A comparative study of outcomes of idarubicin- and etoposide-intensified conditioning regimens for allogeneic peripheral blood stem cell transplantation in patients with high-risk acute leukemia.

To analyze the results of idarubicin (IDA)- versus etoposide (VP16)-intensified myeloablative conditioning regimen in allogeneic hematopoietic stem cell transplantation (allo-SCT) for high-risk acute leukemia. From January 2005 to June 2008, 48 consecutive patients (male: n=29; median age: 30 years, range 14-51 years) with high-risk acute leukemia underwent allo-SCT following an IDA- or VP16-intensified conditioning regimen. The conditioning regimens were modified BUCY2 (busulfan+cyclophosphamide) consisting of IDA (15 mg/m2 per day, days -12 to -10) or VP16 (25 mg/kg per day, days -3 to -2) and CY/TBI (cyclophosphamide/total body irradiation) intensified with IDA (15 mg/m2 per day, days -6 to -5) or VP16 (25 mg/kg per day, days -3 to -2) for acute myeloid leukemia and acute lymphoblastic leukemia, respectively. Between the two groups, no significant differences in terms of baseline characteristics, incidence of acute or chronic graft-versus-host disease (GVHD) or transplant-related mortality (TRM) (P=0.50) were observed. However, the IDA group demonstrated higher incidences of mucositis and Aspergillus pneumonia (P<0.01 and P=0.03, respectively). For the IDA and VP16 groups, relapse rates were 28% and 50%, respectively (P=0.13). For the same groups, the 2-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 72% versus 51% (P=0.04) and 74% versus 53% (P=0.04), respectively. This retrospective analysis suggests that conditioning regimens intensified with IDA can achieve better outcomes than conditioning regimens with VP16 in patients preparing to undergo allo-SCT for high-risk acute leukemia.