A Study of Mesothelin-Targeted CAR T-Cell Therapy in People With Esophagogastric Cancer

Inclusion Criteria: * Aged ≥18 years * Diagnosis of pathologically confirmed EG adenocarcinoma * Diagnosis of metastatic or recurrent disease * ECOG performance status of 0-1 * Life expectancy of ≥4 months Inclusion Criteria for Leukapheresis: * Written informed consent for the study (from participant) * Life expectancy of ≥4 months * ECOG performance status of 0-1 * Histologic diagnosis that \& \>25% of the tumor expresses MSLN by IHC analysis. Archival tissue obtained up to 2 years before study enrollment is acceptable. IHC testing of a cell block from cytology (e.g., ascitic fluid) is acceptable if approved by the study pathologist. If adequate archival tissue is not available at screening, a fresh tumor biopsy should be obtained * Stage IV disease with gross peritoneal carcinomatosis on imaging and/or microscopic peritoneal involvement by cytology or noted during diagnostic laparoscopy * Disease progression or treatment intolerance after receiving at least 1 treatment regimen in the metastatic setting; patients with disease recurrence within 6 months of completing curative systemic therapy (chemotherapy, chemoradiation or adjuvant immunotherapy) are also eligible * Patients with Her2 positive disease must have received ≥1 line of anti-Her2 based therapy * At least 1 measurable or evaluable lesion per RECIST 1.1. Screening imaging must be obtained within 6 weeks of signing the informed consent form * Completion of systemic therapy at least 7 days before leukapheresis …