Efgartigimod Is an Effective Treatment for Triple-Seronegative Generalized Myasthenia Gravis: A Report of Three Patients.

Introduction/aims: Efgartigimod has been approved for treating acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR-Ab+ gMG). The aim of this study was to report the therapeutic effect of efgartigimod in three patients with triple-seronegative (triple-SN) gMG.

Methods: The medical records of three patients with triple-SN gMG who received efgartigimod at a dose of 10 mg/kg weekly for four consecutive weeks (one treatment cycle) were retrospectively reviewed. The patients were evaluated using the quantitative MG (QMG) score and the MG activities of daily living (MG-ADL) scale.

Results: The first patient, who was refractory to conventional immunosuppressive therapies, demonstrated symptom improvement with a QMG reduction of 20 and an ADL reduction of 10 points following efgartigimod therapy. The second patient with a QMG score of 26 and an ADL score of 19, who showed a poor response to immunoglobulin therapy, achieved rapid symptom control after two cycles of efgartigimod treatment by week 10 (QMG: 2, ADL:1). The third patient, diagnosed with MG acute exacerbation (QMG: 6, ADL:5), responded favorably to efgartigimod therapy by week 4 (QMG:0, ADL:0).

Discussion: These patient reports provide preliminary evidence supporting the effectiveness of efgartigimod as a potential alternative treatment for patients with triple-SN gMG who do not respond adequately to traditional therapies. However, multicenter randomized controlled trials are necessary to further evaluate the efficacy and safety of efgartigimod in this patient population.