Efficacy and safety of FcRn inhibitors in patients with Myasthenia gravis: An updated systematic review and meta‑analysis

Abstract

Background: Myasthenia gravis (MG) is a chronic, complex autoimmune disorder characterized by the production of autoantibodies that destroy neuromuscular junctions. Blocking the neonatal Fc receptors (FcRn) enhances IgG catabolism, offering a novel therapeutic approach.

Methods: PubMed, Embase, and the Cochrane Library were searched up to February 2025, for RCTs evaluating FcRn inhibitors in MG. A random effects model to calculate pooled risk ratios (RR) and mean differences with 95 % confidence intervals (CI).

Results: 873 patients from 8 randomized control trials (RCTs) were analyzed. Compared to placebo, FcRn inhibitors significantly reduced Myasthenia Gravis Activities of Daily Living (MG-ADL) scores (MD of -1.45 [95 % CI, -1.91 to -0.99]; P < 0.00001), Quantitative Myasthenia Gravis( QMG) scores (MD = -2.33 [95 % CI, -3.57 to -1.09]; P = 0.0002), and Myasthenia Gravis Composite (MGC) scores (MD = -2.96 [95 % CI, -4.29 to -1.63]; P < 0.0001). The FcRn inhibitors improved MG-ADL responder rates (RR = 1.60 [95 % CI, 1.27-2.02]; P < 0.0001), and Myasthenia Gravis Quality of Life (MGQoL15r) scores (MD = -2.18 [95 % CI, -3.35 to -1.00]; P = 0.0003). Serious adverse events were lower with the FcRn inhibitors (32/519) than the placebo (39/397). Subgroup analysis revealed that Rozanolixizumab and Nipocalimab improved MG-ADL scores, but had inferior responder rates. Additionally, Rozanolixizumab significantly improved MGC scores but had more adverse events.

Conclusion: FcRn inhibitors demonstrated good efficacy and safety in MG, with efgartigimod and nipocalimab showing strong efficacy without added risk. Further research is required to evaluate long-term outcomes and optimize treatment.

Keywords: FcRn inhibitors; Myasthenia gravis; Neuromuscular junction; Nipocalimab; Rozanolixizumab.