A Study of Single and Multiple Doses of HRS-6257 in Healthy Subjects

Inclusion Criteria: 1. Aged between 18 and 55 years old (based on the time of signing the informed consent form), both males and females are eligible. 2. The body weight of males ≥ 50 kg, and that of females ≥ 45 kg, and body mass index (BMI): 19 - 28 kg/m². 3. Female subjects must be non-pregnant or non-childbearing potential; 4. Subjects must understand the study procedures and methods, voluntarily participate in this study and sign the ICF in person. Exclusion Criteria: 1. History of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological disease; 2. Known or suspected hypersensitivity to trial product(s) or related products; 3. 12-lead ECG demonstrating QTcF \>450 msec or history or risk factors for QT prolongation; 4. Blood donation of more than 200 mL within the last 6 months 5. Use of prescription or nonprescription drugs and dietary and herbal supplements within 14 days or 7 half-lives; 6. Positive screening tests for hepatitis B or C, HIV, alcohol, drugs of abuse. 7. Previous administration with an investigational product (drug or vaccine) within 3 months;