Effectiveness of dupilumab on lung function in severe eosinophilic asthma

<bold>Background:</bold> Dupilumab is recommended by international guidelines to reduce exacerbations in severe eosinophilic asthma (SEA). Our study aimed to evaluate the effectiveness of dupilumab on lung function (LF), including static lung volumes and airway resistance among SAE patients after 16 weeks of treatment. <bold>Methods:</bold> Prospective, observational, longitudinal study that recruited a cohort of adult SEA patients, treated with Dupilumab (300mg every 2 weeks) and followed at the Pulmonology service (ULSSM, Portugal), from January 2022 to December 2023. Spirometry, plethysmography and bronchodilator test was performed at baseline and after 16 weeks of treatment with Dupilumab. Pre and post mean values were compared using paired t-test at the 5% significance level. <bold>Results:</bold> Thirteen SEA patients were enrolled. Most were female (n=9, 69.2%), with atopy (n=8, 61.5%), previously treated with omalizumab (n=8, 61.5%), corticosteroid-dependent (n=7, 53.8%), mean aged 53,5 years (SD 12.8). After 16 weeks of treatment, a significant increase (<italic>p</italic>-value<0.05) in pre-bronchodilator FEV1(0,369L), FVC (0,285L), FEV₁/FVC ratio (4,9%), mFEF-25/75 (0,472L) and decrease in Raw (28,1%) were observed from baseline. Pre-bronchodilator ITGV, RV and RV/TLC decreased during the study period despite not statistically significant. Post-bronchodilator FEV₁ (0,352L) and FVC (0,370L) were significantly increased (<italic>p</italic>-value <0.01). <bold>Conclusions:</bold> Add-on Dupilumab treatment in SEA patients led to a rapid improvement in forced ventilatory flows and airway resistance, even in patients under previous biological therapy. Although not statistically significant, a reduction in static lung volumes was observed. More studies are needed to support these results.