NEW YORK (Reuters Health) – Early initiation of interferon beta-1b therapy delays the development of confirmed disability in patients with multiple sclerosis (MS), according to a report in the August 4th issue of The Lancet.

The results stem from a 3-year follow-up analysis of the Betaferon/Betaseron in Newly Emerging multiple sclerosis For Initial Treatment (BENEFIT) study.

In the initial phase, patients with a first event suggestive of MS and with at least two silent lesions on MRI were randomized to receive interferon beta-1b or placebo every other day for 2 years or until they had been diagnosed with clinically definite MS. At that point, the subjects could enter an open-label interferon phase.

The current analysis focused on whether immediate treatment with interferon provided better outcomes than delayed treatment. Of the 468 patients in the original randomization group, 392 entered the follow-up phase and had 3 years of data available for analysis.

The percentage of patients developing clinically definite MS in the immediate treatment group was 37%, significantly lower than the 51% seen in the delayed treatment group, lead author Dr. Ludwig Kappos, from University Hospital in Basel, Switzerland, and colleagues report.

Similarly, early treatment was associated with a 40% reduced risk of progression to confirmed disability: 16% with early treatment vs. 24% with delayed treatment.

The researchers "present the first evidence that interferon beta-1b treatment has a beneficial effect on accumulation of confirmed disability in patients with a first event suggestive of multiple sclerosis," Dr. Sean J. Pittock, from the Mayo Clinic in Rochester, Minnesota, comments in a related editorial.

"The results should, however, be interpreted with care because the magnitude of benefit, although statistically significant, is clinically small. This follow-up should not be misconstrued as evidence for a treat-all approach," he emphasizes.

Lancet 2007;370:363-364,389-397.

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