Inclusion Criteria:

          1. Male and female patients aged ≥ 18 years.

          2. Patients with relapsed /refractory AML, ALL, or MLL with rearrangement of the MLL
             gene, including 11q23 or PTD, are eligible for the expanded cohort:

               -  At least one prior therapy;

               -  Refractory disease on most recent therapy, or disease recurrence following
                  remission on most recent therapy;

               -  Received and failed all known effective therapies for their disease;

               -  Not a candidate for allogeneic stem cell transplantation

               -  > 10% blasts or biopsy-documented leukemia cutis or myeloid sarcoma.

          3. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.

          4. Patients must have the following clinical laboratory values:

               -  Serum creatinine ≤2 mg/dL or creatinine clearance > 60 mL/minute;

               -  Total bilirubin ≤2.0 times the ULN for the institution, unless considered due to
                  Gilbert's syndrome;

               -  ALT or AST ≤ twice the upper limit of normal (ULN), unless considered due to
                  organ leukemic involvement;

               -  Absolute neutrophil count ≥1,000/µL (unless due to documented leukemic
                  involvement of the bone marrow at the time of study entry)

               -  Platelets ≥100,000/µL (unless due to documented leukemic involvement of the bone
                  marrow at the time of study entry).

               -  PT or aPTT < 1.5 times the ULN

          5. Able and willing to give written informed consent.

          6. Life expectancy of at least 3 months

        Exclusion Criteria:

          1. Uncontrolled intercurrent illness or psychiatric illness/social situations that would
             limit compliance with study requirements.

          2. Active heart disease

          3. Receiving any other standard treatment for their hematologic malignancy.

          4. Receiving strong CYP3A4 inhibitors/ inducers.

          5. Known history of cerebrovascular accident in the past 6 months.

          6. Known bleeding diathesis.

          7. Known, active (symptomatic) involvement of the central nervous system by leukemia.

          8. On immunosuppressive therapy.

          9. Known active infection.

         10. Pregnant or nursing females.