By VETTAPHARMA reporter: BeOne Medicines Ltd. announced positive Phase 3 results from the HERIZON-GEA-01 trial evaluating ZIIHERA® (zanidatamab) in combination with chemotherapy, with or without the PD-1 inhibitor TEVIMBRA® (tislelizumab), as a first-line treatment for patients with HER2-positive locally advanced or metastatic gastroesophageal adenocarcinoma (GEA).
According to the company, the study met its dual primary endpoint of progression-free survival (PFS), with both experimental arms demonstrating statistically significant and clinically meaningful improvements compared with the current standard of care, trastuzumab plus chemotherapy. Importantly, the combination of ZIIHERA, TEVIMBRA, and chemotherapy also achieved a statistically significant improvement in overall survival (OS) at the first interim analysis.
Median overall survival reached 26.4 months, which was both statistically significant (HR=0.72 [95% CI: 0.57, 0.90]; P=0.0043) and clinically meaningful, in patients receiving ZIIHERA plus TEVIMBRA and chemotherapy, representing a 28% reduction in the risk of death compared with the control arm. This translated into an improvement of more than seven months in median OS. Benefits were observed regardless of PD-L1 expression status, including in patients whose tumors had PD-L1 expression below 1%, a subgroup that historically has shown limited benefit from checkpoint inhibitor therapy.
ZIIHERA combined with chemotherapy alone also demonstrated a clinically meaningful survival benefit, with a median OS of 24.4 months, showing a strong trend toward statistical significance at the time of the interim analysis. Both experimental arms significantly improved median PFS to 12.4 months, compared with 8.1 months observed in the trastuzumab-based control arm.
Additional efficacy measures supported the regimen’s potential. Objective response rates exceeded 69% in both experimental arms, with the addition of TEVIMBRA notably extending the durability of response, achieving a median duration of response of 20.7 months.
The safety profile of ZIIHERA in combination with chemotherapy, with or without TEVIMBRA, was consistent with known HER2-directed and immunotherapy treatments, and no new safety signals were identified. While higher rates of Grade 3 or greater treatment-related adverse events were observed in the triple-combination arm, treatment discontinuations due to adverse events were relatively uncommon, and treatment-related diarrhea was generally manageable and resolved early.
The results will be presented as a Late-Breaking Abstract Oral Presentation at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI) on January 8, 2026. BeOne indicated plans to submit supplemental Biologics License Applications to the U.S. Food and Drug Administration and China’s National Medical Products Administration based on these findings.
BeOne highlighted the significance of these data for Asia-Pacific markets, where the burden of GEA is highest and where the company holds commercial rights for ZIIHERA, positioning the regimen as a potential new first-line standard of care for HER2-positive advanced GEA.
Source Credit:
- BeOne Medicines Ltd. (2026, January 6). ZIIHERA plus TEVIMBRA and chemotherapy: A potential new standard for first-line HER2+ advanced GEA [Press release]. Business Wire. Click here
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