilities		105			250
Lease right-of-use assets obtained in exchange for new finance lease liabilities		122			3,630

See accompanying notes to unaudited condensed consolidated financial statements.

AGENUS INC. AND SUBSIDIARIES

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

March 31, 2024

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 current good manufacturing practice ("cGMP") 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 assets, botensilimab (a multifunctional immune cell activator and human Fc-enhanced cytotoxic T-lymphocyte antigen 4 (CTLA-4) blocking antibody, also known as AGEN1811) and balstilimab (a programmed death receptor-1 (PD-1) blocking antibody).

•

Our saponin-based vaccine adjuvant platform, primarily centered around our STIMULON™ cultured plant cell (“cpc”) QS-21 adjuvant (“STIMULON cpcQS-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 include product research, preclinical and clinical development, intellectual property prosecution, manufacturing, regulatory and clinical affairs, corporate finance and development activities, and support of our collaborations. Our product candidates require successful clinical trials and approvals from regulatory agencies, as well as acceptance in the marketplace. Part of our strategy is to develop and commercialize some of our product candidates by continuing our existing arrangements with academic and corporate collaborators and licensees and by entering into new collaborations.

Our cash and cash equivalents at March 31, 2024 were $52.9 million, a decrease of $23.3 million from December 31, 2023. Cash and cash equivalents of our subsidiary, MiNK, at December 31, 2023, were $3.4 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.

As of March 31, 2024, we had an accumulated deficit of $2.0 billion and $13.0 million of subordinated notes maturing in February 2025. Since our founding we have financed our operations principally 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 $52.9 million at March 31, 2024, plus the $75.0 million to be received from Ligand Pharmaceuticals and the exercise at their option of an additional $25.0 million under a Purchase and Sale Agreement (see Note P), plus additional funding we may receive from multiple other sources, including out-licensing and/or partnering opportunities, and the repayment of our subordinated notes, will be sufficient to satisfy our liquidity requirements through the end of the year and into 2025. Potential partnership and collaboration transactions along with potential accelerated approval of our lead products, botensilimab and balstilimab, and potential commercial revenues from these products, can extend our runway and allow us to be cash flow positive from our operations.

We are also in discussions with several other parties to participate in the Purchase and Sale Agreement for up to an additional $125.0 million under the same structure as the Ligand transaction. In addition, we are also in discussions with several potential corporate collaborators. These transactions could also extend our cash resources. However, because the completion of such transactions is not entirely within our control, in accordance with accounting guidance we are required to disclose that substantial doubt exists about our ability to continue as a going concern for a period of one year after the date of filing of this Quarterly Report on Form 10-Q. The financial statements have been prepared on a basis that assumes Agenus will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

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., Merck Sharpe & Dohme and Incyte Corporation; out-licensing and/or partnering opportunities for our portfolio programs and product candidates with multiple parties; additional third-party agreements; asset sales; further 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 three months ended March 31, 2024, are not necessarily indicative of the results that may be expected for the year ending December 31, 2024. 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, 2023 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 (loss) in total stockholders’ deficit.

On April 4, 2024, we executed a reverse stock split of our issued and outstanding common stock, par value $0.01, at a ratio of 1-for-20 with a record date of April 12, 2024 (the “Reverse Stock Split”). All common share, per share and related information included in the accompanying financial statements and footnote disclosures have been adjusted retroactively, where applicable, to reflect the Reverse Stock Split. See Note P for further details.

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 March 31, 2024 and 2023, as they would be anti-dilutive (in thousands):


	Three Months Ended March 31,
	2024		2023
Warrants		99		99
Stock options		2,205		2,184
Non-vested shares		26		127
Series A-1 convertible preferred stock		17		17

Note C – Investments

Cash equivalents and short-term investments consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024				December 31, 2023
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Institutional money market funds	$	49,220	$	49,220	$	70,485	$	70,485
Total	$	49,220	$	49,220	$	70,485	$	70,485

As a result of the short-term nature of these investments, there were minimal unrealized holding gains or losses for the three months ended March 31, 2024 and 2023.

As of both March 31, 2024 and December 31, 2023, all of the investments listed above were classified as cash equivalents on our condensed consolidated balance sheets.

Note D – Goodwill and Acquired Intangible Assets

The following table sets forth the changes in the carrying amount of goodwill for the three months ended March 31, 2024 (in thousands):


Balance, December 31, 2023	$	24,723
Effect of foreign currency		(25	)
Balance, March 31, 2024	$	24,698

Acquired intangible assets consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	As of March 31, 2024
	Amortization period (years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Intellectual property	7-15 years	$	16,841	$	(15,268	)	$	1,573
Trademarks	4-4.5 years		1,199		(1,193	)		6
Other	2-7 years		1,932		(1,338	)		594
In-process research and development	Indefinite		2,057		—			2,057
Total		$	22,029	$	(17,799	)	$	4,230


	As of December 31, 2023
	Amortization period (years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Intellectual property	7-15 years	$	16,841	$	(15,184	)	$	1,657
Trademarks	4-4.5 years		1,213		(1,185	)		28
Other	2-7 years		1,988		(1,319	)		669
In-process research and development	Indefinite		2,057		—			2,057
Total		$	22,099	$	(17,688	)	$	4,411

The weighted average amortization period of our finite-lived intangible assets is 9 years. Amortization expense related to acquired intangibles is estimated at $0.4 million for the remainder of 2024, $0.5 million for the years ending December 31, 2025 and 2026, $0.4 million for the year ending December 31, 2027 and $0.3 million for the year ending December 31, 2028.

Note E – Debt

Debt obligations consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


Debt instrument	Balance at March 31, 2024
Current Portion:
Debentures	$	146
2015 Subordinated Notes		12,817
Other		612
Total	$	13,575


Debt instrument	Balance at December 31, 2023
Current Portion:
Debentures	$	146
Long-term Portion:
2015 Subordinated Notes		12,768
Total	$	12,914

As of March 31, 2024 and December 31, 2023, the principal amount of our outstanding debt balance was $13.8 million and $13.1 million, respectively.

Note F – Liability Related to the Sale of Future Royalties and Milestones

The following table shows the activity within the liability account in the three months ended March 31, 2024 (in thousands):


	Period from December 31, 2023 to March 31, 2024
Liability related to sale of future royalties and milestones - beginning balance	$	257,296
Non-cash royalty revenue		(27,767	)
Non-cash interest expense recognized		29,531
Liability related to sale of future royalties and milestones - ending balance		259,060
Less: unamortized transaction costs		(223	)
Liability related to sale of future royalties and milestones, net	$	258,837

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 STIMULON QS-21 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 three months ended March 31, 2024, we recognized $27.8 million of non-cash royalty revenue, and we recorded $29.5 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 three months ended March 31, 2024, our estimate of the effective annual interest rate over the life of the agreement decreased to 48.0%, which results in a life of contract interest rate of 26.5%.

Note G – Accrued and Other Current Liabilities

Accrued liabilities consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024		December 31, 2023
Payroll	$	18,514	$	14,512
Professional fees		6,195		7,101
Contract manufacturing costs		5,334		7,613
Research services		6,274		10,807
Other		4,974		5,250
Total	$	41,291	$	45,283

Other current liabilities consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024		December 31, 2023
Finance lease liabilities	$	10,738	$	10,457
Other		3,293		3,458
Total	$	14,031	$	13,915

Note H – Fair Value Measurements

Assets and liabilities measured at fair value are summarized below (in thousands):


Description	March 31, 2024		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents (Note C)	$	49,220	$	49,220	$	—	$	—
Long-term investments		1,834		1,834		—		—
Total	$	51,054	$	51,054	$	—	$	—
Liabilities:
Contingent purchase price considerations	$	318	$	—	$	—	$	318
Total	$	318	$	—	$	—	$	318

Description	December 31, 2023		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents (Note C)	$	70,485	$	70,485	$	—	$	—
Long-term investments		3,222		3,222		—		—
Total	$	73,707	$	73,707	$	—	$	—
Liabilities:
Contingent purchase price consideration	$	318	$	—	$	—	$	318
Total	$	318	$	—	$	—	$	318

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 both March 31, 2024 and December 31, 2023, of $0.3 million, 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 March 31, 2024 and December 31, 2023 was $13.6 million and $13.0 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 March 31, 2024 and December 31, 2023 was $13.8 million and $13.1 million, respectively.

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

No revenue was recognized for the three months ended March 31, 2024. For the three months ended March 31, 2023, we recognized approximately $2.3 million of research and development revenue based on the partial satisfaction of the over time performance obligations as of quarter end.

Disaggregation of Revenue

The following table presents revenue (in thousands) for the three months ended March 31, 2024 and 2023, 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 March 31, 2024
	United States		Rest of World		Total
Revenue Type
Other services	$	—	$	238	$	238
Non-cash royalties		27,767		—		27,767
	$	27,767	$	238	$	28,005

	Three months ended March 31, 2023
Revenue Type
Research and development services		267		—		267
Other services		—		1,184		1,184
Recognition of deferred revenue		2,345		—		2,345
Non-cash royalties		19,106		—		19,106
	$	21,718	$	1,184	$	22,902

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):


Three months ended March 31, 2024	Balance at beginning of period		Additions		Deductions			Balance at end of period
Contract liabilities:
Deferred revenue	$	1,161	$	5	$	(10	)	$	1,156

We also recorded a $0.5 million receivable as of March 31, 2024, for research and development and other services provided.

During the three months ended March 31, 2024, we did not recognize any revenue from amounts included in the contract asset or the contract liability balances from performance obligations satisfied in previous periods. None of the costs to obtain or fulfill a contract were capitalized.

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 three months ended March 31, 2024 is presented below:


	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding at December 31, 2023		2,141,360		$	65.00
Granted		164,506			17.44
Exercised		—			—
Forfeited		(11,982	)		48.61
Expired		(88,971	)		63.66
Outstanding at March 31, 2024		2,204,913		$	61.55		6.61	$	—
Vested or expected to vest at March 31, 2024		2,204,913		$	61.55		6.61	$	—
Exercisable at March 31, 2024		1,558,872		$	69.34		5.88	$	—

The weighted average grant-date fair values of stock options granted during the three months ended March 31, 2024 and 2023 were $8.82 and $30.60, respectively.

As of March 31, 2024, there was approximately $18.6 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 1.7 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 three months ended March 31, 2024 is presented below:


	Non-vested Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2023		27,163		$	37.20
Granted		10,406			12.16
Vested		(7,989	)		31.08
Forfeited		(4,000	)		41.72
Outstanding at March 31, 2024		25,580		$	28.21

As of March 31, 2024, there was approximately $1.3 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 3.5 years.

During the three months ended March 31, 2024, 11,816 shares were issued under the 2019 Employee Stock Purchase Plan and 7,989 shares were issued as a result of the vesting of non-vested stock.

