Re: Hutchinson M, Fox RJ, Havrdova E, et al. Efficacy and safety of BG-12 (dimethyl fumarate) and other disease modifying therapies for the treatment of relapsing-remitting multiple sclerosis: a systematic review and mixed treatment comparison. Curr Med Res Opin 2014;30:613-27

Dimethyl fumarate in the management of multiple sclerosis: appropriate patient selection and special considerations

Delayed-release dimethyl fumarate (DMF), also known as gastroresistant DMF, is the most recently approved oral disease-modifying treatment (DMT) for relapsing multiple sclerosis. Two randomized clinical trials (Determination of the Efficacy and Safety of Oral Fumarate in Relapsing-Remitting MS [DEFINE] and Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis [CONFIRM]) demonstrated significant efficacy in reducing relapse rate and radiological signs of disease activity, as seen on magnetic resonance imaging. The DEFINE study also indicated a significant effect of DMF on disability worsening, while the low incidence of confirmed disability worsening in the CONFIRM trial rendered an insignificant reduction among the DMF-treated groups when compared to placebo. DMF also demonstrated a good safety profile and acceptable tolerability, since the most common side effects (gastrointestinal events and flushing reactions) are usually transient and mild to moderate in severity. Here, we discuss the place in therapy of DMF for individuals with relapsing multiple sclerosis, providing a tentative therapeutic algorithm to manage newly diagnosed patients and those who do not adequately respond to self-injectable DMTs. Literature data supporting the potential role of DMF as a first-line therapy are presented. The possibility of using DMF as switching treatment or even as an add-on strategy in patients with breakthrough disease despite self-injectable DMTs will also be discussed. Lastly, we argue about the role of DMF as an exit strategy from natalizumab-treated patients who are considered at risk for developing multifocal progressive leukoencephalopathy.

Appropriate use of information in therapeutic decision-making: reflections on indirect comparisons

Although the statistical strength of direct comparative randomized controlled trials is generally acknowledged, the particular demands of therapeutic decision making will often require indirect comparisons to be made, based on pooled data from multiple trials. As for all post-hoc analyses, the process of indirect comparison runs the risk of introducing significant bias into the results and consequently a robust statistical approach is required, in order to minimise the risk. To address this problem, a range of different methodologies have been developed over the past twenty years, using both frequentist and Bayesian models. It is important to appreciate the strengths and limitations of these techniques: however, the technical complexities tend to make this type of analysis somewhat opaque to the non-specialist reader. In this article, we consider the use of a simple, non-specialist critical appraisal tool developed by ISPOR, which allows methodological and interpretive errors to be identified and flagged as potential sources of bias, even when the detailed statistical methodology is not well understood by the reader.