Repeated Cycles of G‐CSF‐Combined Postremission Chemotherapy for Acute Myeloid Leukemia in a First Complete Remission: A Pilot Study

Abstract 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.