“…Two other recent reports support the activity of ipilimumab/ nivolumab combination immunotherapy in patients with advanced biliary tract cancer who have progressed on chemotherapy and/or anti-PD-1 monotherapy and subsequently have obtained durable responses to combination immunotherapy. 5,6 In view of these findings, ipilimumab/nivolumab combination therapy may have a role in the treatment of advanced biliary tract cancers in later lines of therapy. Biomarker research will be crucial for better defining the patient population that derives a treatment benefit; the tumor mutation burden of the 39 patients with biliary tract cancer who were enrolled in CA209-538 was overall low and did not differ between responders and nonresponders, 7 whereas PD-L1 expression on tumor cells was enriched for response (O Klein MD, A Behren PhD May 2021).…”