A Phase 1/2 Study of Bleximenib in Participants With Acute Leukemia (cAMeLot-1)

Inclusion Criteria: Phase 1: * Age 2 years to less than (\<) 18 years of age (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 \<= 20\*10\^9/liter (L) and (b) renal function; For adult participants, estimated or measured glomerular filtration rate \>= 30 milliliter per minute (mL/min) per four variable MDRD equation. For pediatric participants an estimated or measured glomerular filtration rate \>=40 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 \< 16 years of age) or \>=70 Karnofsky scale (for participants \>=16 years of age) * A female of childbear…