Combined Kidney and Blood Stem Cell Transplant from HLA-Identical Sibling Donors Using Radiation and Rabbit Anti-Thymocyte Globulin to Reduce Immunosuppressive Medication After Kidney Transplant

What this Trial Is About

Researchers are investigating an investigational treatment for kidney transplant recipients who receive a kidney from an HLA-identical sibling donor. The study aims to determine if this treatment can help patients stop taking immunosuppressive medications after transplant while preventing rejection of the new kidney. It builds on previous results showing that a combination of drugs and radiation may promote a state called mixed chimerism, where donor and recipient immune cells coexist, potentially allowing for immune tolerance. The treatment involves a pre-conditioning regimen starting at the time of transplant with five daily doses of rabbit anti-thymocyte globulin rATG and ten doses of total lymphoid irradiation TLI. Around day 11 post-transplant, patients receive an intravenous infusion of donor blood stem cells, including CD34 and CD3 cells, mobilized and enriched from the same sibling who donated the kidney. The goal is to achieve durable mixed chimerism, which may enable safe withdrawal of immunosuppressive drugs, including tacrolimus, at 12 months if certain conditions are met. Participants will be monitored over time with blood tests to measure chimerism, kidney function tests, and protocol biopsies of the transplanted kidney to check for rejection and graft health. The primary outcome is withdrawal from immunosuppressive drugs at 12 months post-transplant. Secondary outcomes include rates and timing of graft rejection and failure, as well as participant survival monitored up to 48 months. The study involves close medical supervision and follow-up for several years to assess long-term outcomes and safety.

Study of Combined Kidney and Blood Stem Cell Transplant From a Brother or Sister Donor