A Second Infusion (Early Reinfusion) of Tisagenlecleucel in Children and Young Adults With B-Cell Acute Lymphoblastic Leukemia(B-ALL)

Inclusion Criteria: * Patients with R/R B-ALL who have received commercial tisagenlecleucel and have (an) additional dose(s) available for early reinfusion * History of CD19 expressing (in peripheral blood or bone marrow by flow cytometry) BALL prior to tisagenlecleucel infusion * Peripheral blood B-cell aplasia (BCA) within 14 days prior to reinfusion (See section 13.8: B-cell aplasia will be defined as peripheral blood (PB) absolute B lymphocyte count ≤ 50/μL. If BCA evaluation is repeated at any timepoint prior to reinfusion, it must be negative to proceed with reinfusion * Minimal residual disease negative complete remission (CR/CRi) in bone marrow within 14 days prior to reinfusion, including resolution of extramedullary disease * Patients with tisagenlecleucel that is deemed out of specification (OOS) will be permitted on this protocol if the reason for OOS is deemed to not impact the toxicity and efficacy profile of CAR T cell therapy °Reasons for product being OOS include cell viability \< 80%, total nucleated cell count \<2 × 10\^9 in leukapheresis product, failed interferon-γ release assay, leukapheresis product collected \>9 months prior, and determination of residual beads \>50 beads per 3 × 10\^6 cells * Patients age: \< 26 years at time of first tisagenlecleucel order placement * Recovered from severe toxicities following initial dose of tisagenlecleucel * CRS * Neurotoxicity/ICANS * Adequate organ function at time of treatment is required and is define…