Efficacy and Safety of Ravulizumab in Chinese Adults Participants With Generalized Myasthenia Gravis (gMG)

The primary purpose of this study is to evaluate the efficacy, safety, pharmacokinetics, pharmacodynamics, and immunogenicity of ravulizumab in Chinese adult participants with Acetylcholine receptor (AChR) + Generalized Myasthenia Gravis (gMG).

Inclusion (key) * Confirmed generalized MG: Diagnosis ≥6 months before screening, anti-AChR antibody positive, and supportive diagnostic evidence (e.g., abnormal SFEMG/RNS or response to anticholinesterase therapy). * Disease severity: MGFA Class II-IV at screening. * Symptoms threshold: MG-ADL ≥6 at screening and on Day 1. * Meningococcal vaccination: Up to date within 3 years or vaccinated before first dose to mitigate risk with complement inhibition. * Body weight: ≥40 kg. * Vaccinated against meningococcal infections within the 3 years prior to, or at the time of, initiating study drug. Exclusion (key) * Thymic disease: * Untreated thymic malignancy/carcinoma/thymoma excluded. * Prior thymic malignancy allowed only if treatment completed \>5 years, no recurrence in last 5 years, and clear CT/MRI within 6 months. * Prior benign thymoma allowed if confirmed benign, treatment \>12 months ago, no recurrence in last 12 months, and clear CT/MRI within 6 months; otherwise follow malignancy rules. * Thymectomy within the last 12 months * Infection risk: * History of meningococcal disease or unresolved infection, or active systemic infection within 14 days of Day 1 excluded. * Persistent/recurrent infections in past 12 months that add risk * HIV, active HBV (HBsAg+ or anti-HBc+ with anti-HBs-), or active HCV (unless documented successful treatment/SVR) * Safety/medical status: * Hypersensitivity to study drug components (including murine proteins) * Recent hospitalization ≥24 hours within 28 days of screening * Substance use disorder per DSM within 12 months. * Recent/other malignancy within 5 years (except as above for thymic). * Prior/Concomitant Therapy * Complement inhibitor within \< 5 half-lives before Day 1. * Human neonatal Fc receptor (FcRn) inhibitor within \< 5 half-lives before Day 1. * Rituximab, ocrelizumab or other B cell-depleting therapy within ≤ 6 months (180 days) before Day 1. * Periodic (chronic) administration of PP/PE, or IVIg as maintenance therapy received or scheduled within ≤ 6 months before Day 1 * Key labs: * ALT \>2× ULN, direct bilirubin \>2× ULN. * eGFR \