Myasthenia Gravis Inebilizumab Trial

Inclusion Criteria:

1. Diagnosis of MG with anti-AChR or anti-MuSK antibody.
2. MGFA Clinical Classification Class II, III, or IV.
3. MG-ADL score of 6 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. Participants must be on:

   1. Corticosteroids only, with no dose increase within 4 weeks prior to randomization, or
   2. One allowed non-steroidal immunosuppressive therapy (IST), with continuous use for at least 6 months prior to randomization and no dose increase within 4 months prior to randomization, or
   3. Combination of (1) corticosteroids with no dose increase within 4 weeks prior to randomization and (2) one allowed non-steroidal IST with continuous use for at least 6 months prior to randomization and no dose increase within 4 months prior to randomization.

Allowed ISTs, alone or in combination with corticosteroids, are azathioprine, mycophenolate mofetil, and mycophenolic acid.

Exclusion Criteria:

1. Receipt of the following medications within the 4 weeks prior to Day 1:

   1. Cyclosporine (except eye drops)
   2. Tacrolimus (except topical)
   3. Methotrexate
2. Current use of:

   1. Corticosteroids (Prednisone \> 40 milligram (mg)/day or \> 80 mg over a 2-day period (or equivalent dose of other corticosteroids).
   2. Acetylcholinesterase inhibitors (pyridostigmine) \> 480 mg/day) or unstable dose in the 2 weeks prior to Day 1.
   3. Azathioprine \> 3 mg/kilogram (kg)/day
   4. Mycophenolate mofetil \> 3 grams/day or mycophenolic acid \> 1440 mg/day
   5. Any IST, alone or in combination with corticosteroids, except for azathioprine, mycophenolate mofetil, and mycophenolic acid.