Inclusion Criteria:

          -  Participants must be at least 18 years old for Part 1 and, at least 12 years old for
             Part 2.

          -  Participant must be diagnosed with AML by World Health Organization (WHO) criteria
             (2017) and either be planning for allogeneic stem cell transplantation or have
             received allogeneic stem cell transplantation within the past 14 days.

          -  Blast percentage in bone marrow before transplant must be < 10%.

          -  Blast count in peripheral blood must be "0" and Blast percentage in bone marrow must
             be < 5% after transplant.

          -  Participant meet adequate renal, hepatic and hematologic criteria as described in the
             protocol.

          -  Participants >= 17 years old must have a Karnofsky Performance Scale (KPS) score > 50
             and participants between 12 to 16 years old must have a Lansky Play Performance Scale
             score > 40.

        Exclusion Criteria:

          -  History of disease progression during prior treatment with venetoclax.

          -  History of any other malignancy within 2 years prior to study entry, except for:
             Adequately treated in situ carcinoma of the cervix uteri or carcinoma in situ of
             breast; basal cell carcinoma of the skin or localized squamous cell carcinoma of the
             skin; previous malignancy confined and surgically resected (or treated with other
             modalities) with curative intent; Myelodysplastic Syndrome.

          -  Participant has known infection with HIV or history of being positive for hepatitis B
             virus (HBV) or hepatitis C virus (HCV) infection.

          -  Presence of clinical or laboratory symptoms/signs of extramedullary myeloid
             malignancy.