Perioperative Trastuzumab, Capecitabine and Oxaliplatin in Patients with HER2-positive Resectable Gastric or Gastro-Oesophageal Junction Adenocarcinoma: NEOHX Phase II Trial

Introduction: Perioperative chemotherapy improves overall survival (OS) and disease-free survival (DFS) compared with surgery alone in patients with resectable gastric adenocarcinoma (GA) or gastro-oesophageal junction adenocarcinoma (GEJA). The addition of trastuzumab to chemotherapy improves outcomes in patients with HER2-positive advanced gastric cancer (GC), and we aimed to explore its role in the perioperative setting. Material and methods: This Spanish, multicentre, open-label phase II trial evaluated the efficacy and toxicity of perioperative capecitabine, oxaliplatin and trastuzumab (XELOX-T) in patients with HER2-positive resectable GA or GEJA. The primary end-point was 18-months DFS; and secondary end-points included pathological complete response (pCR) rate, R0 resection rate, OS and toxicity (NCT01130337). Results: Thirty-six patients were included. After three cycles of preoperative treatment, 14 patients (38% of the intention-to-treat population) had partial response and 18 (50%) had stable disease. Surgery was performed in 31 patients: 28 (90%) had R0 resection, three (9.6%) had a pCR and three (9.6%) died due to surgical complications. A total of 24 patients received postoperative XELOX-T, 22 of whom completed trastuzumab maintenance. Main grade III/IV toxicities included diarrhoea (33%), nausea and vomiting (8%). After a median follow-up of 24.1 months, 18-month DFS was 71% (95% confidence interval [CI], 53-83%); and an update after 102 months of follow-up showed a median OS of 79.9 months and a 60-month OS of 58% (95% CI, 40-73%). Conclusions: These data suggest that perioperative XELOX-T in patients with HER2-positive GA and GEJA is feasible and active. Further investigation in randomised studies is warranted. (C) 2020 Elsevier Ltd. All rights reserved.