Development of interferon-beta as a therapy for multiple sclerosis.

The introduction of interferon (IFN) therapy represents a milestone in multiple sclerosis (MS) treatment. This class of drugs is part of an evolving area of MS therapy that utilises immunomodulating agents to alter the immune processes thought to be integral to the development of MS. IFN-beta has been developed in three different formulations that have proven benefit in reducing exacerbations in relapsing-remitting MS. Two of the formulations consist of the naturally-occurring amino acid sequence of IFN-beta and are referred to as IFN-beta(1a). One is delivered intramuscularly (IM IFN-beta(1a)), and the second form of IFN-beta(1a) is delivered subcutaneously (SC IFN-beta(1a)). The third formulation of IFN-beta, known as IFN-beta(1b), consists of a modified amino acid sequence containing a cysteine to serine mutation at amino acid 17 and a deletion of the amino terminal methionine. This review describes the evolution of IFNs as therapeutics for MS.