Updated 7:48 PM ET May 8, 2001
NEW YORK (Reuters) - German drug maker Schering AG Tuesday released results of a study suggesting that its multiple sclerosis drug, Betaseron, is more effective than a rival drug, Biogen Inc.'s Avonex.
The study, conducted by Italian researchers, tested 188 patients at 6-month intervals and showed that the results between six and 12 months after the initial treatments favored Betaseron.
While 84 percent of patients on Betaseron were free of relapses of the disease, 72 percent of patients on Avonex showed no recurrences.
The trial results also state that patients on Betaseron exhibited less damage to the brain than patients on Avonex as tracked by magnetic resonance imagining, or MRI, tests.
Multiple sclerosis is a nerve disorder that can cause tingling, numbness, weakness and trembling in the arms, legs, body or face. Avonex is the top-selling medicine for the disorder.
Biogen spokeswoman Kathleen O'Donnell said the Schering study "flies in the face" of previous research.
To obtain U.S. Food and Drug Administration approval, Biogen proved in 1996 that Avonex was clinically superior to Betaseron, O'Donnell said.
O'Donnell said the Italian study was small and mainly gauged relapses of MS rather than reduction of symptoms or stopping the progression of the disorder.
"Looking at more than just relapses is more important to doctors and patients," she said.
The Italian study said that the most common side effects "shared between interferon therapies" such as Betaseron and Avonex include flu-like symptoms.
Results of testing patients on the drugs for two years should be released by the end of 2001.
Betaseron is known as Betaferon in several markets outside of North America.
The results were the second potential blow to Biogen Tuesday, after Swiss firm Serono SA released data showing its Rebif drug was more effective than Avonex in reducing relapses of multiple sclerosis symptoms.
A Biogen official earlier in the day criticized the Serono trial, saying the data reflected interim results and did "not show any important differences" between Rebif and Avonex.
Cambridge, Mass.-based Biogen released a statement late Tuesday saying the Serono study was "an incomplete measure giving a snapshot view of a serious disease that must be treated over the long-term."
Serono would have to prove its drug is significantly superior to Avonex to obtain FDA approval.