EORTC 1707 VESTIGE: Adjuvant immunotherapy in patients with resected gastric cancer following preoperative chemotherapy with high risk for recurrence (ypN+ and/or R1)—An open-label randomized controlled phase II study.

TPS4156 Background: Gastroesophageal adenocarcinoma (GEA) patients with metastatic lymph nodes (ypN+) or a microscopically incomplete surgical resection (R1) following neoadjuvant chemotherapy are at high risk of disease recurrence. Current practice is to continue with the same perioperative chemotherapy used prior to surgery, despite these suboptimal outcomes. Adjuvant immunotherapy with nivolumab has shown efficacy in poor risk GEA patients following chemoradiotherapy and surgery in the CheckMate 577 trial, and nivolumab and ipilimumab have demonstrated activity in advanced GEA. We hypothesise that high risk (ypN+ and/or R1) post resection GEA patients who are treated with nivolumab and …