Clinical Research Directory

Inclusion Criteria: * Aged between 18 and 80 years; * Diagnosed with refractory chronic cough or unexplained chronic cough, with a cough lasting for ≥1 year; * Chest CT at screening shows no abnormalities that the investigator believes may lead to chronic cough; * Cough severity VAS score ≥40 mm ; * Female participants of childbearing potential must have a negative pregnancy test and must not be breastfeeding; male and female participants must have no plans for pregnancy during the entire clinical trial and within 6 months after the last dose, and agree to use medically accepted reliable contraceptive methods during the trial and within 6 months after the last dose; * Fully understand the study, voluntarily sign the informed consent form, and be able to comply with the study procedures and follow-up requirements. Exclusion Criteria: * Currently smoking, or having quit smoking within 12 months prior to screening; * A smoking history of \>20 pack-years; * Ongoing exposure to inhaled toxic substances within 12 months prior to screening or currently; * A history of drug abuse or alcoholism (weekly alcohol consumption of 14 units of alcohol: 1 unit = 285 mL of beer, or 25 mL of spirits, or 100 mL of wine); * Diagnosed with chronic obstructive pulmonary disease (COPD), chronic bronchitis, cystic fibrosis, pulmonary sarcoidosis, idiopathic pulmonary fibrosis, bronchial asthma (except for cough variant asthma), or other airway/respiratory diseases that may affect coughing; * Respiratory tract infection or significant changes in lung status within 4 weeks prior to screening; * FEV1/FVC)\<60%; * Clinically significant electrocardiogram abnormalities, such as QTc interval ≥450 ms, long QT syndrome, etc.; * Use of angiotensin-converting enzyme inhibitors (ACEIs) within 3 months prior to screening; * Plans to initiate new treatment for RCC/UCC during the trial period; * Taste disturbance within 1 month prior to screening; * Use of any P2X3 receptor antagonist within 1 year prior to screening;