Multinational phase 3 trial of perioperative durvalumab plus FLOT for G/GEJ adenocarcinoma: final results from MATTERHORN

The phase 3 MATTERHORN trial, at 147 centers in 20 countries, evaluated perioperative durvalumab plus fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) for resectable gastric and gastro-esophageal junction (G/GEJ) adenocarcinoma. Final overall survival results from the trial have now been published. Adults with resectable stage II-IVa G/GEJ adenocarcinoma were randomized 1:1 to perioperative durvalumab plus FLOT (n=474) or placebo plus FLOT (n=474). The median duration of follow-up was 43.0 months (IQR 39.3-47.1) in the durvalumab plus FLOT group and 42.9 months (39.1-46.8) in the placebo plus FLOT group. Overall survival was significantly better in the durvalumab plus FLOT group (HR 0.78; p=0.021). Significant overall survival benefit was seen in many subgroups. Adverse events with the outcome of death possibly related to any trial treatment occurred in 6 (1%) of participants in the durvalumab plus FLOT group and in 2 (<1%) of participants in the placebo plus FLOT group. The authors conclude that perioperative durvalumab plus FLOT improved overall survival versus placebo plus FLOT and is a new standard treatment option for patients with resectable G/GEJ adenocarcinoma.