Inclusion Criteria: 1. Adult subject must understand and voluntarily sign an ICF prior to any study-related assessments/procedures being conducted. 2. Arm A (CC-90009 + venetoclax/azacitidine): 1. Part A: Newly diagnosed AML with poor/adverse risk genetic abnormalities and is either ≥ 75 years of age or is ineligible for intensive chemotherapy OR 2. Part A: Primary Refractory AML, or AML in first relapse, and is ≥ 18 years of age 3. Part B: Newly diagnosed AML and is ≥ 75 years of age or intensive chemotherapy ineligible 3. Arm B (CC-90009 + gilteritinib): 1. Subject is ≥ 18 years of age. 2. Fms-like tyrosine kinase 3 (FLT3) mutation positive. 3. Gilteritinib treatment naïve 4. Subject has Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2. 5. Subject must have the following screening laboratory values: - Total White Blood Cell count (WBC) < 25 x 10^9/L prior to study treatments. Treatment with hydroxyurea to achieve this level is allowed. - Selected electrolytes within normal limits or correctable with supplements. - Participant must have adequate liver function as demonstrated by: Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 x upper limit of normal (ULN) and bilirubin ≤ 1.5 x ULN - Participant has adequate renal function as demonstrated by an estimated serum creatinine clearance of ≥ 30 mL/min. 6. Agree to follow the CC-90009 Pregnancy Prevention Plan (PPP) and combination agents' requirements. Exclusion Criteria: 1. Subject with acute promyelocytic leukemia (APL) 2. Subject has received systemic anticancer therapy (including investigational therapy) or radiotherapy < 28 days or 5 half-lives, whichever is shorter, prior to the start of study treatment 3. Patients with prior autologous hematopoietic stem cell transplant (HSCT) who, in the investigator's judgment, have not fully recovered from the effects of the last transplant (eg, transplant related side effects) 4. Prior allogeneic HSCT with either standard or reduced intensity conditioning ≤ 6 months prior to dosing 5. Subject on systemic immunosuppressive therapy post HSCT at the time of screening, or with clinically significant graft-versus-host disease (GVHD). The use of topical steroids for ongoing skin or ocular GVHD is permitted 6. Subject has persistent, clinically significant non-hematologic toxicities from prior therapies which have not recovered to < Grade 2 7. Subject has or is suspected of having central nervous system (CNS) leukemia. Evaluation of cerebrospinal fluid is only required if CNS involvement by leukemia is suspected during screening. 8. Disorders or conditions disrupting normal calcium homeostasis or preventing calcium supplementation. 9. Impaired cardiac function or clinically significant cardiac diseases, including any of the following: 1. Left ventricular ejection fraction (LVEF) < 45% as determined by multiple gated acquisition (MUGA) scan or echocardiogram (ECHO). 2. Complete left bundle branch or bifascicular block. 3. Congenital long QT syndrome. 4. Persistent or clinically meaningful ventricular arrhythmias. 5. QTcF ≥ 470 ms (Arm A) or > 450 ms (Arm B) on Screening electrocardiogram (ECG) 6. Unstable angina pectoris or myocardial infarction ≤ 6 months prior to starting study treatments or unstable arrhythmia. 7. Cardiovascular disability status of New York Heart Association Class ≥2. Class 2 is defined as cardiac disease in which patients are comfortable at rest but ordinary physical activity results in fatigue, palpitations, dyspnea, or anginal pain. 10. Subject is a pregnant or lactating female 11. Additional exclusion criteria based on combination agent: a. For Combination Arm A (venetoclax/azacitidine): - Received strong or moderate CYP3A inhibitors or inducers or P-gp inhibitors within 7 days prior to initiation of first venetoclax dose. - Subject has consumed grapefruit, grapefruit products, Seville oranges (including marmalade containing Seville oranges), or Star fruit within 3 days prior to first venetoclax dose through last dose of venetoclax. 12. Previous SARS-CoV-2 infection within 10 days for mild or asymptomatic infections or 20 days for severe/critical illness prior to C1D1. a. Acute symptoms must have resolved and based on investigator assessment in consultation with the medical monitor, there are no sequelae that would place the participant at a higher risk of receiving study treatment. 13. Previous SARS-CoV-2 vaccine within 14 days of C1D1.