FDA Grants Durvalumab Priority Review and Breakthrough Therapy Designation for LS-SCLC

The US Food and Drug Administration (FDA) has accepted a supplemental Biologics License Application (BLA) for durvalumab (Imfinzi) as a treatment for limited-stage small cell lung cancer (LS-SCLC) and granted it priority review, according to an announcement from AstraZeneca.

The supplemental BLA is based on the phase 3 ADRIATIC trial, which evaluated durvalumab in patients with LS-SCLC whose disease has not progressed following platinum-based concurrent chemoradiotherapy. David R. Spigel, MD, a medical oncologist and the chief scientific officer at Sarah Cannon Research Institute, gave a plenary presentation on the phase 3 ADRIATIC trial during the 2024 American Society of Clinical Oncology Annual Meeting.

“The ADRIATIC study hit both of its primary end points, both overall survival that was improved with an advance of nearly 2 years… and progression-free survival was improved with an advance of about 7.4 months,” Dr. Spigel told Lung Cancers Today in an interview at the 2024 American Society of Clinical Oncology Annual Meeting. “The regimen was safe, and these results will translate into durvalumab being a new standard of care. Patients with [LS-SCLC] who get chemoradiotherapy should then get up to 2 years of durvalumab, a great advance for our patients.”

The study showed that durvalumab reduced the risk of death by 27% compared with the placebo (overall survival (OS) hazard ratio [HR], 0.73; P=.0104), with an estimated median OS of 55.9 months, nearly 2 years longer than the estimated median OS of 33.4 months in patients receiving the placebo. The 3-year survival rate was 57% in those receiving durvalumab, compared with 48% in those receiving the placebo.

The phase 3 ADRIATIC study also showed that durvalumab reduced the risk of disease progression or death by 24% compared with the placebo (progression-free survival [PFS] HR, 0.76; P=.0161).

The median PFS was 16.6 months in patients receiving durvalumab, compared with 9.2 months in those receiving the placebo. Study investigators estimate that 46% of patients receiving durvalumab had not experienced disease progression at 2 years, compared with 34% of those receiving the placebo.

“This Priority Review reinforces the potential of Imfinzi to transform outcomes for patients as the first and only immunotherapy to demonstrate a survival benefit in limited-stage small cell lung cancer,” AstraZeneca Executive Vice President of Oncology Research and Development Susan Galbraith said in a statement. “There is an urgent need for new treatment options that improve upon the standard of care in this setting, which has not changed in 40 years, and we look forward to working with the FDA to bring Imfinzi to patients as quickly as possible.”

The safety profile for durvalumab “was generally manageable and consistent with the known profile of this medicine,” and “no new safety signals were observed,” officials said in the announcement.

The FDA also recently granted Breakthrough Therapy Designation to durvalumab in this setting. The Prescription Drug User Fee Act date, the FDA action date for the regulatory decision, is “anticipated during the fourth quarter of 2024,” officials said.

Source: AstraZeneca