The impact on our results of operations from share-based compensation for the three months ended March 31, 2024 and 2023, was as follows (in thousands):


	Three Months Ended March 31,
	2024		2023
Research and development	$	1,314	$	1,733
General and administrative		2,882		3,752
Total share-based compensation expense	$	4,196	$	5,485

Note K – Restricted Cash

As of both March 31, 2024, and December 31, 2023, we maintained non-current restricted cash of $3.7 million. This amount is included within “Other long-term assets” in our condensed consolidated balance sheets and is comprised of deposits under 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):


	Three Months Ended March 31, 2024				Three Months Ended March 31, 2023
	Beginning of Period		End of Period		Beginning of Period		End of Period
Cash and cash equivalents	$	76,110	$	52,856	$	178,674	$	164,819
Restricted cash		3,669		3,669		2,669		2,669
Cash, cash equivalents and restricted cash	$	79,779	$	56,525	$	181,343	$	167,488

Note L – Equity

On March 14, 2024, we filed a Post-effective Amendment to an Automatic Shelf Registration Statement on Form POSASR (file no. 333-272911) and a Post-Effective Amendments for Registration Statement on Form POS AM (file no. 333-272911) (together, the “Registration Statement”). The Registration Statement included both a base prospectus that covered the potential offering, issuance and sale from time to time of up to $300.0 million 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 6,725,642 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 months ended March 31, 2024, we received net proceeds of approximately $17.2 million from the sale of approximately 1.2 million shares of our common stock in at-the-market offerings under the Sales Agreement.

Note M – Non-controlling Interest

Non-controlling interest recorded in our condensed consolidated financial statements as of March 31, 2024 and December 31, 2023, relates to the following approximate interests in certain consolidated subsidiaries, which we do not own.


	March 31, 2024			December 31, 2023
MiNK Therapeutics, Inc.		37	%		37	%
SaponiQx, Inc.		30	%		30	%

Changes in non-controlling interest for the periods ended March 31, 2024 and December 31, 2023, were as follows (in thousands):


	March 31, 2024			December 31, 2023
Beginning balance	$	11,949		$	6,376

Net loss attributable to non-controlling interest		(1,568	)		(11,676	)

Other items:
Distribution of subsidiary shares to Agenus stockholders		—			14,888
Purchase of subsidiary shares		—			(2,546	)
Issuance of subsidiary shares for employee bonus		—			1,011
Issuance of subsidiary shares for employee stock purchase plan and exercise of options		7			71
Subsidiary share-based compensation		719			3,825
Total other items		726			17,249

Ending balance	$	11,107		$	11,949

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 0.292 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 year ended December 31, 2023, we purchased 446,494 shares of MiNK common stock in multiple open market 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. No expenses were incurred in the three months ended March 31, 2024. For the three months ended March 31, 2023, approximately $228,000 related to these services is included in “Research and development” expense in our condensed consolidated statements of operations.

Note O – Recent Accounting Pronouncements

Recently Issued, Not Yet Adopted

In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. ASU 2023-07 requires incremental annual and quarterly disclosures about segment measures of profit or loss as well as significant segment expenditures. It also requires public entities with a single reportable segment to provide all segment disclosures required by the amendments and all existing segment disclosures in Topic 280. ASU 2023-07 is

effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. As we have a single reportable segment, we expect the adoption of this standard to result in increased disclosures in the notes to our consolidated financial statements.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 requires incremental annual disclosures around income tax rate reconciliations, income taxes paid and other related disclosures. For public business entities, ASU 2023-09 is effective for fiscal years beginning after December 15, 2024. Early adoption is permitted for any annual periods for which financial statements have not been issued or made available for issuance. We are currently evaluating the impact that ASU 2023-09 will have on the notes to our consolidated financial statements.

No other new accounting pronouncement issued or effective during the three months ended March 31, 2024 had or is expected to have a material impact on our consolidated financial statements or disclosures.

Note P – Subsequent Events

Reverse Stock Split

On April 3, 2024, our stockholders approved a proposal to amend our Amended and Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), to effect a reverse stock split of our issued and outstanding common stock at a ratio of 1-for-20 (the “Reverse Stock Split”). On April 4, 2024, we filed a Certificate of Eighth Amendment (the “Certificate of Amendment”) to our Certificate of Incorporation with the Secretary of State of the State of Delaware to effect the Reverse Stock Split. Pursuant to the Certificate of Amendment, the Reverse Stock Split became effective at 12:01 a.m., Eastern Time, on April 12, 2024. As of the opening of trading on April 12, 2024, our common stock began trading on a post-split basis under CUSIP number 00847G 804.

All common share, per share and related information included in the accompanying financial statements and footnote disclosures have been adjusted retroactively, where applicable, to reflect the Reverse Stock Split.

Purchase Agreement

On May 6, 2024, we, and certain wholly-owned subsidiaries, entered into a Purchase and Sale Agreement (the “Purchase Agreement”) with Ligand Pharmaceuticals Incorporated (“Ligand”) for the sale to Ligand of (i) 31.875% of the development, regulatory and commercial milestone payments we are eligible to receive under our agreements with Bristol-Myers Squibb Company, UroGen Pharma Ltd., Gilead Sciences, Inc., Merck Sharpe & Dohme and Incyte Corporation, (the “Covered License Agreements”) (ii) 18.75% of the royalties the Company receives under the Covered License Agreements; and (iii) a 2.625% synthetic royalty on worldwide net sales of botensilimab and balstilimab (collectively the “Purchased Assets”).

The total amounts payable to Ligand are subject to a 50% reduction in the event total payments to Ligand exceed a specified return hurdle. The synthetic royalty is subject to a reduction if annual worldwide net sales exceed a specified level, and a cap on annual worldwide net sales if annual worldwide net sales exceed a higher specified level. The synthetic royalty can increase by 1% based on the occurrence of certain future events.

In consideration for the sale of the Purchased Assets, we will receive $75.0 million, less certain reimbursable expenses, on the closing date. The Purchase Agreement permits additional sales of the Purchased Assets to third parties on substantially similar terms on a pro rata basis, up to a maximum of $200.0 million. In addition, Ligand has a time-based option to invest an additional $25.0 million on a pro rata basis.

The Purchase Agreement contains customary representations, warranties and agreements by us and Ligand, indemnification obligations of the parties and certain other obligations of the parties. As part of the transaction, we will grant Ligand security over certain assets related to the Purchased Assets pursuant to security agreements, subject to certain customary exceptions. Closing of the transaction is subject to customary conditions, including execution of customary ancillary documents for a transaction of this type. The transaction is expected to close in May 2024.

In connection with the sale of the Purchased Assets, we issued to Ligand a warrant (“Warrant”) to purchase 867,052 shares of our common stock, at an exercise price equal to $17.30. The exercise price of the Warrant and the number of shares issuable upon exercise of the Warrant are subject to adjustments for stock splits, combinations, stock dividends or similar events. The Warrant is exercisable until May 6, 2029.

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Forward Looking Statements

This Quarterly Report on Form 10-Q and other written and oral statements we make from time to time contain certain “forward-looking” statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 (the “Exchange Act”). You can identify these forward-looking statements by the fact they use words such as “could,” “expect,” “anticipate,” “estimate,” “target,” “may,” “project,” “guidance,” “intend,” “plan,” “believe,” “will,” “potential,” “opportunity,” “future” and other words and terms of similar meaning and expression in connection with any discussion of future operating or financial performance. You can also identify forward-looking statements by the fact that they do not relate strictly to historical or current facts. Such forward-looking statements are based on current expectations and involve inherent risks and uncertainties, including factors that could delay, divert or change any of them, and could cause actual outcomes to differ materially from current expectations. These statements relate to, among other things, our business strategy, our research and development, our product development efforts, our ability to commercialize our product candidates, the activities of our licensees, our prospects for initiating partnerships or collaborations, the timing of the introduction of products, the effect of new accounting pronouncements, uncertainty regarding our future operating results and our profitability, anticipated sources of funds as well as our plans, objectives, expectations, and intentions.

More detailed descriptions of these risks and uncertainties and other risks and uncertainties applicable to our business that we believe could cause actual results to differ materially from any forward-looking statements are included in in Part I-Item 1A “Risk Factors” of our Annual Report on Form 10-K for the fiscal year ended December 31, 2023. We encourage you to read those descriptions carefully. Although we believe we have been prudent in our plans and assumptions, no assurance can be given that any goal or plan set forth in forward-looking statements can be achieved. We caution investors not to place significant reliance on forward-looking statements contained in this document; such statements need to be evaluated in light of all the information contained in this document. Furthermore, the statements speak only as of the date of this document, and we undertake no obligation to update or revise these statements.

Overview

We are 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.

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.

•

Our saponin-based vaccine adjuvant platform, primarily centered around our STIMULON™ cultured plant cell (“cpc”) QS-21 adjuvant (“STIMULON cpcQS-21”).

•

A pipeline of novel allogeneic invariant natural killer T cell (“iNKT”) therapies for treating cancer and other immune-mediated diseases, controlled by MiNK.

We regularly evaluate development, commercialization, and partnering strategies for each product candidate based on various factors, including pre-clinical and clinical trial results, competitive positioning, funding requirements, and available resources. Our lead program, botensilimab (AGEN1181), is progressing through multiple clinical programs designed to support accelerated

development as a monotherapy and in combination with balstilimab. In April 2023, botensilimab in combination with balstilimab received Fast Track designation from the U.S. Food and Drug Administration ("FDA") for the treatment of patients with not-microsatellite instability-high ("MSI-H")/deficient mismatch repair ("dMMR") metastatic colorectal cancer with no active liver involvement. Patients targeted with this designation are heavily pretreated with standard of care chemotherapy, anti-VEGF and anti-EGFR if RAS wild type. We completed enrollment of patients with refractory MSS mCRC non-active liver metastases ("NLM") in a Phase 1 trial (n~150) and randomized Phase 2 trial (n~230) in October 2023. We are pursuing a global regulatory strategy and aim to initiate submission of a biologics license application ("BLA") to the FDA for a potential accelerated approval by the end of 2024, followed by a planned submission to the European Medicines Agency.

We have established collaborations with several companies, including Bristol-Myers Squibb Company (“BMS”), Betta Pharmaceuticals Co., Ltd. (“Betta”), UroGen Pharma Ltd. ("UroGen"), Gilead Sciences, Inc. (“Gilead”), Incyte Corporation (“Incyte”), and Merck Sharpe & Dohme (“Merck”). These collaborations, along with our internal programs, have resulted in over a dozen antibody pre-clinical or clinical development programs.

Pursuant to our collaboration agreement with Incyte, we have exclusively licensed to Incyte monospecific antibodies targeting GITR, OX40, TIM-3 and LAG-3, which Incyte is currently advancing in various clinical trials, as well as an additional undisclosed target that Incyte is advancing in preclinical studies. Under the terms of our agreement, Incyte is responsible for all future development expenses, and we are eligible to receive up to an additional $315.0 million in potential milestone payments plus royalties on any future sales. Incyte has terminated the OX40 program, effective October 2023, and has notified us of their intent to terminate both the GITR program and undisclosed program, effective May 2024. Upon termination, the rights to the OX40, GITR, and undisclosed programs revert back to us.

