[Clinical Analysis of Blinatumomab in the Treatment of 21 Children with Relapsed/Refractory B-Cell Acute...

To evaluate the efficacy and safety of blinatumomab in the treatment of children with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL), and to explore the factors affecting the efficacy of blinatumomab.

The clinical data of 21 children with R/R B-ALL who received treatment with blinatumomab in the Department of Pediatrics, Peking University People's Hospital from April 2021 to December 2023 were retrospectively analyzed.

Among the 21 children, there were 10 boys and 11 girls, with a median age of 4(2-17) years. There were 5 cases of isolated bone marrow relapse, 1 case of bone marrow combined with central nervous system relapse, 3 cases of isolated minimal residual disease (MRD) relapse, 5 cases of isolated molecular relapse, 2 cases of MRD combined with molecular relapse, and 5 cases of refractory disease. In 8 children with baseline blasts ≥5% before blinatumomab treatment, 7 cases (87.5%) achieved complete remission (CR) after treatment, and 3 cases (37.5%) achieved MRD negativity. There were 13 children with positive MRD and/or molecular markers (with bone marrow CR) before blinatumomab treatment, of whom 12 cases (92.3%) achieved MRD and/or molecular negativity after treatment. The median follow-up time of the 21 children was 13.1(6.5-34.9) months, with a 1-year overall survival (OS) rate of (92.3±7.4)%. The factors affecting the short-term efficacy of blinatumomab included the baseline blasts (P =0.026) and MRD level (P =0.026) before treatment. No grade 3 or higher cytokine release syndrome (CRS) occurred, and no neurological events were observed.

The short-term efficacy of blinatumomab in pediatric R/R B-ALL is excellent, particularly in children with low tumor burden. The clinical adverse events are controllable, and the safety profile is favorable.