Findings from pivotal nipocalimab Phase 3 study in a broad antibody positive population of people living with generalized myasthenia gravis (gMG) published in The Lancet Neurology

Nipocalimab Clinical Trial Results - Nipocalimab demonstrated a sustained reduction in autoantibody levels by up to 75% over 24 weeks in antibody-positive adult patients with generalized myasthenia gravis (gMG) [1] - The Phase 3 Vivacity-MG3 study met its primary endpoint, showing statistically significant and clinically meaningful improvement in MG-ADL scores over 24 weeks [1] - Nipocalimab had a tolerable safety profile, with adverse event discontinuation rates similar to placebo (5.1% vs 7.1%) [1] gMG Disease Overview - gMG is a chronic, rare, autoantibody-driven disease affecting an estimated 700,000 people worldwide [4] - The disease is characterized by fluctuating weakness of skeletal muscles, leading to symptoms like limb weakness, drooping eyelids, and difficulties with chewing, swallowing, speech and breathing [4] - Approximately 10-15% of new MG cases are diagnosed in adolescents, with over 65% of pediatric MG cases in the US diagnosed in girls [4] Nipocalimab Mechanism and Designations - Nipocalimab is an investigational monoclonal antibody designed to block FcRn and reduce levels of circulating IgG antibodies, including autoantibodies [6] - The therapy has received multiple FDA designations, including Fast Track for gMG in December 2021 and Breakthrough Therapy for Sjögren's disease in November 2024 [8] - Nipocalimab was granted Priority Review by the FDA in Q4 2024 for gMG treatment [8] Vivacity-MG3 Study Design - The Phase 3 study enrolled 199 gMG patients, with 153 being antibody-positive, in a 24-week double-blind placebo-controlled trial [5] - Patients received either nipocalimab plus standard of care (30 mg/kg IV loading dose followed by 15 mg/kg every two weeks) or placebo plus standard of care [5] - The primary endpoint was mean change in MG-ADL score from baseline over Weeks 22-24 in antibody-positive patients [5] Regulatory Submissions - Johnson & Johnson submitted a Biologics License Application to the FDA on August 29, 2024 and a Marketing Authorisation Application to the EMA on September 11, 2024 for nipocalimab in gMG [1] - The Priority Review designation by the FDA was supported by findings from the Phase 3 Vivacity-MG3 study [1]