Study of Bioavailability, Pharmacodynamics and Safety of SHR-1209 Administered by Single Subcutaneous Injection at Different Sites in Healthy Volunteers

Inclusion Criteria: 1. Understanding the research procedures and methods, being able to complete the research in accordance with the procedure requirements, and sign the informed consent; 2. The age on the date of signing the informed consent must be ≥18 years old and ≤55 years old; 3. Body mass index (BMI) at screening period must be ≥18.5 kg/m2 and \<30.0 kg/m2, weight of male must≥ 50.0 kg and \<90.0 kg, and female≥ 45.0 kg and \<90.0 kg; 4. The subjects and their female partners are willing to have no reproductive plan from 2 weeks before screening to 6 months after the administration of the study drug, and voluntarily take effective contraceptive measures and do not plan to donate sperm or ovum. Exclusion Criteria: 1. History of the following diseases or treatments: Diseases that affect drug absorption, distribution, metabolism, and excretion determined by the investigator; Serious infection within 3 months before screening; History of drug allergy or atopic allergic disease (asthma, urticaria). 2. Any one of the following tests at Screening period or Baseline period: Human immunodeficiency virus antibody (HIV-Ab), syphilis serological examination, hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibody (HCV-Ab) positive; Positive blood pregnancy test. 3. General situation: Have a history of drug use or drug abuse; Women who are pregnant or breastfeeding. 4. Subjects who are considered by the investigator to have any other factors which are not suitable for participating in this study.