MATTERHORN — Perioperative durvalumab plus FLOT chemotherapy versus placebo plus FLOT in resectable gastric and gastroesophageal junction adenocarcinoma (MATTERHORN)

Phase 3 · Gastric Cancer, Gastroesophageal Junction Cancer

Population

Resectable gastric or gastroesophageal junction adenocarcinoma eligible for perioperative FLOT chemotherapy and surgery.

Primary Endpoint

Event-free survival

Rationale

Perioperative FLOT is the standard for resectable esophagogastric cancer, but relapse remains common. MATTERHORN tests whether adding PD-L1 blockade to perioperative chemotherapy improves cure rates.

What It Could Change

Could add perioperative immunotherapy to FLOT as a new standard of care for resectable gastric and gastroesophageal junction adenocarcinoma.