• First presentation of BOT+BAL melanoma data in heavily pretreated patients whose disease had resisted prior checkpoint therapy and who had poor-risk disease features
  • In the overall BOT+BAL treated population, median overall survival was 16.6 months and 42% of patients were alive at two years
  • Responses were durable with median duration of response not reached and 86% of responders remaining in response at 12 months

Agenus Inc. (NASDAQ:AGEN), a leader in immuno-oncology innovation, today announced the first disclosure of Phase 2 data from the C-800-23 study evaluating botensilimab (BOT), Agenus' multifunctional Fc-enhanced anti-CTLA-4 antibody, with balstilimab (BAL), an anti-PD-1 antibody, in patients with advanced cutaneous melanoma refractory or resistant to prior anti-PD-(L)1 therapy, including patients previously treated with anti-CTLA-4 therapy. The full dataset will be presented by Dr. Michael Atkins on May 31, 2026 at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.

The BOT+BAL combination arm included 36 heavily pretreated patients with advanced cutaneous melanoma. Most had disease that had resisted prior checkpoint therapy, and many had poor-risk features, including visceral disease and elevated LDH. In this setting, where patients have often exhausted the benefit of currently available checkpoint approaches, the most meaningful signals were the durability of benefit and survival outcomes observed with BOT+BAL.

In the overall BOT+BAL population, median overall survival was 16.6 months, 42% of patients were alive at two years, and median duration of response was not reached. Among responders, 86% remained in response at 12 months. Confirmed objective response rate was 22%, providing evidence of antitumor activity in a population where durable disease control is difficult to achieve.

Survival and durability were particularly notable in the subgroup of patients whose disease was refractory or resistant to both prior anti-PD-(L)1 and anti-CTLA-4 therapy. Published benchmarks show median overall survival of approximately 13 to 14 months among patients refractory or resistant to both anti-PD-(L)1 and anti-CTLA-4 therapyi,ii. In this dual checkpoint-exposed subgroup, median overall survival was not reached and 64% of patients were alive at two years. Median duration of response was also not reached, with all responders remaining in response at 12 months.