AstraZeneca Imfinzi gets USFDA priority review for limited-stage small cell lung cancer

The Food and Drug Administration (FDA) grants Priority Review to applications for medicines that, if approved, would offer significant improvements over available options by demonstrating safety or efficacy improvements, preventing serious conditions or enhancing patient compliance. The Prescription Drug User Fee Act date, the FDA action date for their regulatory decision, is anticipated during the fourth quarter of 2024.

Imfinzi was also recently granted Breakthrough Therapy Designation (BTD) by the FDA in this setting. BTD accelerates the development and regulatory review of potential new medicines intended to treat a serious condition and address a significant unmet medical need.

Small cell lung cancer (SCLC) is a highly aggressive form of lung cancer that typically recurs and progresses rapidly despite initial response to chemotherapy and radiotherapy in LS-SCLC patients. The prognosis for LS-SCLC is particularly poor, as only 15-30% of these patients will be alive five years after diagnosis.

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said, “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. There is an urgent need for new treatment options that improve upon the standard of care in this setting, which has not changed in forty years, and we look forward to working with the FDA to bring Imfinzi to patients as quickly as possible.”

The sBLA is based on data from the ADRIATIC Phase III trial recently presented during the Plenary Session at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting.

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In the trial, Imfinzi reduced the risk of death by 27% versus placebo (based on an overall survival [OS] hazard ratio [HR] of 0.73; 95% confidence interval [CI] 0.57-0.93; p=0.0104). Estimated median OS was 55.9 months for Imfinzi (95% CI 37.3-not estimable [NE]) versus 33.4 months for placebo (95% CI 25.5-39.9). An estimated 57% of patients treated with Imfinzi were alive at three years compared to 48% on placebo.

Imfinzi also reduced the risk of disease progression or death by 24% (based on a progression-free survival [PFS] HR of 0.76; 95% CI 0.61-0.95; p=0.0161) versus placebo. Median PFS was 16.6 months for Imfinzi (95% CI 10.2-28.2) versus 9.2 months for placebo (95% CI 7.4-12.9). An estimated 46% of patients treated with Imfinzi had not experienced disease progression at two years compared to 34% on placebo.

The safety profile for Imfinzi was generally manageable and consistent with the known profile of this medicine. No new safety signals were observed.

Read also: FDA Advisory Committee reviewed Imfinzi for resectable non-small cell lung cancer based on AEGEAN Phase III trial results