MS is a degenerative disease of the nervous system that can lead to muscle weakness, blurred vision and disability. About 2.5 million people are estimated to suffer from the disease.

Bayer said new data from a study showed immediate use of Betaseron in patients with the first signs of multiple sclerosis can cut the risk of permanent neurological damage by 40 percent over three years compared with delayed treatment.

"This is a truly novel finding that has not yet been demonstrated for any other immunomodulatory MS treatment," said Dr Mark Freedman of the University of Ottawa, who led the study.

The results underscored the urgent need to treat patients early rather than waiting for further signs of the disease to develop, Freedman said in a statement.

The BENEFIT study -- Betaseron in newly emerging multiple sclerosis for initial treatment -- involved 468 patients and was presented at the American Academy of Neurology in Boston o­n Tuesday.