Efficacy and Safety of Romiplostim in Adult Subjects With Persistent or Chronic Immune Thrombocytopenia (ITP)

Study Overview
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Brief Summary
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The objective is to evaluate the efficacy and safety of romiplostim for injection in adlut subjects with persistent or chronic primary immune thrombocytopenia (ITP).

Official Title
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A Multi-center, Randomized, Placebo-controlled, Double-blinded Then Open 2 Stages Clinical Trial to Evaluate the Efficacy and Safety of Romiplostim in Adult Subjects With Persistent or Chronic Primary Immune Thrombocytopenia (ITP)

Conditions
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Immune Thrombocytopenia

Intervention / Treatment
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* Drug: Romiplostim
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosed with immune thrombocytopenia (ITP) for at least 6 months prior to signing the informed consent form (ICF). Subject is ≥ 18 years old while signing the ICF. Patients who have no response or relapsed after splenectomy. Or patients who have not been splenectomised and have no response or relapse to at least 1 prior treatment for immune thrombocytopenia (ITP). The mean of 3 scheduled platelet counts taken during the screening period must be: < 30 ×10^9/L, with none >35×10^9/L. Exclusion Criteria: Any known history of bone marrow stem cell disorder. Any abnormal bone marrow findings other than those typical of ITP. Any active malignancy. If prior history of cancer other than basal cell carcinoma or cervical carcinoma in situ, and no treatment or active disease within 5 years prior to signing the ICF.. Received hematopoietic growth factors (e.g., granulocyte colony-stimulating factor, macrophage colony-stimulating factor, erythropoietin, interleukin-11) for any reason within 4 weeks prior to signing the ICF. Received myeloproliferative leukemia (MPL) stimulation product other than the subject who had suspended recombinant human thrombopoietin (rHuTPO) for injection for 4 weeks before signing ICF. Received any anti-malignancy agents (e.g., cyclophosphamide, 6-mercaptopurine, vincristine, vinblastine, Interferon-alfa) for any reason within 8 weeks prior to signing the ICF. Received any monoclonal antibody drugs (e.g., rituximab) for any reason within 14 weeks prior to signing the ICF. Less than 4 weeks since end of any clinical trials about therapeutic drug or device prior to signing the ICF. Pregnant or breastfeeding. In the opinions of the principal investigator or investigators, the patients are not suitable for participation in this trial.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: multi-center, Randomized, Placebo-controlled, Double-blinded then Open-label
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Subjects received placebo for injection treatment will be administered subcutaneously once a week | Drug: Placebo<br> <br> |
| Experimental: Drug<br>Subjects received Romiplostim for injection treatment will be administered subcutaneously once a week | Drug: Romiplostim<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of weeks in which the platelet response counts increase above 50×10^9/L |  | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of subjects whose platelet counts relative to the baseline increase ≥ 20×10^9/L |  | 6 weeks | 
| Proportion of subjects who have received emergency treatment to increase the platelet counts |  | 6 weeks |