Rituximab for the Treatment of Thymoma-Associated and De Novo Myasthenia Gravis: 3 Cases and Review

Myasthenia gravis (MG) is an immune-mediated disorder associated with autoantibodies against postsynaptic nicotinic acetylcholine receptors at neuromuscular junctions. Rituximab, a monoclonal antibody specific for CD20, is used primarily to treat B-cell non-Hodgkin lymphoma. Although it has been used for treatment of a number of autoimmune diseases, there is limited experience in MG.Three patients with refractory MG (2 with concurrent thymoma) were given rituximab.Symptoms stabilized and reductions in immunosuppressive medications were tolerated for extended periods, without adverse effects or infectious complications.These observations support the concept that rituximab may be helpful for the treatment of MG. Remissions in patients with or without thymoma are achievable with rituximab given in combination with commonly used modalities. Furthermore, rituximab is not necessarily contraindicated for the treatment of MG in patients being treated for thymoma. Controlled studies are called for to define its role in the treatment of refractory MG.