HERIZON-GEA-01 second OS interim at #ESMO26, and I'm a triplet believer.

In January I wondered if tislelizumab was necessary. With 35 months of follow-up, my answer is yes.

914 patients, 1L HER2+ GEA, randomized 1:1:1 to zani + chemo ± tislelizumab vs trastuzumab + chemo.

Median OS
• Zani + chemo + tisle: 27.0 mo
• Zani + chemo: 22.9 mo
• Tras + chemo: 19.6 mo
3-year OS: 39.8% vs 31.5% vs 22.9%

The doublet now has its own OS win over trastuzumab (HR 0.76, 95% CI 0.62–0.93, p=0.0088). The triplet vs trastuzumab got better with time (HR 0.72 at IA1, now 0.65).

Triplet vs doublet: HR 0.81 (95% CI 0.65–1.00), p=0.0502.
Yes, it technically misses. But 4 more months of median OS is clinically meaningful in metastatic gastric cancer.

Patients also stayed on the triplet longer (~47 vs ~30 weeks), with no new safety signal.

Takeaway: zani + chemo + tisle is my 1L default for HER2+ GEA.
Bring on the bispecifics 🔥
@OncoAlert @TheGutOncLab
@OncoAlert