"I do think that improvement of overall survival is quite striking," says Alice Shaw, a Harvard professor who has done leading research in lung cancer. But Merck has run clinical trials that have proved Keytruda has clear benefits in previously untreated lung cancer patients, giving it an entrée into one of cancer's biggest markets. For the Bristol study, patients were 21% less likely to die, about half the difference for the Merck study. Keytruda was initially only approved for previously untreated lung cancer patients if they had high levels of PD-L1. "If you have metastatic lung cancer and there are other alternatives, you don't want to wait that long before you get treated."

Source: Forbes April 16, 2018 13:30 UTC