Agenus Reports Landmark BOT+BAL Data Showing 33% Three-Year Overall Survival in Refractory MSS Metastatic Colorectal Cancer Without Active L

Fully enrolled 123-patient Phase 1b cohort demonstrated 21.2-month median overall survival, 33% three-year overall survival, and a survival curve plateau beyond two years Data presented in a heavily pretreated population where durable long-term survival is rarely reported 17% of patients alive and off all systemic anticancer therapy at last follow-up Extended safety follow-up showed no new safety signals, no treatment-related deaths, and 98% resolution of immune-mediated diarrhea/colitis Agenus Inc. (NASDAQ: AGEN ), a leader in immuno-oncology innovation, today announced three-year landmark Phase 1b data from the fully enrolled C-800-01 cohort evaluating botensilimab (BOT), an Fc-enhanced multifunctional anti–CTLA-4 antibody, plus balstilimab (BAL), an anti–PD-1 antibody, in patients with refractory microsatellite-stable (MSS) metastatic colorectal cancer (mCRC) without active liver metastases. The data were presented at the European Society for Medical Oncology Gastrointestinal Cancers (ESMO GI) Congress 2026 on July 2 in Munich, Germany.