TIL Therapy Combined With Pembrolizumab for Advanced or Metastatic Refractory Stomach and Esophageal Cancer

This study tests whether combining tumor-infiltrating lymphocyte (TIL) therapy — where immune cells are taken from a patient's own tumor, grown in a lab, and infused back in — with pembrolizumab (an immunotherapy drug) can help people with advanced stomach cancer or esophageal cancer that has stopped responding to standard treatments. These are difficult cancers to treat once they've progressed, and this combination aims to harness the immune system more powerfully. **You may be eligible if...** - You are 16 to 90 years old with confirmed advanced, relapsed, or metastatic stomach or esophageal cancer - Your cancer has failed standard treatment or no standard treatment is available - You have a tumor that can be safely biopsied or removed to make the TIL therapy - You have at least one measurable tumor on a scan - You are in reasonably good health (Karnofsky score ≥60 or ECOG 0-2) - Your blood counts and organ function meet minimum thresholds **You may NOT be eligible if...** - You need high-dose steroids (more than 15mg prednisone daily) - You have had recent cancer treatment (within 28 days of tumor removal for TIL) - You are pregnant or not using effective contraception - You have active autoimmune disease requiring treatment - You have active brain metastases or uncontrolled CNS disease Talk to your doctor to see if this trial is right for you.