A Study to Determine the Safety, Tolerability, PK and Preliminary PD of SSS11 in Chinese Healthy Adult Volunteers

Inclusion Criteria: * Subjects in the age range between 18 and 45 years old (inclusive), male or female * In good health (no significant clinical symptoms or abnormal laboratory test results without clinical significance) * BMI within the range between 19 and 28 kg/m2 (inclusive) * Voluntarily sign the written informed consent * Be able to understand and comply with the requirements of clinical protocols, expected to complete the whole trial process * Subjects achieving full recovery if had the surgical treatment Exclusion Criteria: * Subjects cannot tolerate intravenous injection * Allergies or previous history of drug allergy, or allergic history of PEG-drugs, or previous history of allergies to two or more substances * Any abnormalities detected in three allergen tests (Special allergen screening - mixed mould, total IgE assay, special allergen screening - HX2) * Subjects having anti- PEG antibody * Taking any medicine before enrollment, and the regimen was less than five half-life periods or 4 weeks (Subject to the longest of the two) * Has a history of vaccination within 12 weeks before enrollment, or intend to receive vaccines during the study * Taking any other clinical trials within 12 weeks before enrollment,or have used similar drugs to the study drug * Having a history of blood donation within 12 weeks before enrollment * Having a history of glucose-6-phosphate dehydrogenase (G6PD) deficiency or abnormal G6PD detection * Having a history of catalase deficiency or evidence that individuals meet the criteria for catalase deficiency * Having a history of serious diseases, including but not limited to digestive system, cardiovascular system, respiratory system, urinary system, musculoskeletal system, endocrine system, neuropsychiatric system, blood system, immune system diseases and metabolic abnormalities * Having abnormalities and clinical significances in laboratory tests (blood routine, urine routine, blood biochemistry, etc.) and electrocardiogram findings within two weeks before enrollment * The HBsAg, anti-HIV, anti-HCV and treponema pallidum antibody were positive * The female within lactation, pregnancy, or having birth plan within 24 weeks * Blood pregnancy test was positive(female) * Male subjects who did not take effective contraception or their spouse plan to be born within 24 weeks * Disabled person in mental or law * Subjects having a history of alcohol abuse within 24 weeks prior to screening, equal to exceed 14 unit alcohol per week (1 unit = 12 ounces or 360 mL of beer, 1.5 ounces or 45 mL of 40% alcohol, 5 ounces or 150 mL of wine) * Smoking more than 5 cigarettes per day within 24 weeks before screening * Those who have had halo and fainting history * Drug abuse test or alcohol test was positive * Drinking more than 1L of tea, coffee and/or caffeinated beverages daily * Those who do not understand the content of informed consent and other those who do not meet the criteria for trial inclusion * Participants who researchers believe are not suitable (such as infirmity, etc.)