Eculizumab in refractory myasthenia gravis: a real-world single-center experience.

Introduction: Immunosuppressive treatment is effective in most Myasthenia gravis patients, but 10-15% of patients areconsidered refractory due to inadequate response or intolerance to therapy. Eculizumab, a humanized monoclonalantibody directed against C5 complement protein, was approved in Italy to treat Ab-AchR generalized refractoryMG (rMG) in October 2022.

Aim: We aim to describe a real-world Italian experience in a population of refractory myasthenia gravis patients with oneyear follow up.

Methods: A retrospective data analysis was conducted on patients with refractory generalized MG treated with eculizumabbetween November 2022 and May 2024. Clinical assessment through specific scales (MG ADL - QMG - MGFA -PIS), rescue, and background therapy was recorded after one, three, six, and twelve months.

Results: 21 rMG patients were treated with eculizumab with a medium follow up of 10.4 months and 14 patients had at leastone year follow up. A clinically meaningful reduction in total MG-ADL and QMG scores was achieved in the firstmonth. It was maintained throughout the first, third, sixth, and twelfth month along with concomitant reduction ofimmunosuppressive treatments. A drastic reduction of myasthenic exacerbations and crisis was observed duringfollow up and intravenous immunoglobulin treatment was discontinued in all patients except one. The total dailydose of prednisone was significantly reduced.

Discussion: This single-center real-world study confirmes safety and effectiveness of eculizumab. Eculizumab improved rapidlyall clinical outcome measures, leading to discontinuation of intravenous immunoglobulin treatment and remarkable immunosuppressant-sparing benefits.