Comparative Effectiveness of Busulfan and Fludarabine versus Fludarabine and 400 cGy Total Body Irradiation Conditioning Regimens for Acute Myeloid Leukemia/Myelodysplastic Syndrome.

Allogeneic hematopoietic cell transplantation conditioning regimen intensity has varied for patients with acute myeloid leukemia and myelodysplastic syndrome. A comparative effectiveness analysis was performed to assess outcomes of busulfan and fludarabine (BuFlu) versus those of fludarabine and 400 cGy total body irradiation (FluTBI) conditioning. Thirty-three subjects received BuFlu and 38 received FluTBI. The BuFlu group received more red blood cell transfusions (P = .02) and had a longer time to platelet recovery (P = .004). There were no differences between the regimens regarding incidence of acute or chronic graft-versus-host disease (GVHD), quality of life, or 2-year outcome estimates for relapse (48; 95% confidence interval [CI], 30 to 64 and 50; 95% CI, 33 to 65), nonrelapse mortality (29; 95% CI, 14 to 45 and 29; 95% CI, 15 to 44), relapse-free survival (27; 95% CI, 13 to 43 and 29; 95% CI, 16 to 44), and overall survival (35; 95% CI, 19 to 51; and 37; 95% CI, 22 to 52), respectively. These comparable outcomes have implications for health care resource utilization. Future prospective investigation comparing these regimens with larger patient cohorts and additional strategies to prevent relapse and limit toxicities as well as cost-effectiveness analyses are warranted.