Real-world use of tisagenlecleucel in infant acute lymphoblastic leukemia

Infants with B-cell acute lymphoblastic leukemia (B-ALL) have poor outcomes because of chemotherapy resistance leading to high relapse rates. Tisagenlecleucel, a CD19-directed chimeric antigen receptor T-cell (CART) therapy, is US Food and Drug Administration approved for relapsed or refractory B-ALL in patients #25 years; however, the safety and efficacy of this therapy in young patients is largely unknown because children,3 years of age were excluded from licensing studies. We retrospectively evaluated data from the Pediatric Real-World CAR Consortium to examine outcomes of patients with infant B-ALL who received tisagenlecleucel between 2017 and 2020 (n 5 14). Sixty-four percent of patients (n 5 9) achieved minimal residual disease-negative remission after CART and 50% of patients remain in remission at last follow-up. All patients with high disease burden at time of CART infusion (.M1 marrow) were refractory to this therapy (n 5 5). Overall, tisagenlecleucel was tolerable in this population, with only 3 patients experiencing $grade 3 cytokine release syndrome. No neurotoxicity was reported. This is the largest report of tisagenlecleucel use in infant B-ALL and shows that this therapy is safe and can be effective in this population. Incorporating this novel immunotherapy into the treatment of infant B-ALL offers a promising therapy for a highly aggressive leukemia.