A Dose Escalation Study of Bradanicline in Refractory Chronic Cough

Inclusion Criteria: * Chest radiograph or computed tomography (CT) scan of the thorax within the last 1 year not demonstrating any abnormality considered to be significantly contributing to the refractory chronic cough * Diagnosis of refractory chronic cough or unexplained cough for at least one year * Women of child-bearing potential who use 2 forms of acceptable birth control method * Male subjects and their partners of child-bearing potential who use 2 methods of acceptable birth control * Has provided written informed consent Exclusion Criteria: * Current smoker (cigarettes or e-cigarettes) or has given up smoking within the past 12 months * Currently taking an ACE-inhibitor or requiring treatment with an ACE-inhibitor during the study or within 12 weeks prior to the Baseline Visit * Has an upper or lower respiratory tract infection or recent significant change in pulmonary status within 4 weeks of the Baseline Visit * Has a history of cystic fibrosis * Has a history of malignancy within 5 years prior to the Baseline Visit * Has active hepatitis infection * Has a history of human immunodeficiency virus (HIV) infection * Has a positive test for any drug of abuse * Has a history of hypersensitivity to bradanicline or any of its components