Phase II study of FLAGM (fludarabine + high-dose cytarabine + granulocyte colony-stimulating factor + mitoxantrone) for relapsed or refractory acute myeloid leukemia

Given the poor prognosis of patients with relapsed/refractory acute myeloid leukemia (AML), better therapy is needed. Fludarabine enhances the efficacy of Ara-C (cytarabine) by increasing intracellular Ara-C-triphosphate. The FLAG (fludarabine, high-dose Ara-C, supported with granulocyte colony-stimulating factor) regimen has been tested for use in AML patients by other investigators. In the phase II study reported here, we evaluated the efficacy and toxicity of FLAGM therapy (FLAG with mitoxantrone), further intensified by adding mitoxantrone, based on the results of a phase I study by our group. The major endpoints were complete remission (CR) rate and early death. From June 2004 to February 2008, 41 patients (median age 52 years; range 18-64 years) were enrolled. Thirty (73% 95% CI 58-84%) patients achieved CR, which met the primary endpoint; there was a single case of early death from pneumonia. Two-year overall survival was 39.4% (95% CI 25.2-55.6%). Of those who achieved CR, 27 underwent allogeneic stem cell transplantation (SCT), and 12 SCT recipients showed long-term survival. Grade 3/4 non-hematological adverse events included infection (59%), nausea/vomiting (15%), diarrhea (7%), and elevated liver enzymes (7%). In conclusion, FLAGM is an effective and safe salvage therapy for patients with relapsed/refractory AML, and facilitated SCT for a large proportion of patients.