TPO-RA in Primary Immune Thrombocytopenia (ITP) in Patients Older Than 14 Years

Inclusion Criteria:

• Men and women greater than or equal to 14 years of age.

• Participants diagnosed with primary immune thrombocytopenia with two platelet countsof < 30x10^9/L or with bleeding at least 7 days apart，do not have evidence of othercauses of thrombocytopenia (e.g.,pseudothrombocytopenia, myeloid fibrosis).

• Previous treatment with poor response to first-line therapy and any of the maximum 4-week doses of eltrombopag, herombopag, avatrombopag, or 300U/kg/ day × 14-dayrhTPO with no response to treatment (platelet count < 30×109/L after treatment, orplatelet count increase less than twice the baseline value, or with bleeding)

• Participants willing and able to comply with the requirements of the study protocol,and sign the informed consent.

Exclusion Criteria:

• Patients diagnosed with secondary immune thrombocytopenia.

• A history of arteriovenous thrombosis, disseminated intravascular coagulation,myocardial infarction, cerebral obstruction, thrombotic microangiopaemia, autoimmunediseases, malignant tumors, liver cirrhosis and other diseases that were noteligible for inclusion.

• Liver disease with one of the following indicators: a. total bilirubin ≥ 2 times ofthe upper limit of normal; b. alanine aminotransferase (ALT) and aspartateaminotransferase (AST) ≥ 2 times the upper limit of normal value; Patients withrenal disease (serum creatinine ≥ 1.5 times the upper limit of normal);

• Subjects with known allergies to eltrombopag, herombopag, rh-TPO, avatrombopag, orany of excipients;

• Have used rituximab in the past 3 months;

• Splenectomy in recent 3 months;

• Those who are not considered suitable for this study by the researcher;

• Women who are pregnant or who intend to become pregnant in the near future areexcluded.