Natalizumab: a guide to its use in relapsing–remitting multiple sclerosis
The humanized monoclonal antibody natalizumab (Tysabri®) is the first targeted therapy to be approved for the treatment of relapsing–remitting multiple sclerosis (RRMS). The annualized relapse rate, the risk of sustained progression of disability and the number of T2-hyperintense and gadolinium-enhancing lesions on magnetic resonance imaging were significantly lower with intravenous natalizumab than with placebo at 2 years in patients with RRMS in a phase III trial. In addition, treatment with natalizumab was generally associated with improved health-related quality of life and was well tolerated. Progressive multifocal leukoencephalopathy (PML) is an uncommon complication of treatment with natalizumab. As long as the risk of PML is managed effectively, natalizumab is a valuable therapeutic option for adults with highly active relapsing forms of MS.