Clinical Trials

Inclusion Criteria:

• Having refractory chronic cough (including unexplained chronic cough) for at least 1 year.
• If female and of childbearing potential, agreement to use one of the allowed contraceptive methods.
• Capable of giving signed informed consent.

Exclusion Criteria:

• Currently smokes or uses potentially irritating inhalational agents (e.g., e-cigarettes, smokeless cigarettes, vaping); stopped smoking or using potentially irritating inhalational agents within the last year; or has a smoking history of 20 pack-years or more.
• Has chronic obstructive pulmonary disease or uncontrolled asthma.
• Has a clinically unstable medical condition.
• History of or ongoing significant psychiatric disorder.
• History of respiratory tract infection or significant change in lung function or a pulmonary condition in the last 4 weeks.
• History of malignancy in the last 5 years.
• History of severe drug allergy.
• History of alcohol or drug abuse in the last year or currently uses any form of marijuana or illicit drugs.
• Has a clinically significant finding on a chest x-ray or chest computed tomography (CT) scan in the last year.
• Has systolic blood pressure > 160 mm Hg or diastolic blood pressure > 90 mm Hg.
• Received S-600918 previously.
• Received an investigational drug in the last 3 months.
• Received an angiotensin converting enzyme (ACE) inhibitor in the last 3 months or requires such treatment.
• Has a positive serologic test for human immunodeficiency virus (HIV) antigen or antibody, hepatitis B virus surface antigen, or hepatitis C virus ribonucleic acid (RNA).
• If female, pregnant or trying to become pregnant or breastfeeding.