Repeated cycles of G-CSF-combined postremission chemotherapy for acute myeloid leukemia in a first complete remission: a pilot study.

The cure rate of acute myeloid leukemia might increase if G-CSF were given concurrently with repeated postremission chemotherapy. However, this therapy might cause severe complications, including depletion of normal hematopoietic progenitors as a long-term toxicity. Thus, we conducted a pilot study of this strategy. Twenty-six acute myeloid leukemia patients in a first complete remission (CR) were treated with two courses of consolidation chemotherapy (10-day BHAC-DMP, consisting of behenoyl cytosine arabinoside, daunorubicin, 6-mercaptopurine and prednisolone) and repeated maintenance-intensification therapy including eight cycles of six-day BHAC-DMP. G-CSF (filgrastim) was administered concurrently with these BHAC-DMP therapies. Toxicity during the therapeutic period was not significant in the study group compared with the historical control, treated with the same regimen without G-CSF. Neutrophil recovery after the consolidation therapy was more rapid in the study group than in the historical control (p = 0.066 and 0.024 for the first and second consolidation courses, respectively). Long-term toxicity, such as cytopenia, has not been seen in eight patients who have remained in CR for a long period (range: 39-58 months). At a median follow-up of 39 months, the predicted rate of 42-month CR duration for these 26 patients was 50% (95% confidence limits: 30% to 71%). We conclude that G-CSF-combined repeated BHAC-DMP postremission therapy is feasible. Full elucidation of the clinical benefit of this strategy will require further study.