A Phase I clinical study of randomized, double-blind, placebo-controlled, dose-escalation to evaluate the safety, tolerability, and pharmacokinetic characteristics of QR052107B tablets after multiple administrations in healthy Chinese adult subjects

INTERVENTION: 400 mg dose group:Oral administration of QR052107B tablets or matching placebo;25 mg dose group:Oral administration of QR052107B tablets or matching placebo;100 mg dose group:Oral administration of QR052107B tablets or matching placebo; CONDITION: Refractory or unexplained chronic cough PRIMARY OUTCOME: Incidence of adverse events, adverse drug reactions, and serious adverse events;Number of participants and events with drug‐related SAEs, Grade 2 or higher AEs, and Grade 3 or higher AEs; SECONDARY OUTCOME: Pharmacokinetic parameters of QR052107B after the first dose (Cmax, Tmax, and AUC0‐24h);Pharmacokinetic parameters of QR052107B after multiple dosing and the last dose (Cmax, Tmax, AUC0‐24h, AUClast, AUC0‐inf, Vz/F, CL/F, Cmin, Cav, PTF, Rac, t1/2, and MRT); INCLUSION CRITERIA: 1. Subjects who can understand and are willing to strictly abide by the clinical trial protocol to complete the trial and sign the informed consent form. 2. Male and female subjects aged 18 to 65 years old (including both upper and lower limits), with an appropriate gender ratio. 3. Female subjects weigh >= 45 kg, male subjects weigh >= 50 kg, and their body mass inde X(BMI) is 19–26 kg/m² (including the upper and lower limits). 4. The result of the blood human chorionic gonadotropin (HCG) pregnancy test for women of childbearing age during screening is negative. 5. The subjects and their sexual partners are willing to have no childbearing plans from 2 weeks before screening to 6 months after the last administration of the study drug, voluntarily take effective contraceptive measures, have no plans to donate sperm or eggs, and ensure that they use one or more non‐pharmacological contraceptive measures during sexual activity from 2 weeks before screening