This study investigates the use of an investigational medication with standard chemotherapy in children, adolescents, and young adults who have high-risk B-cell acute lymphoblastic leukemia (HR B-ALL). HR B-ALL is a type of cancer that affects the blood and bone marrow. The purpose is to find the best dose of the investigational medication and see if it makes chemotherapy more effective.
Participants will receive either the investigational medication or a placebo along with their chemotherapy. A placebo is an inactive substance that looks like the investigational medication but does not contain any medicine. The study will compare the effects, both good and bad, of using the investigational medication with chemotherapy.
- Who can participate: Participants must be children, adolescents, or young adults diagnosed with high-risk Ph-like B-ALL. They should have completed a 4-drug induction therapy regimen and meet certain genetic criteria. Individuals with BCR-ABL1-rearranged ALL or Down syndrome are excluded.
- Study details: Participants will be randomly assigned to receive either the investigational medication or a placebo along with standard chemotherapy.

