Overview

Randomized, double-blind, placebo-controlled, parallel-group study with optional open-label extension.

Eligibility

Inclusion Criteria:

1. Diagnosis of MG with anti-AChRantibody.
2. MGFA Clinical Classification Class II, III, or IV.
3. MG-ADL score of 5 or greater at screening and at randomization with > 50% of this score attributed to non-ocular items.
4. QMG score of 11 or greater.
5. Subjects must be on:
   1. Cholinesterase inhibitor, with no dose increase within 4 weeks prior to randomization;
   2. Corticosteroids, with no dose increase within 4 weeks prior to randomization; or/and c. non-steroidal IST (including azathioprine, mycophenolate mofetil, tacrolimus, cyclosporine A), with continuous use for at least 6 months prior to randomization and no dose increase within 4 months prior to randomization.

Exclusion Criteria:

1. Participants had clinically relevant active infections (such as sepsis, pneumonia, or abscess) or severe infections (resulting in hospitalization or requiring antibiotic treatment) in the 4 weeks before randomization;
2. Those with a history of high-risk tuberculosis infection, acquired tuberculosis infection, and chronic hepatitis;
3. Human immunodeficiency virus (HIV) infection;
4. Thymomas that have received thymectomy or planned thymectomy during RCP within 6 months before randomization, or require chemotherapy and/or radiotherapy at any time;
5. Received rituximab treatment in the past 6 months before randomization;
6. Received tocilizumab or eculizumab treatment within 3 months before randomization;
7. Received IVIG or plasma exchange within 4 weeks before randomization;
8. Unresected thymoma.
9. History of other tumor diseases.