Pursuant to our collaboration and license agreement with Merck, we exclusively licensed to Merck a monospecific antibody targeting ILT4 (MK-4830), which Merck advanced in a Phase 2 clinical trial. Merck is responsible for all future development expenses, and we are eligible to receive up to an additional $85.0 million in potential milestone payments, as well as royalties on future sales. In 2024 Merck notified us that the further clinical development of MK-4830 will be limited to a neoadjuvant ovarian study of MK-4830 in combination with pembrolizumab and chemotherapy with or without bevacizumab that is ongoing.

In September 2018, we, through our wholly-owned subsidiary, Agenus Royalty Fund, LLC, entered into a royalty purchase agreement (the “XOMA Royalty Purchase Agreement”) with XOMA (US) LLC (“XOMA”). Pursuant to the terms of the XOMA Royalty Purchase Agreement, XOMA purchased 33% of all future royalties and 10% of all future milestone payments that we are entitled to receive from Incyte and Merck, net of certain of our obligations to a third party. After taking into account our obligations under the XOMA Royalty Purchase Agreement, as of March 31, 2024, we remain eligible to receive up to $283.5 million and $76.5 million in potential development, regulatory, and commercial milestones from Incyte and Merck, respectively.

In December 2018, we entered into collaboration agreements with Gilead for the development and commercialization of up to five novel I-O therapies (the “Gilead Collaboration Agreements”). Gilead received worldwide exclusive rights to our bispecific antibody, AGEN1423, and the exclusive option to license AGEN1223, a bispecific antibody, and AGEN2373, a monospecific antibody. Gilead elected to return AGEN1423 to us in November 2020 and terminated the license agreement. We ceased development of AGEN1223 in the third quarter of 2021, and the option and license agreement for AGEN1223 were formally terminated in October 2021. The AGEN2373 option agreement remains in place, and we are responsible for developing the program until the option decision point. If Gilead exercises the option, we may opt-in to share development and commercialization costs in the United States in exchange for a 50:50 profit (loss) share and revised milestone payments. In March 2022, we received a $5.0 million clinical milestone under the AGEN2373 option agreement. Pursuant to the terms of the AGEN2373 option agreement, we remain eligible to receive a $50.0 million option exercise fee and up to an additional $520.0 million in aggregate milestone payments, as well as royalties on future sales.

In November 2019, we entered into a license agreement with UroGen, granting them an exclusive, worldwide license (not including Argentina, Brazil, Chile, Colombia, Peru, Venezuela and their respective territories and possessions) to develop, manufacture, and commercialize zalifrelimab for the treatment of cancers of the urinary tract via intravesical delivery. We received an upfront payment of $10.0 million and are eligible to receive up to $200.0 million in milestone payments, as well as royalties on future sales.

In June 2020, we entered into a license and collaboration agreement (the “Betta License Agreement”) with Betta, pursuant to which we granted Betta an exclusive license to develop, manufacture and commercialize balstilimab and zalifrelimab in Republic of China, Hong Kong, Macau and Taiwan (“Greater China”). Under the terms of the Betta License Agreement, we received $15.0 million upfront and are eligible to receive up to $100.0 million in milestone payments plus royalties on any future sales in Greater China.

In May 2021, we entered into a License, Development, and Commercialization Agreement with BMS for our pre-clinical anti-TIGIT bispecific antibody program, AGEN1777. BMS received an exclusive worldwide license to develop, manufacture, and commercialize AGEN1777 and its derivatives. We retained an option to access the licensed antibodies for use in clinical studies in combination with certain pipeline assets. We received a non-refundable upfront cash payment of $200.0 million and, as of March 31, 2024, are eligible to receive up to $1.32 billion in development, regulatory, and commercial milestone payments, along with tiered royalties. BMS is responsible for all associated costs, and we have the option to co-fund a minority of global development costs in exchange for increased tiered royalties. We also have the option to co-promote AGEN1777 in the U.S. In October 2021, we achieved a $20.0 million milestone upon the dosing of the first patient in the AGEN1777 Phase 1 clinical trial and in December 2023, we announced that the first patient was dosed in an AGEN1777 Phase 2 clinical trial, triggering the achievement of a $25.0 million milestone. We received this milestone in January 2024.

In September 2021, we launched SaponiQx to lead innovation in novel adjuvant discovery and vaccine design, focusing on our saponin-based adjuvants. We are particularly dedicated to the development of the next-generation cultured plant cell QS-21. To support this initiative, we partnered with Ginkgo Bioworks, Inc. to develop SaponiQx’s saponin products from sustainably sourced raw materials. Our goal is to meet the demands of the vaccine industry, especially for pandemic vaccines.

Our bark extract QS-21 adjuvant is partnered with GSK and plays a vital role in multiple GSK vaccine programs. These programs are at various stages, including GSK’s approved shingles and RSV vaccines, SHINGRIX and AREXVY, which received FDA approval in the United States in October 2017 and May 2023, respectively.

In January 2018, we entered into a Royalty Purchase Agreement with Healthcare Royalty Partners III, L.P. and its affiliates (“HCR”). HCR purchased our worldwide rights to receive royalties from GSK on GSK’s sales of vaccines containing our QS-21 adjuvant. We do not incur clinical development costs for products partnered with GSK.

Under the agreement with HCR, we were entitled to receive milestone payments based on GSK’s vaccine sales. These milestones include $15.1 million upon GSK reaching $2.0 billion in last-twelve-months net sales prior to 2024 (the “First HCR Milestone”) and $25.25 million upon GSK reaching $2.75 billion in last-twelve-months net sales prior to 2026 (the “Second HCR Milestone”). We received the First HCR Milestone after GSK’s net sales of SHINGRIX for the twelve months ended December 31, 2019, exceeded $2.0 billion, and we received the Second HCR Milestone after GSK’s net sales of SHINGRIX for the twelve months ended June 30, 2022, exceeded $2.75 billion.

Our business activities include product research and preclinical and clinical development, intellectual property prosecution, manufacturing, regulatory and clinical affairs, corporate finance and development activities, and support of our collaborations. Our product candidates require successful clinical trials and approvals from regulatory agencies, as well as acceptance in the marketplace. Part of our strategy is to develop and commercialize some of our product candidates by continuing our existing arrangements with academic and corporate collaborators and licensees and by entering into new collaborations.

In October 2021, we completed the initial public offering (“IPO”) of MiNK, which trades on the Nasdaq Capital Market under the ticker symbol “INKT”. MiNK is a clinical stage biopharmaceutical company focused on developing allogeneic invariant natural killer T (“iNKT”) cell therapies to treat cancer and other life-threatening immune diseases. MiNK’s most advanced product candidate, agenT-797, is an off-the-shelf, allogeneic, native iNKT cell therapy. Expansion of clinical programs is currently underway, notably a Phase 2 clinical trial in 2L gastric cancer at Memorial Sloan Kettering Cancer Center. MiNK is also evaluating agenT-797 as a variant-agnostic therapy for patients with viral acute respiratory distress syndrome (“ARDS”). In addition to its lead clinical program, MiNK announced a collaboration with ImmunoScape, Inc. ("ImmunoScape") to discover and develop next-generation T-cell receptor therapies against novel targets in solid tumors. MiNK will combine its unique, proprietary library of T cell antigens with ImmunoScape’s platform for rapid discovery of novel T cell receptor.

Historical Results of Operations

Three months ended March 31, 2024 compared to the three months ended March 31, 2023

Research and development revenue

We did not recognize any research and development revenue in the three months ended March 31, 2024, but recognized research and development revenue of approximately $2.6 million during the three months ended March 31, 2023. Research and development revenues in the first quarter of 2023 primarily consisted of $2.3 million related to the recognition of deferred revenue earned under our Gilead Collaboration Agreements

Non-cash royalty revenue related to the sale of future royalties

In January 2018, we sold 100% of our worldwide rights to receive royalties from GSK on sales of GSK’s vaccines containing our STIMULON QS-21 adjuvant to HCR. As described in Note F to our Condensed Consolidated Financial Statements, this transaction has been recorded as a liability that amortizes over the estimated life of our Royalty Purchase Agreement with HCR. As a result of this liability accounting, even though the royalties are remitted directly to HCR, we record these royalties from GSK as revenue. Non-cash royalty revenue related to our agreement with GSK increased $8.7 million, to approximately $27.8 million for the three months ended March 31, 2024, from $19.1 million for the three months ended March 31, 2023, due to increased net sales of GSK’s vaccines containing our STIMULON QS-21 adjuvant, including net sales of AREXVY, that GSK launched in the third quarter of 2023.

Research and development expense

Research and development expense includes the costs associated with our internal research and development activities, including compensation and benefits, occupancy costs, manufacturing costs, costs of consultants, and administrative costs. Research and development expense decreased 23% to $43.9 million for the three months ended March 31, 2024 from $57.1 million for the three months ended March 31, 2023. Decreased expenses in the three months ended March 31, 2024 primarily relate to a $7.4 million decrease in third-party services and other expenses, largely due to the timing of expenses related to the advancement of our antibody programs, a $2.1 million decrease in personnel related expenses, mainly due to a decrease in headcount, and a $4.4 million decrease in expenses attributable to the activities of our subsidiaries. These decreases were partially offset by a $0.7 million increase in other research and development expenses.

General and administrative expense

General and administrative expense consists primarily of personnel costs, facility expenses, and professional fees. General and administrative expenses decreased 8% to $16.9 million for the three months ended March 31, 2024 from $18.2 million for the three months ended March 31, 2023. Decreased expenses in the three months ended March 31, 2024 primarily relate to $0.1 million decrease in professional fees and a $1.5 million decrease in expenses attributable to the activities of our subsidiaries. These decreases were partially offset by a $0.1 million increase in personnel related expenses, and a $0.2 million increase in other general and administrative expenses.

Interest expense, net

Interest expense, net increased to approximately $29.5 million for the three months ended March 31, 2024 from $16.6 million for the three months ended March 31, 2023, mainly due to increased non-cash interest recorded in connection with our Royalty Purchase Agreement with HCR.

Research and Development Programs

For the three months ended March 31, 2024, our research and development programs consisted largely of our antibody programs as indicated in the following table (in thousands).


		Three Months Ended March 31,		Year Ended December 31,
Research and Development Program	Product	2024		2023		2022		2021
Antibody programs	Various	$	33,157	$	178,445	$	133,108	$	141,266
Vaccine adjuvant	STIMULON cpcQS-21		586		10,296		10,789		5,912
Cell therapies	Various		2,668		16,283		24,300		15,507
Other research and development programs	Various		7,514		29,545		18,494		15,923
Total research and development expenses		$	43,925	$	234,569	$	186,691	$	178,608

Research and development program costs include compensation and other direct costs plus an allocation of indirect costs, based on certain assumptions and our review of the status of each program. Our product candidates are in various stages of development and significant additional expenditures will be required if we start new clinical trials, encounter delays in our programs, apply for regulatory approvals, continue development of our technologies, expand our operations, and/or bring our product candidates to market. The total cost of any particular clinical trial is dependent on a number of factors such as trial design, length of the trial, number of clinical sites, number of patients, and trial sponsorship. The process of obtaining and maintaining regulatory approvals for new therapeutic products is lengthy, expensive, and uncertain. Because of the current stage of our product candidates, among other factors, we are unable to reliably estimate the cost of completing our research and development programs or the timing for bringing such programs to various markets or substantial partnering or out-licensing arrangements, and, therefore, when, if ever, material cash inflows are likely to commence.

