Heidi Ko

ASCO GI is upon us. The data leakage has begun 👀🔥 Late-breaking press release ahead of ASCO GI for HERIZON-GEA-01, testing zanidatamab + chemo, with or without tislelizumab, vs trastuzumab + chemo in first-line HER2+ locally advanced or metastatic GEA. Important caveat up front: this is a press release, not a paper. But the signal is hard to ignore. 🧬 PFS improved in both zanidatamab arms Median PFS 12.4 months for both doublet and triplet vs 8.1 months with trastuzumab Roughly a 35% reduction in risk of progression 🧠 The real interest lies in OS Triplet median OS 26.4 months vs 19.2 months with trastuzumab That’s more than two years median OS in metastatic GEA The doublet also crossed 24 months with a strong trend (is tisle necessary?) 🧐 Key nuance: PFS is essentially identical between doublet and triplet OS clearly separates This looks like depth and durability rather than early disease control 📊 ORR is similar across arms, but duration of response is dramatically longer DoR 20.7 months with the triplet vs 8.3 months with trastuzumab 💧 Toxicity note Diarrhea is the standout issue and will need proactive management Grade 3 or higher diarrhea occurred in roughly 20 to 25 percent, with overall diarrhea rates around 40 percent Open question I would love to see this compared head-to-head against current SoC chemo + trastuzumab + pembrolizumab. That said, it’s hard to argue with a two-year median OS and a clear survival tail. Takeaway: If confirmed on full presentation, zanidatamab looks poised to replace trastuzumab in first-line HER2+ GEA. The next step may not be whether it works, but how much intensity each patient really needs. #GI26 @OncoAlert @TheGutOncLab investor.jazzpharma.com/news…