Imfinzi Receives Priority Review and Breakthrough Therapy Status for Limited-Stage Small Cell Lung Cancer
AstraZeneca’s supplemental Biologics License Application (sBLA) for Imfinzi (durvalumab), based on positive results from the ADRIATIC Phase III trial, has been accepted by the US Food and Drug Administration (FDA) and granted Priority Review.
This application pertains to the use of Imfinzi in patients with limited-stage small cell lung cancer (LS-SCLC) whose disease has not progressed following platinum-based concurrent chemoradiotherapy (cCRT). The FDA's Priority Review is designed for medicines that offer significant improvements in safety, efficacy, or patient compliance over existing treatments.
Imfinzi received Breakthrough Therapy Designation (BTD) from the FDA for this indication, aimed at expediting the development and review of treatments that address unmet medical needs in serious conditions.
Imfinzi is a monoclonal antibody that targets PD-L1, blocking its interaction with PD-1 and CD80, which helps the immune system target and destroy cancer cells. It is currently the global standard of care for unresectable, Stage III non-small cell lung cancer (NSCLC) in patients who have not progressed after chemoradiotherapy.
Small cell lung cancer (SCLC) is an aggressive form of lung cancer that often recurs and progresses rapidly despite an initial response to treatment. LS-SCLC patients face poor survival rates, with only 15-30% surviving five years post-diagnosis.
The trial demonstrated that Imfinzi reduced the risk of death by 27% compared to placebo, with an overall survival (OS) hazard ratio (HR) of 0.73. Median OS was 55.9 months for Imfinzi compared to 33.4 months for placebo. At three years, 57% of patients treated with Imfinzi were alive, compared to 48% on placebo.
Imfinzi also reduced the risk of disease progression or death by 24%, with a progression-free survival (PFS) HR of 0.76. The median progression-free survival (PFS) was 16.6 months with Imfinzi, compared to 9.2 months with the placebo. At two years, 46% of patients on Imfinzi had not experienced disease progression, compared to 34% on placebo.
The ADRIATIC trial was a global, randomised, double-blind, placebo-controlled Phase III study involving 730 patients with LS-SCLC who had not progressed following cCRT. The trial assessed Imfinzi monotherapy and a combination of Imfinzi with Imjudo (tremelimumab), comparing both to placebo.The primary endpoints were PFS and OS for Imfinzi monotherapy, while secondary endpoints included PFS, OS for combination therapy, safety, and quality of life.