Liquidity and Capital Resources

We have incurred annual operating losses since inception, and we had an accumulated deficit of $2.0 billion as of March 31, 2024. We expect to incur significant losses over the next several years as we continue development of our technologies and product candidates, manage our regulatory processes, initiate and continue clinical trials, and prepare for potential commercialization of products. To date, we have financed our operations primarily through corporate partnerships, advance royalty sales and the issuance of equity. From our inception through March 31, 2024, we have raised aggregate net proceeds of approximately $1.9 billion through the sale of common and preferred stock, the exercise of stock options and warrants, proceeds from our Employee Stock Purchase Plan, royalty monetization transactions, and the issuance of convertible and other notes.

We maintain an effective registration statement (the “Registration Statement”) covering up to $300.0 million of common stock, preferred stock, warrants, debt securities and units. The Registration Statement includes prospectuses covering the offer, issuance and sale of up to 6.7 million shares of our common stock from time to time in “at-the-market offerings” pursuant to an At Market Issuance Sales Agreement (the “Sales Agreement”) with B. Riley Securities, Inc. as our sales agent. During the three months ended March 31, 2024, we sold approximately 1.2 million shares of our common stock pursuant to the Sales Agreement, for aggregate net proceeds of $17.2 million. As of March 31, 2024, approximately 6.7 million shares remained available for sale under the Sales Agreement.

We have funded our operations largely from cash received from partners, royalty financing transactions and equity offerings. We transact at-the-market sales from time to time in order to manage our cash balances to make sure cash balances do not drop below a certain level based on our anticipated uses of cash. We execute at-the-market offerings based on market conditions and our stock price. We do not have in place a program whereby at-the-market offerings are executed automatically based on our trading volume.

As of March 31, 2024, we had debt outstanding of $13.8 million in principal. In November 2022, we amended all of the outstanding 2015 Subordinated Notes, extending the due date by two years to February 2025.

Since our founding we have financed our operations principally 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 $52.9 million as of March 31, 2024, plus the $75.0 million to be received from Ligand Pharmaceuticals and the exercise at their option of an additional $25.0 million under a Purchase and Sale Agreement (see Note P), plus additional funding we may receive from multiple other sources, including out-licensing and/or partnering opportunities, and the repayment of our subordinated notes, will be sufficient to satisfy our liquidity requirements through the end of the year and into 2025. Potential partnership and collaboration transactions along with potential accelerated approval of our lead products, botensilimab and balstilimab, and potential commercial revenues from these products, can extend our runway and allow us to be cash flow positive from our operations.

We are also in discussions with several other parties to participate in the Purchase and Sale Agreement for an additional $125.0 million under the same structure as the Ligand transaction. In addition, we are also in discussions with several potential corporate collaborators. These transactions could also extend our cash resources. However, because the completion of such transactions is not entirely within our control, in accordance with accounting guidance we are required to disclose that substantial doubt exists about our ability to continue as a going concern for a period of one year after the date of filing of this Quarterly Report on Form 10-Q. The financial statements have been prepared on a basis that assumes Agenus will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

Management continues to address the Company’s liquidity needs and can exercise its 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., Merck Sharpe & Dohme and Incyte Corporation; out-licensing and/or partnering opportunities for our portfolio programs and product candidates with multiple parties; additional third-party agreements; asset sales; further royalty monetization; project financing, and/or sales of equity securities.

Our future cash requirements include, but are not limited to, supporting clinical trial and regulatory efforts and continuing our other research and development programs. Since inception, we have entered into various agreements with contract manufacturers, institutions, and clinical research organizations (collectively “third party providers”) to perform pre-clinical activities and to conduct and monitor our clinical studies and trials. Under these agreements, subject to the enrollment of patients and performance by the applicable third-party provider, we have estimated our total payments to be $649.8 million over the term of the related activities. Through March 31, 2024, we have expensed $574.5 million as research and development expenses and $533.4 million has been paid under these agreements. The timing of expense recognition and future payments related to these agreements is subject to the enrollment of patients and performance by the applicable third-party provider. We plan to enter into additional agreements with third party providers and we anticipate significant additional expenditures will be required to initiate and advance our various programs.

Part of our strategy is to develop and commercialize some of our product candidates by continuing our existing collaboration arrangements with academic and collaboration partners and licensees and by entering into new collaborations. As a result of our collaboration agreements, we will not completely control the efforts to attempt to bring those product candidates to market.

Net cash used in operating activities for the three months ended March 31, 2024 and 2023 was $38.2 million and $58.5 million, respectively. Our future ability to generate cash from operations will depend on achieving regulatory approval and market acceptance of our product candidates, achieving benchmarks as defined in existing collaboration agreements, and our ability to enter into new collaborations. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Forward Looking Statements” in Part I, Item 2 of this Quarterly Report on Form 10-Q and the risks highlighted in Part I, Item 1A "Risk Factors" of our 2023 Form 10-K.

Item 3. Quantitative and Qualitative Disclosures About Market Risk

Our primary market risk exposure is foreign currency exchange rate risk. International revenues and expenses are generally transacted by our foreign subsidiaries and are denominated in local currency. Approximately 1.0% of our cash used in operations for both the three months ended March 31, 2024 and the year ended December 31, 2023, was from our foreign subsidiaries. We are exposed to foreign currency exchange rate fluctuation risk related to our transactions denominated in foreign currencies. We do not currently employ specific strategies, such as the use of derivative instruments or hedging, to manage these exposures. Our currency exposures vary but are primarily concentrated in the British Pound and Euro, in large part due to our subsidiaries, Agenus UK Limited and AgenTus Therapeutics Limited, both with operations in England, and AgenTus Therapeutics SA, a company formerly with operations in Belgium.

We had cash and cash equivalents at March 31, 2024 of $52.9 million, which are exposed to the impact of interest rate changes, and our interest income fluctuates as interest rates change. Additionally, in the normal course of business, we are exposed to fluctuations in interest rates as we seek debt financing and invest excess cash. Due to the short-term nature of our investments in money market funds, our carrying value approximates the fair value of these investments at March 31, 2024.

There has been no material change to our interest rate exposure and our approach toward interest rate and foreign currency exchange rate exposures, as described in our Annual Report on Form 10-K for the year ended December 31, 2023.

We invest our cash and cash equivalents in accordance with our investment policy. The primary objectives of our investment policy are to preserve principal, maintain proper liquidity to meet operating needs, and maximize yields. We review our investment policy periodically and amend it as deemed necessary. Currently, the investment policy prohibits investing in any structured investment vehicles and asset-backed commercial paper. Although our investments are subject to credit risk, our investment policy specifies credit quality standards for our investments and limits the amount of credit exposure from any single issue, issuer, or type of investment. We do not invest in derivative financial instruments. Accordingly, we do not believe that there is currently any material market risk exposure with respect to derivatives or other financial instruments that would require disclosure under this item.

Item 4. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

Under the supervision and with the participation of our management, including our Principal Executive Officer and Principal Financial Officer, we conducted an evaluation of the effectiveness of our disclosure controls and procedures, as such term is defined under Rule 13a-15(e) and Rule 15d-15(e) promulgated under the Exchange Act. Based on this evaluation, our Principal Executive Officer and our Principal Financial Officer concluded that, as of the end of the period covered by this Quarterly Report on Form 10-Q, our disclosure controls and procedures were effective and were designed to ensure that information we are required to disclose in the reports that we file or submit under the Exchange Act is accumulated and communicated to management, including our Principal Executive Officer and Principal Financial Officer, as appropriate, to allow timely decisions regarding required disclosure, and is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules

and forms. It should be noted that any system of controls is designed to provide reasonable, but not absolute, assurances that the system will achieve its stated goals under all reasonably foreseeable circumstances. Our Principal Executive Officer and Principal Financial Officer have each concluded that our disclosure controls and procedures as of the end of the period covered by this report are effective at a level that provides such reasonable assurances.

Changes in Internal Control Over Financial Reporting

There was no change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the three months ended March 31, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II - OTHER INFORMATION

Item 1. Legal Proceedings

We are not currently a party to any material legal proceedings. From time to time, we may be subject to various legal proceedings and claims that arise in the ordinary course of our business activities. Regardless of the outcome, litigation can have a material adverse effect on us because of defense and settlement costs, diversion of management resources and other factors.

Item 1A. Risk Factors

Our results of operations and financial condition are subject to numerous risks and uncertainties described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023. There have been no material changes to the risk factors described in Part I, Item 1A "Risk Factors" of our 2023 Form 10-K.

Item 5. Other Information

Trading Plans of Our Directors and Officers

During the quarter ended March 31, 2024, none of our directors or executive officers adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each item is defined in Item 408 of Regulation S-K.

Item 6. Exhibits


Exhibit No.		Description

31.1		Certification of Principal Executive Officer pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as amended. Filed herewith.

31.2		Certification of Principal Financial Officer pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as amended. Filed herewith.

32.1		Certification of Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350 as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. Submitted herewith.

101.INS		XBRL Instance Document (the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document)

101.SCH		Inline XBRL Taxonomy Extension Schema Document

101.CAL		Inline XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF		Inline XBRL Taxonomy Extension Definition Linkbase Document

101.LAB		Inline XBRL Taxonomy Extension Label Linkbase Document

101.PRE		Inline XBRL Taxonomy Extension Presentation Linkbase Document

104		Cover Page Interactive Data File (embedded within the Inline XBRL document and included in Exhibit 101)

AGENUS INC.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.


Date:	May 7, 2024	AGENUS INC.

		/s/ CHRISTINE M. KLASKIN
		Christine M. Klaskin VP, Finance, Principal Financial Officer, Principal Accounting Officer

Exhibit 31.1

Certification Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as amended

I, Garo H. Armen, certify that:

I have reviewed this Quarterly Report on Form 10-Q of Agenus Inc.;

Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the Registrant as of, and for, the periods presented in this report;

The Registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the Registrant and have:

designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the Registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with U.S. generally accepted accounting principles;

evaluated the effectiveness of the Registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

disclosed in this report any change in the Registrant’s internal control over financial reporting that occurred during the Registrant’s most recent fiscal quarter (the Registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the Registrant’s internal control over financial reporting; and

The Registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the Registrant’s auditors and the audit committee of the Registrant’s board of directors (or persons performing the equivalent function):

all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Registrant’s ability to record, process, summarize and report financial information; and

any fraud, whether or not material, that involves management or other employees who have a significant role in the Registrant’s internal control over financial reporting.


