Effects of Benralizumab on Clinical Outcomes and Small Airway Function in Patients with Severe Eosinophilic Asthma: A Real-World Study

OBJECTIVE: To evaluate the real-world efficacy and safety of benralizumab in Chinese patients with severe eosinophilic asthma (SEA), focusing on small airway dysfunction. METHODS: This retrospective cohort study analyzed SEA patients treated with benralizumab for ≥6 months. Outcomes included ACQ-5 scores, blood eosinophils, IgE, FeNO, spirometry, functional electrical impedance tomography (fEIT), and adverse events. ROC curve analysis identified baseline predictors of clinical remission. RESULTS: (P < 0.05). fEIT sensitively detected regional pulmonary ventilation improvements. Overall, 79.2% of patients achieved clinical remission at 6 months. Baseline eosinophil counts were significantly higher in remitters and strongly predicted clinical remission (AUC = 0.845; optimal cut-off: 460 cells/μL). Treatment was well-tolerated, with only one mild fever reported. CONCLUSION: Benralizumab significantly improves asthma control, global lung function, and regional small airway ventilation in Chinese SEA patients. Baseline blood eosinophils serve as a robust biomarker to predict clinical remission and guide precision patient selection.Trial registration: ChiCTR2600121928.