Mepolizumab for the Treatment of Chronic Cough With Eosinophilic Airways Diseases

This is a 9-visit randomized, double-blind, placebo-controlled, parallel-group Phase IV study. The purpose of this study is to evaluate the effectiveness of mepolizumab for the treatment of refractory chronic cough in patients with eosinophilic airway disease. Patients will be recruited from secondary care clinics. Patient eligibility will be assessed against the study inclusion/exclusion criteria and patients will undergo informed consent in the research centre. Subjects who provide informed consent and are enrolled in the study will undergo screening procedures. The study will consist of a Mepolizumab treatment arm and placebo arm (normal saline). Fifteen subjects will be randomly assigned to the treatment arm and fifteen subjects will be randomly assigned to the placebo arm in a 1:1 ratio. Following screening and randomization, subjects will under an 12-week treatment period during which they will receive 4 doses of the study drug at days 0, 28, 56, and 84. The primary study outcomes will be measured at week 14 week, 2 weeks following the treatment period. At Visit 1 (screening), subjects will undergo screening procedures: complete medical history, physical examination, methacholine challenge, spirometry, sputum induction, and blood sampling. Subjects will complete the Leicester Cough Questionnaire and modified Borg Scale. At Visit 2, subjects will be fitted with a 24-hour cough monitor. At Visit 3, 24-hour cough monitors will be removed and subjects will undergo spirometry, blood sampling and sputum induction. Subjects will complete the Leicester Cough Questionnaire, modified Borg Scale, and Cough Severity Visual Analogue Scale. The first dose of the study drug will be administered in the clinical research facility by a study physician. At Visit 4, subjects will undergo spirometry and blood sampling and complete the Leicester Cough Questionnaire, modified Borg Scale, and Cough Severity Visual Analogue Scale. The second dose of the study drug will be administered in the clinical research facility by a study physician. At Visit 5, the third dose of the study drug will be administered in the clinical research facility by a study physician. Subjects will be fitted with a 24-hour cough monitor. At Visit 6, 24-hour cough monitors will be removed and subjects will undergo spirometry, sputum induction and blood sampling and complete the Leicester Cough Questionnaire, modified Borg Scale, and Cough Severity Visual Analogue Scale. At Visit 7, subjects will undergo spirometry and blood sampling and complete the Leicester Cough Questionnaire, modified Borg Scale, and Cough Severity Visual Analogue Scale. The fourth dose of the study drug will be administered in the clinical research facility by a study physician. At Visit 8, subjects will be fitted with a 24-hour cough monitor. At Visit 9, the 24-hour cough monitors will be removed and subjects will undergo spirometry, methacholine challenge, sputum induction, and blood sampling. Subjects will complete the Leicester Cough Questionnaire, modified Borg Scale, and Cough Severity Visual Analogue Scale. All study procedures will be performed according to local standard operating procedures and be conducted by trained and experienced staff with supervision by medical doctors. Study physicians will administer all study drug injections. Safety will be assessed throughout the study by monitoring for adverse events and serious adverse events.