Clinical trials in CIDP and chronic autoimmune demyelinating polyneuropathies

Abstract

The main chronic autoimmune neuropathies include chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and anti-myelin-associated glycoprotein (MAG) demyelinating neuropathy. On the basis of randomized controlled studies, corticosteroids, intravenous immunoglobulin (IVIg), and plasmapheresis provide short-term benefits in CIDP. MMN responds only to IVIg. Because in MMN and CIDP, IVIg infusions are required every 3-6 weeks to sustain benefits or long-term remissions, there is a need for "IVIg-sparing" agents. In CIDP, immunosuppressive drugs, such as azathioprine, cyclosporine, methotrexate, mycophenolate, and cyclophosphamide, are used, but controlled trials have not shown that they are effective. Controlled trials have also not shown benefit to any agents in anti-MAG neuropathy. However, clinicians use many immunosuppressive drugs in both settings, but all have potentially serious side effects and are only effective in some patients. Thus, there is a need for new therapies in the inflammatory and paraproteinemic neuropathies. New agents targeting T cells, B cells, and transmigration and transduction molecules are discussed as potential treatment options for new trials. The need for biomarkers that predict therapeutic responses or identify patients with active disease is emphasized, and the search for better scoring tools that capture meaningful changes after response to therapies is highlighted.