Long-term follow-up of patients with myasthenia gravis treated with low-dose rituximab

Myasthenia gravis (MG) is a disease of the neuromuscular junction, usually caused by an autoimmune process associated with antibodies against the acetylcholine receptor (AChR) or muscle-specific kinase (MuSK). Rituximab (RTX), a monoclonal antibody targeting CD20, has emerged as a potential treatment in the management of MG, in particular for MuSK positive patients.1 2 Most (80%) patients received 375 mg/m2 of RTX per week for 4 weeks, with lower doses being infrequently reported. We previously reported on our experience with low-dose RTX in the treatment of MG3 and now report our long-term experience from an enlarged cohort. We identified retrospectively all patients with MG treated with RTX between May 2006 and July 2017 in South East Queensland, Australia. Cases were identified via review of pharmacy and hospital records as well as by direct contact with the treating neurologists. The clinical states of patients were scored using the Myasthenia Gravis Association of America (MGFA) Clinical Research Standards. Disease severity and concurrent therapies were documented through review of medical records (Timepoints: Diagnosis, RTX treatment, 3-monthly for the first year, annually thereafter). Wilcoxon ranked test was used to assess difference in steroid doses. ### Patient characteristics A total of 38 patients were treated (AChR: 28 patients (74%, female:male (F:M)=18:10), MuSK: six patients (16%, F:M=4:2), antibody negative four patients (10%, all female)). The mean age at initial treatment was 51.5 (range 22–87 years) with mean disease duration prior to …