Clofarabine, Cytarabine, and G-CSF in Treating Patients With Myelodysplastic Syndromes

Overview

RATIONALE: Drugs used in chemotherapy, such as clofarabine and cytarabine, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Colony-stimulating factors, such as G-CSF, may increase the number of immune cells found in bone marrow or in peripheral blood and may help the immune system recover from the side effects of chemotherapy. Giving clofarabine and cytarabine together with G-CSF may kill more cancer cells. PURPOSE: This phase I/II trial is studying the side effects and best dose of clofarabine and to see how well it works when given together with cytarabine and G-CSF in treating patients with myelodysplastic syndromes.

OBJECTIVES: Primary * To determine the maximum tolerated dose (MTD) of clofarabine when administered with low-dose cytarabine and filgrastim (G-CSF) in patients with intermediate-2 or high-risk myelodysplastic syndromes (MDS). * To evaluate efficacy as measured by hematologic response rates in patients who are treated with this novel combination of drugs and who are not candidates for more intensive treatment for intermediate-2 and high-risk MDS. Secondary * To assess effects on quality of life of this patient population. * To assess the time to acute myeloid leukemia transformation or death. * To assess cytogenetic response rates. * To assess changes in flow cytometric patterns. OUTLINE: This is a phase I, nonrandomized, dose-escalation study of clofarabine followed by a phase II study. * Phase I: Patients receive clofarabine IV over 1 hour and low-dose cytarabine subcutaneously (SC) on days 1-5. Patients also receive filgrastim (G-CSF) SC beginning 1 day prior to the start of chemotherapy and continuing through completion of chemotherapy until blood counts recover. Treatment repeats every 6 weeks for up to 10 courses in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of clofarabine until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. * Phase II: Patients receive clofarabine at the MTD, cytarabine, and G-CSF as in phase I. Quality of life is assessed at baseline, prior to course 4, and after completion of study therapy. Patients undergo bone marrow biopsy at baseline and prior to courses 3, 6, and 8 for evaluation of treatment response. Bone marrow samples are analyzed for myeloblast phenotypic expression profiles, which include the following parameters: percentage of CD34-positive myeloblasts; antigen expression density of CD13, CD34, CD45, and CD117; and aberrant myeloblast expression of CD4, CD11c, CD15, and CD56.