A retrospective study was performed in adult patients with refractory generalized MG referred to our center from January/2015 to October/2020 with a follow-up of at least 24 months. Anti-acetylcholine receptor (AChR) and anti-muscle-specific kinase (MuSK) autobodies were analyzed. The Myasthenia Gravis Status and Treatment Intensity (MGSTI) score was used to assess outcomes, and CD19/CD20+ B-cell counts were serially monitored.

Sixteen MG patients (13 = female; mean age = 45 years) treated with RTX were included. They were previously studied with autoimmune antibodies (AChR = 8 and MuSK = 8), and presented a median MGFA score of 4A-B. Patients were undergoing treatment with 2 immunosuppressants and they had received at least one cycle of intravenous immunoglobulin (10 requiring intensive care). Low-dose RTX protocols were used during induction (7 = 2000 mg, 7 = 1000 mg and 2 = 1500 mg), and only 5 patients received maintenance doses. During follow-up, all patients maintained undetectable CD20 levels at 6 and 12 months after induction, without new relapses. All patients presented MGFA-PIS and MGSTI scores ≤2; the earlier the treatment with RTX was initiated, the faster the score was reached.