AstraZeneca has picked off another label expansion for its cancer blockbuster Imfinzi (durvalumab) as the FDA has blessed the PD-L1 inhibitor for limited-stage small cell lung cancer (LS-SCLC) patients who have not had disease progression after concurrent chemotherapy and radiation treatments.
With the nod, Imfinzi becomes the first immunotherapy for LS-SCLC, an aggressive form of the disorder with a survival rate between 15% and 30% after diagnosis. The subtype includes roughly 30% of all SCLC cases. It often recurs and progresses rapidly despite initial response to standard-of-care chemo and radiation treatment.
The approval is backed by results from the ADRIATIC trial which showed that, compared to placebo, Imfinzi extended patients’ lives by 27% among those who had not progressed following chemoradiotherapy. The estimated median overall survival was 55.9 months for Imfinzi versus 33.4 months for placebo.
Imfinzi also prolonged the time before tumor progression or death by 24%. The median progression-free survival for Imfinzi was 16.6 months versus 9.2 months for placebo. Additionally, at two years, an estimated 46% of Imfinzi patients had not experienced disease progression compared to 34% for placebo.
“This finding represents the first advance for this disease in four decades,” Suresh Senan, Ph.D., professor of clinical experimental radiotherapy at the Amsterdam University Medical Centers and international coordinating investigator of the trial, said in a release. “The ADRIATIC trial showed 57 percent of patients were still alive at three years after being treated with durvalumab, which underscores the practice-changing potential of this medicine in this setting.”
In 2020, Imfinzi was approved—in tandem with chemotherapy—for previously untreated patients with extensive-stage SCLC. That nod came after a trial showed that the combo reduced the risk of death by 27% compared to placebo alone. With the approval, Imfinzi joined Roche’s immunotherapy Tecentriq in the indication.
Imfinzi hit the market in 2017 after the FDA signed off on it to treat bladder cancer. It has also been endorsed for biliary tract, endometrial and three forms of non-small cell lung cancer (NSCLC).
In another part of the ADRIATIC study—which remains blinded—AZ is investigating its other immunotherapy Imjudo on top of Imfinzi. Two years ago, the FDA signed off on a combination of Imfinzi, Imjudo and chemotherapy to treat metastatic NSCLC.
Imfinzi is one of the most important therapies in the portfolio of oncology powerhouse AZ. Of its $37.6 billion in revenue in the first three quarters of this year, more than $16 billion came from its cancer treatments. While NSCLC standout Tagrisso has generated (PDF) $4.9 billion through Q3, Imfinzi has accounted for sales of $3.5 billion.