Purpose of Review FcRn inhibitors represent a novel, targeted therapeutic class that selectively lowers pathogenic IgG autoantibodies while preserving other immunoglobulin isotypes, offering a significant advance in the management of autoimmune neuromuscular disorders such as generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP). This review provides an overview of the currently FDA-approved FcRn inhibitors Efgartigimod (Vyvgart and Vyvgart Hytrulo), rozanolixizumab (Rystiggo), and Nipocalimab (Imaavy) focusing on their mechanisms, approved indications, dosing regimens, pivotal trial data, efficacy, safety profiles, and practical considerations for use in neuromuscular medicine. Recent Findings As of 2026, three FcRn inhibitors are FDA-approved for neuromuscular indications. Efgartigimod is approved for AChR antibody-positive gMG (both intravenous and subcutaneous formulations) and is the only agent approved for CIDP (subcutaneous Vyvgart Hytrulo). In the phase 3 ADAPT trial, Efgartigimod achieved MG-ADL responder rates of 67.7% versus 29.7% with placebo. The ADHERE trial demonstrated a significant reduction in relapse risk in CIDP (hazard ratio 0.394). Rozanolixizumab, approved for both AChR- and MuSK-positive gMG, showed mean MG-ADL improvements of −3.4 points versus −0.8 with placebo in the MycarinG trial, with benefits observed across AChR+ and MuSK+ patients. Nipocalimab, the most recently approved (April 2025) and broadest in scope (AChR or MuSK positive gMG in adults and adolescents ≥12 years), provided sustained MG-ADL reductions of −4.7 versus −3.3 points in the Vivacity-MG3 trial with continuous biweekly dosing. All agents achieve substantial IgG reduction (60–75%), correlating with clinical improvement, though they differ in administration route, dosing schedule (cyclic vs continuous), and serotype/age coverage. Common adverse events are primarily mild-to-moderate infections and administration-related reactions, with generally favorable tolerability. Summary FcRn inhibitors have rapidly transformed treatment options in neuromuscular medicine by providing rapid, effective, and relatively selective IgG antibody reduction with manageable safety profiles. While cyclic therapies (Efgartigimod and Rozanolixizumab) offer dosing flexibility, continuous dosing with Nipocalimab may provide more stable disease control and rapid IgG reduction, particularly useful in severe cases. Ongoing head-to-head trials and pipeline agents will further guide therapeutic selection. These therapies reduce reliance on nonspecific immunosuppression and corticosteroids, representing a major step forward in the precision management of autoimmune neuromuscular diseases.

A Review of FcRn Inhibitors in Neuromuscular Medicine and a Future Outlook

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发表日期：

2026年4月24日

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Sukhraj Gill

摘要

Purpose of Review

FcRn inhibitors represent a novel, targeted therapeutic class that selectively lowers pathogenic IgG autoantibodies while preserving other immunoglobulin isotypes, offering a significant advance in the management of autoimmune neuromuscular disorders such as generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP). This review provides an overview of the currently FDA-approved FcRn inhibitors Efgartigimod (Vyvgart and Vyvgart Hytrulo), rozanolixizumab (Rystiggo), and Nipocalimab (Imaavy) focusing on their mechanisms, approved indications, dosing regimens, pivotal trial data, efficacy, safety profiles, and practical considerations for use in neuromuscular medicine.

Recent Findings

As of 2026, three FcRn inhibitors are FDA-approved for neuromuscular indications. Efgartigimod is approved for AChR antibody-positive gMG (both intravenous and subcutaneous formulations) and is the only agent approved for CIDP (subcutaneous Vyvgart Hytrulo). In the phase 3 ADAPT trial, Efgartigimod achieved MG-ADL responder rates of 67.7% versus 29.7% with placebo. The ADHERE trial demonstrated a significant reduction in relapse risk in CIDP (hazard ratio 0.394). Rozanolixizumab, approved for both AChR- and MuSK-positive gMG, showed mean MG-ADL improvements of −3.4 points versus −0.8 with placebo in the MycarinG trial, with benefits observed across AChR+ and MuSK+ patients. Nipocalimab, the most recently approved (April 2025) and broadest in scope (AChR or MuSK positive gMG in adults and adolescents ≥12 years), provided sustained MG-ADL reductions of −4.7 versus −3.3 points in the Vivacity-MG3 trial with continuous biweekly dosing. All agents achieve substantial IgG reduction (60–75%), correlating with clinical improvement, though they differ in administration route, dosing schedule (cyclic vs continuous), and serotype/age coverage. Common adverse events are primarily mild-to-moderate infections and administration-related reactions, with generally favorable tolerability.

Summary

FcRn inhibitors have rapidly transformed treatment options in neuromuscular medicine by providing rapid, effective, and relatively selective IgG antibody reduction with manageable safety profiles. While cyclic therapies (Efgartigimod and Rozanolixizumab) offer dosing flexibility, continuous dosing with Nipocalimab may provide more stable disease control and rapid IgG reduction, particularly useful in severe cases. Ongoing head-to-head trials and pipeline agents will further guide therapeutic selection. These therapies reduce reliance on nonspecific immunosuppression and corticosteroids, representing a major step forward in the precision management of autoimmune neuromuscular diseases.