MGCD0103 in Elderly Patients With Previously Untreated AML/High Risk MDS or Adults With Relapsed/Refractory Disease

Inclusion Criteria: * Pathologic confirmation of AML or high risk MDS. * Elderly cohort (70 years of age or more): no prior chemotherapy treatment for AML/high risk MDS and not currently candidates for intensive chemotherapy. * Relapsed/refractory cohort (18 years of age or more): relapsed or refractory to prior treatment. * ECOG performance status of 0 or 1. * Total bilirubin \< 1.5 x upper limit of normal (ULN). * AST/SGOT and ALT/SGPT \< 2.5 x ULN. * Serum creatinine \< 1.5 x ULN. * Patients must read, understand, and sign a written informed consent form (ICF). * Women of childbearing potential and male patients' female partners must use an acceptable method of contraception while on study, and for 3 months after study drug treatment. Exclusion Criteria: * Pregnant or lactating women. * Patients with uncontrolled, intercurrent illness, active or uncontrolled infections, or a fever \> 38.5C (not due to tumor fever) on the day of scheduled dosing. * Patients with serious illnesses or medical conditions, including laboratory results, which, in the investigator's opinion, would interfere with a patient's participation, or with the interpretation of the results. * Patients treated with an investigational drug within 30 days prior to study initiation. * Known hypersensitivity to HDAC inhibitors or to any of the components of MG-0103. * Known HIV or active hepatitis B or C. * Any condition that may affect the patient's ability to sign the ICF and undergo study procedures. * Any conditions that will put the patient at undue risk or discomfort as a result of adherence to study procedures.