Interferon beta and multiple sclerosis: look at the evidence.

Recent advances in therapy for multiple sclerosis (MS) have centred on the use of the disease-modifying drugs glatiramer acetate (GA) and interferon (IFN) beta. Several large-scale clinical trials have been carried out on the use of these compounds, but there have been few studies that have directly compared their efficacy in MS. Furthermore, there has been controversy and confusion over the IFN beta therapy regimen that will achieve the best possible clinical outcome for MS patients. This review focuses principally on clinical trials of IFN beta-1a, where data that allow direct comparison of different treatment regimens are now available. Current data indicate that IFN beta, and in particular IFN beta-1a, has important advantages over GA in the treatment of relapsing-remitting MS (RRMS). Additionally, IFN beta-1a (Rebif, Serono), 44 microg administered subcutaneously (s.c.) three times weekly (t.i.w.), is significantly more effective than IFN beta-1a (Avonex, Biogen), 30 microg administered intramuscularly once weekly. For optimal management of RRMS, treatment with IFN beta-1a, 44 microg s.c. t.i.w., should begin as early as possible after diagnosis.