Phase 2 Study of Azacitidine (Vidaza) vs MGCD0103 vs Combination in Elderly Subjects With Newly Diagnosed Acute Myeloid Leukemia (AML) or Myelodysplastic Syndrome (MDS)

Inclusion Criteria: * Able to provide written informed consent, and be willing and able to comply with all the study procedures * Must be 60 years of age or older * Must have a pathologic confirmation of newly diagnosed (de novo or untreated secondary) AML or newly diagnosed Int-2 or high-risk MDS (IPSS classification) according to WHO criteria * Must have a Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 * Must have adequate organ function, including total bilirubin ≤ 1.5 x upper limit of normal (ULN); AST \& ALT ≤ 2.5 x ULN; and serum creatinine ≤ 2.0 x ULN. Exclusion Criteria: * Considered fit for intensive chemotherapy and opt to be treated with intensive chemotherapy * Prior transplantation or any prior anticancer therapy (standard or investigational, including chemotherapy, treatment with HDAC inhibitors, or combination HDAC and azacitidine) administered to treat AML or MDS. * Clinical evidence of central nervous system (CNS) involvement by leukemia * A diagnosis of promyelocytic leukemia * Previous or concurrent malignancy except adequately treated basal cell or squamous cell skin cancer; in situ carcinoma of the cervix, or other solid tumor treated curatively, and without evidence of recurrence for at least 3 years prior to study entry * Active and uncontrolled clinically significant infection * Known positive serology for hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV Ab) or human immunodeficiency virus (HIV) * Less than 4 weeks elapsed since any major surgery * Any prior or active disease that may interfere with the procedures or evaluations to be conducted in the study