Exelixis unlikely to move Bristol’s renal needle for now

Bristol Myers Squibb and Exelixis have shown that adding a small molecule to dual checkpoint blockade can delay disease progression in first-line kidney cancer, but this is unlikely to help them catch up with Merck & Co in this space. Interim analysis of the Cosmic-313 study showed that Cabometyx on top of the approved Opdivo plus Yervoy combo cut risk of progression or death by 27%. So far so good, but Bristol’s problem is that Opdivo plus Yervoy itself cuts risk by just 18% versus Sutent, Pfizer’s benchmark renal cancer drug against which Merck’s Keytruda plus Lenvima scored a stunning 61% reduction in Keynote-581. Thus – on a very rough cross-trial basis – the Cosmic-313 triplet seems to have beaten Sutent by something like 40%, which will not move the needle against Keytruda plus Lenvima. Exelixis fell 5% in early trade today. Overall survival remains an unknown quantity, and while it was not significant in Cosmix-313’s interim analysis this could be down to statistical allocation. For now Bristol/Exelixis would do better to stick with the approved Opdivo plus Cabometyx combo, as Yervoy will likely add toxicity – though how much remains unknown until we see the full data.