The effects of benralizumab on lung volume changes during exercise in experimental setting in severe asthmatics: a pilot study

Introduction: The most severe forms of asthma are characterised by the occurrence of dyspnoea on exertion, impacting on daily activities and quality of life. It has been demonstrated that dynamic hyperinflation (DH) during exercise represents a mechanism of physical activity limitation in severe asthmatics. Inspiratory capacity (IC) at rest may be an indicator of static hyperinflation, and the change in IC during exercise can be regarded as a marker of DH. The study aims to assess whether Benralizumab is able to improve IC and to reduce DH. Materials and methods: A pilot study on severe asthmatics was conducted. Assessments of asthma control and quality of life, lung function evaluation and 6-min walk test (6MWT) were carried out on the day of the first drug administration (T-0) and after a period of 6 months (T-1). Results: Twelve severe asthmatics were recruited. Significant improvements of dynamic volumes, asthma control and quality of life were observed after anti IL-5R treatment. At T-0, pre-6MWT-IC and post-6MWT-IC were 2.40 +/- 0.48 L and 1.60 +/- 0.83 L, respectively (p < 0.0001). Minute ventilation (VE) at the beginning of the 6MWT was 13.88 +/- 4.44 Lmin(-1) and post 6MWT was 23.77 +/- 12.11 Lmin(-1) (p < 0.0001). At T-1, IC pre 6MWT was higher than IC pre 6MWT at T-0 (2.74 +/- 1.14, p = 0.010) and did not change after exercise (IC post 6MWT: 2.85 +/- 1.22 L, p = 0.53). VE did not change at T-1. Discussion: These findings show the effect of Benralizumab in improving IC during exercise. The disappearance of DH provides a potential explanation for the beneficial effect of biologics in severe asthmatics.