An investigational CAR T-cell therapy, bicistronic CD19/CD22, induced complete remission in 99.1% of relapsed or refractory childhood B-ALL patients, with 75.5% EFS and 93.5% OS at 1 year. CRS occurred in all patients, with 45.7% experiencing grade 3/4 events. Consolidative allogeneic stem cell transplant improved EFS but not OS. The therapy aims to address gaps in current treatments, particularly for isolated central nervous system relapses.