Fludarabine Melphalan, Reduced-dose Busulfan Versus Fludarabine, Melphalan, Full-dose Busulfan in Patients Receiving Cord Blood Transplantation

Abstract

BackgroundVarious reduced-intensity conditioning/reduced-toxicity conditioning regimens have been developed for patients receiving allogeneic hematopoietic cell transplantation. The balance between disease relapse and toxicity can be partly dependent on reduced-intensity conditioning/reduced-toxicity conditioning regimens.This retrospective study aimed to compare the nonrelapse mortality, relapse incidence, progression-free survival, and overall survival rates between the fludarabine/melphalan/reduced-dose busulfan (Flu/Mel/Bu2; busulfan at a dose of 6.4 mg/kg intravenously) and fludarabine/melphalan/full-dose busulfan (Flu/Mel/Bu4; busulfan at a dose of 12.8 mg/kg intravenously) regimens in patients receiving umbilical cord blood transplantation (UCBT). MethodEighty-seven adult patients who received the Flu/Mel/Bu2 (n = 45) or Flu/Mel/Bu4 (n = 42) regimen as a conditioning regimen before UCBT at our institution between January 2013 and December 2022 were included in this study. ResultsThere were no significant differences in terms of clinical outcomes including nonrelapse mortality, relapse incidence, progression-free survival, and overall survival rates between the two regimens. Further, even in higher risk patients classified according to the Refined Disease Risk Index, the Flu/Mel/Bu2 regimen was comparable to the Flu/Mel/Bu4 regimen. ConclusionThe novel Flu/Mel/Bu2 regimen could be applied in clinical settings as it can be tolerated and effective in older patients.