By Richard Robins
LONDON, ENGLAND -- June 22, 2001
-- High-dose interferon beta-1a decreases the relapse rate in multiple
sclerosis compared to standard dosing, according to a study presented at
the 17th World Congress of Neurology in London, June 17-22 2001.
The study was the first head-to-head
comparison between two brands of interferon beta-1a, Rebif, dosed at 44
mcg three times weekly by subcutaneous injection, and Avonex, dosed at
30 mcg once weekly by intramuscular injection. Unlike Avonex, Rebif is
not available in the United States and this FDA-approved trial is meant
to position the drug for approval prior to the expiration of Avonex's orphan
drug status in 2003.
Lead investigator Patricia Coyle,
Professor of Neurology at the School of Medicine, Stony Brook, New York,
outlined the trial and presented the results. She and colleagues in nine
countries enrolled 677 patients with relapsing-remitting MS, including
440 in the USA. Patients had to be interferon-naive, with at least two
relapses in the past two years. Assessments included biweekly patient interview
to determine occurrence of relapse, the primary endpoint of the study,
as well as monthly MRI scans. While patients knew which drug they were
receiving, assessing physicians did not.
After six months, 75 percent of Rebif
patients and 63 percent of Avonex patients remained relapse-free, a difference
significant at the p=0.0005 level, Dr. Coyle reported. The average number
of relapses for the study period was also significantly fewer for Rebif,
with 0.29, versus 0.40 for Avonex. MRI activity was correlated with these
outcomes, with about one half of Rebif patients, and one third of Avonex
patients, showing no new disease activity during the study.
Correlated with the increased number
of injections, Rebif patients had more injection-site reactions and elevated
liver enzymes. Ninety-five percent of all patients completed the study,
however, with no significant difference between the two treatments.
Based on the strength of these study
results, Dr. Coyle said, the manufacturer, Serono Laboratories, will be
submitting the data to the FDA in an effort to gain approval for marketing
Rebif in the United States.
Special to DG News