Myasthenia gravis (MG) is an autoimmune disorder driven by pathogenic IgG autoantibodies, leading to muscle weakness and impaired quality of life. Conventional immunosuppressant therapies are often limited by side effects and incomplete efficacy. Nipocalimab-aahu (N-a), recently FDA-approved, is a novel neonatal Fc receptor (FcRn) antagonist that reduces circulating IgG levels, targeting the underlying disease mechanism. This review synthesizes evidence on N-a's efficacy, safety, and clinical positioning. Phase 2 and 3 trials (Vivacity-MG/MG3) demonstrated that N-a significantly improves the Myasthenia Gravis Activities of Daily Living (MG-ADL) score compared to placebo, with a favorable safety profile. The most common adverse events were nasopharyngitis and headache, with no increased serious infection risk or clinically significant hypoalbuminemia. Compared to other biologics, N-a offers a distinct mechanism, selective IgG reduction without broad immunosuppression and a convenient bi-weekly dosing regimen. While it shows promise for reduced systemic immunosuppression and potentially greater efficacy in MG-ADL improvement than some alternatives, cross-trial comparisons are limited. Key limitations include the need for long-term safety data and more research in underrepresented populations, including pediatric and seronegative patients. In conclusion, N-a represents a significant advancement in generalized MG (gMG) treatment, providing a targeted, effective, and well-tolerated option that addresses a key unmet need for patients with acetylcholine receptor (AChR) or muscle-specific kinase (MuSK) antibody-positive disease.
| [1] |
Bubuioc AM, Kudebayeva A, Turuspekova S, Lisnic V, Leone MA. The epidemiology of myasthenia gravis. J Med Life. 2021; 14(1):7-16.
|
| [2] |
Drugs.com. Imaavy (nipocalimab-aahu) FDA approval history. Accessed September 20, 2025. https://www.drugs.com/history/imaavy.html
|
| [3] |
Antozzi C, Guptill J, Bril V, et al. Safety and efficacy of nipocalimab in patients with generalized myasthenia gravis: results from the randomized phase 2 Vivacity-MG study. Neurology. 2024; 102(2):e207937.
|
| [4] |
Antozzi C, Vu T, Ramchandren S, et al. Safety and efficacy of nipocalimab in adults with generalised myasthenia gravis (Vivacity-MG3): a phase 3, randomised, double-blind, placebo-controlled study. Lancet Neurol. 2025; 24(2):105-116.
|
| [5] |
Vanoli F, Mantegazza R. Ravulizumab for the treatment of myasthenia gravis. Expert Opin Biol Ther. 2023; 23(3):235-241.
|
| [6] |
Heo YA. Efgartigimod alfa in generalised myasthenia gravis: a profile of its use. CNS Drugs. 2023; 37(5):467-473.
|
| [7] |
Drugs.com. Ravulizumab dosage guide + max dose, adjustments. Accessed August 18, 2025. https://www.drugs.com/dosage/ravulizumab.html
|
| [8] |
Saccà F, Pane C, Espinosa PE, Sormani MP, Signori A. Efficacy of innovative therapies in myasthenia gravis: a systematic review, meta-analysis, and network meta-analysis. Eur J Neurol. 2023; 30(12):3854-3867.
|
| [9] |
Johnson & Johnson. Johnson & Johnson receives FDA approval for IMAAVYTM (nipocalimab-aahu), a new FcRn blocker offering long-lasting disease control in the broadest population of people living with generalized myasthenia gravis (gMG). July 17, 2025, Accessed September 20, 2025. https://www.jnj.com/media-center/press-releases/johnson-johnson-receives-fda-approval-for-imaavytm-nipocalimab-aahu-a-new-fcrn-blocker-offering-long-lasting-disease-control-in-the-broadest-population-of-people-living-with-generalized-myasthenia-gravis-gmg
|
| [10] |
International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Hospital resource utilization and estimated costs associated with nipocalimab: post-hoc analysis of the placebo-controlled VIVACITY-MG3 trial in generalized myasthenia gravis. May 18-22, 2025, Accessed September 20, 2025. https://www.ispor.org/heor-resources/presentations-database/presentation-cti/ispor-2025/poster-session-2/hospital-resource-utilization-and-estimated-costs-associated-with-nipocalimab-post-hoc-analysis-of-the-placebo-controlled-vivacity-mg3-trial-in-generalized-myasthenia-gravis
|
| [11] |
International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Cost per responder for FcRn inhibitors for generalized myasthenia gravis. May 5-8, 2024, Accessed September 13, 2025. https://www.ispor.org/heor-resources/presentations-database/presentation/intl2024-3897/137915
|
| [12] |
Zhu LN, Hou HM, Wang S, et al. FcRn inhibitors: a novel option for the treatment of myasthenia gravis. Neural Regen Res. 2022; 18(8):1637-1644.
|
| [13] |
Bhandari V, Bril V. FcRn receptor antagonists in the management of myasthenia gravis. Front Neurol. 2023; 14:1229112.
|
| [14] |
Menon D, Bhandari V. FcRn inhibitors in the context of myasthenia gravis. Expert Opin Emerg Drugs. 2025; 30(1):7-10.
|
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2025 The Author(s). Ibrain published by Affiliated Hospital of Zunyi Medical University (AHZMU) and Wiley-VCH GmbH.
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