A Study on the Bioavailability of SHR-1819 Injection Administered Subcutaneously Using Different Injection Devices in Healthy Subjects

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 ≥19.0 kg/m2 and \<26.0 kg/m2, weight of male must≥ 50.0 kg and \<80.0 kg;
4. The subjects and their female partners are willing to have no reproductive plan from signing the informed consent to 3 months after the last 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: (1) Receipt of a live-attenuated vaccine within 1 month prior to screening or planned receipt during the study; (2) Previous participation in a clinical trial involving any investigational product (drug or device) within 3 months before screening; (3) History of food or drug allergy or atopic allergic disease (asthma, urticaria);
2. Any one of the following tests at Screening period or Baseline period: (1) Human immunodeficiency virus antibody (HIV-Ab), syphilis serological examination, hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibody (HCV-Ab) positive; (2) Exclude individuals who have experienced severe trauma or undergone major surgery within the past 6 months, or who plan to undergo surgery during the trial period;
3. General situation: (1) Have a history of drug use or drug abuse; (2) Investigators, site staff, or any other individuals directly involved in the conduct of the protocol;
4. Subjects who are considered by the investigator to have any other factors which are not suitable for participating in this study.