Changes in airway structure/function with benralizumab treatment of severe eosinophilic asthma (SEA) observed with Functional Respiratory Imaging (FRI)

<bold>Background:</bold> Eosinophilic inflammation contributes to airway changes in asthma including mucus hypersecretion and greater mucus crosslinking/viscosity, leading to increased mucus volume and symptom burden. <bold>Aim:</bold> To evaluate changes in airway structure/function in adults with SEA following eosinophil depletion by benralizumab. <bold>Methods:</bold> This multicentre, single-arm, Phase 4 study recruited adults (18–70 years) with SEA inadequately controlled by high-dose inhaled corticosteroid and long-acting β2-agonist. Benralizumab 30 mg (SC) was given every 4 weeks (3 doses total). Computed tomography scans were analysed using FRI. The primary endpoint was change from baseline to Week 13 in total mucus volume at total lung capacity. Secondary endpoints included change from baseline to Week 13 in mucus plug scores and airway structure/function. <bold>Results:</bold> The primary analysis set included 39 patients (mean [SD] 54.5 [11.4] years). Benralizumab was associated with a reduction in total mucus volume in most patients, with the reduction more pronounced in those with ≥4 mucus plugs at baseline (Fig 1A). Similarly, reductions were observed in mucus plug scores (Fig 1B). No statistically significant changes from baseline were observed in air trapping, airway wall volume, specific airway volume, and lung volume. <bold>Conclusion:</bold> Patients receiving benralizumab showed a decrease in mucus plugging. <fig><object-id>erj;66/suppl_69/PA4727/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>