A Study of TACI（Transmembrane Activator and Calcium-modulator and Cyclophilin Ligand (CAML) Interactor）-Antibody Fusion Protein Injection (RC18) in Subjects With Systemic Myasthenia Gravis

Study Overview
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Brief Summary
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The purpose of this study is to initially observe the safety and effectivity of RC18 in Participants with systemic myasthenia gravis.

Official Title
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A Study of RC18, a Recombinant Human B Lymphocyte Stimulator Receptor:Immunoglobulin G( IgG ) Fc Fusion Protein for Injection for the Treatment of Subjects With Systemic Myasthenia Gravis

Conditions
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Systemic Myasthenia Gravis

Intervention / Treatment
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* Biological: RC18 160mg
* Biological: RC18 240 mg


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Voluntarily signed informed consent ; Patient diagnosed with systemic myasthenia gravis according to The following conditions. Seropositive at screening for AChR（Acetylcholine receptor）-Ab or MuSK（Muscle specific tyrosine kinase）-Ab; MGFA（Myasthenia Gravis Foundation of America） Clinical classification Ⅱ-IIIb; QMG score≥8,and QMG score>2 in four or more items; Maintained any one of the stable standard treatment programs in the trial protocol. Exclusion Criteria: Combined autoimmune diseases, such as systemic lupus erythematosus,rheumatoid arthritis, systemic sclerosis and so on,except for hypothyroidism and hyperthyroidism; Abnormal laboratory parameters need to be excluded, including but not limited to: Immunosuppressive agents except agents of standard treatment programs were used within one month prior to randomization.; Use of biological agents for targeted therapy within 6 months prior to randomization; Intravenous immunoglobulin therapy or plasma exchange therapy within 2 months before randomization; Active infection during screening(For example,herpes zoster,HIV antibody positive,active tuberculosis,etc); Currently suffering from active hepatitis or severe liver lesions and history; Diabetics with poor blood sugar control:HbAlc>9.0% or FBG≥11.1mmol/L; Currently having a thymic tumor ,or had a thymectomy within 6 months prior to screening; Received live vaccines within 3 months before randomization,or scheduled to administer vaccine during the trial; Malignant tumor patients; Allergic to human biological preparations; Have participated in any clinical trial within 28 days before randomization,or in 5 times half-life period of the drugs of any clinical trial(taking the longer time). Pregnant , lactating women and men or women who have birth plans during the research; Having alcohol or drug abuse that affect the experimental conditions; Investigator considers candidates not appropriating for the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: RC18 160mg<br>Patients received the test group RC18 160mg weekly administered subcutaneously for 24 times. | Biological: RC18 160mg<br>* subcutaneous injection<br>|
| Experimental: RC18 240 mg<br>Patients received the test group RC18 240mg weekly administered subcutaneously for 24 times. | Biological: RC18 240 mg<br>* subcutaneous injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The average variation of QMG scores of the twenty-fourth week compared to the QMG scores of baseline | QMG score=Quantitative Myasthenia Gravis Score | week 24 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The average variation of clinical absolute score for myasthenia gravis of the twelfth and twenty-fourth weeks compared to Clinical absolute score for myasthenia gravis of baseline | It is best that the assessors in each center are fixed during the study. | week 12，24 | 
| The average variation of QMG score of the twelfth week compared to the OMG scores of baseline | QMG score=Quantitative Myasthenia Gravis Score | week 12 |