Jazz Pharmaceuticals plc (Nasdaq: JAZZ), an Ireland-based pharmaceutical company, announced on Monday positive results from the Phase 3 IMforte study of Zepzelca (lurbinectedin) in combination with atezolizumab (Tecentriq) as a first-line maintenance treatment for people with extensive-stage small cell lung cancer (ES-SCLC), following induction therapy with carboplatin, etoposide and atezolizumab.

According to the company, the study met both primary endpoints, demonstrating statistically significant improvements in progression-free survival (PFS) and overall survival (OS) compared to atezolizumab alone.

IMforte is the first global Phase 3 trial to demonstrate clinically meaningful PFS and OS benefits in the first-line maintenance setting for ES-SCLC and supports maintenance therapy with Zepzelca plus atezolizumab as a new standard of care for patients. The data were presented on Monday in an oral session at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, and published simultaneously in The Lancet. Data from the trial served as the basis for the supplemental New Drug Application (sNDA) submission to the US Food and Drug Administration (FDA).

Following induction therapy with carboplatin, etoposide and atezolizumab, patients who did not have disease progression were randomised to receive Zepzelca plus atezolizumab or atezolizumab alone. From the point of randomisation, the median PFS was 5.4 months for the Zepzelca plus atezolizumab combination versus 2.1 months for atezolizumab alone (stratified HR = 0.54, 95% CI: 0.43–0.67; p < 0.0001), and median OS was 13.2 months versus 10.6 months (stratified hazard ratio [HR] = 0.73; 95 percent CI: 0.57–0.95; p = 0.0174). The combination reduced the risk of disease progression or death by 46% and the risk of death by 27% compared to atezolizumab alone. The Zepzelca plus atezolizumab combination had no new or unexpected safety signals.

The Zepzelca plus atezolizumab combination as maintenance therapy was generally well tolerated with no new safety signals identified.

"In the US, approximately 30,000 new cases of small cell lung cancer are diagnosed each year, and the IMforte results demonstrate a combination treatment approach that can meaningfully extend the survival benefit for people with extensive-stage small cell lung cancer who complete induction therapy without progression," said Stephen V. Liu, M.D., associate professor of Medicine, Lombardi Comprehensive Cancer Center, Georgetown University, and IMforte trial investigator.