Immunosuppressive treatments in multiple sclerosis

Multiple sclerosis (MS) is a heterogeneous autoimmune disorder of the central nervous system that is enigmatic, relapsing, and in some instances progressive. Prior to the discovery, study, and utilization of the US Food and Drug Administration (FDA)-approved disease-modifying therapies (i.e., interferon class of medications or glatiramer acetate), and even before the advent of magnetic resonance imaging technology as a diagnostic or clinical surveillance tool, immunosuppressive treatments served as essential medical therapy for patients with MS. Currently, immunosuppressive agents are being utilized as monotherapy or in combination with parenterally administered immunomodulators for those who are suboptimal responders, are intolerant or experience adverse reactions to disease-modifying treatments, or for patients who exhibit an aggressive disease course. This chapter focuses on the most widely used immunosuppressive treatments in MS: cyclophosphamide, methotrexate, azathioprine, mycophenolate mofetil, and the only FDA-approved chemotherapeutic agent for the treatment of MS, mitoxandrone. Seminal data regarding its use in MS, the known mechanism(s) of action, and contemporary studies focusing on efficacy and safety data will be reviewed. The role of these chemotherapeutic agents in the management of MS and implications for therapeutic intervention are also discussed.