Agenus’s phase 3 doubts grow

More bad news came for Agenus on Monday, with the FDA apparently blasting the chances of success of a phase 3 study of botensilimab plus balstilimab in late-line colorectal cancer that the agency had previously said was a precondition of approval. At the latest meeting with the agency the FDA said the treatment effect with bot-bal “does not appear to meet the standard of reasonably likely to predict benefit”, according to Agenus. The study, now known as Battman and once expected to start in 2023, won’t begin until the fourth quarter of 2025, and that's assuming that Agenus can fund it. As of March Agenus had just $18.5m in cash, though the group has since sold its manufacturing sites to Zydus Lifesciences for $75m up front plus $16m in equity, and is currently trying to reduce its annual cash burn to under $50m, from a previous target of $100m. Agenus shares sank 15% on Monday as the group updated results of a basket study but has still said nothing about survival in a more recent phase 2 trial in microsatellite-stable colorectal cancer. The group had once hoped to get accelerated approval for bot-bal in relapsed MSS colorectal cancer, but was last year told to run a phase 3 with a bot monotherapy cohort. One silver lining is that this monotherapy arm is no longer necessary, Agenus claims.

Notable bot-bal trials in colorectal cancer

Note: *investigator-sponsored trial. CRC=colorectal cancer; MSS=microsatellite stable. Source: OncologyPipeline & company presentation.