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

Asthma and bronchiectasis are different conditions that frequently coexist. The prevalence of bronchiectasis rises considerably in subjects with severe asthma (25%-51%).

We evaluated the clinical and biological efficacy of mepolizumab on our pilot population of severe uncontrolled asthmatics with bronchiectasis not related to other pathologies.

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.

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 FEV₁ (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 +).

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.