zongertinib + trastuzumab

**Zongertinib + trastuzumab** is an investigational, combination therapy for advanced, metastatic cancers characterized by HER2 positivity, primarily metastatic breast cancer and metastatic gastric, gastroesophageal junction, or esophageal adenocarcinoma. Zongertinib is an orally administered, HER2-selective tyrosine kinase inhibitor (TKI) that spares EGFR, designed to block HER2-driven signaling and tumor growth. Trastuzumab is a monoclonal antibody that binds to HER2, inhibiting downstream oncogenic signaling, and also mediates antibody-dependent cellular cytotoxicity against HER2-overexpressing cancer cells. The combination aims to overcome resistance to prior HER2-directed therapies, enhance antitumor activity, and minimize off-target toxicities. Studies are ongoing to optimize the dosing and evaluate safety, tolerability, and efficacy in patients who have progressed on or after prior trastuzumab-based treatments[3][5].