PRAISE-IR Versus CIBMTR Controls

Inclusion Criteria: Arm A: Model-based ATG dosing CD34-selection (PRAISE-IR population) * Patients who participated in the PRAISE-IR single center phase II study * Patient age at transplant: ≥ 1 year and \< 66 years * HLA 8/8 MRD or MUD * Conditioning intensity: myeloablative * Conditioning regimens: Model-based ATG with TBI/Thiotepa/Cyclophospamide (TBI/Thio/Cy) or Busulfan/Melphalan/Fludarabine (Bu/Mel/Flu). * Morphologic complete remission at the time of alloHCT Arm B: Standard ATG dosing CD34-selection (CIBMTR population) * First AlloHCT in the US between 2021-2023 * Patient age at transplant: ≥ 1 year and \< 66 years * Disease: Patients with AML, MDS, and ALL * HLA 8/8 MRD or MUD * Peripheral blood stem cell allograft * Conditioning intensity: myeloablative conditioning * Conditioning regimens: standard dose ATG (2.5 mg/kg/day given on Day -4 and Day -3) * GVHD prophylaxis: ex vivo CD34 selection * Morphologic complete remission at the time of alloHCT Arm B\*:Standard ATG dosing CD34-selection (BMT CTN 1301 population) * Patients in BMT CTN 1301, who received the CD34-selected graft * Patient age at transplant: ≥ 1 year and \< 66 years * Disease:Patients with AML, MDS, and ALL * HLA 8/8 MRD or MUD * Peripheral blood stem cell allograft * Conditioning intensity: myeloablative conditioning * Conditoning regmens: TBI/Thiotepa/Cyclophospamide (TBI/Thio/Cy) or Busulfan/Melphalan/Fludarabine (Bu/Mel/Flu) and standard dose ATG (2.5 mg/kg/day given on Day -4 and Day -3) * GVHD prophylaxis: ex vivo CD34 selection * Morphologic complete remission at the time of alloHCT Arm C: Control CIBMTR population * First AlloHCT in the US between 2021-2023 * Patient age at transplant: ≥ 1 year and \< 66 years * Disease:Patients with AML, MDS, and ALL * HLA 8/8 MRD or MUD * Peripheral blood stem cell * Conditioning intensity: myeloablative conditioning * Conditioning regimens: Busulfan/Cyclophosphamide (Bu/Cy), Busulfan/Fludaranbine (Bu/Flu), Cyclophosphamide/TBI (Cy/TBI), TBI/Etopsoside * GVHD prophyalxis: / CNI or PTCy-based * CNI-based: CNI (tacrolimus or ciclosporin) plus MTX * PTCy-based: Cyclophosphamide on day +3 and +4 (50 mg/kg/d) combined with CNI and mycophenolate mofetil (MMF) Exclusion Criteria: Patients will be entered into this trial only if they meet none of the following criteria: Arm A: Model-based ATG dosing CD34-selection (PRAISE-IR population) * HLA \<8/8 MRD or MUD Arm B: Standard ATG dosing CD34-selection (CIBMTR population) * Patients who participated in the PRAISE-IR study * Patients who did not sign consent for research * Patient transplanted at a center that does not meet CIBMTR data quality standards * Use of CNI-(Tac/MTX) or PTCy-based GVHD prophylaxis Arm B\*:Standard ATG dosing CD34-selection (BMT CTN 1301 population) * Patients who did not sign consent for research * Patient transplanted at a center that does not meet CIBMTR data quality standards * Use of CNI- or PTCy-based GVHD prophylaxis Arm C: Control CIBMTR population * Patients who did not sign consent for research * Patient transplanted at a center that does not meet CIBMTR data quality standards * Use of ATG and/or alemtuzumab * Patients who received PTCy with sirolimus (and not a CNI) * Use of ex vivo CD34 selection