Durable remissions achieved with reinfusion of CD19‐directed CAR‐T despite failure to induce or maintain B‐cell aplasia and single‐center experience with reinfusion of tisagenlecleucel

CD19‐directed chimeric antigen receptor T lymphocytes (CAR‐T) have led to durable remissions in children with refractory and/or multiply relapsed B‐lymphoblastic leukemia. For those who relapse or lose B‐cell aplasia post CAR‐T, the role of CAR‐T reinfusion is unclear. We report two cases of durable remission with tisagenlecleucel reinfusion despite failure to achieve or maintain B‐cell aplasia, and compare these cases to six additional children who received multiple tisagenlecleucel infusions at our institution. Our experience suggests that reinfusion is safe and may be a definitive therapy for a small subset of patients. Reinfusion can also reintroduce remission and/or B‐cell aplasia, allowing for subsequent therapies.