By Jennifer Corbett Dooren
Of DOW JONES NEWSWIRES
WASHINGTON -(Dow Jones)- A proposed Acorda Therapeutics (ACOR) drug to treat multiple sclerosis increased walking speed, but U.S. Food and Drug Administration staff questioned whether the improvement was clinically meaningful.
The proposed drug fampridine-SR faces a review by an FDA panel of outside medical experts next Wednesday. The FDA posted its review of the drug on its Web site Friday.
The panel is being asked to vote on whether it thinks the drug is safe and effective at improving the walking of patients with MS. The panel will also be asked if Acorda should be required to study the drug at a lower dose.
The active ingredient in the drug - fampridine - has been compounded in pharmacies for more than 20 years and used to improve walking in a number of neurological conditions. The drug is currently not approved by the FDA for any use. Fampridine has been associated with a risk of seizures especially at higher doses of the drug than the 10-milligram dose Acorda is seeking approval for.
The FDA said data from the clinical trial of fampridine-SR at 10-milligrams given twice a day didn't show a difference in the seizure risk compared to patients treated with a placebo, or fake drug. However, the agency said there was a 10-fold increase in the risk of a seizure when the drug was dosed at 20-milligrams twice daily, "a concerning finding suggesting a narrow therapeutic index."
Acorda is planning a risk-management program that would include educating patients and doctors about the importance of sticking to the 10-milligram dose and not taking two pills at once, for example.
In a document also posted to FDA's Web site, Acorda noted that walking impairment is one of the most common side-effect related to MS and said there's currently no FDA-approved treatment that directly addresses walking impairment.
"Fampridine-SR offers people with MS the potential for improvement of walking ability, an important unmet need with a low risk of intolerable or severe adverse effects," Acorda said.
-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; jennifer.corbett@dowjones.com