The interview aims to explore the clinical significance of the MATTERHORN Phase III data supporting the FDA approval of Imfinzi plus FLOT chemotherapy as the first perioperative immunotherapy regimen for resectable Stage II–IVA gastric and gastroesophageal junction cancers. Discussion will examine event-free survival and overall survival improvements, relevance across PD-L1 expression groups, tolerability considerations, and potential implications for treatment sequencing and standard-of-care evolution.