Date: May 7, 2024			/s/ GARO H. ARMEN, PH.D.
			Garo H. Armen, Ph.D.
			Chief Executive Officer and Principal Executive Officer

Exhibit 31.2

Certification Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as amended

I, Christine M. Klaskin, certify that:

I have reviewed this Quarterly Report on Form 10-Q of Agenus Inc.;

any fraud, whether or not material, that involves management or other employees who have a significant role in the Registrant’s internal control over financial reporting.


Date: May 7, 2024			/s/ CHRISTINE M. KLASKIN
			Christine M. Klaskin
			VP, Finance and Principal Financial Officer

Exhibit 32.1

Certification

Pursuant to 18 U.S.C. Section 1350,

As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Quarterly Report on Form 10-Q of Agenus Inc. (the “Company”) for the quarterly period ended March 31, 2024 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), each of the undersigned to his/her knowledge hereby certifies, pursuant to 18 U.S.C. Section 1350, that:

(i)

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(ii)

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.


	/s/ GARO H. ARMEN, PH.D.
	Garo H. Armen, Ph.D.
	Chief Executive Officer and Principal Executive Officer

	/s/ CHRISTINE M. KLASKIN
	Christine M. Klaskin
	VP, Finance and Principal Financial Officer

Date: May 7, 2024

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

The foregoing certification is being furnished to the Securities and Exchange Commission as an exhibit to the Report and should not be considered filed as part of the Report.

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2024	May 03, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2024
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2024
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		20,999,261
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 Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
ASSETS
Cash and cash equivalents	$ 52,856	$ 76,110
Accounts receivable	476	25,836
Prepaid expenses	3,895	8,098
Other current assets	3,125	2,372
Total current assets	60,352	112,416
Property, plant and equipment, net of accumulated amortization and depreciation of $65,080 and $61,943 at March 31, 2024 and December 31, 2023, respectively	130,330	133,421
Operating lease right-of-use assets	29,340	29,606
Goodwill	24,698	24,723
Acquired intangible assets, net of accumulated amortization of $17,799 and $17,688 at March 31, 2024 and December 31, 2023, respectively	4,230	4,411
Other long-term assets	7,609	9,336
Total assets	256,559	313,913
LIABILITIES AND STOCKHOLDERS' DEFICIT
Current portion, long-term debt	13,575	146
Current portion, liability related to sale of future royalties and milestones	133,588	132,502
Current portion, deferred revenue	13	18
Current portion, operating lease liabilities	2,811	2,587
Accounts payable	50,693	61,446
Accrued liabilities	41,291	45,283
Other current liabilities	14,031	13,915
Total current liabilities	256,002	255,897
Long-term debt, net of current portion	0	12,768
Liability related to sale of future royalties and milestones, net of current portion	125,249	124,556
Deferred revenue, net of current portion	1,143	1,143
Operating lease liabilities, net of current portion	61,756	62,511
Other long-term liabilities	2,732	5,420
Commitments and contingencies
STOCKHOLDERS" DEFICIT
Common stock, par value $0.01 per share; 800,000,000 shares authorized; 20,994,143 and 19,718,662 shares issued at March 31, 2024 and December 31, 2023, respectively	210	197
Additional paid-in capital	1,816,985	1,796,095
Accumulated other comprehensive loss	(1,071)	(955)
Accumulated deficit	(2,017,554)	(1,955,668)
Total stockholders' deficit attributable to Agenus Inc.	(201,430)	(160,331)
Non-controlling interest	11,107	11,949
Total stockholders' deficit	(190,323)	(148,382)
Total liabilities and stockholders' deficit	256,559	313,913
Series A-1 convertible preferred stock [Member]
STOCKHOLDERS" DEFICIT
Series A-1 convertible preferred stock; 31,620 shares designated, issued, and outstanding at March 31, 2024 and December 31, 2023; liquidation value of $33,940 at March 31, 2024	$ 0	$ 0

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property plant and equipment, accumulated amortization and depreciation	$ 65,080	$ 61,943
Acquired intangible assets, accumulated amortization	$ 17,799	$ 17,688
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	20,994,143	19,718,662
Common stock, shares outstanding	20,994,143	19,718,662
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	$ 33,940

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Total revenues	$ 28,005	$ 22,902
Operating expenses:
Cost of service revenue	(107)	(2,294)
Research and development	(43,925)	(57,118)
General and administrative	(16,855)	(18,237)
Contingent purchase price consideration fair value adjustment	0	406
Operating loss	(32,882)	(54,341)
Other income (expense):
Non-operating income (expense)	(1,106)	40
Interest expense, net	(29,466)	(16,592)
Net loss	(63,454)	(70,893)
Dividends on Series A-1 convertible preferred stock	(54)	(53)
Net loss attributable to non-controlling interest	(1,568)	(2,639)
Net loss attributable to Agenus Inc. common stockholders	$ (61,940)	$ (68,307)
Per common share data:
Basic net loss attributable to Agenus Inc. common stockholders	$ (3.04)	$ (4.31)
Diluted net loss attributable to Agenus Inc. common stockholders	$ (3.04)	$ (4.31)
Weighted average number of Agenus Inc. common shares outstanding:
Basic	20,368	15,855
Diluted	20,368	15,855
Other comprehensive income (loss):
Foreign currency translation income (loss)	$ (116)	$ 2
Other comprehensive income (loss)	(116)	2
Comprehensive loss	(62,056)	(68,305)
Research and Development [Member]
Revenue:
Total revenues	0	2,612
Service Revenue [Member]
Revenue:
Total revenues	238	1,184
Non-Cash Royalty Revenue Related to the Sale of Future Royalties [Member]
Revenue:
Total revenues	$ 27,767	$ 19,106

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-controlling Interest [Member]	Accumulated Deficit [Member]	Series A-1 convertible preferred stock [Member] Preferred Stock [Member]
Stockholders' Equity, Beginning Balance at Dec. 31, 2022	$ (54,902)	$ 153	$ 1,647,561		$ 915	$ 6,376	$ (1,709,907)
Balance, shares at Dec. 31, 2022		15,278
Temporary Equity, Beginning Balance at Dec. 31, 2022								$ 0
Temporary Equity, shares at Dec. 31, 2022								32
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	$ 17	60,566
Shares sold at the market, shares		1,689
Issuance of director deferred shares	983	$ 1	982
Issuance of director deferred shares, shares		13
Issuance of shares for services	318		318
Issuance of shares for services, shares		7
Issuance of subsidiary shares to noncontrolling interest	726					726
Exercise of stock options and employee share purchases	374		329			45
Exercise of stock options and employee share purchases, shares		10
Issuance of shares for employee bonus	1,796	$ 1	4,224	$ (2,429)
Issuance of shares for employee bonus, Shares		136		(1)
Retirement of treasury shares	2,419	$ (1)	(9)	$ 2,429
Retirement of treasury shares, share		(50)		1
Stockholders' Equity, Ending Balance at Mar. 31, 2023	(53,109)	$ 171	1,718,537		917	5,427	(1,778,161)
Temporary Equity, Ending Balance at Mar. 31, 2023								$ 0
Balance, shares at Mar. 31, 2023		17,083
Temporary Equity, shares at Mar. 31, 2023								32
Stockholders' Equity, Beginning Balance at Dec. 31, 2022	(54,902)	$ 153	1,647,561		915	6,376	(1,709,907)
Balance, shares at Dec. 31, 2022		15,278
Temporary Equity, Beginning Balance at Dec. 31, 2022								$ 0
Temporary Equity, shares at Dec. 31, 2022								32
Share-based compensation						3,825
Stockholders' Equity, Ending Balance at Dec. 31, 2023	(148,382)	$ 197	1,796,095		(955)	11,949	(1,955,668)
Temporary Equity, Ending Balance at Dec. 31, 2023								$ 0
Balance, shares at Dec. 31, 2023		19,718
Temporary Equity, shares at Dec. 31, 2023								32
Net loss	(63,454)					(1,568)	(61,886)
Other comprehensive income (loss)	(116)				(116)
Share-based compensation	4,196		3,477			719
Shares sold at the market	17,171	$ 13	17,158
Shares sold at the market, shares		1,249
Payment of CEO payroll in shares	89		89
Payment of CEO payroll In shares, shares		7
Vesting of nonvested shares, shares		8
Exercise of stock options and employee share purchases	173		166			7
Exercise of stock options and employee share purchases, shares		12
Stockholders' Equity, Ending Balance at Mar. 31, 2024	$ (190,323)	$ 210	$ 1,816,985		$ (1,071)	$ 11,107	$ (2,017,554)
Temporary Equity, Ending Balance at Mar. 31, 2024								$ 0
Balance, shares at Mar. 31, 2024		20,994
Temporary Equity, shares at Mar. 31, 2024								32

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (63,454)	$ (70,893)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,374	2,562
Share-based compensation	4,152	5,485
Non-cash royalty revenue	(27,767)	(19,106)
Non-cash interest expense	29,595	17,273
Loss disposal of assets, net	9	21
Other, net	1,125	(406)
Changes in operating assets and liabilities:
Accounts receivable	25,341	1,291
Prepaid expenses	4,202	2,965
Accounts payable	(10,733)	2,032
Deferred revenue	(4)	(2,382)
Accrued liabilities and other current liabilities	(3,622)	5,158
Other operating assets and liabilities	(409)	(2,526)
Net cash used in operating activities	(38,191)	(58,526)
Cash flows from investing activities:
Purchases of plant and equipment	(35)	(1,842)
Sale of long-term investment	264
Purchases of available-for-sale securities		(14,647)
Proceeds from sale of available-for-sale securities		5,000
Net cash provided by (used in) investing activities	229	(11,489)
Cash flows from financing activities:
Net proceeds from sale of equity	17,171	60,583
Proceeds from employee stock purchases and option exercises	173	374
Purchase of treasury shares to satisfy tax withholdings		(2,819)
Payment of finance lease obligation	(2,514)	(1,888)
Net cash provided by financing activities	14,830	56,250
Effect of exchange rate changes on cash	(122)	(90)
Net decrease in cash, cash equivalents and restricted cash	(23,254)	(13,855)
Cash, cash equivalents and restricted cash, beginning of period	79,779	181,343
Cash, cash equivalents and restricted cash, end of period	56,525	167,488
Supplemental cash flow information:
Cash paid for interest	667	830
Supplemental disclosures - non-cash activities:
Purchases of plant and equipment in accounts payable and accrued liabilities		3,893
Insurance financing agreement	612	707
Issuance of subsidiary shares for employee bonus		726
Lease right-of-use assets obtained in exchange for new operating lease liabilities	105	250
Lease right-of-use assets obtained in exchange for new finance lease liabilities	122	3,630
Payment for Services [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		318
Employee Bonus [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock		$ 4,215
Issuance of subsidiary options	$ 133

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical)	Mar. 31, 2023 $ / shares
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

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024
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 of Presentation

3 Months Ended

Mar. 31, 2024

Description Of Business [Abstract]

Business, Liquidity and Basis of Presentation

Note A – Business, Liquidity and Basis of Presentation

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.

