AstraZeneca's supplemental Biologics License Application (sBLA) for Imfinzi (durvalumab), in combination with standard-of-care chemotherapy, has been accepted and granted Priority Review in the US for patients with locally advanced or metastatic biliary tract cancer (BTC). The Food and Drug Administration (FDA) grants Priority Review to applications for medicines that, if approved, would offer significant improvements over available options by demonstrating safety or efficacy improvements, preventing serious conditions, or enhancing patient compliance. The Prescription Drug User Fee Act date, the FDA action date for their regulatory decision, is during the third quarter of 2022.

BTC is a group of rare and aggressive cancers that occur in the bile ducts and gallbladder. Approximately 23,000 people in the US are diagnosed with BTC each year.2 These patients have a poor prognosis, with approximately 5% to 15% of patients with BTC surviving five years. The sBLA was based on results from an interim analysis of the TOPAZ-1 Phase III trial presented during the 2022 American Society of Clinical Oncology Gastrointestinal Cancers (ASCO GI) Symposium.

The data showed Imfinzi plus chemotherapy (gemcitabine plus cisplatin) reduced the risk of death by 20% versus chemotherapy alone (based on a hazard ratio [HR] of 0.80; 95% confidence interval [CI], 0.66-0.97; 2-sided p=0.021). An estimated one in four (25%) patients treated with Imfinzi plus chemotherapy were alive at two years compared to one in 10 (10%) treated with chemotherapy alone. Results also showed a statistically significant 25% reduction in the risk of disease progression or death with Imfinzi plus chemotherapy (HR, 0.75; 95% CI, 0.64-0.89; 2-sided p=0.001).

The Imfinzi combination was generally well tolerated and did not increase the discontinuation rate due to adverse events compared to chemotherapy alone.