Agenus to Present BOT+BAL Long-Term Survival Data and Translational Research With agenT-797 in Colorectal Cancer at SITC 2026

LEXINGTON, Mass.--(BUSINESS WIRE)--$AGEN#BOT--Agenus Inc.(Nasdaq: AGEN),a leader in immuno-oncology innovation, today announced that two posters highlighting research on botensilimab (BOT), an Fc-enhanced multifunctional anti-CTLA-4 antibody, in combination with balstilimab (BAL), an anti-PD-1 antibody, have been accepted for presentation at the Society for Immunotherapy of Cancer (SITC) 2026 Annual Meeting, taking place November 4-8, 2026, in Phoenix, Arizona.

The clinical poster will review the features of long-term survivors of refractory microsatellite-stable (MSS) metastatic colorectal cancer (mCRC) who have been treated with BOT+BAL. A second poster will highlight translational research of BOT+BAL in combination with MiNK Therapeutics’ agenT-797 (iNKT cell therapy) with in a preclinical model of colorectal cancer liver metastases.

Abstract Title:Clinical features of long-term survivors treated with next-generation anti-CTLA-4 (botensilimab) plus anti-PD-1 (balstilimab) in refractory microsatellite-stable metastatic colorectal cancerPresenter:Anthony El-Khoueiry, MD.; USC Norris Comprehensive Cancer Center, Los Angeles, CADate:Saturday, November 7, 2026Time:10:00 a.m. - 2:00 p.m. and 6:00-8:10 p.m. MSTLocation:North Building, Lower Level, Exhibition Halls 4–5–6Poster No.: 472

Abstract Title:AgenT-797, an allogeneic iNKT cell therapy, enables tumor-cell killing in a human organoid model of immune checkpoint inhibitor–refractory colorectal cancer liver metastasesPresenter:Shanmugarajan Krishnan, Ph.D., M.S., B.S.; Agenus Inc., Lexington, MADate:Saturday, November 7, 2026Time:10:00 a.m. to 2:00 p.m. and 6:00 to 8:10 p.m. MSTLocation:North Building, Lower Level, Exhibition Halls 4–5–6Poster No.: 270

About AgenusAgenus is a leading immuno-oncology company targeting cancer with a comprehensive pipeline of immunological agents. The company was founded in 1994 with a mission to expand patient populations benefiting from cancer immunotherapy through combination approaches, using a broad repertoire of antibody therapeutics, adoptive cell therapies (through MiNK Therapeutics) and adjuvants. Agenus has robust end-to-end development capabilities, across commercial and clinical cGMP manufacturing facilities, research and discovery, and a global clinical operations footprint. Agenus is headquartered in Lexington, MA. For more information, visitwww.agenusbio.comor @agenus_bio. Information that may be important to investors will be routinely posted on our website and social media channels.

Botensilimab (BOT) is a human multifunctional, Fc-enhanced anti-CTLA-4 antibody designed to boost both innate and adaptive anti-tumor immune responses. Its novel design leverages mechanisms of action to extend immunotherapy benefits to “cold” tumors which generally respond poorly to standard of care or are refractory to conventional PD-1/CTLA-4 therapies and investigational therapies. Botensilimab augments immune responses across a wide range of tumor types by priming and activating T cells, reducing intratumoral regulatory T cells, activating myeloid cells and inducing durable memory responses.

Approximately 1,300 patients have been treated with botensilimab and/or balstilimab in phase 1 and phase 2 clinical trials. Botensilimab alone, or in combination with Agenus’ investigational PD-1 antibody, balstilimab, has shown clinical responses across nine metastatic, late-line cancers. For more information about botensilimab trials, visitwww.clinicaltrials.gov.

Balstilimab is a novel, fully human monoclonal immunoglobulin G4 (IgG4) designed to block PD-1 (programmed cell death protein 1) from interacting with its ligands PD-L1 and PD-L2. It has been evaluated in more than 900 patients to date and has demonstrated clinical activity and a favorable tolerability profile in several tumor types.

This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the federal securities laws, including statements regarding its botensilimab and balstilimab programs, expected regulatory timelines and filings, and any other statements containing the words "may," "believes," "expects," "anticipates," "hopes," "intends," "plans," "forecasts," "estimates," "will," “establish,” “potential,” “superiority,” “best in class,” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially. These risks and uncertainties include, among others, the factors described under the Risk Factors section of our most recent Annual Report on Form 10-K for 2025, and subsequent Quarterly Reports on Form 10-Q filed with the Securities and Exchange Commission. Agenus cautions investors not to place considerable reliance on the forward-looking statements contained in this release. These statements speak only as of the date of this press release, and Agenus undertakes no obligation to update or revise the statements, other than to the extent required by law. All forward-looking statements are expressly qualified in their entirety by this cautionary statement.