Background: The sensitization of leukemic cells with hematopoietic growth factors can enhance the cytotoxicity of chemotherapy in acute myeloid leukemia (AML). Intensified remission induction (RI) therapy can also improve the treatment results for AML. Therefore, the current trial attempted to evaluate the efficacy and toxicity of granulocyte colony-stimulating factor (G-CSF) priming and a dose intensification of Ara-C in RI chemotherapy for AML.
Methods: A total of 29 patients with newly diagnosed AML received G-CSF-priming RI chemotherapy consisting of idarubicin (12 mg/m2, days 1-3), G-CSF (150 microg/m2, days 3-8) and Ara-C (500 mg/m2, b.i.d., days 4-8), and the outcomes were compared with those of a historical group treated with a standard regimen consisting of idarubicin (12 mg/m2, days 1-3) and Ara-C (100 mg/m2, days 1-7).
Results: There was no difference in sex, age, subtype and cytogenetic risk between the two groups. The complete remission rate and treatment-related mortality were 72 and 17% for the G-CSF-primed group (p = 0.89) and 71 and 10% for the historical group (p = 0.32), respectively. The time to neutrophil recovery (25 vs. 24 days, p = 0.17) and platelet recovery (24 vs. 23 days, p = 0.23) did not differ significantly between the two groups. Similarly, the duration of fever was not significantly different (5 vs. 7 days, p = 0.58). Thirteen patients (45%) experienced fever and 5 patients (17%) manifested skin rashes during the G-CSF priming. After a median follow-up of 336 days, the 1-year overall survival, disease-free survival and event-free survival rates were 72 vs. 63% (p = 0.83), 74 vs. 56% (p = 0.059) and 53 vs. 38% (p = 0.32), respectively.
Conclusion: The sensitization of leukemic cells with growth factors and dose intensification seem to be clinically applicable means to enhance the efficacy of RI chemotherapy only in selected patients with AML, thereby warranting further studies focusing on specific subgroups of AML patients.
2007 S. Karger AG, Basel