The addition of perioperative durvalumab in gastric and gastroesophageal junction cancer improved event-free survival, according to findings from the MATTERHORN study. “This trial will be an important milestone,” said Yelena Y. Janjigian, MD, chief of the Gastrointestinal Oncology Service at Memorial Sloan Kettering Cancer Center in New York City, who presented the findings at the 2025 American Society of Clinical Oncology Annual Meeting. She spoke with Robert A. Figlin, MD, the interim director of Cedars-Sinai Cancer in Los Angeles and Steven Spielberg Family Chair in Hematology-Oncology, about the significance of the data. “We demonstrated improvement in event-free survival, and this is the first regimen in the perioperative setting to do so,” Dr. Janjigian noted. She also shared next steps for the research and broader questions that the data raise across oncology. Dr. Janjigian reported various financial relationships. Dr. Figlin reported various financial relationships.