Efgartigimod in refractory autoimmune myasthenia gravis

Area of Science:

• Neurology
• Immunology
• Pharmacology

Background:

• Myasthenia gravis (MG) is a rare autoimmune disorder affecting neuromuscular junctions.
• Efgartigimod, a neonatal Fc-receptor inhibitor, offers a novel therapeutic approach for MG.
• Refractory MG cases present ongoing challenges in treatment efficacy.

Purpose of the Study:

• To evaluate the short- and long-term effectiveness of efgartigimod in patients with refractory MG.
• To assess clinical outcomes using standardized MG assessment tools.

Main Methods:

• Retrospective cohort study of 16 patients with refractory autoimmune acetylcholine receptor MG.
• Treatment with efgartigimod between January 2021 and March 2023.
• Data collected on MG-ADL, QMG, MGC, and MG-QoL15r scores.

Main Results:

• 56% of patients showed favorable outcomes at the last measurement.
• Clinically meaningful improvements observed in MG-ADL, QMG, and MGC scores by week 4.
• Significant improvement in MG-QoL15r from baseline to week 4, maintained long-term.
• Reduced need for concurrent medications (prednisolone, azathioprine, IVIg) and plasma exchange in most patients.

Conclusions:

• Efgartigimod demonstrated effectiveness in at least half of patients with refractory MG.
• Concurrent medication reduction or discontinuation was achieved in 80% of patients.
• Higher dosing frequency was required compared to the ADAPT phase 3 trial.