This is a randomized, double-blind, placebo-controlled Phase III clinical study designed to demonstrate that TQB3473 tablets significantly improve the sustained response rate compared to placebo in adult patients with chronic ITP who have previously received standard corticosteroid therapy and have failed or relapsed after at least one standard ITP treatment.
The study consists of a treatment period and a safety follow-up period.
Subjects voluntarily join this study, sign the informed consent form (ICF), and demonstrate good compliance;
Male or female subjects aged 18 to 75 years (calculated based on the date of signing the informed consent form);
Eastern Cooperative Oncology Group (ECOG) score of 0-1;
Diagnosis of primary ITP prior to randomization, with a duration of ≥12 months;
Evidence of secondary causes of ITP (e.g., untreated Helicobacter pylori infection, leukemia, lymphoma, history of autoimmune diseases such as systemic lupus erythematosus, Hashimoto's thyroiditis, etc.) or drug-induced causes (e.g., anticonvulsants, antibiotics, heparin, etc.), or immune-mediated cytopenia involving two or more cell lines such as Evans syndrome or immune-related cytopenia;
Subjects with a history or current diagnosis of myelofibrosis, myelodysplastic syndrome, aplastic anemia, lymphoproliferative disorders, or other malignant hematologic diseases;
History of or concurrent other malignancies within the past 3 years. Exceptions include: other malignancies treated with a single surgical procedure and achieving continuous 5-year disease-free survival (DFS); cured cervical carcinoma in situ, non-melanoma skin cancer, and superficial bladder tumors [Ta (non-invasive tumor), Tis (carcinoma in situ), and T1 (tumor invading the basement membrane)];
Conditions affecting venous blood sampling or multiple factors affecting oral medication (e.g., inability to swallow, chronic diarrhea, intestinal obstruction, etc.);