• Webcast on Tuesday, October 21, 2025 at 4:00 p.m. ET

LEXINGTON, Mass. / Oct 16, 2025 / Business Wire / Agenus Inc. (“Agenus”) (Nasdaq: AGEN), a leader in immuno-oncology, will host a virtual Stakeholder Briefing on Tuesday, October 21, 2025, at 4:00 p.m. ET. The webcast will feature updates from leading experts on recent clinical progress and expanding international access for its immunotherapy combination botensilimab (BOT) and balstilimab (BAL). The session will be moderated by Garo Armen, PhD, Founder, Chairman, and CEO, and conclude with a live Q&A.

Featured Topics and Speakers

1. Expanding Immunotherapy’s Reach: ESMO 2025 Highlights
   Michael S. Gordon, MD, HonorHealth Research Institute
   
   Dr. Gordon will discuss results from his oral presentation at the European Society for Medical Oncology (ESMO) Congress 2025, featuring data from over 400 patients treated with BOT/BAL across multiple refractory solid tumors.
   
2. Access Beyond Borders: France’s Autorisation d’Accès Compassionnel (AAC) Program and BOT/BAL’s Inclusion
   Alexander M.M. Eggermont, MD, PhD, world-renowned immuno-oncologist and former Director General of the Gustave Roussy Cancer Center in France
   
   Professor Eggermont will provide perspective on the French AAC program and its implications for oncologists and patients living with refractory MSS colorectal cancer.

Stakeholder Briefing Details:

Webcast Link | https://riverside.fm/studio/agenus-presentation
Pre-registration is not required.

This session marks the second in Agenus’ 2025 Stakeholder Briefing Series, following the August event highlighting corporate strategy, clinical milestones, and the launch of the global Phase 3 BATTMAN trial. A third session will follow in November, continuing the dialogue on BOT/BAL’s progress and corporate milestones.

About Agenus

Agenus 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, visit www.agenusbio.com or @agenus_bio. Information that may be important to investors will be routinely posted on our website and social media channels.

About Botensilimab (BOT)

Botensilimab is a multifunctional, human Fc enhanced CTLA-4 blocking 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, downregulating intratumoral regulatory T cells, activating myeloid cells and inducing long-term memory responses.

Botensilimab alone, or in combination with Agenus’ investigational PD-1 antibody, balstilimab, has shown clinical responses across nine metastatic, late-line cancers. Approximately 1,200 patients have been treated across the botensilimab/balstilimab program in phase 1 and phase 2 clinical trials. For more information about botensilimab trials, visit www.clinicaltrials.gov.

About Balstilimab (BAL)

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 >900 patients to date and has demonstrated clinical activity and a favorable tolerability profile in several tumor types.

Forward-Looking Statements

This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the federal securities laws, including statements regarding the botensilimab and balstilimab clinical programs, expected trial initiations and regulatory plans, and the potential benefits of the combination therapy. Words such as “may,” “believes,” “expects,” “anticipates,” “hopes,” “intends,” “plans,” “forecasts,” “estimates,” “will,” “potential,” and similar expressions are intended to identify forward-looking statements. These statements are subject to risks and uncertainties that could cause actual results to differ materially from current expectations. Factors that could cause actual results to differ include, but are not limited to, those described under the “Risk Factors” section of Agenus’ most recent Annual Report on Form 10-K for 2024 and subsequent Quarterly Reports on Form 10-Q filed with the SEC. Agenus cautions investors not to place undue reliance on forward-looking statements in this release, which speak only as of the date of this announcement. The company undertakes no obligation to update or revise these statements, except as required by law. All forward-looking statements are expressly qualified in their entirety by this cautionary statement.