Reduced Intensity Conditioning for Adults With Sickle Cell Disease
Alasbali R, Alzahrani M, Wilkerson K, et al. Excellent Outcomes Using a Novel Reduced Intensity Conditioning With Thiotepa and Post-Transplant Cyclophosphamide for HLA-Matched Donor Transplant in Adolescents and Adults With Sickle Cell Disease. Bone Marrow Transplantation. 2026; (doi: 10.1038/s41409-026-02876-3).
Researchers describe a novel reduced-intensity conditioning protocol that could potentially resolve a common treatment barrier for adults with sickle cell disease (SCD). Children with SCD overwhelmingly benefit from myeloablative HLA-matched related donor hematopoietic stem cell transplantation, but myeloablative conditioning regimens are associated with treatment-related mortality in adults with SCD. To address this issue, investigators developed a reduced intensity conditioning regimen that combines thymoglobulin, thiotepa, cyclophosphamide, fludarabine, and total-body irradiation. The regimen resulted in zero graft failures and favorable survival outcomes in a group of 25 adults, ages 18-32 years, with severe SCD who took part in a multisite trial. The researchers report day +28 median whole blood chimerism of 100% and day +365 of 97%. The overall survival rate at 2-year follow-up was 100%, while 5-year event-free survival was estimated at 96%. Acute graft-versus-host disease (GVHD) was documented in one patient in the year following transplantation, with no cases of chronic GVHD.