Inclusion Criteria:  - Age at the date of signing the informed consent form (ICF): Arm 1 and Arm 2: ≥ 18 years  - Participants diagnosed with AML based on WHO 2016 classification (Arber et al 2016) who are ineligible for standard induction chemotherapy and: Arm 1 : have received at least 2 cycles and not more than 4 cycles of first-line venetoclax plus azacitidine treatment and have not achieved a CR, CRi, CRh or MLFS.  Arm 2 : newly diagnosed AML with adverse genetic risk stratification (according to ELN 2017) (except TP53 mutation positive participants).  Participant must be considered ineligible for standard of care intensive induction chemotherapy defined by the following:  75 years of age; OR 18 to 74 years of age with at least one of the following co-morbidities: Eastern Cooperative Oncology Group (ECOG) Performance Status of 2 or 3; Cardiac history of congestive heart failure (CHF) requiring treatment or Ejection Fraction ≤ 50% or chronic stable angina; DLCO ≤ 65% or FEV1 ≤ 65%.  Participants must have an ECOG performance status:  0 to 2 for participants ≥ 75 years of age. OR 0 to 3 for participants ≥ 18 to 74 years of age.  WBC < 25x109/L AST and ALT ≤ 3 × ULN Estimated Glomerular Filtration Rate (eGFR)≥ 60 mL/min/1.73 m2  Exclusion Criteria:  Prior exposure to MDM2-inhibitor therapy at any time. Participants with TP53 mutation positive, as defined by local TP53 testing. Participants with del17p. Participants with AML-M3 / APL (Acute promyelocytic leukemia) with PML-RARA (Promyelocytic leukemia/retinoic acid receptor alpha) or with AML secondary to Down's syndrome. Participants treated with FLT3 inhibitors Participants who require treatment with moderate or strong CYP3A4 inducers within 14 days prior to starting study treatment, or are expected to receive moderate or strong CYP3A4 inducers during the entire study Participants who require treatment with substrates of CYP3A4/5 with a narrow therapeutic index.  Other protocol-defined inclusion/exclusion criteria may apply at the end