A Study Evaluating Safety and Efficacy of Venetoclax in Combination With Azacitidine Versus Standard of Care After Allogeneic Stem Cell Transplantation (SCT) in Participants With Acute Myeloid Leukemia (AML)

Inclusion Criteria:

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

• Participant must be diagnosed with Acute Myeloid Leukemia (AML) by World HealthOrganization (WHO) criteria (2017) and either be planning for allogeneic stem celltransplantation or have received allogeneic stem cell transplantation within thepast 60 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 mustbe < 5% after transplant.

• Participant meet adequate renal, hepatic and hematologic criteria as described inthe 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 PerformanceScale 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 ofbreast; basal cell carcinoma of the skin or localized squamous cell carcinoma of theskin; previous malignancy confined and surgically resected (or treated with othermodalities) with curative intent; Myelodysplastic Syndrome, Myeloproliferativeneoplasm (only allowed if it transformed to AML and AML should be the indication formarrow transplantation).

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

• Presence of clinical or laboratory symptoms/signs of extramedullary myeloidmalignancy.