Significant improvement in lung function and asthma control after benralizumab treatment for severe refractory eosinophilic asthma

Severe eosinophilic asthma is a complex disease and much effort has been made to fully understand its mechanisms. Bronchial remodeling and loss of lung function are important features in asthma, however their key aspects are not completely clear, especially the impact that biological drugs may have on them. One of the key cytokines involved in the pathophysiology of eosinophilic asthma is interleukin-5 (IL-5), which plays a very important role together with other type 2 cytokines and chemokines in the development, transmigration and persistence of eosinophils into airways, such as eotaxin-2 and 3, thymic stromal lymphopoietin (TSLP), IL-33, as well as IL-4 and IL-13. Several monoclonal antibodies have been developed against this cytokine (mepolizumab, reslizumab) or its receptor (benralizumab). Data on the improvement of respiratory function in patients who undergo benralizumab treatment are scarce and partly conflicting. Real-life studies may play a crucial role in clarifying this important aspect. The aim of this retrospective observational real-world study was to evaluate the effect of benralizumab on lung function improvement, exacerbation rate, oral corticosteroids (OCS) reduction and asthma control questionnaire (ACQ) score before and after six months of treatment with benralizumab in a cohort of 20 consecutive patients with severe refractory asthma (SRA) treated at the Pneumology Unit of Local Health Authority, Reggio Emilia, Italy. Add-on therapy with benralizumab allowed to completely suspend OCS in 19 out of 20 patients. Notably, the number of moderate/severe exacerbations dropped significantly (p < 0,0001); as well as an improvement in ACQ score (p < 0,0001). The most relevant data concern respiratory function: the average pre-bronchodilator FEV1 increased by 21.3% (+680 ml) compared to baseline (p = 0,0006). Moreover, the improvement in morning PEF (+66,6 l/min) confirmed the benefit of benralizumab (p = 0,02). The improvement in respiratory function was significantly higher in patients with blood eosinophilia greater than 500 cells/μL and chronic rhinosinusitis with nasal polyps (CRSwNP). This study underlies a noticeable improvement in respiratory function, much higher than what has been observed in literature so far. This aspect, together with the others aforementioned, should be considered when choosing a treatment option in the context of precision medicine.