Bristol-Myers was on the lookout for an acquisition for quite some time now to bolster its portfolio. The company's top drug, Opdivo, has fallen behind Merck's ( MRK - Free Report ) Keytruda in capturing market share in the anti PD-1/PD-L1 category. Moreover, competition is rising in the category with the presence of Roche's ( RHHBY - Free Report ) Tecentriq. Both Keytruda and Tecentriq are approved for first-line non-small cell lung cancer ("NSCLC"), which has the largest patient population among all cancer indications.