Real-WorlD ZolbetUximab in Patients With HER-2 Negative and CLaudin 18.2 PosItive MetastatiC AdEnocarcinoma

Inclusion Criteria: * Patient with histologically confirmed diagnosis of gastric or gastroesophageal junction adenocarcinoma. * Patient with locally advanced, unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma. * Patient whose tumor expresses claudin18.2 in ≥ 75% of tumor cells demonstrating moderate to strong membranous CLDN18 staining as determined by local or central immunohistochemistry testing. * Patient with a Human epidermal growth factor receptor 2 negative tumor by local testing on a gastric or gastroesophageal junction tumor specimen. * Patient with Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1. * Patient who can have access to the Zolbetuximab EAP program or locally authorized and reimbursed (AIFA) procedure. * Patient who has about to start first-line Zolbetuximab + FOLFOX/XELOX or who has an ongoing Zolbetuximab FOLFOX/XELOX with available clinical data. Exclusion Criteria: * Patient has previously received treatment in a clinical trial of zolbetuximab, or a clinical trial that included zolbetuximab as 1 of the treatment options, even if the patient was not given zolbetuximab. * Patient has known dihydropyrimidine dehydrogenase deficiency. * Patient has received prior systemic chemotherapy for locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma. However, patient may have received either neoadjuvant or adjuvant chemotherapy, immunotherapy or other systemic anticancer therapies as long as it was completed at least 6 months prior to participation.