Venetoclax in Combination With Azacitidine (VEN/AZA) Followed by Donor Lymphocyte Infusion (DLI) for Patients With Very High-Risk Acute Myeloid Leukemia (AML) Undergoing Allogeneic Hematopoietic Cell Transplant (HCT)

Inclusion Criteria:

1. Male and female patients between the ages of 18-75.

2. Patients with a histologic diagnosis of AML in morphological remission (<5% bonemarrow (BM) blasts) prior to allogeneic hematopoietic cell transplantation and veryhigh-risk for relapse defined as: (i) Presence of measurable residual disease (MRD)by multicolor flow cytometry (MFC) prior to transplant and receiving a reducedintensity conditioning (RIC) or nonmyeloablative (NMA) regimen (ii) Presence of MRDby MFC at day +30 post-transplant (iii) All patients with monosomal karyotype (MK)and those with 17p/tumor protein p53 (TP53) mutated disease irrespective of MRDstatus and intensity of conditioning regimen.

3. Adequate hematopoietic recovery after HCT, defined as:

• Absolute neutrophil count (ANC) >= 1 x 10^9/L without daily use of myeloidgrowth factors

• Platelet count >= 50 x 10^9/L without platelet transfusion within 1 week

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

5. Serum creatinine =< 1.5 mg/dL or creatinine clearance greater or equal than 40cc/min

6. Serum bilirubin =< 1.5 x upper limit of normal (ULN)

7. Aspartate transaminase (AST) or alanine transaminase (ALT) =< 2.5 x ULN

8. Alkaline phosphatase =< 2.5 x UL

9. Negative serum or urine pregnancy test for women with reproductive potential.

10. A negative donor-specific antibody (DSA) assay (i.e., Micro-Flow Imaging (MFI) <m3000) for recipients of any mismatched graft (including haploidentical) HCT.

Exclusion Criteria:

1. Active disease (>5% blasts or any evidence of extra-medullary disease) at the timeof transplantation or at day +30

2. Active acute graft-versus-host disease (aGVHD) requiring systemic IST or history ofaGVHD grade III or higher.

3. Active chronic GVHD requiring systemic immunosuppressive therapy (IST).

4. Active uncontrolled systemic fungal, bacterial, or viral infection

5. Known active viral infection with human immunodeficiency virus (HIV), hepatitis Bvirus (HBV), or hepatitis C virus (HCV)

6. Significant active cardiac disease within the previous 6 months, including: New YorkHeart Association (NYHA) class III or IV congestive heart failure. Unstable angina,angina requiring surgical or medical intervention, and/or myocardial infarction.

7. History of any other malignancy within 2 years prior to study entry, except for:adequately treated in situ carcinoma of the cervix 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 othermodalities) with curative intent; myelodysplastic syndrome.