Retrospective comparison of clofarabine versus fludarabine in combination with high-dose cytarabine with or without granulocyte colony-stimulating factor as salvage therapies for acute myeloid leukemia.

We recently reported that clofarabine, high-dose cytarabine, and granulocyte colony-stimulating factor (GCLAC) produced a 46% complete remission rate in relapsed/refractory acute myeloid leukemia. GCLAC differs from FLAG by substitution of clofarabine for fludarabine, raising the question of the relative efficacy of these two regimens. We compared GCLAC given at the University of Washington Medical Center/Fred Hutchinson Cancer Research Center to fludarabine and cytarabine (FA) and FLAG given at MD Anderson Cancer Center. Independent multivariate analyses conducted at both institutions showed that after accounting for duration of first complete remission, salvage number, age, and cytogenetics, GCLAC was associated with a higher complete remission rate (odds ratio 9.57, P<0.0001) and longer survival (mortality hazard ratio 0.43, P=0.0002). Despite the retrospective nature of the analyses, GCLAC may be superior to FA/FLAG, particularly in patients with short duration of first complete remission or unfavorable cytogenetics.