TLI- and ATG-Enabled Minimization Protocol in Liver Transplantation

The unmet medical need in solid organ transplantation is to eliminate the lifelong requirement of powerful immune suppression drug combinations with their attendant side effects, and to prevent immune mediated rejection of the organ transplant. The proposed trial is designed to study if following a 'standard of care' deceased donor liver transplant host conditioning using Total Lymphoid Irradiation (TLI) and Anti-Tthymocyte Globulin (ATG) will result in operational tolerance and ultimately allow for immunosuppression drug minimization or cessation. It has been hypothesized that the ATG and TLI conditioning regimen post liver transplant will be safe and well tolerated and will result in recipients successfully being withdrawn from immunosuppression within 2 years after liver transplantation. We will test the hypothesis that by using a conditioning regimen of ATG and TLI to induce this operational tolerance will allow immunosuppressive drug minimization and cessation while maintaining normal graft function and without the risk of graft rejection. Importance of this knowledge: Operational tolerance occurs spontaneously in a minority of liver transplant recipients; however, predictable and reproducible induction of tolerance remains an unmet need. Building on extensive experience with TLI-based tolerance induction in kidney transplantation at Stanford, this study aims to evaluate whether a non-myeloablative conditioning regimen using TLI and ATG can safely facilitate immunosuppression minimization and withdrawal in liver transplant recipients without the use of donor hematopoietic cell infusion.