The DG-01 trial investigated the efficacy and safety of 6.4 mg/kg T-DXd (n = 125) compared with chemotherapy (n = 62; 55 patients received irinotecan and 7 patients received paclitaxel) in previously treated patients with HER2-positive advanced gastric or gastroesophageal junction (GEJ) adenocarcinomas. Here, ERBB2 is linked to gastroesophageal junction adenocarcinoma.