Real-World Safety and Effectiveness of Benralizumab in Japanese Patients with Severe Asthma: A Multicenter Prospective Observational Study

Introduction: This study aimed to demonstrate whether benralizumab maintained the safety and effectiveness profiles established in randomized controlled trials among all patients with severe uncontrolled asthma initially prescribed benralizumab in the real-world setting in Japan. Methods: This was a prospective, observational, multicenter post-marketing study (ClinicalTrial.gov, NCT03588546). The safety and tolerability of benralizumab over 1 year were assessed by the incidence of adverse events (AEs), serious AEs, adverse drug reactions (ADRs), and serious ADRs. Patient background characteristics indicating a more frequent onset of ADRs with benralizumab were explored. The main effectiveness assessment was the change in Asthma Control Questionnaire-5 (ACQ-5) score from baseline. Patients with baseline ACQ-5 scores ≥1.5 were defined as having severe uncontrolled asthma. Results: In total, 632 patients were evaluated for safety and 274 for effectiveness; 139 patients were included in the severe uncontrolled asthma subgroup. ADRs were reported in 12.7% and serious AEs in 13.0% of patients. Serious infections occurred in 3.8%, serious hypersensitivity in 0.3%, and malignancy in 0.3% of patients. No helminthic infections occurred. In the effectiveness population, benralizumab improved the mean (standard deviation [95% confidence interval]) ACQ-5 score by −1.16 (1.40 [−1.36, −0.96]) from baseline; forced expiratory volume in 1 second by 0.151 (0.440 [0.09, 0.21]) L; and Mini-Asthma Quality of Life questionnaire score by 1.16 (1.29 [0.94, 1.38]) at the last observation. The annual asthma exacerbation rate was 0.42. A greater ACQ-5 score improvement was observed among patients with eosinophilic asthma characteristics. Conclusion: No new safety concerns were raised, and patients experienced benefits consistent with previous studies of benralizumab, thus supporting the use of benralizumab for the add-on maintenance treatment of patients with eosinophilic severe uncontrolled asthma.