Experience Using Efgartigimod to Treat Juvenile Myasthenia Gravis in China: A Multicenter Retrospective Study

Current therapeutic management of juvenile myasthenia gravis (JMG) predominantly relies on conventional immunosuppressive therapies and expert consensus extrapolated from adult data, creating a critical gap in high-quality, pediatric-specific clinical evidence. The aim of this study was to assess the efficacy and safety of efgartigimod in the pediatric population.

This multicenter retrospective study enrolled JMG patients (under 18 years), from 12 Chinese centers, who received at least one dose of efgartigimod. Efgartigimod was administered as weekly intravenous infusions. Study visits included W0 (baseline: pretreatment) and W1-W4 (weekly posttreatment follow-ups). Efficacy was assessed via MG-related Activities of Daily Living (MG-ADL) score, Quantitative Myasthenia Gravis (QMG) score, and the MG Composite (MGC) scale.

Seventeen JMG patients (3 males, 14 females) with a median disease duration of 23 months were included. At W0, 88.2% of patients were classified as Myasthenia Gravis Foundation of America (MGFA) class II-V and were anti-acetylcholine receptor (anti-AchR) antibody positive. After efgartigimod treatment, clinically meaningful improvement (CMI) was observed in 70.6% (W1), 73% (W2), and 91.7% (W4); 66.7% achieved minimal symptom expression by W4. MG-ADL and QMG scores decreased by 30% and 30.1% (W1) and by 87.6% and 71.8% (W4) compared to W0. No treatment-related adverse events occurred.

Our study suggests efgartigimod is an effective therapeutic option for JMG, with favorable efficacy and safety profiles. Further studies are necessary to validate the efficacy and safety of efgartigimod in the pediatric population.