Jazz Pharmaceuticals(US:JAZZ) Prnewswire·2025-06-02 16:35Core Insights - Jazz Pharmaceuticals announced long-term data from a Phase 2 trial of Ziihera (zanidatamab-hrii), showing a median overall survival (OS) of 36.5 months after four years of follow-up in patients with HER2-positive gastroesophageal adenocarcinoma [1][4][10] Group 1: Trial Results - The Phase 2 trial included 46 patients with HER2-expressing mGEA, with a median progression-free survival (PFS) of 12.5 months and a median OS of 36.5 months [3][8] - Among 41 patients with centrally confirmed HER2-positive tumors, the median PFS was 15.2 months, indicating durable clinical benefit [2][6] - The confirmed objective response rate (cORR) was 83.8%, with a median duration of response (DOR) of 20.4 months [7][6] Group 2: Safety Profile - The safety profile of Ziihera combined with chemotherapy showed low discontinuation rates and no new safety signals, with common Grade 3-4 treatment-related adverse events including diarrhea (39%) and hypokalemia (22%) [9][4] - The incidence of Grade 3 diarrhea decreased from 52% to 24% after implementing antidiarrheal prophylaxis [9] Group 3: Future Developments - A Phase 3 trial (HERIZON-GEA-01) is currently underway, evaluating Ziihera in combination with standard chemotherapy, with top-line results expected in the second half of 2025 [10][4] - The ongoing development of Ziihera aims to address the high unmet need for effective first-line treatment options for patients with HER2-positive gastroesophageal adenocarcinoma [4][11]