• Participants with AML diagnosis, who underwent one allo-SCT to treat AML and are currently at ≥ Day 60 but no later than Day 120 (≤ Day 120) post allo-SCT.

• Pre-allo-SCT - Participants must have any of the following risk factors that put them at high risk for relapse:

• • AML in first CR (CR1) prior to allo-SCT with one of the following:

• Adverse risk genetic abnormalities per 2017 ELN risk stratification. Patients with TP53 mutant AML at diagnosis are eligible if they meet eligibility criteria.

• Therapy-related AML (t-AML).

• Secondary AML (sAML) \[AML secondary to antecedent myelodysplastic syndrome (MDS) or AML secondary to myeloproliferative neoplasm (MPN)\].

• • AML in second or greater CR (≥CR2) prior to allo-SCT.

• Allo-SCT must have the following characteristics:

‣ Unmanipulated/T cell-replete bone marrow or peripheral blood stem cells as a graft source.

⁃ Matched related (family) donor (MFD) or matched unrelated donor (MUD): Human Leukocyte Antigen (HLA) matching of donor and recipient should be at a minimum of 8/8 antigen or allele matched at HLA-A, -B, -C, -DRB1 loci.

⁃ Any conditioning regimen intensity is permitted, the use of anti-thymocyte globulin (ATG) or alemtuzumab or post-transplant cyclophosphamide as a part of conditioning is allowed.

• Donor lymphocytes are collected, cryopreserved and available for infusion (DLI), or obtaining donor lymphocytes for DLI is feasible (applicable only for part 2)

• Post-allo-SCT, participants must have achieved CR or CRi with no current evidence of hematologic relapse

• Eastern Cooperative Oncology Group (ECOG ) performance status 0, 1 or 2.

• Laboratory test results indicating adequate liver and kidney function laboratory test results

• Evidence of adequate engraftment: Absolute Neutrophil Count (ANC) ≥ 1.0x109/L, Platelets (PLT) ≥ 75x109/L, Hemoglobin (Hgb) ≥ 8 g/dL (within 14 days prior to start of study treatment)