Background: Nipocalimab (a fully human, effectorless anti-neonatal Fc receptor (FcRn) monoclonal antibody) may ameliorate gMG disease manifestations by selectively targeting FcRn IgG recycling and lowering IgG, including pathogenic autoantibodies in generalized myasthenia gravis (gMG). The objective was to evaluate the effectiveness and safety of intravenous nipocalimab added to background standard-of-care therapy in adolescents with gMG. Methods: Seropositive patients (12-<18 years) with gMG (MGFA Class II-IV) on stable therapy but inadequately controlled, were enrolled in a 24-week open label study. Nipocalimab was administered as a 30 mg/kg IV loading dose followed by 15 mg/kg IV every 2 Weeks. Results: Seven adolescents were enrolled; 5 completed 24-weeks of dosing. The mean(SD) age was 14.1(1.86) years; seven were anti-AChR+, six were female. Mean(SD) baseline MG-ADL/QMG scores were 4.29(2.430)/12.50(3.708). Nipocalimab showed a significant reduction in total serum IgG at week-24; the mean(SD) change from baseline to week-24 for total serum IgG was -68.98%(7.561). The mean(SD) change in MG-ADL/QMG scores at week-24 was -2.40(0.418)/-3.80(2.683); 4 of 5 patients achieved minimum symptom expression (MG-ADL score 0-1) by week-24. Nipocalimab was well-tolerated; there were no serious adverse events. There were no clinically meaningful laboratory changes. Conclusions: Nipocalimab demonstrated efficacy and safety in this 6-month trial in seropositive adolescents with gMG.