Patients with high-risk thalassemia meeting the eligibility criteria for this study will be entered sequentially until completion or closure of the study.~The hypothesis is that a reduced-toxicity conditioning regimen combined with pre-transplant immunosuppression, followed by abatacept and sirolimus as graft-versus-host disease (GVHD) prophylaxis for allogeneic transplant with either Human Leukocyte Antigen (HLA)-matched sibling donors or haploidentical donors is feasible and safe and can be delivered with less toxicity, durable donor engraftment, and minimal GVHD.
The purpose of this study is to evaluate a novel transplant strategy for the long-term benefit of patients with transfusion dependent high-risk thalassemia.