[A Case of Unresectable Gastric Cancer Treated with Zolbetuximab].

The patient was a 78-year-old man. He had poor appetite and postprandial vomiting. The diagnosis was pyloric stenosis associated with gastric cancer. Surgery was performed, but local progression was observed and curative resection was difficult, so gastrojejunostomy and cholecystectomy were performed. Based on biomarker results, he was started on CAPOX +zolbetuximab. Chemotherapy showed a significant response. On the other hand, edema due to hypoalbuminemia was observed as a serious side effect, and administration of an albumin product was also necessary when CAPOX + zolbetuximab was administered. Zolbetuximab was launched in June 2024 as an anticancer drug useful for patients with CLDN18.2 positive and HER2 negative curatively unresectable advanced or recurrent gastric cancer. The mechanism and response to side effects such as hypoalbuminemia are still unclear, and more cases need to be accumulated.