Retrospective review of patients with myasthenia gravis switched from plasma exchange therapy to efgartigimod treatment.

INTRODUCTION/AIMS: Therapeutic plasma exchange (TPE) is sometimes used as maintenance therapy for the treatment of myasthenia gravis (MG). Efgartigimod is a newly approved monoclonal antibody targeting the neonatal Fc receptor, effectively reducing immunoglobulin G levels in the treatment of MG. The aim of this study was to describe the clinical experience of switching patients from maintenance TPE treatment to efgartigimod infusions.

METHODS

A retrospective review of medical records was performed on patients previously treated with maintenance TPE for the diagnosis of MG and subsequently switched to efgartigimod infusions. Clinical characteristics and response to treatment switch were described.

RESULTS

Five of seven patients demonstrated improvement on Myasthenia Gravis Foundation of America-post intervention status, one was unchanged and one was in pharmacological remission. This was reflected in pre- and postswitch MG activities of daily living and MG manual muscle testing scores. All patients have continued on efgartigimod therapy. The duration of treatment with efgartigimod at the time of this review ranged from 1 to 13 months. Recurrent uncomplicated infections were noted in two patients on efgartigimod therapy. Maintenance dosing regimens of efgartigimod varied based on clinical response to treatment and side effects.

DISCUSSION: In this series, efgartigimod appeared effective and well tolerated in patients switched from TPE.