Immuno-oncology is Merck & Co's (NYSE:MRK) world - everyone else just lives in it. US approval of Keytruda in first-line non-small cell lung cancer in combination with chemotherapy for now makes this the PD-1 to beat, especially given setbacks to rivals from Bristol-Myers Squibb (NYSE:BMY) and Roche (OTCQX:RHHBY).
What was once a neck-and-neck duel for dominance of this space has turned decidedly against Bristol's Opdivo, reflected in investor reaction to yesterday's post-market announcement. Merck shares rose 3% in post-market trading - reflecting the belief that a potential outcome was a three-month delay - while Bristol shares sank 1%.
The chemo-combo approval opens the door to wider use of Keytruda in the first-line setting since, unlike its first-line monotherapy approval, patients need not show any expression of PD-L1. Combining with chemo can turn the tumour immunogenic and make it amenable for checkpoint blockade (Event - Merck's daring bid for lung cancer domination, April 28, 2017).
