Inclusion Criteria:

          -  Agreement to avoid pregnancy or fathering children.

          -  Participants who are transfusion-dependent or present with symptomatic anemia

        For MDS participants:

          -  Ineligible to receive or have not responded to available therapies for anemia such as
             ESAs or lenalidomide.

          -  Not requiring cytoreductive therapy other than hydroxyurea.

          -  BM and peripheral blood myeloblast count < 10%.

          -  Histologically confirmed diagnosis of the MDS, CMML and unclassifiable MDS/MPN overlap
             syndromes.

        For MM participants:

          -  Histologically confirmed diagnosis of MM.

          -  After failure of available standard treatments such as alkylating agents,
             glucocorticoids, immunomodulatory drugs (lenalidomide,pomalidomide, or thalidomide),
             proteasome inhibitors (bortezomib or carfilzomib), and daratumumab.

        Exclusion Criteria:

          -  Any prior allogeneic stem cell transplantation or a candidate for such
             transplantation.

          -  Any major surgery within 28 days before the first dose of study drug.

          -  Any prior chemotherapy, immunomodulatory drug therapy, immunosuppressive therapy,
             biological therapy, endocrine therapy, targeted therapy, or antibody or
             hypomethylating agent to treat the participant's disease within 5 half-lives or 28
             days (whichever is shorter) before the first dose of study drug.

          -  Undergoing treatment with another investigational medication or having been treated
             with an investigational medication within 28 days before the first dose of study drug.
             -Undergoing treatment with ESAs, granulocyte colony-stimulating factor or
             granulocyte/macrophage colony-stimulating factor, romiplostin, or eltrombopag at any
             time within 28 days before the first dose of study drug.

          -  Undergoing treatment with a strong or potent inhibitor or inducer of CYP3A4/5 within
             28 days or 5 half-lives (whichever is longer) before the first dose of study drug or
             expected to receive such treatment during the study.

          -  History of clinically significant or uncontrolled cardiac disease.

          -  History or presence of an abnormal ECG that, in the investigator's opinion, is
             clinically Meaningful.

          -  Presence of chronic or current active infectious disease requiring systemic
             antibiotic, antifungal, or antiviral treatment.

          -  Diagnosis of chronic liver disease.