Rituximab as induction therapy in refractory myasthenia gravis: 18month follow-up study.

Abstract

Myasthenia gravis is an immune-mediated disorder characterized by easy fatigability and diurnal variation in skeletal muscle weakness. Aim of therapy is to prevent crisis and maintain remission. However, despite standard therapy, some remain refractory to treatment. To look for efficacy of rituximab in treating refractory myasthenia gravis (MG) in the form of MGFA-PIS score, number of crisis, and dose reduction in immunotherapies. A retrospective study was performed in patients with myasthenia gravis (MG) referred to the All India Institute of Medical Sciences (AIIMS) from January 2012 to December 2017 with follow-up of at least 6 months. Eight refractory MG patients (six AchR positive and two Musk-positive) were identified on oral corticosteroids and azathioprine. After four cycles of rituximab, all patients showed a dose reduction of whom seven were completely tapered off prednisone and there was a 53.8% dose reduction in azathioprine. All patients were continued on AZA after RTX infusion unless contraindicated. Seven achieved minimal manifestation (MM)-2 status as per the MGFA-PIS scale. None of the patients had infusion associated reactions or cytopenia post-RTX infusion. In this small retrospective study, we used RTX as induction therapy and results suggest that repeated RTX infusions may not be necessary as it adds to cost of therapy, especially in LMIC like India.