Glatiramer acetate: a review of its use in patients with relapsing-remitting multiple sclerosis and in delaying the onset of clinically definite multiple sclerosis.

Glatiramer acetate (Copaxone(®)) is a synthetic analogue of the multiple sclerosis (MS)-associated antigen, myelin basic protein. Although its exact mechanisms of action in MS remain to be fully elucidated, the key mechanisms of action of glatiramer acetate appear to be modulation of the inflammatory response and neuroprotective and/or neuroregenerative effects. Subcutaneous glatiramer acetate is indicated for the treatment of adult patients with relapsing-remitting MS (RRMS) and the treatment of patients who have experienced a well-defined first clinical episode and have magnetic resonance imaging (MRI) features consistent with MS or have been determined to be at high risk of developing clinically definite MS (CDMS). In clinical trials in patients with RRMS, glatiramer acetate reduced the frequency of relapses and reduced the burden and activity of disease on MRI, was more effective than placebo and showed generally similar efficacy to subcutaneous interferon (IFN) β-1a and IFNβ-1b. Furthermore, the beneficial effects of glatiramer acetate were sustained during up to 15 years of treatment in an extension study. In patients with clinically isolated syndrome (CIS), glatiramer acetate significantly delayed the onset of CDMS compared with placebo. The drug was generally well tolerated in these patient populations, with injection-site reactions being the most commonly occurring adverse events. Therefore, glatiramer acetate remains a valuable first-line option in the treatment of RRMS and is an option for delaying the onset of CDMS in patients with CIS.