Abstract
OBJECTIVES: To study the safety and short-term effectiveness of blinatumomab in the treatment of childhood relapsed/refractory acute lymphoblastic leukemia (R/R-ALL). METHODS: Six children with R/R-ALL who received blinatumomab treatment from August 2021 to August 2022 were included as subjects, and a retrospective analysis was performed for their clinical data. RESULTS: Among the six children, there were three boys and three girls, with a median age of 10.5 (5.0-13.0) years at the time of inclusion. Of all six children, one had refractory ALL and did not achieve remission after several times of chemotherapy, and 5 relapsed for the first time, with a median time of 30 (9-60) months from diagnosis to relapse. Minimal residual disease (MRD) before treatment was 15.50% (0.08%-78.30%). Three children achieved complete remission after treatment, among whom two had negative conversion of MRD. Five children had cytokine release syndrome (CRS), among whom 3 had grade 1 CRS and 2 had grade 2 CRS. Four children were bridged to allogeneic hematopoietic stem cell transplantation, with a median interval of 50 (40-70) days from blinatumomab treatment to transplantation. The six children were followed up for a median time of 170 days, and the results showed an overall survival rate of 41.7% (95%CI: 5.6%-76.7%) and a median survival time of 126 (95%CI: 53-199) days. CONCLUSIONS: Blinatumomab has good short-term safety and effectiveness in the treatment of childhood R/R-ALL, and its long-term effectiveness needs to be confirmed by studies with a larger sample size.