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More MS news articles for March 2004

Interferon in relapsing-remitting multiple sclerosis

Updated April 1, 2004
Rice G PA, Incorvaia B, Munari L, Ebers G, Polman C, D'Amico R, Filippini G.
Cochrane Review Abstracts

A substantive amendment to this systematic review was last made on 30 July 2001. Cochrane reviews are regularly checked and updated if necessary.


Recombinant interferons have been shown to suppress both the clinical and magnetic resonance imaging (MRI) measures of disease activity in patients with relapsing remitting multiple sclerosis (RRMS).


The objective of this review was to assess the effects of recombinant interferons in adults with RRMS.

Search strategy:

We searched the Cochrane Multiple Sclerosis Group trials register (searched December 2000), MEDLINE (January 1966 to December 2000), EMBASE (January 1985 to December 2000) and reference lists of articles. We also contacted manufacturers and researchers in the field

Selection criteria:

The trials selected were double-blind, placebo-controlled, randomised trials of RRMS patients who were treated with recombinant interferon, given by the subcutaneous or the intramuscular route.

Data collection and analysis:

All four reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

Main results:

Although seven trials involving 1215 participants were included in this review, only 919 (76%) contributed to the results concerning exacerbations and progression of the disease at two years. Specifically interferon significantly reduced the occurrence of exacerbations (Relative risk [RR] 0.80, 95% confidence interval [CI] 0.73 to 0.88, p < 0.001) and progression of the disease (RR 0.69, 95% CI 0.55 to 0.87, p = 0.002) two years after randomisation. However, the correct assignment of dropouts was essential to the demonstration of efficacy, most conspicuously concerning the effect of the drug on disease progression. If interferon-treated participants who dropped out were deemed to have progressed (worst case scenario) the significance of these effects was lost (RR 1.31, 95% CI 0.60 to 2.89, p = 0.5). The evolution in magnetic resonance imaging (MRI) technology in the decade in which these trials were performed and different reporting of data among trials made it impossible to perform a quantitative analysis of the MRI results. Both clinical and laboratory side effects reported in the trials were more frequent in treated participants than in controls; there was no information after two years of follow-up. The impact of interferon treatment (and its side effects) on the quality of life of patients was not reported in any trial included in this review.

Reviewers' conclusions:

The efficacy of interferon on exacerbations and disease progression in patients with relapsing remitting MS was modest after one and two years of treatment. Longer follow-up and more uniform reporting of clinical and MRI outcomes among these trials might have allowed for a more convincing conclusion.


Rice G PA, Incorvaia B, Munari L, Ebers G, Polman C, D'Amico R, Filippini G. Interferon in relapsing-remitting multiple sclerosis (Cochrane Review). In: The Cochrane Library, Issue 2, 2004. Chichester, UK: John Wiley & Sons, Ltd.

Copyright © 2004, The Cochrane Collaboration