Myeloablative Versus Reduced-Intensity Conditioning With Fludarabine/Busulfan for Myelodysplastic Syndrome: A Propensity Score-Matched Analysis

There are limited data comparing myeloablative conditioning with fludarabine/busulfan (Flu/Bu4) and reduced-intensity conditioning with fludarabine/busulfan (Flu/Bu2) in patients with myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed nationwide registry data and compared the outcomes of adult patients with MDS receiving Flu/Bu4 and Flu/Bu2 by propensity score (PS) matching. Patients who met the following criteria were eligible for enrollment: (1) age ≥16 years; (2) diagnosis of de novo MDS; (3) first allo-HSCT between 2006 and 2018; (4) related bone marrow transplantation (BMT) or peripheral blood stem cell transplantation from an HLA-matched donor, unrelated BMT from an HLA-matched or HLA-1 allele-mismatched donor, or unrelated cord blood transplantation; and (5) receiving Flu/Bu4 or Flu/Bu2 as a conditioning regimen. Flu/Bu4 comprised intravenous busulfan (total dose, 12.8 mg/kg) combined with fludarabine (total dose, 125-180 mg/m