An update on new and emerging therapies for relapsing-remitting multiple sclerosis.

Disease-modifying therapies (DMTs), known to actively reduce relapses and delay disability progression, have been used for the treatment of relapsing-remitting multiple sclerosis (RRMS) for over a decade. These well-known therapies include intramuscular (IM) interferon (IFN) beta-1a (Avonex), subcutaneous (SC) IFN beta-1a (Rebif), SC IFN beta- 1b (Betaseron; Extavia), and SC glatiramer acetate (Copaxone). These first-line therapies have shown only partial benefits for controlling multiple sclerosis (MS) disease activity and are often associated with inadequate patient adherence. Low patient adherence to therapy may be related to the mode of administration or to the side effects associated with treatment. The intravenous DMT natalizumab (Tysabri; dosed monthly) provides high therapeutic efficacy and good compliance but is considered a second-line intervention because of the associated increased risk for progressive multifocal leukoencephalopathy. In 2010, fingolimod (Gilenya), the first oral DMT, was approved by the US Food and Drug Administration (FDA) for the treatment of MS. Recently, 2 new oral DMTs received FDA approval for the treatment of RRMS: teriflunomide (Aubagio) and dimethyl fumarate (Tecfidera). In addition, oral laquinimod, several monoclonal antibodies (eg, alemtuzumab, daclizumab, and ocrelizumab), and other agents have shown preliminary beneficial results in relapsing MS in phase 3 clinical trials. These new and emerging DMTs may provide a more efficacious individualized therapeutic approach, more favorable methods of administration (eg, oral administration), and/or a lower frequency of infusions (eg, annually, 3-5 daily infusions over a year for alemtuzumab) that may improve patient adherence and clinical outcomes.