FDA Grants Priority Review to Zepzelca and Atezolizumab Combo for First-Line Maintenance in Extensive-Stage SCLC

Jazz Pharmaceuticals plc has announced that the U.S. Food and Drug Administration (FDA) has accepted its supplemental New Drug Application (sNDA) for Zepzelca® (lurbinectedin) combined with atezolizumab (Tecentriq®) as a first-line maintenance therapy for patients suffering from extensive-stage small cell lung cancer (ES-SCLC). This application has been accepted under Priority Review, with the Prescription Drug User Fee Act (PDUFA) target date set for October 7, 2025. Priority Review is reserved for drugs that potentially offer significant advancements in the treatment, diagnosis, or prevention of serious health conditions.

The Priority Review designation underscores the importance of Zepzelca in combination with atezolizumab, highlighting the need for novel therapeutic strategies in treating ES-SCLC, a condition marked by limited treatment options and a substantial unmet need. Jazz Pharmaceuticals’ executive vice president, Rob Iannone, expressed satisfaction with the FDA’s decision, citing the promising data presented from the IMforte trial at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting. The trial results were also published in The Lancet, marking significant progress towards providing patients with a more effective first-line maintenance treatment.

The sNDA is supported by the Phase 3 IMforte trial results, which demonstrated that the combination of Zepzelca and atezolizumab significantly improved progression-free survival (PFS) and overall survival (OS) compared to atezolizumab alone. Participants who completed initial therapy with carboplatin, etoposide, and atezolizumab and showed no disease progression were randomized to receive either the combination therapy or atezolizumab alone. Results showed that the median PFS was 5.4 months for the combination therapy compared to 2.1 months for atezolizumab alone. Similarly, the median OS was 13.2 months for the combination versus 10.6 months for the monotherapy. The trial indicated that the combination therapy reduced the risk of disease progression or death by 46% and the risk of death by 27% versus atezolizumab alone, without presenting any new safety concerns.

Jazz Pharmaceuticals plans to host an investor webcast to discuss the trial findings, featuring insights from a leading expert on small cell lung cancer alongside company executives. The event aims to provide detailed information about the implications of the trial data and the potential impact of Zepzelca as a maintenance treatment in the ES-SCLC setting.

Small cell lung cancer (SCLC) represents approximately 13% of lung cancer cases in the U.S., with around 30,000 new diagnoses annually. Factors such as smoking, exposure to secondhand smoke, asbestos, certain chemicals, radiation, and air pollution are known risk components. SCLC is distinguished by its aggressive nature and ability to rapidly spread to other organs, including the brain, liver, and bones. While initial responses to treatment can be promising, the cancer frequently returns, becoming more resistant to previously effective therapies.

Zepzelca, classified as an alkylating agent, binds to guanine residues in DNA, initiating a series of events that disrupt the cell cycle, potentially leading to cancer cell death. The drug was initially approved by the FDA in June 2020 for treating adult patients with metastatic SCLC showing disease progression post-platinum-based chemotherapy. The approval was based on the observed overall response rate and duration of response in a monotherapy clinical study.

This progress in developing Zepzelca for first-line maintenance treatment offers hope for enhancing patient survival and quality of life, addressing the urgent need for improved therapeutic options in the treatment of extensive-stage small cell lung cancer.