Advances and challenges in the treatment of myasthenia gravis.

Myasthenia gravis (MG) is a chronic autoimmune disease with fluctuating muscle weakness and fatigability. Standard immunomodulatory treatment may fail to achieve sufficient improvement with minimal symptom expression or remission of myasthenic symptoms, despite adequate dosing and duration of treatment. Treatment-resistant MG poses a challenge for both patients and treating neurologists and requires new therapeutic approaches. The spectrum of upcoming immunotherapies that more specifically address distinct targets of the main immunological players in MG pathogenesis includes T-cell directed monoclonal antibodies that block the intracellular cascade associated with T-cell activation, monoclonal antibodies directed against key B-cell molecules, as well as monoclonal antibodies against the fragment crystallizable neonatal receptor (FcRn), cytokines and transmigration molecules, and also drugs that inhibit distinct elements of the complement system activated by the pathogenic MG antibodies. The review gives an overview on new drugs being evaluated in still ongoing or recently finished controlled clinical trials and drugs of potential benefit in MG due to their mechanisms of action and positive effects in other autoimmune disorders. Also, the challenges associated with the new therapeutic options are discussed briefly.