Findings from pivotal nipocalimab Phase 3 study in a broad antibody positive population of people living with generalised myasthenia gravis 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 patients with generalized myasthenia gravis (gMG) [2] - The Phase 3 Vivacity-MG3 study met its primary endpoint, showing statistically significant improvement in MG-ADL score over 24 weeks [2] - Nipocalimab had a tolerable safety profile, with adverse events leading to discontinuation similar to placebo (5.1% vs 7.1%) [2] gMG Disease Overview - gMG is a chronic, rare autoantibody disease affecting an estimated 700,000 people worldwide and 56,000-123,000 in Europe [3] - The disease is characterized by fluctuating weakness of skeletal muscles, leading to symptoms like limb weakness, drooping eyelids, and breathing difficulties [9] - Approximately 10-15% of new MG cases are diagnosed in adolescents (12-17 years), with over 65% of pediatric cases in the EU occurring in girls [8] Nipocalimab Mechanism and Designations - Nipocalimab is an investigational FcRn blocker that reduces circulating IgG antibodies, including pathogenic autoantibodies [3] - The therapy has received multiple FDA designations including Priority Review for gMG, Breakthrough Therapy for Sjögren's disease, and Orphan Drug status for several conditions [6][15] - Johnson & Johnson submitted Marketing Authorization Applications to EMA and FDA in 2024 seeking approval for gMG treatment [5] 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 [10] - 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 SOC [10] - The primary endpoint was mean change in MG-ADL score from baseline over Weeks 22-24 in antibody positive patients [10] Clinical Impact and Future Directions - Nipocalimab plus SOC demonstrated significantly greater reduction in MG-ADL response (≥2-point improvement) compared to placebo plus SOC (p=0.0213) [4] - A 1-2 point change in MG-ADL score can significantly impact patients' daily functioning, such as eating and breathing [4] - The publication of Phase 3 data in The Lancet Neurology and FDA Priority Review status mark important milestones in gMG treatment development [5]