In pharma, imitation is an extremely irritating form of flattery.
The market to sell immuno-oncology (IO) drugs, which boost the immune system to fight cancer, has for a while now been a two-company race between Bristol-Myers Squibb and Merck. Bristol has dominated because its drug Opdivo can be prescribed without a biomarker test for the best-suited patients; Merck's Keytruda needs such a test.
