Clofarabine, Cytarabine, and G-CSF in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

PRIMARY OBJECTIVES: I. To determine the maximum tolerated dose of clofarabine, and the dose-limiting toxicities of the combination of clofarabine and cytarabine with G-CSF priming, in the treatment of patients with relapsed or refractory AML. SECONDARY OBJECTIVES: I. To determine the hematological and non-hematological side effect profile of the combination of clofarabine, cytarabine, and G-CSF. II. To determine the efficacy of clofarabine in combination with cytarabine and G-CSF priming in the treatment of patients with relapsed or refractory AML. III. To determine the disease-free and overall survival after therapy with clofarabine, cytarabine, and G-CSF for relapsed or refractory AML. OUTLINE: This is a dose escalation study of clofarabine. PART I: INDUCTION THERAPY: Patients receive clofarabine IV over 1 hour and cytarabine IV over 2 hours on days 1-5, and filgrastim (G-CSF) subcutaneously once daily beginning 24 hours prior to chemotherapy and continuing until blood count recover. Patients with residual leukemia (\>= 5% blasts by morphology) at day 14 and if blast remain \> 5% by day 21 receive a second course of induction therapy. CONSOLIDATION THERAPY: Patients receive clofarabine, cytarabine, and G-CSF as in induction therapy. Patients may receive a second course of consolidation therapy depending on response and whether additional therapy (e.g., stem cell transplant or donor lymphocyte infusion) is planned. PARTS II and III: Patients receive induction therapy and consolidation therapy as in part 1. After completion of study treatment, patients are followed every 3 months for 2 years and then annually for 3 years.