AstraZeneca's Imfinzi snags an I-O first as key FDA decisions in liver and lung cancers near

For a long time, AstraZeneca’s Imfinzi has mainly been limited to stage III non-small cell lung cancer. Now, the PD-L1 inhibitor has snatched a first for the immuno-oncology class, with two other important expansions awaiting FDA verdicts.

The FDA has cleared Imfinzi and chemotherapy to treat locally advanced or metastatic biliary tract cancer, making it the first immunotherapy-based treatment option for this aggressive cancer type, AstraZeneca said Monday.

For this breakthrough, the FDA gave AZ the VIP treatment, accelerating the evaluation process with a priority review. The application was also included in Project Orbis, which allows for concurrent review of cancer drugs among multiple international regulators.

The approval comes on the back of phase 3 data from the Topaz-1 trial, which showed that adding Imfinzi to chemo cut the risk of death by 20%. At the two-year point, an estimated 25% of patients who took Imfinzi and chemotherapy were still alive, versus 10% of those on chemotherapy alone.

The addition of Imfinzi didn’t come with worrisome extra toxicity. The rate of discontinuation of any treatment component because of side effects was 13% in the combo group, versus 15.2% in the control group.

Based on the Topaz-1 results, the National Comprehensive Cancer Network in July added the Imfinzi-chemo regimen to its treatment guidelines for biliary tract cancer with the highest category of recommendation for newly diagnosed patients.

While biliary tract cancer marks a first-in-class indication for Imfinzi, AZ is angling the med for two other larger—and more competitive—markets.

In what could be the first FDA nods for AZ’s underachieving CTLA-4 inhibitor tremelimumab, the FDA is examining applications for the drug’s combination with Imfinzi or Imfinzi alone in newly diagnosed liver cancer. If approved, AZ would go up against Roche, which has a Tecentriq-Avastin approval in the same setting. In a potential relief for AZ, Merck’s Keytruda-Lenvima combination just failed there.

Hoping to expand Imfinzi into metastatic NSCLC, AZ is also awaiting an FDA decision based on data from the Poseidon trial. The Imfinzi-tremelimumab-chemotherapy combo will have a hard time carving out the front-line NSCLC market given Merck’s solid lead with Keytruda.

Besides those upcoming regulatory decisions, AZ is also looking to report results from the Emerald-1 study of Imfinzi in locoregional liver cancer later this year. Another phase 3 dubbed Pearl will read out Imfinzi monotherapy data against chemo in patients with newly diagnosed metastatic NSCLC bearing high PD-L1 expression.