Effect of benralizumab on airway mucus, air-trapping and airway volume, assessed by functional respiratory imaging in severe eosinophilic asthma

<bold>Introduction:</bold> Severe eosinophilic asthma (SEA) responds favorably to benralizumab, owing to its anti-eosinophilic effects. However, its influence on airway physiology is less well understood. Using Functional Respiratory Imaging (FRI), this study explored benralizumab's short-term effects on airway pathology in SEA. <bold>Methods:</bold> A single-arm trial involving 20 SEA patients that started benralizumab, with HRCT scans at FRC and TLC at baseline, 4, and 12 weeks, was performed. FRI-based outcomes included mucus score (MS), air-trapping (AT) and airway volume (SIVAW). Spirometry, oscillometry, bodyplethysmography, FeNO, ACQ and SGRQ were other outcome parameters. Data were analyzed using linear mixed models. <bold>Results:</bold> Significant (p<0.05) LSM differences in MS (−0.52 point) and AT (−5.5 points) were observed at week 12 (figure shows an individual response). An inverse relationship between MS and FEV1 was observed, where each MS point decrease resulted in a 1.33% increase in FEV1. Significant improvements in SIVAW were noted by week 12 at TLC (+14%) and FRC (+27%). <bold>Conclusion:</bold> Benralizumab decreases airway mucus, increases airway volume and reduces air-trapping in SEA, as shown by FRI. FRI visualizes the capability of benralizumab to modify mucus plugging in the short-term. This could support selection and monitoring of biologic therapies for SEA. <fig><object-id>erj;64/suppl_68/PA5367/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>