Agenus Inc (NASDAQ: AGEN) Releases Phase 1b Balstilimab and Botensilimab Study in MMSS CRC

Agenus Inc (NASDAQ: AGEN) has released expanded findings from Phase 1b balstilimab (ant-PD-1) and botensilimab (FC-enhanced anti-CTLA-4) study in microsatellite stable colorectal cancer (MMSS CRC) patients. The data showed that this combination provides better stability and efficacy compared to that of the standard of care (SoC) and other experimental therapies in 2L+ MSS CRC that have been reported in independent trials.

Data supports the therapeutic potential of balstilimab and botensilimab

Chief Medical Officer Steven O’Day said, “These data reinforce the strong therapeutic potential of botensilimab, when used in combination with balstilimab, in cold tumors such as MSS CRC. Thus far, botensilimab has demonstrated activity in nine cold and treatment-resistant cancers, and we plan to initiate a robust, global Phase 2 program, including in MSS CRC, later this year.”

Around 41 evaluable people who are diagnosed with MSS CRC received 1, 2, or 3 mg/kg botensilimab every six days (Q6W) and 3 mg/kg balstilimab every two days (Q2W), respectively. With a median of four previous Therapy lines, participants had had a lot of pre-treatment, and 34% had previously received immunotherapy. Compared to what was observed in separate studies for the standard of care (SoC) and other currently being developed combinations, the botensilimab/balstilimab mixture produced greater responses and high durability.

The overall objective response rate was 24%, while the disease control rate (stable disease + partial response)  was 73%, with  50% of the objective responses showing more than 50% reduction in tumors. Regarding durability, the drug showed 80% objective responses at the data cut-off and 30% objective responses at one year.

Colorectal cancer is the second leading cause of cancer-related deaths 

Antony El-Khoueiryy, Phase I Program  Director at USC Norris Comprehensive Cancer Center, said, “Colorectal cancer is the second leading cause of cancer-related death worldwide, with roughly 95% classified as microsatellite stable and historically unresponsive to immunotherapy. Treatment resistant MSS CRC patients lack effective options, with standard of care offering only a 1-2% response rate and a median expected survival ranging from 6 to 7 months.”

Botensilimab and balstilimab combination’s strong response rate, tolerability, and durability promote future research and development of the two drugs in MSS CRC.