AstraZeneca’s Imfinzi approved by FDA for adults with advanced biliary tract cancer

AstraZeneca’s human monoclonal antibody, Imfinzi (durvalumab) has been approved by the US Food and Drug Administration (FDA) to treat adults with locally advanced or metastatic biliary tract cancer (BTC) in combination with chemotherapy (gemcitabine plus cisplatin).

The FDA based its decision on the results from the TOPAZ-1 phase 3 trial – a randomised, double-blind, placebo controlled, multicentre, global study – that showed Imfinzi plus chemotherapy reduced the risk of death by 20% versus chemotherapy alone.

An estimated 25% of patients treated with Imfinzi plus chemotherapy were still alive after two years compared to 10% who had been treated with chemotherapy alone. The results proved consistent across all pre-specified subgroups, regardless of PD-L1 expression or tumour location.

The phase 3 results were presented at the 2022 American Society of Clinical Oncology Gastrointestinal Cancers (ASCO GI) Symposium and were published in the New England Journal of Medicine Evidence, with the data demonstrating that Imfinzi plus chemotherapy was generally well tolerated and did not increase the discontinuation rate due to adverse events, compared to chemotherapy alone.

Imfinzi plus chemotherapy was added to the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology in July 2022 as a category 1 preferred regimen as first-line therapy for locally advanced or metastatic BTC based on the data from TOPAZ-1.

BTC applies to a group of rare and aggressive cancers that appear in the bile ducts and gallbladder, with around 23,000 people in the US being diagnosed with the condition each year. These patients often have a poor prognosis, as approximately only 5-15% of patients diagnosed with BTC survive for five years.

Dave Fredrickson, executive vice president, oncology business unit, AstraZeneca, said: “For the first time, patients in the US with advanced biliary tract cancer have an immunotherapy-based treatment option that meaningfully extends survival and is well-tolerated.

“This approval for Imfinzi and chemotherapy advances our ambition to challenge treatment expectations and transform care for patients with gastrointestinal cancers with high unmet need.”

The FDA’s approval was made after Imfinzi received a Priority Review and Orphan Drug Designation in the US for this setting. Regulatory applications are also currently pending in Europe, Japan and several other countries.