Approval in 2011 of Bristol-Myers Squibb Co.'s CTLA-4 checkpoint inhibitor Yervoy (ipilimumab) in melanoma signaled the start of the immunotherapy revolution in the field of cancer therapy, followed by the PD-1 inhibitors and with new mechanisms nearing the market. Data presented at the Society for Immunotherapy and Cancer (SITC) annual meeting in November revealed that PD-1/L1 inhibitors such as Bristol's Opdivo (nivolumab) and Merck & Co. Inc.'s Keytruda (pembrolizumab) are being tested in about 1,500 clinical trials, of which 74% are evaluating combination approaches with other immunotherapies and traditional targeted agents. (Also see "Bristol's Strong SITC: IDO, 1L Kidney Cancer And New Mechanism Data Bode Well" - Scrip, 14 November, 2017.)
Development has been fueled by high unmet need and regulatory willingness to speed approvals for drugs aimed at life-threatening diseases....