Long-term β interferon in MS: safe, but what effect on disability?
- Correspondence to Professor Neil J Scolding, University of Bristol Institute of Clinical Neurosciences, Department of Neurology, Frenchay Hospital, Bristol BS16 1LE, UK; n.j.scolding{at}bristol.ac.uk
- Received 24 February 2010
- Accepted 24 February 2010
- Published Online First 22 June 2010
Multiple sclerosis (MS) affects around 2.5 million people worldwide. It costs the European economy some €9 billion annually—not least through the direct and indirect consequences of progressive disability in sufferers. MS has been known since its first description to cause such disability, notwithstanding the defining (usual) relapsing-remitting initial course. Over 80% of MS patients develop progressive disease; 40% of patients require a wheelchair within 10 years of diagnosis.
Until perhaps the last decade or so, therapeutic research has concentrated almost exclusively on immune treatments aiming to reduce relapse frequency, the explicit or implicit assumption, or hope, being that relapse prevention would reduce or limit progressive disability. In terms of the first aim, these efforts were not in vain. β interferons and glatiramer acetate both reduce relapse frequency by 20–30%, the newer oral agents fingolimod and cladribine, whose licensing appears imminent, by perhaps 50–60%, and the monoclonal antibodies natalizumab and alemtuzumab (the former already licensed) …
