Granulocyte Colony-Stimulating Factor Improves the Antileukemic Efficacy of the Sequential High-Dose Cytosine Arabinoside and Mitoxantrone Regimen (S-HAM) in Patients Younger than 60 Years with High-Risk Acute Myeloid Leukemia

Patients receiving intensive chemotherapy for advanced acute myeloid leukemia carry a high risk of treatment failure due to infectious complications and early relapses. In this regard, granulocyte colony-stimulating factor (G-CSF) provides an option for optimization of supportive therapy. In a prospective study, 68 evaluable patients with relapsed and refractory acute myeloid leukemia received G-CSF 5 µg/kg/day subcutaneously starting two days after the completion of treatment with the S-HAM regimen consisting of high-dose cytonsine arabinoside twice daily on days 1, 2, 8, and 9 and mitoxantrone on days 3, 4, 10, and 11. Ninety-one evaluable patients receiving S-HAM for refractory and relapsed acute myeloid leukemia without G-CSF support during a preceeding study served as control. The application of the growth factor resulted in a trend towards a lower early death rate (21 vs. 30%). More importantly, a marginally significant increase of the CR rate was achieved (56 vs. 47%, p=0.11). Partial remission occurred in 0% and 7% while persisting leukemias were documented in 24 and 16%, respectively. Probably, these differences are based at least in part on a significant reduction of the duration of critical neutropenia of less than 500/μl (36 vs. 40 days, p=0.008).