Single-center randomized phase 2 trial of SBRT plus nivolumab with or without ipilimumab for metastatic biliary tract cancer

A Simon’s optimal 2-stage design randomized phase 2 trial at Herlev Hospital (Herlev, Denmark) evaluated SBRT plus nivolumab with or without ipilimumab in patients with previously treated metastatic biliary tract cancer (mBTC). The SBRT plus nivolumab only arm was closed after the initial stage based on a clinical benefit rate (CBR) of only 10.5%. In the SBRT plus nivolumab and ipilimumab arm the CBR was 31.0% (95% CI 17.6-47.1) with partial response in 11.9% of the patients. In this group, grade 3 or worse treatment-related adverse events occurred in 31%, with one grade 5 event of immune-related hepatitis. The authors conclude that the combination of SBRT, nivolumab and ipilimumab is tolerated and feasible and induced response in a subgroup of patients with previously treated mBTC.