Screening and enrollment of patients. Fifty-two patients with R/R B-ALL with CNSL were screened for eligibility between November 2016 and April 2021 in the study. CNS-directed bridging therapy included systemic chemotherapy (high-dose methotrexate; range, 3-5 g/m²) and triple intrathecal chemotherapy (IC; 10 mg of methotrexate, 50 mg of cytarabine, and 5 mg of dexamethasone each time). Patients were categorized as CNS-1 (n = 3), CNS-2 (n = 15), and CNS-3 status (n = 30) by the last assessment before CAR T-cell infusion. A total of 48 patients received CAR T-cell infusion and were included in the analysis for response evaluation, survival, and toxicity assessment.