A Phase 1b, Open-label, Single-arm, Dose-escalation Study of PN20 in Patients with Primary Immune Thrombocytopenia (ITP)
The main aim of this clinical trial is to assess the safety and tolerability of PN20 in adult patients with primary immune thrombocytopenia (ITP). The main questions it aims to answer are: * Is PN20 safe in these patients? * Could these patients potentially benefit from PN20 treatment? Participants will * Receive one subcutaneous injection of PN20 according to weight; * Visit the clinic for assessment.
• Aged between 18 and 65 years (inclusive), male or female;
• Diagnosed with primary immune thrombocytopenia (ITP) and have a disease course of more than 6 months;
• Patients who have no response or relapsed after splenectomy. Or patients who have not been splenectomised and have completed at least 1 prior treatment for ITP (such as glucocorticoids, immunoglobulin) and have failed to respond or relapsed after treatment;
• During screening period, the mean of two platelet counts must be \< 30 × 10\^9/L, with none \>35 × 10\^9/L;
• Fully understand and are able to comply with the requirements of the protocol, voluntarily participate and sign the informed consent form.