• Patients ≥ 18 years of age at the time of obtaining informed consent.

• Patients with morphologically documented primary or secondary AML by the World Health Organization(WHO) criteria, whose disease is relapsed/refractory to at least one line of prior therapy, with or without an allogeneic stem cell transplant and for whom no standard therapy that may provide clinical benefit is available or for patients who decline available standard of care.

• Patients with a documented diagnosis of high-risk myelodysplastic syndrome (MDS), whose disease is relapsed/refractory, post at least one line of treatment based on the revised International Prognostic Scoring System (IPSS-R) and for whom no standard therapy that may provide clinical benefit is available

• Patients are able and willing to comply with study procedures as per protocol, including bone marrowbiopsies.

• Patient has an Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.

• Patient must meet the following criteria as indicated on the clinical laboratory tests:

⁃ oWhite blood cell (WBC) count at the time of the first dose of \< 25,000/uL. oAspartate aminotransferase or alanine aminotransferase ≤ 3 × upper limit of normal (ULN; ≤ 5.0× ULN if considered to be due to leukemic involvement). oTotal bilirubin ≤ 2 × ULN (≤ 3 × ULN if considered to be due to leukemic involvement orGilbert's syndrome). oCreatinine clearance of ≥ 60 mL/min.