CTLA4 and non-small cell lung carcinoma: Similarly, CHECKMATE-227 trial357 confirmed that, for stageIV or recurrent NSCLC nivolumab plus ipilimumab (an antibody blocking CTLA-4) as first-line treatment significantly improves the five-year OS rate compared to chemotherapy (for PD-L1 ≥ 1%, 24% vs. 14%; and for PD-L1 < 1%, 19% vs. 7%, respectively).