Busulfan Plus Fludarabine Effective Preparative Regimen for HSCT in Acute Leukemia

In older patients with acute myeloid leukemia (AML), the myeloablative busulfan plus fludarabine conditioning regimen is associated with lower transplant-related mortality than busulfan plus cyclophosphamide while retaining potent antileukemic activity, a new study published online ahead of print in the journal The Lancet Oncology has shown.¹

Because busulfan plus fludarabine has been proposed to reduce non-relapse mortality in patients with AML undergoing allogeneic hematopoietic stem-cell transplantation (HSCT), researchers sought to compare this combination with busulfan plus cyclophosphamide as a preparative regimen.

For the open-label, multicenter, phase 3 trial, researchers enrolled 252 patients age 40 to 65 with AML in complete remission. Patients were randomly assigned 1:1 to receive intravenous busulfan plus cyclophosphamide or busulfan plus fludarabine.

Results showed that 1-year non-relapse mortality was 17.2% (95% CI: 11.6-25.4) in the busulfan plus cyclophosphamide arm and 7.9% (95% CI: 4.3-14.3) in the busulfan plus fludarabine arm (P=0.026).

In regard to safety, 23% of patients in the cyclophosphamide group and 21% of patients in the fludarabine group reported grade 3 or higher gastrointestinal adverse events. Infections occurred in 17% and 10% of patients in the cyclophosphamide and fludarabine groups, respectively.

“This regimen should be regarded as standard of care during the planning of allogeneic transplants for such patients,” the authors concluded.

Reference

1. Rambaldi A, Grassi A, Masciulli A, et al. Busulfan plus cyclophosphamide versus busulfan plus fludarabine as a preparative regimen for allogeneic haemopoietic stem-cell transplantation in patients with acute myeloid leukaemia: an open-label, multicentre, randomised, phase 3 trial [published online ahead of print September 28, 2015]. Lancet Oncol. doi: 10.1016/S1470-2045(15)00200-4.