Disitamab Vedotin Combined With SOX Regimen Versus SOX Alone as Adjuvant Therapy for HER2-Moderate/High Expressing Stage Ⅲ Gastric Cancer: A Prospective, Multicenter, Randomized, Phase Ⅱ Clinical Trial

This trial is testing whether adding a targeted antibody-drug treatment (disitamab vedotin, which delivers chemotherapy directly to cancer cells) to a standard chemotherapy regimen (SOX) improves outcomes for people who had surgery for stage III stomach cancer that has a higher level of the HER2 protein. **You may be eligible if...** - You are between 18 and 75 years old - You had surgery to remove your stomach cancer (radical resection with complete tumor removal — R0) - Your cancer was confirmed to be stage III stomach or gastroesophageal junction adenocarcinoma - Your tumor has moderate to high HER2 expression (IHC 2+ or 3+) - You did not receive chemotherapy or any other treatment before surgery - You are in good general health (ECOG 0 or 1) **You may NOT be eligible if...** - You received treatment before surgery (neoadjuvant therapy) - You have an active autoimmune disease - You have another cancer diagnosed in the last 5 years (with some exceptions) - You are breastfeeding - You have a serious psychiatric illness or uncontrolled systemic disease Talk to your doctor to see if this trial is right for you.