Jazz Pharmaceuticals revealed that the HERIZON-GEA-01 trial of zanidatamab, their bispecific antibody targeting HER2, met its primary endpoint of progression-free survival in first-line HER2-positive gastroesophageal adenocarcinoma (GEA). Patients receiving zanidatamab plus standard chemotherapy achieved a median progression-free survival of 10.8 months versus 7.2 months for chemotherapy alone, representing a 35% reduction in risk of disease progression or death (hazard ratio: 0.65; 95% CI: 0.52–0.82; p<0.001). The benefit was consistent irrespective of PD-L1 expression and extended to overall response rates of 68% compared to 48% in the control arm.

Beyond zanidatamab’s trial success, Jazz underscored three near-term catalysts supporting its oncology pivot. First, anticipated regulatory filings for frontline HER2+ GEA by mid-year could unlock access to an estimated 12,000 U.S. patients annually. Second, the company expects readouts from two additional randomized Phase II studies in HER2-positive breast cancer populations by Q4. Finally, commercial expansion of Zepzelca for small-cell lung cancer is projected to contribute incremental revenues of up to $150 million in the next twelve months, complementing a development portfolio valued at over $5 billion in potential peak sales.