Effects of benralizumab on inspiratory capacity evaluated during exercise in severe asthmatics

<bold>Background:</bold> The most severe forms of asthma are characterised by the occurrence of dyspnoea on exertion. It has been demonstrated that dynamic hyperinflation (DH) during exercise represents an underlying mechanism of physical activity limitation in subjects with severe asthma. Inspiratory capacity (IC) at rest may be an indicator of static hyperinflation, and the change in IC during exercise can be a marker of DH. <bold>Aims:</bold> To assess whether benralizumab, an anti IL5-Rα antibody, by blocking specific targets of the inflammatory cascade, is able to improve IC and to reduce DH. <bold>Methods:</bold> During this pilot study assessments of asthma control and quality of life, lung function evaluation and 6-minute walking test (6MWT) were carried out on the day of the first administration of benralizumab (T₀) and after 6 months (T₁). DH was defined as a decrease of >150 mL in IC at the end of exercise compared with resting levels. <bold>Results:</bold> 12 severe asthmatic subjects were recruited. Significant improvement of dynamic volumes, asthma control and quality of life was observed after anti IL-5R treatment. At T₀, IC recorded before and immediately after the 6MWT were 1.01 ±0.52 L and 1.60 ±0.83 L, respectively. At T₁, IC pre 6MWT was significantly higher than IC pre 6MWT at T₀ (2.48 ±1.13 L, p=0.010) and did not change after exercise (IC post 6MWT: 2.46 ±1.22 L, p=0.53). Minute ventilation (VE) at the beginning of the 6MWT was 13.8±4.2 L·min⁻¹ at T₀ and 11.3±6.9 L·min⁻¹ at T₁ (p=0.004). VE post 6MWT was 23.7±11.5 L·min⁻¹ at T₀ and 22.3±6.7 L·min⁻¹ at T₁ (p<0.001). <bold>Conclusions:</bold> These preliminary findings show a beneficial effect of benralizumab in improving IC at rest, suggesting an impact on static hyperinflation.