A Study of JNJ-75276617 in Participants With Acute Leukemia

Open to people ages 12 years and up

• 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 * 10⁹/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 (m²) 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

• 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)