A randomized, double-blind, placebo-controlled design was designed to evaluate the safety and tolerability, pharmacokinetic/pharmacodynamic profile, and immunogenicity of multiple administration of STSA-1301 subcutaneous injection in healthy subjects and patients with ITP, and to further explore the initial efficacy of STSA-1301 subcutaneous injection in patients with ITP
18 years ≤ age ≤ 50 years, male or female subjects;
Body mass index is 18 kg/m²≤ BMI≤ 26kg/m²;
Subjects (including the subject's partner) are willing to use effective contraception during the study period and have no plans to have children or to donate sperm or eggs from the time of signing the informed consent form until 3 months after the last dose;
Pre-randomization medical history had no effect on enrollment in the trial, and physical examination, laboratory test items, and all tests related to the trial were normal or the investigator determined that the abnormalities were not clinically significant;
Subject has a history of serious medical conditions (including, but not limited to, gastrointestinal, renal, hepatic, neurologic, hematologic, endocrine, pulmonary, immunologic, psychiatric, or cardiovascular disorders) or any disease or sequela known to be likely to interfere with the absorption, distribution, metabolism, or excretion of the test drug;
Subjects with an active infection or with a serious infection (resulting in hospitalization or requiring parenteral antibiotic therapy) within 6 weeks prior to the first dose; subjects with a combination of clinically significant active or chronic uncontrolled bacterial, viral, or fungal infections at screening;
Subjects have a history of immunodeficiency;
Subjects had a history of malignant tumors;