Introduction: Biologic treatment for severe asthma has shown to be effective in improving asthma control and reducing exacerbations in multiple clinical trials.

The aim of the study is to evaluate the effects of treatment with benralizumab in severe eosinophilic asthma patients treated at our center.

Methods: The research included 20 patients of which 12 (60%) received five or more doses between
March 2020 and February 2023. Data were analyzed for the peripheral blood eosinophil count before and 24 hours after the first dose of benralizumab, and Forced Expiratory Volume in the first second (FEV1), Fractional Exhaled Nitric Oxide (FeNO), and Asthma Control Test (ACT) score initially, and after 24 weeks of treatment.

Results: In the examined patient group, with an average age of 51.83 ± 9.67 (41-68) years, the
average number of benralizumab doses administered was 8.75 ± 3.47 (5-15). Peripheral
blood eosinophil count was significantly reduced 24 hours after the first dose (650.42 ±
344.6 vs. 60.83 ± 70.38). After 24 weeks of therapy, a statistically significant increase in FEV1
value (56.22 ± 15.71 vs. 78.3 ± 32.96 %) and the degree of asthma control, measured by
ACT (10.73 ± 4.63 vs. 20.42 ± 4.62), were recorded. Due to unavailability of the test at
treatment initiation, the average values of FeNO, 65.78 ± 67.01 (8-202) ppb, are reported
only after 24 weeks of therapy.

Conclusion: We conclude that treatment with benralizumab in patients with severe eosinophilic asthma
results in a significant depletion of eosinophils in peripheral blood, as well as in improvement of lung function and asthma control.