Experimental MS Drug May Aid Walking

Feb. 26, 2009 -- An experimental drug called fampridine may improve walking in some people with multiple sclerosis.

Researchers report that news in the Feb. 28 edition of The Lancet.

They studied 301 U.S. and Canadian adults with multiple sclerosis (MS). At the study's start, the patients were timed as they walked a distance of 25 feet.

After that, the patients spent a week just taking a placebo pill, and then they took either fampridine or a placebo twice daily for 14 weeks. After that, they spent their last month in the study not taking fampridine or the placebo.

During the study, patients taking fampridine were more likely than those taking the placebo to meet the study's benchmark for the timed walk, to improve their walking speed, and to note greater improvement in walking.

For instance, 25% of the fampridine patients improved their walking speed, compared to 5% of patients taking the placebo.

"We provide evidence that treatment with fampridine produces clinically meaningful improvement in walking ability in some people with multiple sclerosis," write the researchers, who included Andrew Goodman, MD, of the University of Rochester.

More research is needed to confirm the findings, Goodman's team notes.

The researchers report two serious side effects that might have been linked to fampridine. One case was a patient who experienced severe anxiety; the other case was a patient who had a seizure during sepsis, a severe infection.

The study's results are "intriguing," but a better understanding of the drug's risks and benefits, and which patients are the best candidates for fampridine, are needed, according to an editorial published with the study.

The editorialists -- who included Alan Thompson, FRCP, FRCPI, of University College London's Institute of Neurology -- note that the results were clinically meaningful but only apply to a subset of patients, and that fampridine may not be right for patients with a history of seizures.

Goodman's study was funded by Acorda Therapeutics Inc., which makes fampridine and has submitted fampridine for FDA review.