A Study to Compare the Efficacy and Safety of Oral Azacitidine Plus Best Supportive Care Versus Best Supportive Care as Maintenance Therapy in Japanese Participants With Acute Myeloid Leukemia (AML) in Complete Remission

Inclusion Criteria: * ≥ 55 years of age inclusive at the time of signing the informed consent * Newly diagnosed, histologically confirmed de novo Acute Myeloid Leukemia (AML) or AML secondary to prior myelodysplastic syndrome (MDS) or chronic myelomonocytic leukemia (CMML) * Should have undergone induction therapy with intensive chemotherapy with or without consolidation therapy as recommended in appropriate guideline(s) or equivalent regimen according to institutional standard: having achieved first complete remission (CR)/complete remission with incomplete blood count recovery (CRi) status within 4 months prior to starting study therapy Exclusion Criteria: * Suspected or proven acute promyelocytic leukemia; or AML with previous hematologic disorder such as chronic myeloid leukemia or myeloproliferative neoplasms, excluding MDS and CMML * Prior bone marrow or stem cell transplantation * Received therapy with hypomethylating agents for MDS and went on to develop AML within four months of discontinuing the therapy with hypomethylating agents * Have achieved CR/CRi following therapy with hypomethylating agents Other protocol-defined inclusion/exclusion criteria apply