[Clinical Study of Blinatumomab in the Treatment of Adult Relapsed/Refractory Ph-Negative Acute B-Lymphoblastic Leukemia].

Objective: To investigate the efficacy and safety of CD19/CD3 bisecific monoclonalantibody (Blinatumomab) in the treatment of adult patients with relapsed / refractory Ph-negative acute B-lymphoblastic leukemia (R/R-B-ALL).
Methods: Ten adult R/R B-ALL patients were all treated with Blinatumomab. Each treatment cycle was administered for 28 days and stopped for 14 days. The dose was 9 μg/day for the first 7 days of cycle 1, and 28 μg/day for days 8-28 if there were no adverse reactions. From the second cycle onwards, the daily dose was 28 μg. The remission, survival time (EFS and OS) and adverse reactions were observed after treatment.
Results: Nine patients with curative effect could be evaluated. Four patients achieved CR after one course, and one patient achieved CR after two courses, the overall remission rate was 55.6%(5/9). The median EFS was 4 months (1-12 months), and the median OS was 6 months (2-44 months). Nine of the 10 patients had fever of different degrees. Serum levels of cytokines such as IL-6, IL-10, IL-17 and IFN-γ increased. Two patients resumed medication after 1 week of treatment interruption due to neurotoxicity and CRS, respectively. One patient was discontinued due to grade 3 CRS and died of tropical candidiaemia.
Conclusion: Blinatumomab has a good response rate in the treatment of relapsed/refractory B-ALL patients, but the duration of remission is shorter. Drug-related adverse reactions are mainly CRS and neurotoxicity. Inflammatory factors IL-6, IL-10, IL-17 and IFN-γ can be used as indicators to monitor CRS. The bisspecificity MAbs provide an opportunity for subsequent allogeneic hematopoietic stem cell transplantation in R/R-B-ALL patients.