A Study of Nipocalimab in Children Aged 2 to Less Than 18 Years With Generalized Myasthenia Gravis

Key Inclusion Criteria: * Age: For US sites only: 8 to \< 18 years * Diagnosis of myasthenia gravis (MG) with generalized muscle weakness meeting the clinical criteria for generalized myasthenia gravis (gMG) as defined by the Myasthenia Gravis Foundation of America (MGFA) Clinical Classification Class IIa/b, IIIa/b, or IVa/b at screening * Has a positive serologic test for acetylcholine receptor (anti-AChR) antibodies or muscle-specific tyrosine kinase (anti-MuSK) antibodies at screening * A participant using herbal, naturopathic, traditional Chinese remedies, ayurvedic or nutritional supplements, or medical marijuana (with a doctor's prescription) is eligible if the use of these medications is acceptable to the Investigator. These remedies must remain at a stable dose and regimen throughout the study * Has sufficient venous access to allow drug administration by infusion and blood sampling as per the protocol * Participants should have a body weight and body mass index between 5th and 95th percentile for age and sex. Obese participants greater than 95th percentile and underweight participants below 5th percentile may participate following medical clearance * A female of childbearing potential must have a negative highly sensitive serum (beta-human chorionic gonadotropin \[beta-hCG\]) at Screening and a negative urine pregnancy test at Day 1 prior to administration of study intervention Key Exclusion Criteria: * Has a history of severe and/or uncontrolled hepatic (example,…