A Study of JNJ-75276617 in Participants With Acute Leukemia

Inclusion Criteria:

Relapsed or refractory 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
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) (hydroxyurea may be used to lower WBC count at screening and during study; cytoreductive therapy may be considered with sponsor approval; (b) Chemistry: Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) <=2.5 * upper limit of normal (ULN), total serum bilirubin <= 1.5 * ULN (participants with elevated bilirubinemia, such as Gilbert's syndrome, may enroll if conjugated bilirubin is within clinically acceptable range) and renal function; Estimated or measured glomerular filtration rate greater than or equal to (>=) 50 milliliter per minute (mL/min)/1.73 meter square (m^2) per four variable modified diet in renal disease (MDRD) equation
Eastern Cooperative Oncology Group (ECOG) performance status grade of 0 or 1. Adolescent 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 participant 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
A participant must agree to all the following during the study and for 90 days after the last dose of study treatment: (a) wear a condom when engaging in any activity that allows for passage of ejaculate to another person; (b) not to donate sperm or freeze for future use for the purpose of reproduction. In addition, the participant should be advised of the benefit for a female partner to use a highly effective method of contraception as condom may break or leak

Exclusion Criteria:

Acute promyelocytic leukemia, diagnosis of Down syndrome associated leukemia or juvenile myelomonocytic leukemia according to World Health Organization (WHO) 2016 criteria
Active central nervous system (CNS) disease
Prior solid organ transplantation
QTc according to Fridericia's formula (QTcF) for males >= 450 millisecond (msec) or for females >= 470 msec. Participants with a family history of Long QT syndrome are excluded
Exclusion criteria related to stem cell transplant: a. Willing and able to undergo allogeneic stem cell transplant (if clinically indicated); b. Received prior treatment with allogenic bone marrow or stem cell transplant <=3 months before the first dose of study treatment; c. Has evidence of graft versus host disease; d. Received donor lymphocyte infusion <=1 month before the first dose of study treatment; e. Requires immunosuppressant therapy (exception: daily doses <=10 milligrams (mg) prednisone or equivalent are allowed for adrenal replacement)
Prior cancer immunotherapy within 4 weeks prior to enrollment or blinatumomab within 2 weeks prior to enrollment. Additional prior cancer therapies must not be given within 4 weeks prior to enrollment or 5 half-lives of the agent (whichever is shorter)