The present efficacy of multiple sclerosis therapeutics

Abstract

A challenge for the clinician treating patients with multiple sclerosis (MS) is to determine the most effective treatment while weighing the benefits and risks. Results of the phase 2 and phase 3 studies on natalizumab were received with great interest, in part due to the “improved” risk reduction for relapse rate, disease progression, and MRI metrics observed in comparison to results in trials of beta-interferon and glatiramer acetate. However, comparison across trials is invalid, in large part due to differences in the study populations. The increased efficacy observed in more recent trials has also been attributed to a fundamental change in subjects with MS enrolled in recent trials compared with the prior decade. In this article, we debate the relative efficacy of natalizumab vs the older injectable therapies. ARR=absolute risk reduction; CIS=clinically isolated syndrome; DMT=disease-modulating therapy; EDSS=Expanded Disability Status Scale; FDA=Food and Drug Administration; GA=glatiramer acetate; IFN=interferon; MS=multiple sclerosis; NNT=number needed to treat; PML=progressive multifocal leukoencephalopathy; RRMS=relapsing-remitting MS; RRR=relative risk reduction.