A pilot study of zafirlukast as an anti-inflammatory agent in the treatment of adults with cystic fibrosis

Background: Persistent endobronchial inflammation is in part responsible for the attrition of lung function seen in cystic fibrosis. Leukotrienes act as pro-inflammatory mediators. The aim of this study was to assess the efficacy of the leukotriene receptor antagonist zafirlukast as a potential anti-inflammatory agent in the treatment of adult patients with cystic fibrosis. Methods: Clinically stable patients were enrolled in the study if they had no history or clinical evidence of asthma, bronchial hyper-reactivity, or aspergillosis. They were randomised to receive zafirlukast 20 mg twice daily with all routine treatment for four months or routine treatment alone in an open cross-over design. Primary endpoints were changes in respiratory function tests and a modified NIH clinical score. Results: Thirty patients were enrolled and 25 completed. There was a significant improvement in the modified NIH clinical score but no significant increase in respiratory function with zafirlukast. Conclusions: Patients receiving a leukotriene receptor antagonist in addition to routine treatments showed significant improvement in a clinical score which is a composite of clinical wellbeing, chest radiograph appearance, and physical examination. Respiratory function showed a non-significant trend towards improvement with treatment. Zafirlukast may benefit patients with CF. An adequately powered study is justified on the basis of these results.