Here, median progression-free survival was 4.9 months with an ORR of 25% and DCR of 78.1%.238 Combination of nivolumab with the CTLA-4 inhibitor ipilimumab was assessed in a cohort from the CA209-538 trial, a phase II open-label basket study.239 In 39 patients with pretreated CCA (10 p/dCCA, 16 iCCA) ORR was 23% with a disease control rate of 44%. This evidence concerns the gene CTLA4 and cholangiocarcinoma.