•

Our saponin-based vaccine adjuvant platform, primarily centered around our STIMULON™ cultured plant cell (“cpc”) QS-21 adjuvant (“STIMULON cpcQS-21”).

•

A pipeline of novel allogeneic invariant natural killer T cell therapies for treating cancer and other immune-mediated diseases, controlled by MiNK.

Net Loss Per Share

3 Months Ended

Mar. 31, 2024

Earnings Per Share [Abstract]

Net Loss Per Share

Note B – Net Loss Per Share


	Three Months Ended March 31,
	2024		2023
Warrants		99		99
Stock options		2,205		2,184
Non-vested shares		26		127
Series A-1 convertible preferred stock		17		17

Investments

3 Months Ended

Mar. 31, 2024

Cash and Cash Equivalents [Abstract]

Investments

Note C – Investments

Cash equivalents and short-term investments consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024				December 31, 2023
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Institutional money market funds	$	49,220	$	49,220	$	70,485	$	70,485
Total	$	49,220	$	49,220	$	70,485	$	70,485

As a result of the short-term nature of these investments, there were minimal unrealized holding gains or losses for the three months ended March 31, 2024 and 2023.

As of both March 31, 2024 and December 31, 2023, all of the investments listed above were classified as cash equivalents on our condensed consolidated balance sheets.

Goodwill and Acquired Intangible Assets

3 Months Ended

Mar. 31, 2024

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 three months ended March 31, 2024 (in thousands):


Balance, December 31, 2023	$	24,723
Effect of foreign currency		(25	)
Balance, March 31, 2024	$	24,698

Acquired intangible assets consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	As of March 31, 2024
	Amortization period (years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Intellectual property	7-15 years	$	16,841	$	(15,268	)	$	1,573
Trademarks	4-4.5 years		1,199		(1,193	)		6
Other	2-7 years		1,932		(1,338	)		594
In-process research and development	Indefinite		2,057		—			2,057
Total		$	22,029	$	(17,799	)	$	4,230


	As of December 31, 2023
	Amortization period (years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Intellectual property	7-15 years	$	16,841	$	(15,184	)	$	1,657
Trademarks	4-4.5 years		1,213		(1,185	)		28
Other	2-7 years		1,988		(1,319	)		669
In-process research and development	Indefinite		2,057		—			2,057
Total		$	22,099	$	(17,688	)	$	4,411

Debt

3 Months Ended

Mar. 31, 2024

Debt Disclosure [Abstract]

Debt

Note E – Debt

Debt obligations consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


Debt instrument	Balance at March 31, 2024
Current Portion:
Debentures	$	146
2015 Subordinated Notes		12,817
Other		612
Total	$	13,575


Debt instrument	Balance at December 31, 2023
Current Portion:
Debentures	$	146
Long-term Portion:
2015 Subordinated Notes		12,768
Total	$	12,914

As of March 31, 2024 and December 31, 2023, the principal amount of our outstanding debt balance was $13.8 million and $13.1 million, respectively.

Liability Related to the Sale of Future Royalties and Milestones

3 Months Ended

Mar. 31, 2024

Note F – Liability Related to the Sale of Future Royalties and Milestones

The following table shows the activity within the liability account in the three months ended March 31, 2024 (in thousands):


	Period from December 31, 2023 to March 31, 2024
Liability related to sale of future royalties and milestones - beginning balance	$	257,296
Non-cash royalty revenue		(27,767	)
Non-cash interest expense recognized		29,531
Liability related to sale of future royalties and milestones - ending balance		259,060
Less: unamortized transaction costs		(223	)
Liability related to sale of future royalties and milestones, net	$	258,837

Healthcare Royalty Partners

Accrued and Other Current Liabilities

3 Months Ended

Mar. 31, 2024

Other Liabilities Disclosure [Abstract]

Accrued and Other Current Liabilities

Note G – Accrued and Other Current Liabilities

Accrued liabilities consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024		December 31, 2023
Payroll	$	18,514	$	14,512
Professional fees		6,195		7,101
Contract manufacturing costs		5,334		7,613
Research services		6,274		10,807
Other		4,974		5,250
Total	$	41,291	$	45,283

Other current liabilities consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024		December 31, 2023
Finance lease liabilities	$	10,738	$	10,457
Other		3,293		3,458
Total	$	14,031	$	13,915

Fair Value Measurements

3 Months Ended

Mar. 31, 2024

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	March 31, 2024		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents (Note C)	$	49,220	$	49,220	$	—	$	—
Long-term investments		1,834		1,834		—		—
Total	$	51,054	$	51,054	$	—	$	—
Liabilities:
Contingent purchase price considerations	$	318	$	—	$	—	$	318
Total	$	318	$	—	$	—	$	318

Description	December 31, 2023		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents (Note C)	$	70,485	$	70,485	$	—	$	—
Long-term investments		3,222		3,222		—		—
Total	$	73,707	$	73,707	$	—	$	—
Liabilities:
Contingent purchase price consideration	$	318	$	—	$	—	$	318
Total	$	318	$	—	$	—	$	318

Long-term investments are included in "Other long-term assets" in our condensed consolidated balance sheets.

Revenue from Contracts with Customers

3 Months Ended

Mar. 31, 2024

Collaboration [Abstract]

Revenue from Contracts with Customers

Note I – Revenue from Contracts with Customers

Gilead Collaboration Agreement

Collaboration Revenue

Disaggregation of Revenue


	Three months ended March 31, 2024
	United States		Rest of World		Total
Revenue Type
Other services	$	—	$	238	$	238
Non-cash royalties		27,767		—		27,767
	$	27,767	$	238	$	28,005

	Three months ended March 31, 2023
Revenue Type
Research and development services		267		—		267
Other services		—		1,184		1,184
Recognition of deferred revenue		2,345		—		2,345
Non-cash royalties		19,106		—		19,106
	$	21,718	$	1,184	$	22,902

Contract Balances

The following table provides information about contract liabilities from contracts with customers (in thousands):


Three months ended March 31, 2024	Balance at beginning of period		Additions		Deductions			Balance at end of period
Contract liabilities:
Deferred revenue	$	1,161	$	5	$	(10	)	$	1,156

We also recorded a $0.5 million receivable as of March 31, 2024, for research and development and other services provided.

Share-Based Compensation Plans

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement, Noncash Expense [Abstract]

Share-Based Compensation Plans

Note J – Share-based Compensation Plans

A summary of option activity for the three months ended March 31, 2024 is presented below:


	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding at December 31, 2023		2,141,360		$	65.00
Granted		164,506			17.44
Exercised		—			—
Forfeited		(11,982	)		48.61
Expired		(88,971	)		63.66
Outstanding at March 31, 2024		2,204,913		$	61.55		6.61	$	—
Vested or expected to vest at March 31, 2024		2,204,913		$	61.55		6.61	$	—
Exercisable at March 31, 2024		1,558,872		$	69.34		5.88	$	—

The weighted average grant-date fair values of stock options granted during the three months ended March 31, 2024 and 2023 were $8.82 and $30.60, respectively.

A summary of non-vested stock activity for the three months ended March 31, 2024 is presented below:


	Non-vested Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2023		27,163		$	37.20
Granted		10,406			12.16
Vested		(7,989	)		31.08
Forfeited		(4,000	)		41.72
Outstanding at March 31, 2024		25,580		$	28.21

During the three months ended March 31, 2024, 11,816 shares were issued under the 2019 Employee Stock Purchase Plan and 7,989 shares were issued as a result of the vesting of non-vested stock.

The impact on our results of operations from share-based compensation for the three months ended March 31, 2024 and 2023, was as follows (in thousands):


	Three Months Ended March 31,
	2024		2023
Research and development	$	1,314	$	1,733
General and administrative		2,882		3,752
Total share-based compensation expense	$	4,196	$	5,485

Restricted Cash

3 Months Ended

Mar. 31, 2024

Cash and Cash Equivalents [Abstract]

Restricted Cash

Note K – Restricted Cash


	Three Months Ended March 31, 2024				Three Months Ended March 31, 2023
	Beginning of Period		End of Period		Beginning of Period		End of Period
Cash and cash equivalents	$	76,110	$	52,856	$	178,674	$	164,819
Restricted cash		3,669		3,669		2,669		2,669
Cash, cash equivalents and restricted cash	$	79,779	$	56,525	$	181,343	$	167,488

Equity

3 Months Ended

Mar. 31, 2024

Equity [Abstract]

Equity

Note L – Equity

Non-controlling Interest

3 Months Ended

Mar. 31, 2024

Noncontrolling Interest [Abstract]

Non-controlling Interest

Note M – Non-controlling Interest


	March 31, 2024			December 31, 2023
MiNK Therapeutics, Inc.		37	%		37	%
SaponiQx, Inc.		30	%		30	%

Changes in non-controlling interest for the periods ended March 31, 2024 and December 31, 2023, were as follows (in thousands):


	March 31, 2024			December 31, 2023
Beginning balance	$	11,949		$	6,376

Net loss attributable to non-controlling interest		(1,568	)		(11,676	)

Other items:
Distribution of subsidiary shares to Agenus stockholders		—			14,888
Purchase of subsidiary shares		—			(2,546	)
Issuance of subsidiary shares for employee bonus		—			1,011
Issuance of subsidiary shares for employee stock purchase plan and exercise of options		7			71
Subsidiary share-based compensation		719			3,825
Total other items		726			17,249

Ending balance	$	11,107		$	11,949

Distribution of subsidiary shares to Agenus stockholders

Purchase of subsidiary shares

During the year ended December 31, 2023, we purchased 446,494 shares of MiNK common stock in multiple open market transactions.

