Zolbetuximab Claudin18.2 Positive, HER2 Negative, Advanced Gastric Cancer

This study is looking at the outcomes of patients with advanced stomach or gastroesophageal junction cancer who received zolbetuximab — a drug that targets a protein called Claudin 18.2 — as their first-line treatment. It is an observational study tracking real-world results after patients already received this treatment. **You may be eligible if...** - You are 19 years or older - You have been diagnosed with locally advanced, unresectable, or metastatic gastric or GEJ adenocarcinoma - Your tumor expresses high levels of the Claudin 18.2 protein (in ≥75% of tumor cells, moderate to strong staining) - Your cancer is HER2-negative - You received zolbetuximab as part of your first-line treatment - Your general health is reasonably good (ECOG score 0 or 1) **You may NOT be eligible if...** - Your tumor does not express Claudin 18.2 at sufficient levels - Your tumor is HER2-positive - You have not yet received treatment or received it in a later line Talk to your doctor to see if this trial is right for you.