2. Treatment-naïve/ Unfit Cohorts: Previously untreated patients with histological confirmation of AML who are ineligible for treatment with a standard cytarabine and anthracycline induction regimen; or previously untreated patients with intermediate, high, or very high risk MDS. Prior and concurrent therapy with hydroxyurea, oral etoposide, erythroid and/or myeloid growth factors is allowed.