Agenus’ BOT+BAL Yields 17% ORR and 17.2-Month Median Overall Survival
Agenus’ Phase 1b C-800-01 trial in 341 patients with immunologically cold tumors reported a 17% objective response rate, 26% clinical benefit rate and median overall survival of 17.2 months with a 38% two-year survival rate. Blood–tumor biomarker integration achieved a C-index up to 0.73 in MSS mCRC subgroups.
1. Phase 1b C-800-01 Trial Results
In 341 efficacy-evaluable patients with advanced refractory tumors, the combination of botensilimab and balstilimab achieved a 17% objective response rate, 26% clinical benefit rate, median overall survival of 17.2 months and a 38% two-year survival rate.
2. Biomarker Stratification and Survival Prediction
Integrated analyses of blood-based inflammatory markers and tumor microenvironment immune features improved survival stratification in MSS mCRC, yielding a C-index up to 0.73 and identifying patient subgroups with markedly different outcomes.
3. Clinical Activity in Immunologically Cold Tumors
Durable responses were observed across MSS colorectal cancer, ovarian cancer, sarcoma and PD-1 relapsed non-small cell lung cancer, with activity noted even at low levels of tumor-infiltrating lymphocytes (≥34 cells/mm²).
4. Early Immune Activation Correlates with Benefit
Patients experiencing immune-mediated adverse events within 12 weeks had longer median overall survival (22.4 months vs. 13.7 months), linking early immune activation to improved outcomes.