Dual-Target Nectin-4/HER2 CAR-NK Cells in Advanced Urothelial Carcinoma

Inclusion Criteria: * Age 18-75 years at consent. * Histologically confirmed urothelial carcinoma of the bladder, ureter, renal pelvis, or urethra that is unresectable locally advanced or metastatic. * Disease progression after, intolerance to, or ineligibility for standard therapy, including platinum-based chemotherapy and PD-1/PD-L1 blockade when appropriate for the patient and region. Prior enfortumab vedotin and prior HER2-directed therapy are allowed, but a fresh biopsy is strongly preferred after the latest systemic regimen. * At least one measurable lesion per RECIST v1.1. * Tumor tissue available for central review demonstrating Nectin-4 positivity (for example, IHC ≥1+ in ≥10% tumor cells) and HER2 status assessed by IHC/ISH. At least one of the selected therapeutic targets must be present; dose expansion preferentially enrolls Nectin-4-positive disease. * ECOG performance status 0-1. * Adequate bone marrow, hepatic, renal, and coagulation function. * Life expectancy of at least 12 weeks. * Negative pregnancy test for women of childbearing potential and agreement to use highly effective contraception during study treatment and follow-up as defined in the protocol. * Ability to understand and sign informed consent. Exclusion Criteria: * Active or untreated central nervous system metastases or leptomeningeal disease. Previously treated CNS disease is allowed if clinically stable and off escalating corticosteroids. * Prior allogeneic hematopoietic stem cell transplan…