Severe uncontrolled asthma with bronchiectasis: a pilot study of an emerging phenotype that responds to mepolizumab

BACKGROUND: Asthma and bronchiectasis are different conditions that frequently coexist. The prevalence of bronchiectasis rises considerably in subjects with severe asthma (25%–51%). OBJECTIVE: We evaluated the clinical and biological efficacy of mepolizumab on our pilot population of severe uncontrolled asthmatics with bronchiectasis not related to other pathologies. PATIENTS AND METHODS: Four patients with severe uncontrolled asthma and diagnosed as bronchiectasis were recruited and started biological treatment with mepolizumab. Standard investigations were performed in all four patients at baseline (T0), after 3 months (T1) and after 1 year (T2) of treatment. RESULTS: After 1 year (T2) of therapy with mepolizumab, patients showed a significant increment of asthma control test value (12±1.1 vs 24.5±0.3, P<0.01), a reduction of the number of exacerbations/year (5±0.7 vs 0.75±0.75, P<0.01), an increase of pre-bronchodilator FEV(1) (1,680±500 vs 1,860±550 mL, P<0.01) and a reduction of eosinophils in blood (0.75±0.14 vs 0.12±0.02 cells/µL, P<0.01), in the sputum (9.6%±2.1% vs 5.6%±2.7%, P<0.05) and in nasal cytology (++ vs +). CONCLUSION: The efficacy of mepolizumab in terms of reduction of inflammation and increase of control that we observed in our patients might suggest that targeting the IL-5 in severe eosinophilic asthma with bronchiectasis may be a good therapeutic strategy.