A Phase Ib/II Clinical Study in Patients With Refractory Chronic Cough

All potential participants proceed to the screening period (7-14 days) after voluntarily signing the informed consent form, and the investigators conduct eligibility assessment for the participants as per the inclusion and exclusion criteria. 72patients with RCC are planned to be enrolled in this study. All participants will firstly be randomized at a ratio of 1:1:1 to receive one of the three oral doses of three times a day TCR1672 (20mg, 40mg, 60mg). Then patients will further be randomized to two treatment sequences, Dosing Sequence 1 and Dosing Sequence 2. Participants in Dosing Sequence 1 will be given TCR1672 Tablets for 1 weeks, followed by a 1-week washout period, and then crossover to 1-week placebo treatment. Participants in Dosing Sequence 2 will be firstly administered 1-week placebo treatment, followed by a 1-week washout period, and then crossover to TCR1672 tablets for 1-week treatment.