Related Party Transactions

3 Months Ended

Mar. 31, 2024

Related Party Transactions

Note N – Related Party Transactions

Recent Accounting Pronouncements

3 Months Ended

Mar. 31, 2024

Accounting Standards Update and Change in Accounting Principle [Abstract]

Recent Accounting Pronouncements

Note O – Recent Accounting Pronouncements

Recently Issued, Not Yet Adopted

Subsequent Events

3 Months Ended

Mar. 31, 2024

Subsequent Events [Abstract]

Subsequent Events

Note P – Subsequent Events

Reverse Stock Split

Purchase Agreement

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2024

Earnings Per Share [Abstract]

Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding

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 March 31, 2024 and 2023, as they would be anti-dilutive (in thousands):


	Three Months Ended March 31,
	2024		2023
Warrants		99		99
Stock options		2,205		2,184
Non-vested shares		26		127
Series A-1 convertible preferred stock		17		17

Investments (Tables)

3 Months Ended

Mar. 31, 2024

Cash and Cash Equivalents [Abstract]

Schedule of Cash Equivalents

Cash equivalents and short-term investments consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024				December 31, 2023
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Institutional money market funds	$	49,220	$	49,220	$	70,485	$	70,485
Total	$	49,220	$	49,220	$	70,485	$	70,485

Goodwill and Acquired Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2024

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 three months ended March 31, 2024 (in thousands):


Balance, December 31, 2023	$	24,723
Effect of foreign currency		(25	)
Balance, March 31, 2024	$	24,698

Schedule of Acquired Intangible Assets

Acquired intangible assets consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	As of March 31, 2024
	Amortization period (years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Intellectual property	7-15 years	$	16,841	$	(15,268	)	$	1,573
Trademarks	4-4.5 years		1,199		(1,193	)		6
Other	2-7 years		1,932		(1,338	)		594
In-process research and development	Indefinite		2,057		—			2,057
Total		$	22,029	$	(17,799	)	$	4,230


	As of December 31, 2023
	Amortization period (years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Intellectual property	7-15 years	$	16,841	$	(15,184	)	$	1,657
Trademarks	4-4.5 years		1,213		(1,185	)		28
Other	2-7 years		1,988		(1,319	)		669
In-process research and development	Indefinite		2,057		—			2,057
Total		$	22,099	$	(17,688	)	$	4,411

Debt (Tables)

3 Months Ended

Mar. 31, 2024

Debt Disclosure [Abstract]

Schedule of Debt Obligations

Debt obligations consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


Debt instrument	Balance at March 31, 2024
Current Portion:
Debentures	$	146
2015 Subordinated Notes		12,817
Other		612
Total	$	13,575


Debt instrument	Balance at December 31, 2023
Current Portion:
Debentures	$	146
Long-term Portion:
2015 Subordinated Notes		12,768
Total	$	12,914

Liability Related to the Sale of Future Royalties and Milestones (Tables)

3 Months Ended

Mar. 31, 2024

Schedule of Liability Account

The following table shows the activity within the liability account in the three months ended March 31, 2024 (in thousands):


	Period from December 31, 2023 to March 31, 2024
Liability related to sale of future royalties and milestones - beginning balance	$	257,296
Non-cash royalty revenue		(27,767	)
Non-cash interest expense recognized		29,531
Liability related to sale of future royalties and milestones - ending balance		259,060
Less: unamortized transaction costs		(223	)
Liability related to sale of future royalties and milestones, net	$	258,837

Accrued and Other Current Liabilities (Tables)

3 Months Ended

Mar. 31, 2024

Other Liabilities Disclosure [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024		December 31, 2023
Payroll	$	18,514	$	14,512
Professional fees		6,195		7,101
Contract manufacturing costs		5,334		7,613
Research services		6,274		10,807
Other		4,974		5,250
Total	$	41,291	$	45,283

Schedule of Other Current Liabilities

Other current liabilities consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31, 2024		December 31, 2023
Finance lease liabilities	$	10,738	$	10,457
Other		3,293		3,458
Total	$	14,031	$	13,915

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2024

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	March 31, 2024		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents (Note C)	$	49,220	$	49,220	$	—	$	—
Long-term investments		1,834		1,834		—		—
Total	$	51,054	$	51,054	$	—	$	—
Liabilities:
Contingent purchase price considerations	$	318	$	—	$	—	$	318
Total	$	318	$	—	$	—	$	318

Description	December 31, 2023		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents (Note C)	$	70,485	$	70,485	$	—	$	—
Long-term investments		3,222		3,222		—		—
Total	$	73,707	$	73,707	$	—	$	—
Liabilities:
Contingent purchase price consideration	$	318	$	—	$	—	$	318
Total	$	318	$	—	$	—	$	318

Revenue from Contracts with Customers (Tables)

3 Months Ended

Mar. 31, 2024

Collaboration [Abstract]

Summary of Disaggregation of Revenue


	Three months ended March 31, 2024
	United States		Rest of World		Total
Revenue Type
Other services	$	—	$	238	$	238
Non-cash royalties		27,767		—		27,767
	$	27,767	$	238	$	28,005

	Three months ended March 31, 2023
Revenue Type
Research and development services		267		—		267
Other services		—		1,184		1,184
Recognition of deferred revenue		2,345		—		2,345
Non-cash royalties		19,106		—		19,106
	$	21,718	$	1,184	$	22,902

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):


Three months ended March 31, 2024	Balance at beginning of period		Additions		Deductions			Balance at end of period
Contract liabilities:
Deferred revenue	$	1,161	$	5	$	(10	)	$	1,156

Share-Based Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement, Noncash Expense [Abstract]

Schedule of Stock Option Activity

A summary of option activity for the three months ended March 31, 2024 is presented below:


	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding at December 31, 2023		2,141,360		$	65.00
Granted		164,506			17.44
Exercised		—			—
Forfeited		(11,982	)		48.61
Expired		(88,971	)		63.66
Outstanding at March 31, 2024		2,204,913		$	61.55		6.61	$	—
Vested or expected to vest at March 31, 2024		2,204,913		$	61.55		6.61	$	—
Exercisable at March 31, 2024		1,558,872		$	69.34		5.88	$	—

Summary of Non-vested Stock Activity

A summary of non-vested stock activity for the three months ended March 31, 2024 is presented below:


	Non-vested Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2023		27,163		$	37.20
Granted		10,406			12.16
Vested		(7,989	)		31.08
Forfeited		(4,000	)		41.72
Outstanding at March 31, 2024		25,580		$	28.21

Schedule of Share-Based Compensation Expense

The impact on our results of operations from share-based compensation for the three months ended March 31, 2024 and 2023, was as follows (in thousands):


	Three Months Ended March 31,
	2024		2023
Research and development	$	1,314	$	1,733
General and administrative		2,882		3,752
Total share-based compensation expense	$	4,196	$	5,485

Restricted Cash (Tables)

3 Months Ended

Mar. 31, 2024

Cash and Cash Equivalents [Abstract]

Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash


	Three Months Ended March 31, 2024				Three Months Ended March 31, 2023
	Beginning of Period		End of Period		Beginning of Period		End of Period
Cash and cash equivalents	$	76,110	$	52,856	$	178,674	$	164,819
Restricted cash		3,669		3,669		2,669		2,669
Cash, cash equivalents and restricted cash	$	79,779	$	56,525	$	181,343	$	167,488

Non-controlling Interest (Tables)

3 Months Ended

Mar. 31, 2024

Noncontrolling Interest [Abstract]

Schedule Of Approximate Interests In Certain Consolidated Subsidiaries


	March 31, 2024			December 31, 2023
MiNK Therapeutics, Inc.		37	%		37	%
SaponiQx, Inc.		30	%		30	%

Schedule Of Changes In Non-controlling Interest

Changes in non-controlling interest for the periods ended March 31, 2024 and December 31, 2023, were as follows (in thousands):


	March 31, 2024			December 31, 2023
Beginning balance	$	11,949		$	6,376

Net loss attributable to non-controlling interest		(1,568	)		(11,676	)

Other items:
Distribution of subsidiary shares to Agenus stockholders		—			14,888
Purchase of subsidiary shares		—			(2,546	)
Issuance of subsidiary shares for employee bonus		—			1,011
Issuance of subsidiary shares for employee stock purchase plan and exercise of options		7			71
Subsidiary share-based compensation		719			3,825
Total other items		726			17,249

Ending balance	$	11,107		$	11,949

Business, Liquidity and Basis of Presentation (Narrative) (Details) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Apr. 03, 2024 $ / shares	Aug. 31, 2023	Mar. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares	Mar. 31, 2023 USD ($)	Mar. 29, 2023 $ / shares	Dec. 31, 2022 USD ($)
Product Information [Line Items]
Cash, cash equivalents and short term investment			$ 52,900
Decrease cash, cash equivalents and short term investment			23,300
Accumulated deficit			2,017,554	$ 1,955,668
Cash and cash equivalents			$ 52,856	$ 76,110	$ 164,819		$ 178,674
Percentage of reduced workforce		25.00%
Common stock, par value \| $ / shares			$ 0.01	$ 0.01		$ 0.01
Subsequent Event [Member]
Product Information [Line Items]
Common stock, par value \| $ / shares	$ 0.01
Subsequent Event [Member] \| Common Stock [Member]
Product Information [Line Items]
Reverse stock split, ratio	0.05
Reverse stock split ratio, description	1-for-20
Subordinated Notes [Member]
Product Information [Line Items]
Debt instrument, face amount			$ 13,000
Debt instrument maturity month and year			2025-02
MiNK Therapeutics, Inc.
Product Information [Line Items]
Cash and cash equivalents				$ 3,400

Net Loss Per Share (Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding) (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	99,000	99,000
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,205,000	2,184,000
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	26,000	127,000
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	17,000	17,000

Investments (Schedule of Cash Equivalents and Short Term Investments) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	$ 52,900
Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	49,220	$ 70,485
Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	49,220	70,485
Institutional Money Market Funds [Member] \| Cost [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	49,220	70,485
Institutional Money Market Funds [Member] \| Estimated Fair Value [Member]
Cash And Cash Equivalents [Line Items]
Cash equivalents and short term investments	$ 49,220	$ 70,485

Goodwill and Acquired Intangible Assets (Schedule of Changes in Goodwill) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 24,723
Effect of foreign currency	(25)
Ending balance	$ 24,698

Goodwill and Acquired Intangible Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 22,029	$ 22,099
Accumulated amortization	(17,799)	(17,688)
Net carrying amount	4,230	4,411
Indefinite-lived Intangible Assets Acquired	2,057	2,057
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	16,841	16,841
Accumulated amortization	(15,268)	(15,184)
Net carrying amount	$ 1,573	$ 1,657
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	$ 1,199	$ 1,213
Accumulated amortization	(1,193)	(1,185)
Net carrying amount	$ 6	$ 28
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	$ 1,932	$ 1,988
Accumulated amortization	(1,338)	(1,319)
Net carrying amount	$ 594	$ 669
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	7 years

Goodwill and Acquired Intangible Assets (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 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 2024	$ 0.4
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
Finite-Lived Intangible Assets, Estimated Amortization Expense, December 31, 2028	$ 0.3

Debt - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Other	$ 612
Total	13,575	$ 12,914
2015 Subordinated Notes [Member]
Debt Instrument [Line Items]
2015 Subordinated Notes	12,817	12,768
Debentures [Member]
Debt Instrument [Line Items]
Debentures	$ 146	$ 146

Debt (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
Principal amount of outstanding debt	$ 13.8	$ 13.1

Liability Related to the Sale of Future Royalties and Milestones (Schedule of Liability Account) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Liability Related To Sale Of Future Royalties And Milestones [Abstract]
Liability related to sale of future royalties and milestones - beginning balance	$ 257,296
Non-cash royalty revenue	(27,767)
Non-cash interest expense recognized	29,531
Liability related to sale of future royalties and milestones - ending balance	259,060
Less: unamortized transaction costs	(223)
Liability related to sale of future royalties and milestones, net	$ 258,837

