FDA Approval Summary: Durvalumab and Pembrolizumab, Immune Checkpoint Inhibitors for the Treatment of Biliary Tract Cancer

Abstract

On September 2, 2022, the Food and Drug Administration (FDA) approved durvalumab in combination with cisplatin and gemcitabine, for the treatment of patients with unresectable or metastatic biliary tract cancers (BTC). On October 31, 2023, the FDA approved pembrolizumab in combination with cisplatin and gemcitabine for the same indication. Approvals were based on two randomized, multiregional, placebo-controlled trials that randomly allocated patients to receive durvalumab (TOPAZ-1) or pembrolizumab (KEYNOTE-966) in combination with chemotherapy or placebo in combination with chemotherapy. Overall survival (OS) was the primary endpoint in both studies. In both studies, a statistically significant and clinically meaningful improvement in OS was demonstrated. In the TOPAZ-1 trial, the median OS of patients receiving durvalumab was 12.8 months [95% confidence interval (CI), 11.1-14.0] and 11.5 months (95% CI, 10.1-12.5) in patients receiving placebo [hazard ratio (HR), 0.80 (95% CI, 0.66-0.97)]. In the KEYNOTE-966 trial, the median OS of patients receiving pembrolizumab was 12.7 months (95% CI, 11.5-13.6) and 10.9 months (95% CI, 9.9-11.6) in patients receiving placebo [HR, 0.83 (95% CI, 0.72-0.95)]. The addition of checkpoint inhibitors to standard of care chemotherapy for this indication did not reveal any new adverse event signals, and the safety profile was generally consistent with the known clinical experience with durvalumab, pembrolizumab, and the backbone chemotherapy regimen. The approvals of durvalumab and pembrolizumab in combination with standard of care cisplatin and gemcitabine for the treatment of unresectable or metastatic BTC add two new therapeutic options for these patients.

Figure 1.

TOPAZ-1 OS Kaplan Meier curves

Figure 2.

KEYNOTE-966 – OS Kapan Meier curves