Botensilimab/Balstilimab Data in MSS CRC Selected for the American Society of Clinical Oncology 2024 Annual Meeting

Agenus Inc. ("Agenus") (Nasdaq: AGEN), a leader in developing novel immunological agents to treat various cancers, today announced an upcoming presentation from the Phase 1b trial of botensilimab in combination with balstilimab ("BOT/BAL") in patients with relapsed/refractory microsatellite stable colorectal cancer with no active liver metastases (r/r MSS CRC NLM) will be presented at the upcoming American Society of Clinical Oncology (ASCO) Meeting, to be held May 31 ? June 4, 2024, in Chicago, IL. The poster presentation is for a sub-analysis of the r/r MSS CRC cohort of the Phase 1b study. This sub-analysis was done to determine whether treatment outcomes are correlated with specific sites of metastatic disease in patients with non-active liver mets.

Presentation Details:

Abstract Title: Botensilimab plus balstilimab in microsatellite stable metastatic colorectal cancer: Assessing efficacy in non-liver metastatic sites.

Abstract Number: 3556

Presenting Author: Marwan Fakih, MD, Division Head, GI Medical Oncology, City of Hope Comprehensive Cancer Center

Session: Poster Session ? Gastrointestinal Cancer ? Colorectal and Anal

Session Date and Time: June 1, 2024, at 1:30 p.m. ? 4:30 p.m. CT

Complete abstracts will be released Thursday, May 23, 2024, at 5:00 p.m. ET. Data presented at the conference will be available to view in the publications section of the Agenus website (https://agenusbio.com/publications) following the ASCO Meeting.

About Botensilimab

Botensilimab is an investigational multifunctional anti-CTLA-4 immune activator (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.

Approximately 900 patients have been treated with botensilimab 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, visit www.clinicaltrials.gov with the identifiers NCT03860272, NCT05608044, NCT05630183, and NCT05529316.

About Agenus

Agenus is a leading immuno-oncology company targeting cancer and infectious diseases with a comprehensive pipeline of immunological agents. The company's mission is 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 (through SaponiQx). 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.

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 a 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 2022, 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.