RecruitingDrug trialSafety and Efficacy of Asciminib in Pediatrics and Young Adults With Relapse/Refractory (r/r) Philadelphia Positive (Ph+) or ABL-class Ph-like Acute Lymphoblastic Leukemia (ALL)Multi-center, open-label, single arm study of asciminib in participants aged ≥1 year to ≤30 years old with r/r Ph+ or ABL-class Ph-like ALL. This study will have 2 parts: Part 1 dose escalation and Part 2 dose expansion. Part 1 dose escalation will enroll participants aged ≥1 year to ≤30 years to determine the recommended phase 2 dose (RP2D) of asciminib when administered with low intensity chemotherapy. Part 2 dose expansion will enroll participants aged ≥1 year to ≤30 years to evaluate safety, tolerability, and efficacy of asciminib at the RP2D with the treatment regimen.