US approval gives Bristol its mesothelioma head-start

Friday marked an unusual coup for Bristol Myers Squibb’s Opdivo plus Yervoy combo: a US green light for front-line mesothelioma made it the first approval in 16 years for this hard-to-treat cancer. The sharp-eyed will also have noticed the unexpected breadth of the approval, which came in all-comers, even though the supporting study, Checkmate-743, clearly showed the effect to be driven by the 25% of subjects who had the non-epithelioid histology and represent a minority of mesothelioma patients. There was an impressive 56% reduction in risk of death versus chemo among non-epithelioids given the combo in the study, but those with epithelioid histology had a non-significant 15% reduction. It will be up to Bristol to make the most of the advantage, especially as its checkpoint blocker competition is nowhere to be seen. Keytruda’s indication-agnostic approvals mean that some mesothelioma patients can receive the Merck & Co drug, and indeed the Keynote-158 trial, which forms part of the basis for these, did include several with this cancer. But Keytruda recently failed the late-line Promise-meso study, and all phase III trials in this indication except Checkmate-743 have academic groups as primary sponsor.