Functional response, in T2 severe asthmatic patients, treated with mepolizumab for 2 years

Objective: The efficacy of Monoclonal Antibodies in severe asthma has long been established. In terms of clinical remission, several patients can reach, in the first year of treatment, all four goals: 1) tapering/discontinuation in the use of systemic glucocorticoids, 2) reduction in exacerbations, 3) symptom control, and 4) gain in respiratory function. In this study, we aimed to analyze the time course and magnitude of functional improvement assessed by forced spirometry, including Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), and the FEV1/FVC ratio, over 24 months of therapy. Methods: We evaluated data from a cohort of 15 severe asthmatic patients treated with mepolizumab for 24 months, analyzing respiratory function by performing spirometry at baseline and after 1, 2, 3, 6, 12, and 24 months. The main objective was to assess the change in terms of FEV1, FVC, and FEV1/FVC ratio, as well as the temporal pattern of these modifications. Results: The analysis has shown an improvement in FEV1 of 366 ± 271 ml (p = 0.03) after 28 days and of 555 ± 386 ml (p = 0.0084) after 56 days of therapy. This improvement remained stable for the rest of the observation period. For the FVC parameter, the improvement became statistically significant from the third month of therapy (p = 0.034). Conclusion: The increase in FEV1 observed in this cohort of patients shows that functional response is already detectable in the first two months of treatment. These clinical and functional improvements were sustained over two years of biologic therapy, even as pharmacologic treatment-particularly systemic corticosteroids-was progressively reduced.