A Trial Comparing Unrelated Donor BMT With IST for Pediatric and Young Adult Patients With Severe Aplastic Anemia (TransIT, BMT CTN 2202)

This study is a multi-center randomized phase III trial to compare the failure free survival between those randomized to IST vs 9-10/10 HLA matched URD BMT. The study will also address patient-reported outcomes and gonadal function in each arm and explore critical biological correlates including assessing germline genetic mutations associated with pediatric SAA that may lead to a predisposition to the disease and the risk of development of clonal hematopoiesis following IST vs BMT in pediatric and young adult SAA. This clinical trial will randomize 234 children/AYA over 3.3-4.7 years at a 1:1 ratio between initial treatment with immune suppression therapy (IST) with horse ATG (hATG)/cyclosporine (CsA) versus well- matched (9-10/10 allele) unrelated donor (URD) bone marrow transplantation (BMT) using a regimen of rabbit ATG (rATG)/fludarabine/cyclophosphamide and 200 cGy TBI. Duration of subject participation for all study procedures in this study will be up to 2 years after treatment; a single later timepoint between 3 and 5 years will be collected to follow patients for specific protocol defined late effects and survival.