A Study of STSA-1201 in Healthy Subjects

Inclusion criteria

• Healthy subjects, male or female, aged between 18 and 50 years, inclusive.
• Male subjects must have a weight range of 50.0 kg to 75.0 kg inclusive, and female subjects must have a weight range of 45.0 kg to 75.0 kg inclusive. All subjects must have a body mass index (BMI) of 19.0 to 26.0 kg/m^2 inclusive.
• Subjects (and their partners) must abstain from sperm/egg donation and commit to using effective methods of birth control during the trial and for 6 months post-trial.
• Subjects must have a normal or clinically acceptable medical history, physical examination, laboratory test results, chest X-ray and electrocardiogram (ECG).
• Subjects must fully understand the trial procedures, potential adverse reactions, and sign the informed consent form (ICF).

Exclusion criteria

• Subjects with significant clinical disorders or conditions (including but not limited to gastrointestinal, rental, liver, neurological, hematologic, endocrine, oncologic, pulmonary, immunologic, psychiatric, or cardiovascular diseases) and subjects with active or suspected infections (viral, fungal, or parasitic).
• Subjects who underwent major surgery within 2 months prior to screening.
• Subjects with allergic constitution (such as allergies to two or more drugs, foods, and pollen) or potential allergy to the trial product/components.
• Subjects positive for hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV Ab), human immunodeficiency virus antibody (HIV Ab) or treponema pallidum antibody (TP Ab).
• Subjects with Ig E levels exceeding the normal upper limit.
• Subjects who have smoked more than an average of 5 cigarettes per day within the 3 months prior to screening, or who are unable to abstain from using any tobacco or nicotine-containing products during the trial.
• Subjects with a history of alcohol abuse (more than 14 units per week: 1 unit of alcohol =360mL beer or 45mL spirits with 40% alcohol or 100mL wine) within the 6 months prior to screening, or unable to abstain during the trial, or failed alcohol breath test.
• Subjects with drug abuse history (morphine, ketamine, THC, methamphetamine, methylene-dioxymethamphetamine, cocaine) within 1 year prior to screening or those testing positive for urine drug abuse screening.
• Subjects who donated or lost > 400 mL blood within 3 months prior to screening, received blood transfusions or products within 4 weeks prior to enrollment, or plan to donate blood during the trial and 3 months post-trial.
• Subjects who participated in another clinical trial or received investigational drugs/vaccines within 3 months prior to screening.
• Subjects who received biologicals or monoclonal antibodies within 3 months prior to screening; subjects who used any medication (including prescription medications, over the counter medications and herbal medicines) within 14 days prior to screening; subjects previously treated with any drugs targeting thymic stromal lymphopoietin (TSLP).
• Subjects consuming xanthine-rich foods/beverages (such as coffee, strong tea, chocolate) or those that affect drug absorption, distribution, metabolism, and excretion within 48 hours prior to administration.
• Subjects who used long-acting estrogen or progestogen injections or implants within 6 months prior to screening or short-acting contraceptives within 30 days prior to the trial.
• Female subjects who test positive for serum human chorionic gonadotropin (HCG) or have abnormal HCG levels exceeding the normal upper limit.
• Female subjects who are pregnant or lactating.
• Subjects with venipuncture intolerance, history of transfusion issues, or blood/ needle-phobia.
• Subjects with any condition or circumstance which, in the opinion of the Investigator, may compromise the ability to provide informed consent, comply with the study protocol, potentially influence study outcomes, jeopardize their own safety, or any other situation deemed unsuitable for study participation by the investigator.