Claudin 18.2 in Upper GI Cancer: New Target, New Challenges

Drs. Hornstein, Brown, and Grewal discuss how Claudin 18.2 has quickly become an important actionable biomarker in upper GI cancers, with zolbetuximab now entering frontline treatment for selected HER2-negative, microsatellite-stable patients. They review the key phase 3 data supporting its use, while emphasizing that the major challenge in practice is managing the significant nausea and vomiting seen early in treatment. The conversation also highlights how biomarker sequencing now shapes therapy selection and how future strategies, including ADCs, CAR T-cell therapy, and immunotherapy combinations, may further expand the role of Claudin 18.2 targeting.