Study to Evaluate the Safety and Preliminary Efficacy of CD19 CAR-T Cell Therapy (TranspoCART19) in Patients With Refractory Lupus Nephritis

This is a Phase I/IIa, academic, multicenter, open-label, single-arm clinical trial designed to evaluate the safety, tolerability, and preliminary efficacy of TranspoCART19 in adult patients with refractory lupus nephritis. TranspoCART19 is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy manufactured using Sleeping Beauty transposon technology. The CAR construct incorporates an anti-CD19 FMC63 single-chain variable fragment, a 4-1BB co-stimulatory domain, a CD3ζ signaling domain, and a truncated human epidermal growth factor receptor (hEGFRt) safety switch. Eligible participants will undergo leukapheresis for collection of peripheral blood mononuclear cells. Following manufacturing of the investigational product, participants will receive lymphodepleting chemotherapy with fludarabine and cyclophosphamide, or bendamustine when clinically indicated, prior to administration of TranspoCART19. TranspoCART19 will be administered intravenously at a target dose of 1 × 10\^6 CAR-T cells/kg body weight using a fractionated infusion strategy consisting of 10%, 30%, and 60% dose fractions. Participants will remain under close monitoring for early and late treatment-related toxicities. The primary objective is to evaluate the safety and tolerability of TranspoCART19 during the early post-infusion period. Safety assessments include adverse events, serious adverse events, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), severe infections, prolonged cytopenias, and hypogammaglobulinemia. Secondary objectives include evaluation of clinical, renal, histological, and immunological responses; hematologic and immune reconstitution; CAR-T cell persistence and kinetics; corticosteroid and immunosuppressive treatment withdrawal; systemic lupus erythematosus disease activity; and health-related quality of life. Approximately 10 participants will be enrolled. Participants will be followed for 24 months after infusion, and long-term safety monitoring will continue for up to 15 years in accordance with recommendations for genetically modified cellular therapies.