Emerging therapies in adult and paediatric bronchiectasis

Bronchiectasis is a chronic respiratory disorder characterized by persistent productive cough and recurrent chest infections secondary to permanent structural airway damage. The current treatment strategies for this debilitating disorder are limited to prompt antibiotic treatment of infective exacerbations and regular airway clearance techniques. Despite its high morbidity and associated mortality across all age groups, it has been a neglected area of research in respiratory medicine and there remain no licensed disease-modifying therapies. In this review, we have explored the numerous potential therapeutic targets to break the vicious cycle of infection and inflammation seen in these patients and the novel therapeutic agents that have been developed to target them. We have reviewed the role of novel anti-inflammatory agents designed to target the persistent neutrophilic inflammatory infiltrate seen in bronchiectatic airways, including neutrophil elastase inhibitors, CXCR2 (CXC chemokine receptor 2) antagonists, DPP-1 (dipeptidyl peptidase 1) inhibitors, PDE4 (phosphodiesterase 4) inhibitors and statins. Furthermore, we have explored novel targets to improve mucociliary clearance, namely ENaC (epithelial sodium channel) inhibitors, and discussed the potential of alternative antimicrobial strategies such as inhaled phages. Our review highlights the importance of a multi-faceted approach to bronchiectasis management, which aims not only to eradicate or suppress bronchial infection but also to break the cycle of persistent airway inflammation that results in progressive lung damage in these patients.