Agenus Presents Biomarker Data Demonstrating Survival Stratification in MSS mCRC and Other Immunologically Cold Tumors Treated with BOT+BAL

Core Insights - Agenus presented new biomarker data demonstrating survival stratification in microsatellite-stable metastatic colorectal cancer (MSS mCRC) and other immunologically cold tumors treated with the combination of botensilimab (BOT) and balstilimab (BAL) [1] Group 1: Clinical Trial Findings - The Phase 1b C-800-01 trial evaluated BOT in combination with BAL, showing that survival outcomes are influenced by systemic inflammation and tumor immune activity [1] - In 341 efficacy-evaluable patients, the 24-month overall survival rate was 38%, with a median overall survival of 17.2 months, a clinical benefit rate of 26%, and an objective response rate of 17% [1] - Clinical activity was observed across various tumor types, including MSS mCRC, ovarian cancer, sarcoma, and non-small cell lung cancer, with durable benefits noted in patients both naïve to and resistant to prior therapies [1] Group 2: Biomarker Insights - The integration of blood and tumor biomarkers improved survival stratification in MSS mCRC, identifying distinct patient subgroups with different survival outcomes, achieving a C-index of up to 0.73 [1] - Patients experiencing immune-mediated adverse events (imAEs) within the first 12 weeks of treatment had a longer median overall survival of 22.4 months compared to 13.7 months for those without imAEs [1] - Elevated systemic inflammation markers, such as the neutrophil-to-lymphocyte ratio and C-reactive protein, were significantly associated with shorter overall survival [1] Group 3: Mechanism of Action - Botensilimab is designed to enhance both innate and adaptive anti-tumor immune responses, potentially extending immunotherapy benefits to cold tumors that typically respond poorly to standard treatments [2] - The Fc-enhanced mechanism of BOT allows for clinical benefits even at low levels of immune infiltration, suggesting a lower threshold of baseline immunity is required for activity [1] - Approximately 1,200 patients have been treated with BOT and/or BAL in clinical trials, demonstrating clinical responses across nine metastatic, late-line cancers [2]