Abstract: Objective This retrospective study is to compare the safety, efficacy and short-term outcomes between blinatumomab and anti-CD19 CAR-T cell therapy in B-ALL patients treated at our institution. Methods The cohort included 21 patients treated with blinatumomab (2021—2023) and 80 patients treated with anti-CD19 CAR-T cells (2016—2020). Results In blinatumomab group, 52.4% (11/21) of patients experienced cytokine release syndrome (CRS), with no severe CRS or neurotoxicity reported, and 90.5% achieved MRD-negative complete remission (CR). In contrast, 95.5% (64/67) of patients in the CAR-T group experienced CRS, with 38.9% (26/67) classified as severe cases, and 86.7% achieved MRD-negative CR. Based on the results of the subgroup analysis, blinatumomab was associated with milder CRS compared to CAR-T therapy, regardless of pre-treatment tumor burden or relapse status (P<0.05). The efficacy between the two groups was comparable. The median progression-free survival (PFS) and overall survival (OS) were not reached in the blinatumomab group, with 12-month PFS and OS rates of 70.7% and 88.1%, respectively. In the CAR-T group, the median PFS and OS were 12.3 months and 19.0 months, with 12-month rates of 52.0% and 62.4%. Patients who underwent umbilical cord blood transplantation (UCBT) post-treatment had significantly improved PFS (P=0.010 for blinatumomab, P<0.001 for CAR-T). Conclusion In patients with B-ALL across varying tumor burdens and relapse counts, the efficacy of blinatumomab was comparable to that of CD19 CAR-T cell therapy, with a notably lower incidence of cytokine release syndrome (CRS). Post-treatment UCBT significantly enhanced patient survival. However, due to limited sample size and follow-up duration for the blinatumomab group, further research is needed to confirm the long-term efficacy.

Key words: Anti-CD19 CAR-T cell therapy, Blinatumomab, Acute B lymphoblastic leukemia, Hematopoietic stem cell transplantation