A Study to Evaluate the Pharmacokinetics, Pharmacodynamics, Safety and Tolerability of Inebilizumab in Children With Generalized Myasthenia Gravis (gMG)

Inclusion Criteria

• •Participant's legally authorized representative has provided informed consent when the participant is legally too young to provide informed consent and the participant has provided written assent based on local regulations and/or guidelines before any study-specific activities/procedures being initiated.
• •Age ≥ 2 to \< 18 years of age on the day of enrollment.
• •Diagnosis of gMG defined as:
• •* Positive serologic test for anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody (Ab) titers as confirmed at screening (1 retest allowed), and
• •* At least 1 of the following:
• •* History of abnormal neuromuscular transmission test results demonstrated by single-fiber electromyography or repetitive nerve stimulation; or
• •* History of positive anticholinesterase test (eg, edrophonium chloride test); or
• •* Participant demonstrated improvement in gMG signs on oral cholinesterase inhibitors, as assessed by the treating physician; or
• •* Clinical syndrome consistent with a diagnosis of gMG, and not otherwise explained by another condition.
• •Myasthenia Gravis Foundation of America Clinical Classification Class II, III, or IV at the time of screening.
• •Participants must be on:
• •* Corticosteroids only, with no dose increase within 4 weeks prior to screening, or
• •* One allowed non-steroidal immunosuppressive therapies (IST) (azathioprine, mycophenolate mofetil, or mycophenolic acid) with continuous use for at least 6 months prior to screening and no dose increase within 4 months prior to screening, or
• •* Combination of (1) corticosteroids with no dose increase within 4 weeks prior to screening and (2) one allowed non-steroidal IST with continuous use for at least 6 months prior to screening and no dose increase within 4 months prior to screening.
• •Tacrolimus is allowed in Japan only, with continued use for ≥ 6 months prior to screening and no dose increase within 4 months prior to screening.
• •Participants may enter the study on a stable dose of acetylcholinesterase inhibitors (pyridostigmine dose). The acetylcholinesterase inhibitor dose must have been stable for at least 2 weeks prior to enrollment.
• •Vital signs and laboratory parameters within the normal ranges at screening, or, if outside normal ranges, deemed not clinically significant by the investigator.