FDA Grants Priority Review to Zepzelca and Atezolizumab for First-Line Maintenance in Extensive-Stage Small Cell Lung Cancer

Jazz Pharmaceuticals has announced that the U.S. Food and Drug Administration (FDA) has accepted their supplemental New Drug Application (sNDA) for Zepzelca® (lurbinectedin) combined with atezolizumab (Tecentriq®). This combination therapy is proposed as a first-line maintenance treatment for patients with extensive-stage small cell lung cancer (ES-SCLC) whose disease has not advanced after initial treatment with atezolizumab, carboplatin, and etoposide. The FDA has granted Priority Review status with a Prescription Drug User Fee Act (PDUFA) action date of October 7, 2025. Priority Review status is given to drug applications that could significantly improve the treatment of serious conditions.

Rob Iannone, M.D., the executive vice president and chief medical officer at Jazz Pharmaceuticals, expressed the importance of the FDA’s Priority Review designation. He highlighted the urgent need for innovative treatment options for patients with ES-SCLC, a disease with limited therapeutic options. The company presented the significant findings from the IMforte Phase 3 trial at the ASCO 2025 conference, which were also published in The Lancet. These milestones pave the way for offering patients a new first-line maintenance option that aims to prolong the period without disease progression.

The sNDA submission is supported by data from the IMforte Phase 3 trial, which demonstrated statistically significant results in progression-free survival (PFS) and overall survival (OS). Patients underwent an induction therapy phase comprising carboplatin, etoposide, and atezolizumab. Following this, those without disease progression were randomized to receive either Zepzelca plus atezolizumab or atezolizumab alone. From the point of randomization, the median PFS was 5.4 months for the Zepzelca plus atezolizumab group compared to 2.1 months for those receiving only atezolizumab, with a significant reduction in the risk of disease progression or death by 46%. Similarly, the median OS was 13.2 months for the combination therapy versus 10.6 months for atezolizumab alone, reducing the risk of death by 27%. Importantly, no new or unexpected safety concerns were identified with the combined treatment.

The IMforte trial results were originally presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting and concurrently published in The Lancet. Jazz Pharmaceuticals planned to host a webcast on June 10 to discuss these findings in detail, featuring insights from a small cell lung cancer expert and company leaders.

In the United States, small cell lung cancer (SCLC) accounts for approximately 13% of all lung cancer cases, with around 30,000 new diagnoses reported annually. The risk of developing SCLC is significantly higher among smokers and individuals exposed to certain environmental factors like secondhand smoke, asbestos, and air pollution. SCLC is known for its aggressive nature and rapid spread to other body parts, such as the brain, liver, and bones. While many patients initially respond to treatment, the cancer often recurs and becomes more resistant to previously effective therapies.

Zepzelca, an alkylating drug, works by binding to DNA and disrupting cellular processes, potentially leading to cell death. The FDA had previously granted accelerated approval for Zepzelca in June 2020 for adult patients with metastatic SCLC who experienced disease progression after platinum-based chemotherapy. Jazz Pharmaceuticals continues to explore Zepzelca’s efficacy through confirmatory Phase 3 trials, which could further substantiate its benefits and support full approval in the U.S.

Jazz Pharmaceuticals, a global biopharmaceutical company headquartered in Dublin, Ireland, is committed to transforming lives through innovative medicines. They focus on treatments for serious diseases, often with limited therapeutic options, and have a diverse portfolio of marketed drugs and cancer treatments.