Liability Related to the Sale of Future Royalties and Milestones (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 19, 2018	Mar. 31, 2024
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Non-cash royalty revenue recognized		$ 27,767
Non-cash interest expense		29,531
HCR [Member] \| GSK Agreements [Member] \| Royalty Purchase Agreement [Member]
Liability Related To Sale Of Future Royalties And Milestones [Line Items]
Percentage of purchase of worldwide rights to receive royalties	100.00%
Gross proceeds received for royalty rights	$ 190,000
Non-cash royalty revenue recognized		27,800
Non-cash interest expense		$ 29,500
Effective annual interest rate		48.00%
Prospective effective annual interest rate		26.50%

Accrued and Other Current Liabilities (Schedule of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued Liabilities, Current [Abstract]
Payroll	$ 18,514	$ 14,512
Professional fees	6,195	7,101
Contract manufacturing costs	5,334	7,613
Research services	6,274	10,807
Other	4,974	5,250
Total	$ 41,291	$ 45,283

Accrued and Other Current Liabilities (Schedule of Other Current Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Other Liabilities, Current [Abstract]
Finance lease liabilities	$ 10,738	$ 10,457
Other	3,293	3,458
Total	$ 14,031	$ 13,915

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase price considerations	$ 318	$ 318
Long-term Debt, Gross	13,800	13,100
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	$ 13,600	$ 13,000

Fair Value Measurements (Schedule of Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents	$ 49,220	$ 70,485
Long-term investments	1,834	3,222
Total	51,054	73,707
Contingent purchase price considerations	318	318
Total	318	318
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents	49,220	70,485
Long-term investments	1,834	3,222
Total	51,054	73,707
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
Long-term investments	0	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
Long-term investments	0	0
Total	0	0
Contingent purchase price considerations	318	318
Total	$ 318	$ 318

Revenue from Contracts with Customers (Narrative) (Details) - USD ($)		3 Months Ended
	Jan. 23, 2019	Mar. 31, 2024	Mar. 31, 2023	Dec. 20, 2018
Revenue From Contract With Customer [Line Items]
Shares sold at the market		$ 17,171,000	$ 60,583,000
Revenue		28,005,000	22,902,000
Asset impairment charges		0
Contract with customer, liability, revenue recognized		10,000
Receivables for R & D services		500,000
Capitalized contract , cost		0
Research and Development Revenue [Member]
Revenue From Contract With Customer [Line Items]
Revenue		0	2,612,000
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
Revenue		$ 0
Gilead Sciences, Inc. [Member] \| Collaborative Arrangement [Member] \| Research and Development Revenue [Member]
Revenue From Contract With Customer [Line Items]
Revenue			$ 2,300,000

Revenue from Contracts with Customers (Summary of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation Of Revenue [Line Items]
Revenue	$ 28,005	$ 22,902
Research and development services [Member]
Disaggregation Of Revenue [Line Items]
Revenue		267
Other services [Member]
Disaggregation Of Revenue [Line Items]
Revenue	238	1,184
Recognition of deferred revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue		2,345
Non-cash royalty revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	27,767	19,106
Non-Cash Royalty Revenue Related to the Sale of Future Royalties [Member]
Disaggregation Of Revenue [Line Items]
Revenue	27,767	19,106
United States [Member]
Disaggregation Of Revenue [Line Items]
Revenue	27,767	21,718
United States [Member] \| Research and development services [Member]
Disaggregation Of Revenue [Line Items]
Revenue		267
United States [Member] \| Recognition of deferred revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue		2,345
United States [Member] \| Non-cash royalty revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	27,767	19,106
Rest of World [Member]
Disaggregation Of Revenue [Line Items]
Revenue	238	1,184
Rest of World [Member] \| Other services [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 238	$ 1,184

Revenue from Contracts with Customers (Schedule of Information about Contract Assets and Contract Liabilities from Contracts with Customers) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Deferred revenue, Beginning Balance	$ 1,161
Additions	5
Deferred revenue, Deductions	(10)
Deferred revenue, Ending Balance	$ 1,156

Share-Based Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value of options granted	$ 8.82	$ 30.6
Shares issued from vesting of non vested stock	$ 31.08
Employee Stock Option [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense	$ 18.6
Unrecognized share-based compensation expense, weighted average period	1 year 8 months 12 days
Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized share-based compensation expense, Other than option	$ 1.3
Unrecognized share-based compensation expense, weighted average period, Other than option	3 years 6 months
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	11,816
Shares issued from vesting of non vested stock	7,989

Share-Based Compensation Plans (Schedule of Stock Option Activity) (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Options Outstanding, Beginning Balance \| shares	2,141,360
Options Granted \| shares	164,506
Options Forfeited \| shares	(11,982)
Options Expired \| shares	(88,971)
Options Outstanding, Ending Balance \| shares	2,204,913
Options Vested or expected to vest \| shares	2,204,913
Options Exercisable \| shares	1,558,872
Options Outstanding, Weighted Average Exercise Price, Beginning Balance \| $ / shares	$ 65
Options Granted, Weighted Average Exercise Price \| $ / shares	17.44
Options Forfeited, Weighted Average Exercise Price \| $ / shares	48.61
Options Expired, Weighted Average Exercise Price \| $ / shares	63.66
Options Outstanding, Weighted Average Exercise Price, Ending Balance \| $ / shares	61.55
Options Vested or expected to vest, Weighted Average Exercise Price \| $ / shares	61.55
Options Exercisable, Weighted Average Exercise Price \| $ / shares	$ 69.34
Options Outstanding, Weighted Average Remaining Contractual Term	6 years 7 months 9 days
Options Vested or expected to vest, Weighted Average Remaining Contractual Term	6 years 7 months 9 days
Options Exercisable, Weighted Average Remaining Contractual Term	5 years 10 months 17 days

Share-Based Compensation Plans (Summary of Non-vested Stock Activity) (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Non-vested Shares Outstanding, Beginning Balance \| shares	27,163
Non-vested Shares Granted \| shares	10,406
Non-vested Shares Vested \| shares	(7,989)
Non-vested Shares Forfeited \| shares	(4,000)
Non-vested Shares Outstanding, Ending Balance \| shares	25,580
Non-vested Shares Outstanding, Weighted Average Grant Date Fair Value, Beginning Balance \| $ / shares	$ 37.20
Non-vested Shares Granted, Weighted Average Grant Date Fair Value \| $ / shares	12.16
Non-vested Shares Vested, Weighted Average Grant Date Fair Value \| $ / shares	31.08
Non-vested Shares Forfeited, Weighted Average Grant Date Fair Value \| $ / shares	41.72
Non-vested Shares Outstanding, Weighted Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 28.21

Share-Based Compensation Plans (Schedule of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 4,196	$ 5,485
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	1,314	1,733
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 2,882	$ 3,752

Restricted Cash (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Cash and Cash Equivalents [Abstract]
Restricted cash	$ 3.7	$ 3.7

Restricted Cash (Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 52,856	$ 76,110	$ 164,819	$ 178,674
Restricted cash	3,669	3,669	2,669	2,669
Cash, cash equivalents and restricted cash	$ 56,525	$ 79,779	$ 167,488	$ 181,343

Equity (Narrative) (Details) - At Market Issuance Sales Agreement [Member] - B. Riley FBR, Inc. [Member] - New Sales Agreement [Member] $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) shares
Class Of Stock [Line Items]
Shares sold at the market, shares \| shares	6,725,642
Common stock, preferred stock, warrants, debt securities and units \| $	$ 300.0
Net proceeds from issuance of common stock \| $	$ 17.2
Shares sold at the market, shares \| shares	1,200,000

Non-controlling Interest - Schedule Of Approximate Interests In Certain Consolidated Subsidiaries (Details)	Mar. 31, 2024	Dec. 31, 2023
MiNK Therapeutics, Inc.
Minority Interest [Line Items]
Percentage of Non-controlling interest	37.00%	37.00%
SaponiQx, Inc.
Minority Interest [Line Items]
Percentage of Non-controlling interest	30.00%	30.00%

Non-controlling Interest - Schedule Of Changes In Non-controlling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Minority Interest [Line Items]
Beginning balance	$ 11,949
Net loss attributable to non-controlling interest	(1,568)	$ (2,639)
Issuance of subsidiary shares for employee bonus		726
Share-based compensation	4,196	5,485
Ending balance	11,107		$ 11,949
Non-controlling Interest [Member]
Minority Interest [Line Items]
Beginning balance	11,949	6,376	6,376
Net loss attributable to non-controlling interest	(1,568)		(11,676)
Distribution of subsidiary shares to Agenus stockholders			14,888
Purchase of subsidiary shares			(2,546)
Issuance of subsidiary shares for employee bonus			1,011
Issuance of subsidiary shares for employee stock purchase plan and exercise of options	7		71
Share-based compensation	719	$ 919	3,825
Total other items	726		17,249
Ending balance	$ 11,107		$ 11,949

Non-controlling Interest - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended	12 Months Ended
	May 01, 2023	Mar. 29, 2023	Mar. 31, 2023	Dec. 31, 2023	Mar. 31, 2024
Minority Interest [Line Items]
Issuance of subsidiary shares to noncontrolling interest			$ 726
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	$ 0.292
Number of fractional shares issued	0
MiNK Therapeutics, Inc.
Minority Interest [Line Items]
Common stock, par value		$ 0.00001
Purchase of subsidiary shares				446,494

Related Party Transactions (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Related Party Transaction [Line Items]
Related party expenses incurred	$ 0
Research and Development Manufacturing Services [Member]
Related Party Transaction [Line Items]
Total expenses		$ 228,000
Clinical Research Services [Member]
Related Party Transaction [Line Items]
Total expenses	$ 450,000

Subsequent Events (Narrative) (Details) - Subsequent Event [Member] $ / shares in Units, $ in Millions	May 06, 2024 USD ($) $ / shares shares	Apr. 03, 2024
Purchase Agreement [Member] \| Ligand Pharmaceuticals Incorporated [Member]
Subsequent Event [Line Items]
Percentage of synthetic royalty on worldwide net sales of purchased assets	2.625%
Percentage reduction in amounts payable upon overall payments due exceeding specified return hurdle	50.00%
Percentage increase in synthetic royalty based on certain future events	1.00%
Consideration on sale of purchased assets less reimbursable expenses	$ 75.0
Time-based option to invest, additional amount	25.0
Purchase Agreement [Member] \| Ligand Pharmaceuticals Incorporated [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Additional sales of purchased sssets to third parties on pro rata basis	$ 200.0
Purchase Agreement [Member] \| Ligand Pharmaceuticals Incorporated [Member] \| Covered License Agreements [Member]
Subsequent Event [Line Items]
Percentage of sale of development, regulatory and commercial milestone payments eligible to receive	31.875%
Percentage of royalties receipts	18.75%
Common Stock [Member]
Subsequent Event [Line Items]
Reverse stock split, ratio		0.05
Reverse stock split ratio, description		1-for-20
Common Stock [Member] \| Ligand Pharmaceuticals Incorporated [Member]
Subsequent Event [Line Items]
Warrants issued to purchase shars of common stock \| shares	867,052
Warrants, exercise price \| $ / shares	$ 17.3
Warrants, expiration date	May 06, 2029