New treatments for multiple sclerosis

Abstract

Encouraging progress has been made in the development of treatments that reduce disease activity in multiple sclerosis. The relation between disability and such activity (as reflected in the relapse rate or the appearance of new lesions on magnetic resonance imaging) is complex, but recent evidence suggests that it may be possible to delay, though not yet abolish, the progress of irrecoverable neurological deficit. The results of three large randomised controlled trials in ambulant patients with little or moderate disability have been announced during the past 18 months. Only one has been fully reported in the medical literature,1 but two others were widely discussed at a joint meeting of the American Neurological Association and the Association of British Neurologists held last October. Because much uncertainty exists about the potential role of these very expensive treatments it is important that the present position is clearly understood. In the review that follows, the figures for the two recent reports have been derived from information provided by the sponsors of the trials2 3; the data on which the conclusions of these two studies are based have yet to be subjected to peer review. In a trial of interferon beta-1b 372 patients with relapsing and remitting disease were allocated to placebo or a low dose (1.6 MIU) or high dose (8 MIU) of the drug, which was given by subcutaneous injection on alternate days. After two years the relapse rate (the primary end point) was significantly lower in patients receiving the high dose than in those receiving placebo (1.27/year …