Efficacy and Safety of Efgartigimod for Patients With Myasthenia Gravis in a Real‐World Cohort of 77 Patients

Abstract

AIMS: Efgartigimod, a first-in-class neonatal Fc receptor antagonist, is approved for generalized myasthenia gravis (gMG). Its safety and efficacy across MG subtypes remain unclear. METHODS: This single-center real-world study (September 2023-July 2024) analyzed patients from an MG registry study in China. The primary efficacy outcome is the mean MG-ADL score changes from baseline at weeks 4, 8, and 12, analyzed via generalized estimating equations. Safety was assessed by adverse events. RESULTS: Among 77 patients (mean age 56.1 ± 15.2 years; 59.7% male), 76 completed at least one treatment cycle (20 completed 2 cycles; 1 completed 3 cycles). After efgartigimod treatment, MG-ADL scores decreased significantly by week 4 (mean difference -6.4, 95% CI -7.2 to -5.6, p < 0.001), sustaining through week 12 (-6.9, -7.8 to -6.1, p < 0.001). After the second cycle, MG-ADL scores at week 12 trended lower than the first cycle (mean difference: -0.8, 95% CI: -2.0 to -0.5, p = 0.061). Efficacy was consistent across MGFA classes and thymoma status. In refractory patients, efgartigimod reduced MG-ADL scores (p < 0.001). Adverse events occurred in 3.9% (3/77). CONCLUSION: Efgartigimod safely improved MG-ADL scores and reduced steroid use across MG subtypes, with sustained efficacy through multiple treatment cycles. These findings support its potential when conventional therapies fail.