Zymeworks(US:ZYME) Globenewswire·2025-11-17 11:00Core Insights - Zymeworks Inc. announced positive topline results from the Phase 3 HERIZON-GEA-01 trial for Ziihera (zanidatamab-hrii) in combination with chemotherapy for HER2-positive gastroesophageal adenocarcinoma, indicating a significant advancement in treatment options for this patient population [1][5][6] Trial Results - Ziihera plus chemotherapy showed a clinically meaningful and statistically significant improvement in progression-free survival (PFS) compared to trastuzumab and chemotherapy [6][7] - Ziihera plus Tevimbra (tislelizumab) and chemotherapy demonstrated statistically significant improvements in overall survival (OS) and PFS versus the control arm [6][7] - The trial results support Ziihera's potential as the preferred HER2-targeted agent in first-line gastroesophageal adenocarcinoma [6][7] Safety Profile - The safety profile of Ziihera in combination with chemotherapy, with or without Tevimbra, was consistent with known safety profiles, with no new safety signals observed [3] Future Plans - Jazz Pharmaceuticals plans to submit the trial data for presentation at a major medical meeting in Q1 2026 and for publication in a peer-reviewed journal [4] - A supplemental Biologics License Application is expected to be submitted in the first half of 2026 to support Ziihera as a first-line treatment [5][6] Regulatory Designations - Zanidatamab has received Breakthrough Therapy designation and Fast Track designations from the FDA for various indications, including first-line gastroesophageal adenocarcinoma [9] Commercial Strategy - Zymeworks is eligible for additional regulatory and commercial milestones, as well as tiered royalties on net sales of Ziihera from Jazz and BeOne [8] - The company is advancing a robust pipeline of product candidates and leveraging strategic partnerships to enhance its market position [10]