Inclusion Criteria:

          -  De novo or secondary acute myeloid leukemia (AML) (post myelodysplastic syndrome [MDS]
             or myeloproliferative neoplasm [MPN] or after leukemogenic chemotherapy) according to
             WHO 2008 criteria

        For Part A:

        - Participants With AML: treatment naive or relapsed for whom experimental therapy is
        appropriate (as assessed by their treating physician)

        For Part B:

          -  Greater than or equal to (>=) 75 years of age or >= 65 up to 75 years of age and have
             at least one of the following: congestive heart failure or ejection fraction less than
             or equal to (<=) 50 percent; creatinine greater than (>) 2 milligram per deciliter
             (mg/dL); dialysis or prior renal transplant; documented pulmonary disease with lung
             diffusing capacity for carbon monoxide (DLCO) <= 65 percent of expected, or forced
             expiratory volume in 1 second (FEV1) <= 65 percent of expected or dyspnea at rest
             requiring oxygen; eastern cooperative oncology group (ECOG) performance status of 2;
             prior or current malignancy that does not require concurrent treatment; unresolved
             infection; comorbidity that, in the Investigator's opinion, makes the participant
             unsuitable for intensive chemotherapy and must be documented and approved by the
             Sponsor before randomization

          -  Previously untreated AML (except: emergency leukopheresis and/or hydroxyurea during
             the screening phase to control hyperleukocytosis but must be discontinued at least one
             day prior to start of study therapy)

          -  Not eligible for an allogeneic hematopoietic stem cell transplantation

          -  ECOG Performance Status score of 0, 1 or 2

          -  A woman must be either: Not of childbearing potential: postmenopausal (more than [>]
             45 years of age with amenorrhea for at least 12 months; If, of childbearing potential
             must be practicing a highly effective method of birth control

          -  A woman of childbearing potential must have a negative serum (beta-human chorionic
             gonadotropin [beta-hCG]) or urine pregnancy test at screening

          -  A man who is sexually active with a woman of childbearing potential and has not had a
             vasectomy must agree to use a barrier method of birth control eg, either condom with
             spermicidal foam/gel/film/cream/suppository or partner with occlusive cap (diaphragm
             or cervical/vault caps) with spermicidal foam/gel/film/cream/suppository for at least
             3 months after last study treatment

        Exclusion Criteria:

          -  Acute promyelocytic leukemia with t(15;17), or its molecular equivalent (PML-RARalpha)

          -  For Part B only: Known leukemic involvement or clinical symptoms of leukemic
             involvement of the central nervous system

          -  Participants who received prior treatment with a hypomethylating agent

          -  For Part A only: Participants who did not recover from all clinically significant
             toxicities (excluding alopecia and hematologic toxicities) of any previous surgery,
             radiotherapy, targeted therapy, or chemotherapy to less than or equal to Grade 1

          -  Any uncontrolled active systemic infection that requires treatment with intravenous
             (IV) antibiotics

          -  A history of human immunodeficiency virus (HIV) antibody positive or tests positive
             for HIV if tested at screening

          -  Active systemic hepatitis infection requiring treatment or other clinically active
             liver disease