Mismatched Related Donor Versus Matched Unrelated Donor Stem Cell Transplantation for Children, Adolescents, and Young Adults With Acute Leukemia or Myelodysplastic Syndrome

This phase III trial compares hematopoietic (stem) cell transplantation (HCT) using mismatched related donors (haploidentical \[haplo\]) versus matched unrelated donors (MUD) in treating children, adolescents, and young adults with acute leukemia or myelodysplastic syndrome (MDS). HCT is considered standard of care treatment for patients with high-risk acute leukemia and MDS. In HCT, patients are given very high doses of chemotherapy and/or radiation therapy, which is intended to kill cancer cells that may be resistant to more standard doses of chemotherapy; unfortunately, this also destroys the normal cells in the bone marrow, including stem cells. After the treatment, patients must have a healthy supply of stem cells reintroduced or transplanted. The transplanted cells then reestablish the blood cell production process in the bone marrow. The healthy stem cells may come from the blood or bone marrow of a related or unrelated donor. If patients do not have a matched related donor, doctors do not know what the next best donor choice is. This trial may help researchers understand whether a haplo related donor or a MUD HCT for children with acute leukemia or MDS is better or if there is no difference at all.

NCT Number	NCT05457556
Lead Sponsor	Children's Oncology Group
Conditions	Acute Lymphoblastic Leukemia, Acute Myeloid Leukemia, Mixed Phenotype Acute Leukemia, Myelodysplastic Syndrome
Enrollment	66 participants
Start Date	2023-03-15
Primary Completion	2026-06-30 (estimated)
Study Completion	2027-07-07 (estimated)
Updated on ClinicalTrials.gov	2026-07-30