Evaluation of Pharmacokinetics, Pharmacodynamics, Efficacy, Safety, and Immunogenicity of Ravulizumab Administered Intravenously in Pediatric Participants With Generalized Myasthenia Gravis (gMG)

Inclusion Criteria:

• Diagnosis of gMG confirmed by a positive serologic test for anti-AChR antibodies (Abs) obtained at Screening and/or during Screening Period

• Myasthenia Gravis Foundation of America (MGFA) Clinical Classification of Class IIto Class IV at Screening

• Participants receiving treatment must be on a stable dosing regimen of adequateduration prior to Screening and during the Screening Period.

• Eculizumab-experienced participants must have been enrolled and treated witheculizumab in Study ECU-MG-303 for at least 6 months (180 days) and must have beenon a stable dose for ≥ 2 months (60 days) prior to Screening.

• All participants must be vaccinated against meningococcal infection

Exclusion Criteria:

Medical Conditions

• Any untreated thymic malignancy, carcinoma, or thymoma.

• Participants with a history of treated benign thymoma

• History of thymectomy, thymomectomy, or any thymic surgery within the 12 monthsprior to Screening

• History of N meningitidis infection

• Known to be human immunodeficiency virus (HIV) positive

• History of unexplained infections

• Known or suspected history of drug or alcohol abuse or dependence within 1 yearprior to the start of the Screening Period