The shares of Agenus (NASDAQ:AGEN) surged ~24% in the morning hours Wednesday after the immuno-oncology company announced early-stage data for tumor candidates botensilimab and balstilimab in patients with a form of colorectal cancer.
The Phase 1b study was designed to evaluate 1 or 2 mg/kg of anti-CTLA-4 compound, botensilimab and 3 mg/kg of anti-PD-1 molecule balstilimab in patients with microsatellite stable colorectal cancer (MSS CRC).
The study subjects were heavily pre-treated with a median of 4 prior lines of therapy, including 34% of those who had received immunotherapy.
Data from 41 evaluable patients demonstrated a 24% overall response rate, indicating the proportion of patients whose tumor destroyed or significantly reduced by the drugs.
The disease control rate, a measure combining partial response and stable disease, stood at 73%, while 50% of objective responses were found to have more than 50% tumor reduction.
In terms of durability, 80% objective responses were ongoing as of the data cutoff, with 30% objective responses exceeding one year.
Botensilimab was well tolerated during the study, the company said, noting that there were no grade 4/5 treatment-related adverse events.
Agenus (AGEN) intends to begin a global, randomized Phase 2 study for botensilimab/ balstilimab in MSS CRC this year.