Clinical Research Directory

Inclusion Criteria: 1. Voluntarily signed informed consent ; 2. Patient diagnosed with systemic myasthenia gravis according to The following conditions. 3. Seropositive at screening for AChR（Acetylcholine receptor）-Ab or MuSK（Muscle specific tyrosine kinase）-Ab; 4. MGFA（Myasthenia Gravis Foundation of America） Clinical classification Ⅱ-IIIb; 5. QMG score≥8,and QMG score\>2 in four or more items; 6. Maintained any one of the stable standard treatment programs in the trial protocol. Exclusion Criteria: 1. Combined autoimmune diseases, such as systemic lupus erythematosus,rheumatoid arthritis, systemic sclerosis and so on,except for hypothyroidism and hyperthyroidism; 2. Abnormal laboratory parameters need to be excluded, including but not limited to: 3. Immunosuppressive agents except agents of standard treatment programs were used within one month prior to randomization.; 4. Use of biological agents for targeted therapy within 6 months prior to randomization; 5. Intravenous immunoglobulin therapy or plasma exchange therapy within 2 months before randomization; 6. Active infection during screening(For example,herpes zoster,HIV antibody positive,active tuberculosis,etc); 7. Currently suffering from active hepatitis or severe liver lesions and history; 8. Diabetics with poor blood sugar control:HbAlc\>9.0% or FBG≥11.1mmol/L; 9. Currently having a thymic tumor ,or had a thymectomy within 6 months prior to screening; 10. Received live vaccines within 3 months before randomization,or scheduled to administer vaccine during the trial; 11. Malignant tumor patients; 12. Allergic to human biological preparations; 13. 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). 14. Pregnant , lactating women and men or women who have birth plans during the research; 15. Having alcohol or drug abuse that affect the experimental conditions; 16. Investigator considers candidates not appropriating for the study.