This is a combination study to evaluate sapacitabine administered in alternating cycles with decitabine in previously untreated Acute Myeloid Leukemia (AML) or concomitantly with venetoclax in previously treated AML or MDS

This is an open-label, single arm, study of sapacitabine administered in alternating cycles with decitabine in elderly patients with previously untreated AML (Part 1) or concomitantly with venetoclax in adult patients with relapsed or refractory AML or MDS (Part 2). Treatment will be administered on an outpatient basis. One treatment cycle is 4 weeks.

Inclusion Criteria:

• Newly diagnosed AML based on WHO classification (Part 1) or previously treated AML or MDS (Part 2)
• Age 70 years or older for whom the treatment of choice is low-intensity therapy by investigator assessment or who has refused intensive induction therapy recommended by investigator (Part 1); age 18 years or older (Part 2)
• ECOG performance status 0-2
• Adequate renal function
• Adequate liver function
• Able to swallow capsules
• Ability to understand and willingness to sign the informed consent form

Exclusion Criteria:

• AML is of the sub-type of acute promyelocytic leukemia or extramedullary myeloid tumor without bone marrow involvement
• Known central nervous system (CNS) involvement by leukemia
• Uncontrolled intercurrent illness including
• Known hypersensitivity to decitabine (Part 1) or venetoclax (Part 2)
• Known to be HIV-positive