Therapeutic developments in multiple sclerosis.

Abstract

Recently there have been considerable advances made in the treatment of multiple sclerosis. For the first time since its initial clinical description in the 1800s, there are now available several medications which unequivocally exert favourable clinical effects through the lowering of the biological activity of the human illness. The therapeutic efficacy of IFN-beta preparations seems particularly well established in this regard on the basis of five large, independent, trials of this agent. These trials have demonstrated remarkably consistent reductions in both attack rates and disability levels using a combination of clinical and magnetic resonance imaging outcome measures. The therapeutic benefit of glatiramer acetate also has been well established, although there is less available data on this agent than there is for interferon. It is important to recognise, however, that, although these agents represent an important first step in the management of patients with multiple sclerosis, they are only partial therapies. In order to actually cure the illness or even to substantially improve patient outcome we need considerably better agents than we have currently. Nevertheless, it is likely that, with improved knowledge of the role that interferon beta plays in the pathogenesis of multiple sclerosis and with better understanding of the mechanism by which glatiramer acetate exerts its therapeutic effect, greatly improved therapeutic agents will be available in the future. In addition, it seems likely that, in the future (by analogy to the experience in oncology), we will begin utilising combinations of therapies in order to better control the biological activity of this debilitating disease. Such combination therapy will almost certainly include combinations of partially effective agents as well as combinations of these agents with other medications (e.g., the immunosuppressive drugs) which, by themselves, have only been demonstrated to exert marginal clinical benefits on the course of illness. Moreover, it also seems likely that, increasingly, therapeutic strategies that enhance or promote myelin repair will become a major focus of clinical research in this area.