Temozolomide + Nivolumab in MGMT Methylated Oesophagogastric Cancer

This trial is testing a combination of temozolomide (an oral chemotherapy) and nivolumab (an immunotherapy) in people with advanced stomach or esophageal cancer whose tumors have a specific genetic feature called MGMT methylation, which may make them more sensitive to temozolomide. **You may be eligible if...** - You are 18 or older - You have confirmed advanced esophageal, stomach, or gastroesophageal junction cancer that cannot be surgically removed - Your tumor has MGMT methylation (a specific epigenetic marker) - Your tumor's DNA repair is normal (not MSI-high) - You have already received at least 3 months of standard platinum and fluoropyrimidine chemotherapy without getting worse - You are in good health (ECOG 0–1) and can swallow capsules **You may NOT be eligible if...** - Your tumor has high microsatellite instability (MSI-H) - Your blood counts or organ function do not meet required levels - You have active autoimmune disease Talk to your doctor to see if this trial is right for you.