Phase I Clinical Study of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of RSS0343 Tablets in Healthy Subjects After Single and Multiple Oral Administration and the Effect of Food on the Pharmacokinetics of RSS0343

Inclusion Criteria: 1. Age of 18-55 years old (inclusive), male or female; 2. Body mass index in the range of 19-28 kg/m2 (inclusive). Exclusion Criteria: 1. The results of physical examination, vital signs, laboratory tests, chest imaging, abdominal B ultrasound and 12-lead electrocardiogram were abnormal. 2. Hepatitis B surface antigen, hepatitis C antibody, syphilis antibody, HIV antibody positive; 3. Suspected allergy to the study drug or any component of the study drug, or severe allergy to any drug, food, toxin or other exposure; 4. Current active, latent, or inadequately treated M. tuberculosis (i.e., tuberculosis \[TB\]) infection; 5. Investigator-assessed clinically significant infection (e.g., requiring hospitalization or parenteral antimicrobial therapy) within 1 month before screening; A history of more than one previous episode of herpes zoster, or disseminated herpes zoster (one episode); Any history of other infections that the investigator considered might have been aggravated by study participation.