Clofarabine Plus Low-Dose Cytarabine for Patients With Higher-Risk Myelodysplastic Syndrome (MDS)

Inclusion Criteria

• Age >/= 18 years.
• Diagnosis of MDS confirmed within 10 weeks prior to study entry according to World Health Organization (WHO) or French-American-British (FAB) criteria. Patients are either not eligible for or choose not to proceed with a stem cell transplant.
• MDS classified as follows: refractory anemia with excess blasts (RAEB-1) (5%-9% BM blasts); RAEB-2 (10%-19% BM Blasts); chronic myelomonocytic leukemia (CMML) (5%-19% Bone Marrow (BM) blasts); RAEB-t (20%-29% BM blasts) AND/OR by International Prostate Symptom Score (IPSS): intermediate-2 and high risk patients.
• No response, progression, or relapse (according to 2006 International Working Group (IWG) criteria; see section 8 for details) following at least 4 cycles of either azacitidine or decitabine, or following at least 2 cycles of SGI-110, which were completed within the last 2 years - AND/OR - intolerance to azacitidine, decitabine, or SGI-110 defined as drug-related >/= grade 3 hepatic or renal toxicity leading to treatment discontinuation during the preceding 2 years.
• Eastern Cooperative Oncology Group (ECOG) performance status of /= 38 degree Celsius).
• Total bilirubin >/= 1.5 mg/dL and not related to hemolysis or Gilbert's disease. Patients with total bilirubin >/= 1.5 mg/dL to 3 mg/dL are eligible if at least 75% of the bilirubin is indirect.
• Alanine transaminase (ALT/SGPT) or aspartate transaminase (AST/SGOT) >/= 2.5 x the upper limit of normal.
• Serum creatinine > 1.5 mg/dL.
• Female patients who are pregnant or lactating.
• Patients with reproductive potential who are unwilling to following contraception requirements (including condom use for males with sexual partners, and for females: prescription oral contraceptives [birth control pills], contraceptive injections, intrauterine devices (IUD), double-barrier method [spermicidal jelly or foam with condoms or diaphragm], contraceptive patch, or surgical sterilization) throughout the study.
• Female patients with reproductive potential who do not have a negative urine or blood beta-human chorionic gonadotropin (beta HCG) pregnancy test at screening.
• Patients receiving any other concurrent investigational agent or chemotherapy, radiotherapy, or immunotherapy.
• No prior treatment with cytarabine or clofarabine. Prior hydroxyurea for control of leukocytosis or use of hematopoietic growth factors (eg, G-CSF, Granulocyte-macrophage colony-stimulating factor (GM-CSF), procrit, aranesp, thrombopoietins) is allowed at any time prior to or during study if considered to be in the best interest of the patient.
• Psychiatric illness or social situation that would limit the patient's ability to comply with study requirements.