Purpose: Although studies have evaluated benralizumab, a monoclonal IL-5 receptor α antibody in severe eosinophilic asthma (SEA), in real-world settings, additional evidence is needed to further characterize its effectiveness in specific patient populations. Our study aimed to evaluate asthma control over 56 weeks in patients treated with benralizumab in Swiss real-world settings.

Patients and methods: Conducted across 13 centres, this prospective, observational, non-interventional study involved 73 adults with physician confirmed SEA. Benralizumab 30 mg was administered according to the Swiss label at baseline and up to week 56. Primary outcome was the change in Asthma Control Questionnaire (ACQ-5) scores at week 8 compared to baseline. Exacerbations, use of oral corticosteroids (OCS), and lung function were assessed descriptively.

Results: At baseline, the mean ACQ-5 score was 2.76 (SD 1.26), with 82.2% of patients showing not well-controlled asthma (ACQ-5 > 1.5). At week 8, the mean change in ACQ-5 compared to baseline was -0.95 (95% CI: -1.25, -0.66; p < 0.001). More than half of patients (59.1%) reached a clinically relevant improvement (MCID ≥ 0.5) at week 8, with 40.9% of patients doing so at week 1 and 87.2% at week 56. The annualized exacerbation rate (AER) of 3.65 (95% CI: 3.18, 4.18) at baseline was reduced to 0.68 (95% CI: 0.39, 1.19) at week 56. The relative reduction in AER from baseline to week 56 was 81.3%. Maintenance usage of OCS at baseline (median 25.0 mg/day) decreased over the study leading to a median change of 17.50 mg/day (95% CI: 10.0; 40.0) from baseline compared to week 56. The mean pre-bronchodilator FEV1 change from baseline to week 56 was 0.23 L (95% CI: 0.08; 0.38, p = 0.003).

Conclusion: Benralizumab demonstrated significant, rapid improvements in asthma control within one week of treatment initiation, with sustained benefits over 56 weeks.