Allogeneic Donor-Derived Anti-CD19 CAR T Cell Is a Promising Therapy for Relapsed/Refractory B-ALL After Allogeneic Hematopoietic Stem-Cell Transplantation

Introduction Currently, effective and safe salvage therapies are limited among patients with relapsed acute lymphoblastic leukemia after allogeneic hematopoietic stem-cell transplantation (allo-HSCT). Anti-CD19 chimeric antigen receptor T (CAR T) cell is a promising treatment. Patients and Methods We studied 11 patients with B-cell acute lymphoblastic leukemia that relapsed after allo-HSCT between September 2017 and October 2019. Patients were treated with a dose of single-infusion donor-derived anti-CD19 CAR T cells. Results Eight patients (72.7%) experienced morphologic remissions. Seven (63.6%) experienced minimal residual disease–negative remission. The ongoing complete remission (CR) duration of 2 patients reached 22 months. The median overall survival was 9 months (range, 2-22 months). Only one patient with grade 1 acute graft-versus-host disease was observed. Two patients (18.2%) developed grade 3/4 cytokine release syndrome. Conclusion This prospective study showed allogeneic donor-derived anti-CD19 CAR T-cell therapy is an effective and safe salvage regimen for patients with relapsed/refractory B-cell acute lymphoblastic leukemia after allo-HSCT. Further randomized and multicenter investigations are needed to evaluate their potential role in relapsed acute lymphoblastic leukemia therapies after allo-HSCT.