Jazz Zepzelca Trial Misses Endpoint, Shares Fall

Jazz Zepzelca Trial Misses Endpoint, Shares Fall

Jazz Pharmaceuticals PLC (NASDAQ:JAZZ) shares declined 1.6% on Friday after the company disclosed that its Phase 3 LAGOON trial of the oncology drug Zepzelca did not achieve the primary endpoint of overall survival. The trial, conducted by PharmaMar, evaluated Zepzelca as monotherapy and in combination with irinotecan against investigators’ choice of topotecan or irinotecan in patients with relapsed metastatic small cell lung cancer. The primary endpoint was not met for either Zepzelca arm.

No new safety signals were observed; the safety profile of Zepzelca remained consistent with known data for each agent. The LAGOON study enrolled a broader patient population than the Phase 2 pivotal trial that supported the accelerated second‑line approval, including patients with a history of central nervous system involvement. Median overall survival across the overall trial population was 8.7 months for Zepzelca monotherapy, 10.9 months for Zepzelca plus irinotecan, and 10.7 months for the control arm.

Jazz emphasized that the LAGOON results do not affect the pending full U.S. approval of Zepzelca scheduled for 2025, which is based on the Phase 3 IMforte trial. In IMforte, Zepzelca combined with atezolizumab as first‑line maintenance for extensive‑stage small cell lung cancer reduced the risk of disease progression or death by 46% and lowered the risk of death by 27% compared with atezolizumab alone.

The company has shared the LAGOON data with the U.S. Food and Drug Administration and will discuss next steps concerning post‑marketing requirements for the second‑line indication. Jazz also stated that the trial outcome does not alter its 2026 financial guidance.