General Information

Ampyra (dalfampridine) is a potassium channel blocker that enhances conduction in damaged nerves. The exact mechanism by which dalfampridine exerts its therapeutic effect has not been fully elucidated.

Ampyra is specifically inidicated as a treatment to improve walking in patients with multiple sclerosis.

Ampyra is supplied as an extended release tablet for oral administration. The maximum recommended dose of Ampyra is one 10 mg tablet twice daily, taken with or without food, and should not be exceeded. Doses should be taken approximately 12 hours apart. Patients should not take double or extra doses if a dose is missed.

Clinical Results

FDA Approval
The FDA approval of Ampyra was based on two clinical trials.
Trial One
This randomized, placebo-controlled, parallel group, 21-week study enrolled 301 patients with multiple sclerosis at 33 centers in the U.S. and Canada. The patients were assigned to Ampyra 10 mg twice daily or placebo. A total of 283 subjects completed the study. The primary measure of efficacy was walking speed (in feet per second) as measured by the Timed 25-foot Walk (T25W), using a responder analysis. A significantly greater proportion of patients taking Ampyra were responders compared to patients taking placebo: 34.8% vs. 8.3%, respectively. The increased response rate was observed across all four major types of MS disease course. During the double-blind treatment period, a significantly greater proportion of patients taking Ampyra 10 mg twice daily had increases in walking speed of at least 10%, 20%, or 30% from baseline, compared to placebo.
Trial Two
This randomized, placebo-controlled, parallel group, 14-week study enrolled 239 patients with multiple sclerosis at 39 centers in the U.S. and Canada. The subjects were assigned to 10 mg twice daily and or placebo. A total of 227 patients completed the study. The primary endpoint was walking speed (in feet per second) as measured by the Timed 25-foot Walk (T25W), using a responder analysis. A significantly greater proportion of patients taking Ampyra were responders compared to patients taking placebo: 42.9% vs. 9.3%, respectively. The increased response rate was observed across all four major types of MS disease course. During the double-blind treatment period, a significantly greater proportion of patients taking Ampyra 10 mg twice daily had increases in walking speed of at least 10%, 20%, or 30% from baseline, compared to placebo.

Mechanism of Action

Ampyra (dalfampridine) is a potassium channel blocker, available in a 10 mg tablet strength. Each tablet contains 10 mg dalfampridine, formulated as an extended release tablet for twice-daily oral administration. The mechanism by which dalfampridine exerts its therapeutic effect has not been fully elucidated.