Prompt initiation of interferon beta-1b (BetaseronR) at the onset of suspected multiple sclerosis (MS) translates into less progression to chronic neurologic disability compared with delayed treatment, researchers announced at the 59th Annual Meeting of the American Academy of Neurology (AAN).

Mark S. Freedman, MD, Director of the Multiple Sclerosis Research Unit at University of Ottawa in Ottawa, Canada, reported that prompt initiation of interferon beta-1b treatment in patients with a first event suggestive of MS was associated with a significant 40 percent reduced likelihood of chronic neurological impairment as measured by the Expanded Disability Status Scale (EDSS) over three years. The EDSS is an established scale for quantifying disability in MS.

"Some patients already have evidence of significant neurological damage when they initially present with MS, which may set the stage for significant disability later on," Dr. Freedman, who is also professor of neurology, observed. "We have shown for the first time that immediate treatment after a first clinical demyelinating event suggestive of MS can reduce the early neurological damage, which may ultimately delay the development of the debilitating sequelae that characterize advanced MS."

The results are from a follow-up of patients enrolled in the Betaseron in Newly Emerging Multiple Sclerosis for Initial Treatment (BENEFIT) trial. The study is the first prospective, placebo-controlled, multi-center investigation to test the impact of randomly assigned early versus delayed initiation of interferon beta therapy at the time of a clinically isolated syndrome (CIS) on further evolution of MS.

Overall, 468 patients with a first clinically demyelinating event suggestive of MS and typical magnetic resonance imaging (MRI) were treated with interferon beta-1b 250 mcg or placebo subcutaneously every other day until either a diagnosis of clinically definite MS was established or they reached two years of evaluation. At this time-point, they were eligible to enter an open-label, follow-up study and were offered interferon beta-1b for up to five years after the start of double-blind treatment.

At three-year follow-up, patients who initiated interferon beta-1b treatment early were 41 percent less likely to progress to clinically definite MS than patients who delayed the start of treatment.

"Formerly, I wasn't convinced of the absolute need for starting treatment immediately following the first attack in the majority of patients," Dr. Freedman said. "Like many physicians, I preferred to wait until patients met diagnostic criteria for MS before starting therapy."

He added: "Based on these data, there is no longer a rationale for withholding therapy, especially given the long-established safety record of a drug like interferon beta-1b."

The study was sponsored by Bayer Healthcare.

Written by: Jill Stein
Jill Stein is a Paris-based medical writer.
Jillstein03@cs.com