Donor-derived CD19 CAR-T Cells versus Chemotherapy Plus Donor Lymphocyte Infusion for Treatment of Recurrent CD19-positive B-ALL After Allogeneic Hematopoietic Stem Cell Transplantation

Objective This study aimed to compare the efficacy of anti-CD19 chimeric antigen receptor T cells (CAR-T cells) versus chemotherapy plus donor lymphocyte infusion (chemo-DLI) for treating relapsed CD19-positive B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods Clinical data of 43 patients with B-ALL who relapsed after allo-HSCT were retrospectively analyzed. Twenty-two patients were treated with CAR-T cells (CAR-T group), and 21 with chemotherapy plus DLI (chemo-DLI group). The complete remission (CR) and minimal residual disease (MRD)-negative CR rates, leukemia-free survival (LFS) rate, overall survival (OS) rate, and incidence of acute graft- versus -host disease (aGVHD), cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were compared between the two groups. Results The CR and MRD-negative CR rates in the CAR-T group (77.3% and 61.5%) were significantly higher than those in the chemo-DLI group (38.1% and 23.8%) ( P =0.008 and P =0.003). The 1- and 2-year LFS rates in the CAR-T group were superior to those in the chemo-DLI group: 54.5% and 50.0% vs. 9.5% and 4.8% ( P =0.0001 and P =0.00004). The 1- and 2-year OS rates in the CAR-T versus chemo-DLI group were 59.1% and 54.5% vs. 19% and 9.5% ( P =0.011 and P =0.003). Six patients (28.6%) with grade 2–4 aGVHD were identified in the chemo-DLI group. Two patients (9.1%) in the CAR-T group developed grade 1–2 aGVHD. Nineteen patients (86.4%) developed CRS in the CAR-T group, comprising grade 1–2 CRS in 13 patients (59.1%) and grade 3 CRS in 6 patients (27.3%). Two patients (9.1%) developed grade 1–2 ICANS. Conclusion Donor-derived anti-CD19 CAR-T-cell therapy may be better, safer, and more effective than chemo-DLI for B-ALL patients who relapse after allo-HSCT.