Bristol's Opdivo/Yervoy Bid Will Show Whether Tumor Mutation Burden Is Ready For Prime Time

Bristol-Myers Squibb Co.'s surprise announcement that its Phase III CheckMate 227 first-line lung cancer study succeeded, but in a subset analysis that had not been prospectively defined, left one burning question – does the company have enough to file for approval? Management suggests the answer is yes, but some leading analysts have doubts.

The CheckMate 227 study is a multi-arm trial evaluating Bristol's PD-1 inhibitor Opdivo (nivolumab) with its CTLA-4 inhibitor Yervoy (ipilimumab) in more than 2,500 patients with first-line non-small cell lung cancer (NSCLC). The study had two core parts. In Part 1a, the company tested the combination vs. monotherapy and chemotherapy in those with at least 1% PD-L1 expression, while Part 1b tested the combination vs