Pediatric AML

The goal of this clinical trial is to learn if sonrotoclax (BGB-11417) is safe and may help treat children and adolescents with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) that has come back after treatment or has not responded to treatment. The study will also learn how the body processes sonrotoclax when it is given with other medicines. The main questions it aims to answer are: * Is sonrotoclax safe and well tolerated when given with other anti-cancer medicines? * How does the body absorb, process, and remove sonrotoclax? * Does treatment with sonrotoclax, in combination with other medicines, help reduce or eliminate leukemia? Researchers will give sonrotoclax together with other anti-cancer medicines to participants with relapsed or refractory AML or ALL. Participants will: * Take sonrotoclax in combination with other anti-cancer medicines * Have regular clinic visits for physical exams, blood tests, heart monitoring, and other safety assessments. * Provide blood samples to measure how the body processes sonrotoclax. * Have tests to evaluate how their leukemia responds to treatment. * Continue treatment as long as it is helping and side effects remain manageable, according to the study plan.

This research study investigates the tolerability of substituting two cycles of chemotherapy into the standard pediatric acute myeloid leukemia (AML) chemotherapy treatment regimen for patients with newly diagnosed AML at intermediate-risk (IR) and high-risk (HR) of relapse. The goal is to achieve similar or better survival with chemotherapy cycles that are intensive but less likely to cause long-term complications. Patients will enroll on this trial at the end of their first induction cycle. The two cycles to be substituted are: * "Ida-FLA" (idarubicin+fludarabine/cytarabine) as Induction 2 * "VIA" (venetoclax+idarubicin+cytarabine) as Intensification 1 of the HR treatment regimen, and Intensification 2 of the IR treatment backbone. Researchers will evaluate side effects and outcomes for up to three years after enrollment. Participants will also have the opportunity to participate in optional research studies including patient surveys and blood and bone marrow sample testing.