[Safety and efficacy of humanized CD19-targeted CAR-T cells in patients with relapsed/refractory acute B cell...

Objective: This study aimed to evaluate the safety and efficacy of humanized CD19-targeted chimeric antigen receptor T-cell (CAR-T) in patients with relapsed/refractory acute B cell lymphoblastic leukemia (R/R B-ALL) . Methods: The clinical data of 41 patients with R/R B-ALL treated with humanized CD19-targeted CAR-T cells in the First Affiliated Hospital of Zhejiang University School of Medicine from February 2020 to July 2021 were analyzed. Results: Cytokine release syndrome occurred in all patients, and 63.4% (26/41) were grades 1-2. Immune effector cell-associated neurotoxicity syndrome developed in three patients. On median day 15 (9-47) , the complete remission rate was 95.1% (39/41) , of which 38 patients tested negative for bone marrow minimal residual disease detected by flow cytometry. Among the 39 patients with complete remission, 17 patients did not receive further treatment, and 70.6% (12/17) remained in remission at the end of follow-up, with a progression-free survival of 11.6 months of the two patients with the earliest infusion. Another 17 patients underwent consolidation allogeneic hematopoietic stem cell transplantation (10 cases) or CD22 CAR-T cell sequential therapy (seven cases) after remission, and 76.5% (13/17) of the patients were still in remission at the end of follow-up. The remaining five patients who did not receive consolidation therapy relapsed at a median of 72 (55-115) days after CAR-T cell therapy. Conclusion: In patients with R/R B-ALL, the humanized CD19-targeted CAR-T cells had a high response and manageable toxicity.