Alemtuzumab is a selective humanized monoclonal antibody directed against the CD52 antigen, and has been found to be a powerful treatment for relapsing remitting multiple sclerosis. Alemtuzumab demonstrated high efficacy in several clinical studies. The risk of relapse and sustained accumulation of disability showed significant reduction in the Phase II CAMMS223 and the Phase III clinical trials CARE MS I and CARE MS II. The data presented at the 32nd Congress of the European Committee for Treatment and Research in Multiple Sclerosis confirmed these results. After completion of a 1-year treatment cycle, alemtuzumab showed a sustained effect. Although the efficacy of alemtuzumab has been widely proven, several severe adverse effects have been reported with its use. Infusion-associated reactions, increased risk of infections, and secondary autoimmunity have been associated with alemtuzumab. Autoimmune disease – mainly of the thyroid – has been reported. Immune thrombocytopenic purpura and autoimmune nephropathies have been observed less frequently. These adverse effects, given the short period of alemtuzumab marketing for relapsing remitting multiple sclerosis, require strict monitoring.

In the therapeutic scenario of disease-modifying therapies for relapsing–remitting multiple sclerosis, the introduction of oral agents, starting in 2010 with fingolimod, has been a huge step forward in therapeutic options due to the easier administration route. Three oral drugs fingolimod, teriflunomide, and dimethyl fumarate, which are clinically approved for the treatment of relapsing–remitting multiple sclerosis, are reviewed in this work. Results of Phase III clinical trials and their extension studies showed that the three oral agents significantly reduced the annualized relapse rate – a superior efficacy compared to placebo. Fingolimod 0.5 mg consistently reduced clinical relapses and brain volume loss. In all Phase III studies, teriflunomide 14 mg dose showed a reduction in the risk of disability accumulation. Regarding safety profile, fingolimod had more safety issues than the other two agents. For this reason, it should be strictly monitored for risks of infections, cancers, and certain transitory effects such as irregular cardiac function, decreased lymphocyte count, and a higher level of liver enzymes. Adverse effects of teriflunomide are well characterized and can be considered manageable. The main risks marked with dimethyl fumarate were flushing and gastrointestinal events.