CTLA4 and head and neck squamous cell carcinoma: In an effort to intensify immune response, the recruiting Checkmate 714 double-blind, randomized (2:1) phase II trial applies first/second line nivolumab (q2w) and ipilimumab (IgG1 CTLA-4 monoclonal antibody, BMS-734016, Bristol-Myers Squibb, q6w) vs. nivolumab (q2w) and placebo (q6w) to R/M SCCHN patients.