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.