Disitamab Vedotin Plus Trastuzumab in Patients With HER2 Positive GC/GEJ Patiens

This study tests a combination of two targeted drugs — disitamab vedotin and trastuzumab — for people with stomach or gastroesophageal junction cancer that is HER2-positive (a specific protein found on the surface of some cancer cells) and has spread or cannot be surgically removed. **You may be eligible if...** - You are 18 to 74 years old - Your cancer has been confirmed as HER2-positive stomach or gastroesophageal junction adenocarcinoma - Your cancer has spread or returned and cannot be removed with surgery - You have at least one measurable tumor - Your performance status is good (ECOG 0–1) - You have already received at least one prior line of treatment that failed **You may NOT be eligible if...** - Your cancer is not HER2-positive - You have never received prior systemic therapy for metastatic disease - You have serious organ problems or other active cancers - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.