Clinical Study of Recombinant Humanized CTLA-4-FC Fusion Protein Injection in Healthy Subjects

Inclusion Criteria:

1. For healthy subjects, health was defined as no abnormality or no abnormality ofclinical significance during the screening period, such as medical history, physicalexamination, electrocardiogram, imaging, and laboratory results;
2. Male or female subjects, between 18 and 45 years old (including boundary values);
3. Male subjects should weigh no less than 50.0 kg and female subjects should weigh noless than 45.0 kg. Body mass index (BMI) between 19.0 and 25.0 kg/m2 (includingcritical value),BMI= weight (kg)/ height 2(m2);
4. Women of reproductive age must use a reliable method of contraception to avoidpregnancy throughout the study period, 4 weeks prior to administration and 3 monthsafter the end of the study, and fertile men must use a reliable method ofcontraception to avoid pregnancy during the study period and 3 months after the end ofthe study;
5. Subjects voluntarily participated in the study and signed informed consent.

Exclusion Criteria:

1. Allergic disposition, known or suspected allergy to the test drug or any excipients (disodium hydrogen phosphate and mannitol) or allergy to alcohol/iodine (or iodophor)/heparin or a history of allergy to any drug, food or pollen, or abnormal serumimmunoglobulin E(IgE) tests, conforming to any of these conditions;
2. Have a fertility plan or sperm/egg donation plan during the study period and within 3months after the study; Female subjects have positive urine/blood pregnancy test atbaseline, or are lactating;
3. Female subjects who took oral contraceptives 30 days before and during the trial, orwho used long-acting estrogen or progesterone injections or implants 6 months beforeand during the trial;
4. Patients with central nervous system, cardiovascular system, liver and kidneydysfunction, digestive system, respiratory system and skeletal system diseases (including but not limited to arrhythmia, bradycardia, hypotension, coronary heartdisease, bronchial asthma, diabetes, hyperthyroidism, Parkinson's disease, epilepsy,paralysis tremor) Or a history of mental illness and any other diseases or physicalconditions that may affect the results of the study;
5. Acute chronic bacterial infection within 3 months before enrollment; At the time ofenrollment, any symptoms, signs or abnormal laboratory examination suggested thepossibility of acute or subacute infection (such as fever, cough, urination, pain,abdominal pain, diarrhea, skin infection, wound, etc.);
6. Those who had undergone major surgical operations (craniotomy or thoracotomy) within 4weeks prior to enrollment, or planned to undergo surgery during the study period, andhad unhealed wounds, ulcers or fractures;
7. Patients with herpes zoster remission less than 2 months before enrollment;
8. Physical examination or ecg reveals abnormal vital signs: heart rate < 50 beats/minor > 100 times/min (at least 5 minutes after resting), systolic pressure > 140 mmHgor diastolic blood pressure > 90 mmHg, or postural hypotension, body temperature (axillary temperature) 37.3;
9. Blood routine examination: White blood cell (WBC)& LT; 3.0 109 / L or & gt; 9.5 109/L,neutrophils < 1.5 109/L, platelet < 100 109/L; Hemoglobin & Lt; 130g/L(male) or < 110 g/L (women); Bilirubin & gt; 1.2 times normal upper limit, serum creatinine > Upper normal value; AST> Upper limit of normal,ALT> Upper limit of normal;
10. Subjects at risk for tuberculosis (TB) :1) have a history of active TB infection; 2)Tuberculin test positive; 3) Radiological examination indicated past tuberculosisinfection;
11. Hiv-ab HCV-AB HBsAg syphilis test results of either positive;
12. Persons with a history of drug or alcohol abuse or positive urine drug screeningwithin 6 months prior to screening;
13. Those who donated blood within 3 months before enrollment or planned to donate bloodduring the study period and 1 month after the study ended;
14. Patients who had received blood transfusion within 4 weeks prior to enrollment;
15. Subjects who were smokers (who had smoked for more than 6 months prior to screeningand smoked more than 5 cigarettes per day), consumed 3 cups of coffee or othercaffeine-containing beverages, or 5 cups of tea per day;
16. Prior to screening, use of any prescription over-the-counter drug or herbal medicinewith an estimated time of less than 5 half-life of the drug or less than 14 days priorto initial administration, whichever is the longest;
17. Those who received vaccination or immunotherapy within 3 months prior to screening;Those who plan to receive the vaccine during the study period or within 3 months ofdiscontinuing the drug;
18. Patients who cannot tolerate venipunctures and have a history of needle sickness andblood sickness;
19. Participants who participated in any drug clinical trials within 3 months prior toenrollment, or who plan to participate in other drug clinical trials during the studyperiod;
20. The investigator considered that participants were not eligible to participate in theclinical trial for other reasons.