GSK2339345 Hypertussive Challenge Study

This study is designed to evaluate the effect of GSK2339345 relative to placebo on the number of coughs in patients with Chronic Idiopathic Cough (CIC) administered by an Aqueous Droplet Inhaler (ADI). The primary aim is to investigate the efficacy of GSK2339345 on reducing objective cough frequency in CIC patients. The secondary aim of this study is to investigate the efficacy of GSK2339345 in inhibiting a hypertussive cough response elicited by capsaicin and citric acid in CIC patients which have a hyperresponsive cough reflex. Following the screening visit, all eligible subjects will attend the unit for dosing at Visits 1-7. At Visits 1, 2 and 3 (Part A of the study), subjects will receive two doses of either GSK2339345 or placebo, 4 hours apart and will undergo 8 hours of cough monitoring. At Visits 4 and 5 (Part B of the study) and Visits 6 and 7 (Part C of the study), subjects will be administered a single dose of either GSK2339345 or placebo. Subjects will then undergo capsaicin (Part B) or citric acid (Part C) tussive challenge and will undergo cough monitoring for 1 hour post dose. The maximum study duration will be approximately 11 weeks, including 3 weeks screening and 2 weeks follow-up. Approximately 30 patients will be randomised into the study, such that approximately 24 patients complete dosing and critical assessments.