FDA Approves Imfinzi for Metastatic Biliary Tract Cancer

A phase 3 trial showed that Imfinzi in combination with chemotherapy reduced the risk of death by 20% compared with chemotherapy alone.

The FDA has approved AstraZeneca’s Imfinzi (durvalumab) to treat adult patients with locally advanced or metastatic biliary tract cancer in combination with chemotherapy (gemcitabine plus cisplatin). Imfinzi is a human monoclonal antibody that binds to the PD-L1 protein and blocks the interaction of PD-L1 with the PD-1 and CD80 proteins.

Biliary tract cancer is a group of rare and aggressive cancers. About 23,000 people in the United States are diagnosed with these cancers each year. These patients have a poor prognosis, with about 5% to 15% of patients surviving five years.

“This approval represents a major step forward for patients with advanced biliary tract cancer, who urgently need new, well-tolerated and effective treatment options after more than a decade of limited innovation,” lead investigator Aiwu Ruth He, M.D., Ph.D., said in a press release. “The combination of durvalumab and chemotherapy should become a new standard of care in this setting, having demonstrated significantly improved survival for these patients who have historically faced a poor prognosis.” She is associate professor of medicine, leader of the GI Cancer Program, Georgetown Lombardi Comprehensive Cancer Center, Medstar Georgetown University Hospital, in Washington, D.C.

The approval was based on the results from the TOPAZ-1 phase 3 trial. In an interim analysis, Imfinzi plus chemotherapy reduced the risk of death by 20% versus chemotherapy alone. An estimated one in four patients treated with Imfinzi plus chemotherapy were still alive at two years compared with one in 10 treated with chemotherapy alone. Results were consistent across all prespecified subgroups, regardless of PD-L1 expression or tumor location.

The TOPAZ-1 results were presented at the 2022 American Society of Clinical Oncology Gastrointestinal Cancers (ASCO GI) Symposium and published in the New England Journal of Medicine Evidence. Imfinziplus chemotherapy was generally well tolerated and did not increase the discontinuation rate due to adverse events.

In July 2022, Imfinzi plus chemotherapy was added to the NCCN Clinical Practice Guidelines in Oncology as a Category 1 preferred regimen as 1st-line therapy for locally advanced or metastatic biliary tract cancer based on the data from TOPAZ-1.

Imfinzi is also approved to treat patients with stage III non-small cell lung cancer, extensive-stage small cell lung cancer, and previously treated advanced bladder cancer. Imfinzi is being assessed in combinations in liver, biliary tract cancer, esophageal and gastric cancers in an extensive development program spanning early to late-stage disease.