Real-world use of efgartigimod in acetylcholine receptor antibody-positive generalized myasthenia gravis: experience from two centers in Greece and Cyprus.

INTRODUCTION

Efgartigimod, an FcRn antagonist that reduces circulating immunoglobulin G (IgG), is approved for the treatment of acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG). While its efficacy has been demonstrated in randomized clinical trials, real-world data describing longitudinal use and management of efgartigimod in routine clinical practice are still emerging.

METHODS

We conducted a retrospective observational study across two neuromuscular referral centers, including adults with AChR antibody-positive gMG treated with intravenous efgartigimod between April 2023 and August 2025. Treatment was initiated across a range of real-world clinical scenarios, including refractory disease, non-crisis symptom relapse, corticosteroid tapering, maintenance of minimal-symptom expression, and bridging before thymectomy or initiation of conventional immunosuppression. Retreatment intervals were individualized based on clinical course. Clinical outcomes, corticosteroid use, serological markers, adjunctive therapies, and safety events were analyzed descriptively.

RESULTS

Thirteen patients received a total of 52 efgartigimod treatment cycles. Most patients experienced repeated improvement in MG-Activities of Daily Living (MG-ADL) during treatment cycles, although clinical status varied over time. Corticosteroid doses were reduced in the majority of patients during follow-up. Episodes of clinically significant worsening occurred outside the setting of myasthenic crisis and were managed with established rescue therapies, after which efgartigimod could often be resumed. Treatment was generally well tolerated.

CONCLUSION

This study describes how efgartigimod is integrated into routine clinical practice as part of longitudinal disease management for AChR antibody-positive gMG. Real-world use encompassed diverse clinical scenarios and required individualized retreatment decisions and ongoing reassessment. These findings highlight the role of FcRn blockade as a flexible therapeutic option that complements established therapy in everyday care.