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 thisscore attributed to non-ocular items.

4. QMG score of 11 or greater.

5. Participants must be on:

6. Corticosteroids only, with no dose increase within 4 weeks prior torandomization, or

7. One allowed non-steroidal immunosuppressive therapy (IST), with continuous usefor at least 6 months prior to randomization and no dose increase within 4months prior to randomization, or

8. Combination of (1) corticosteroids with no dose increase within 4 weeks priorto randomization and (2) one allowed non-steroidal IST with continuous use forat least 6 months prior to randomization and no dose increase within 4 monthsprior 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:

2. Cyclosporine (except eye drops)

3. Tacrolimus (except topical)

4. Methotrexate

5. Current use of:

6. Corticosteroids (Prednisone > 40 milligram (mg)/day or > 80 mg over a 2-dayperiod (or equivalent dose of other corticosteroids).

7. Acetylcholinesterase inhibitors (pyridostigmine) > 480 mg/day) or unstable dosein the 2 weeks prior to Day 1.

8. Azathioprine > 3 mg/kilogram (kg)/day

9. Mycophenolate mofetil > 3 grams/day or mycophenolic acid > 1440 mg/day

10. Any IST, alone or in combination with corticosteroids, except for azathioprine,mycophenolate mofetil, and mycophenolic acid.