PK, PD, Safety, and Efficacy Study of Gefurulimab in Pediatric Patients With AChR+ Generalized Myasthenia Gravis

Who May Qualify: United States of America (USA) specific inclusion criterion: - Participant must be 12 to \< 18 years of age at the time of signing the willing to sign a consent form/assent. - All participants must be vaccinated against meningococcal infection from serogroups A, B, C, W, and Y within 3 years and at least 2 weeks prior to the first dose of study intervention administration. Rest of World (ROW) specific Who May Qualify: - Participant must be 6 to \< 18 years of age at the time of signing the willing to sign a consent form/assent. - All participants must be vaccinated against meningococcal infection from serogroups A, C, W, Y (and B where available) within 3 years prior to study intervention on Day 1. If vaccination occurs \< 2 weeks prior to Day 1, the participants will receive prophylactic antibiotics for at least 2 weeks after initial meningococcal vaccination for serogroups A,C,W,Y (and B, where available) Global Who May Qualify: - Diagnosis of MG with generalized muscle weakness meeting the clinical criteria defined by Myasthenia Gravis Foundation of America (MGFA) Class II, III or IV - Positive serological test for autoantibodies against AChR Who Should NOT Join This Trial: - History of thymectomy, or any other thymic surgery within 12 months prior to Screening - Untreated thymic malignancy, carcinoma, or thymoma - History of Neisseria meningitidis infection - Pregnancy, breastfeeding, or intention to conceive during the course of the study Always talk to your doctor about whether this trial is right for you.