FDA ‘Discourages’ BOT/BAL Accelerated Approval

During an end-of-Phase 2 meeting with Agenus on its immunotherapy combination botensilimab (BOT) and balstilimab (BAL) to treat adults with relapsed/refractory microsatellite stable colorectal cancer with no liver metastases, FDA advised the company not to submit its trial results for accelerated approval, saying that objective response rates may not translate to survival benefits. A company statement says the parties agreed on a BOT/BAL dosing regimen for a Phase 3 trial. FDA recommended that Agenus consider including a BOT monotherapy arm in the Phase 3 study.

The company says its Phase 1 and Phase 2 trial results show a six-month overall survival rate of 90%, with a manageable safety profile.

Botensilimab is described as a human Fe-enhanced CTLA-4 blocking antibody designed to boost both innate and adaptive anti-tumor immune responses. Balstilimab is the company’s investigational PD-1 antibody.