⁃ Phase 1:

• Age 2 years and above (pediatric cohort only), all other cohorts 18 years and above

• Relapsed or refractory (R/R) acute leukemia and has exhausted, or is ineligible for, available therapeutic options

• Acute leukemia harboring histone-lysine N-methyltransferase 2A (KMT2A), nucleophosmin 1 gene (NPM1) or nucleoporin 98 gene or nucleoporin 214 gene (NUP98 or NUP214) alterations

⁃ Phase: 2

• Participants greater than 18 years are eligible

• Must have had an initial diagnosis of acute myeloid leukemia (AML) per the WHO 2022 classification criteria and have relapsed/refractory disease

• AML harboring KMT2A-r (gene rearrangement/translocation) or NPM1 mutations only

⁃ For Both Phase 1 and 2:

• Pretreatment clinical laboratory values meeting the following criteria: (a) Hematology: white blood cell (WBC) count less than or equal to (\<=) 20\*10\^9/liter (L) and (b) renal function; For adult participants, estimated or measured glomerular filtration rate greater than equal (\>=) 30 milliliter per minute (mL/min) per four variable MDRD equation. For pediatric participants an estimated or measured glomerular filtration rate \>50 mL/min per the CKiD (Chronic Kidney Disease in Children) Schwartz formula

• Eastern Cooperative Oncology Group (ECOG) performance status grade of 0, 1 or 2. Pediatric participants only: Performance status \>=70 by Lansky scale (for participants less than \[\<\]16 years of age) or \>=70 Karnofsky scale (for participants \>=16 years of age)

• A female of childbearing potential must have a negative highly sensitive serum beta-human chorionic gonadotropin at screening and within 48 hours prior to the first dose of study treatment

• Participant must agree to all protocol required contraception requirements and avoid sperm or egg donations or freezing for future reproductive use while on study and for 90 days (males) or 6 months (females) after the last dose of study treatment