Enhanced Potential of Durvalumab in the Initial Treatment of Advanced Biliary Tract Cancer

The prognosis of biliary tract cancer is extremely poor, with a 5-year survival rate of 20%. Surgery is the only treatment that can be expected to cure biliary tract cancer, but because many cases are unresectable or recurrent, chemotherapy has become the standard treatment. The effects of first-line administration of durvalumab have not been explored. This study examined whether durvalumab has an additive effect in the first line.

Twenty-three patients who were diagnosed with recurrent or non-resected biliary tract cancer requiring anticancer chemotherapy were recruited. Three of these cases were excluded because they had only received one course of durvalumab. We retrospectively collected clinical and laboratory data. Progression-free survival (PFS) and overall survival (OS) were compared between patients who received durvalumab as first-line therapy (first group, FG) and those who received it as second-line or later therapy (second group, SG). PFS and OS were also compared in durvalumab-treated patients aged 75 years and older (older group) and in younger patients. Immune-related adverse events (irAEs) were graded using the Common Terminology Criteria for Adverse Events (CTCAE v5) based on the clinical notation available in the patient charts.

Kaplan-Meier curves showed that SG was significantly associated with worse PFS (p=0.018), and the FG group also showed significantly prolonged OS (p=0.030). In addition, PFS from the start of durvalumab treatment was significantly longer in the older group compared to the younger group. However, no significant difference in OS was observed between the two groups.

Durvalumab appears to contribute to prolonged PFS and OS when administered as an initial treatment. It may also contribute to improved outcomes in older patients with biliary tract cancer.