Refractory biliary tract cancer (BTC) is a rare type of cancer that occurs in a bile duct, resulting in pruritus, jaundice, and weight loss. While the cancer is rare, it is aggressive, and surgery, chemotherapy, and radiation are the only potential treatments. Preclinical data suggest that nivolumab could be used as a second-line treatment in patients with refractory BTC. This study aims to assess the anticancer efficacy of nivolumab in patients with advanced refractory BTC.

This multicenter, single-group, phase-2 study included a total of 46 patients with histologically confirmed BTC. The patients were assigned to receive nivolumab, 240 mg intravenously every 2 weeks for 16 weeks, followed by 480 mg intravenously every 4 weeks until disease progression or treatment-related adverse events. The primary outcome of the study was the treatment response rate, along with progression-free survival, overall survival, and adverse events.

Out of 46 patients examined for the objective response, the response rate was 22%, and the disease control rate was 59%. All responders developed mismatch repair protein-proficient tumors. During the follow-up of 12.4 months, the median progression-free survival was 3.68 months, and median overall survival was 14.24 months. Common treatment-related adverse events were hyponatremia (6%) and increased alkaline phosphatase (4%).

The findings suggested that nivolumab showed a modest response rate, efficacy, and safety in patients with refractory BTC.