[Efficacy of Blinatumomab in the Treatment of Pediatric B-cell Acute Lymphoblastic Leukemia].

Objective: To retrospectively analyze the clinical characteristics of 15 children with B-cell acute lymphoblastic leukemia (B-ALL) treated with blinatumomab, and summarize the efficacy and safety of blinatumomab in the treatment of pediatric B-ALL.

Methods: Fifteen children who received treatment with blinatumomab from February 2022 to January 2023 were enrolled in this study. One course (28 days) of blinatumomab concurrent with intrathecal chemotherapy was given according to the standard regimen, except for 2 cases who had shortened course of treatment due to hematopoietic stem cell transplantation (HSCT) and did not receive combined intrathecal chemotherapy, and 1 case had a shortened course of treatment due to economic problems. The efficacy and safety of the treatment were evaluated.

Results: In terms of efficacy, for the children who had achieved complete molecular remission (CMR) before treatment, blinatumomab treatment could effectively maintain CMR status; For the children who did not achieve CMR, the CMR rate after one standard course of treatment with blinatumomab reached 66.7%(4/6); For the children with relapsed/refractory ALL (R/R ALL) who had minimal residual disease (MRD), the MRD clearance rate reached 75.0%(3/4). The statistical results of the incidence of adverse events showed that 13.3%(2/15) of the children did not experience any adverse events. The most common adverse events were cytokine release syndrome (CRS) (73.3%, 11/15) and transaminase elevation (26.7%, 4/15); 33.3%(5/15) of the children experienced grade 3 or higher adverse events. All the adverse events were resolved after symptomatic treatment.The level of IgG decreased significantly after 4-7 weeks of treatment with blinatumomab, and gradually recovered after 8 weeks of treatment.

Conclusion: Blinatumomab can be used as a safe and effective treatment for inducing deep remission in pediatric R/R-ALL patients and as a bridge therapy for the pediatric ALL patients who are intolerant to chemotherapy.