Abstract
INTRODUCTION: High-dose intravenous methylprednisolone (IVMP) is effective in treating generalized myasthenia gravis (gMG), but early-stage transient aggravation and MG crisis can occur. This study evaluated the safety and efficacy of efgaitigimod in combination with different doses of IVMPs in patients with severe gMG. METHODS: This was a single-center, retrospective cohort study that retrospectively collected patients with myasthenia gravis who presented to Hebei Myasthenia Gravis Diagnosis and Treatment Center from December 2023 to May 2024, divided into IVMP monotherapy (1000 mg, Group A, n = 20) or efgartigimod combined with IVMP: 1000 mg (Group B, n = 7), 500 mg (Group C, n = 10), or 250 mg (Group D, n = 20). Patients received efgartigimod (10 mg/kg) intravenously on days 1 and 8 while receiving IVMP. Efficacy was assessed via quantitative myasthenia gravis (QMG) scores at baseline, week 2, and week 12. RESULTS: Groups A, C, and D demonstrated progressive QMG reductions over 12 weeks. Group B showed a week 12 QMG rebound (vs. week 2) but remained below baseline. At week 2, Group A had significantly less QMG improvement than Group B (p = 0.004), which was not different from group C/D. After 12 weeks, no significant difference was found among the groups (p = 0.639). Transient exacerbations and adverse events were significantly higher in Group A versus C/D. CONCLUSION: Efgartigimod combined with 250 mg IVMP is associated with improvement of symptoms, reduction of transient exacerbations, and adverse event rates compared with higher IVMP doses or IVMP monotherapy, offering a promising regimen for severe gMG. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Chictr2400080921).