Ampyra

Analyst Outlook

Ampyra (dalfampridine; Acorda Therapeutics/Biogen) is the only approved drug specifically to improve

walking in patients with multiple sclerosis. Despite not being a disease-modifying drug, Ampyra can

still be used in a large proportion of multiple sclerosis patients due to the high prevalence of

ambulatory symptoms among sufferers. Its moderate efficacy and seizure risk leave room for potential

competitors to improve upon Ampyra, but it has nevertheless performed well commercially since its

first launch in 2010.

Drug Overview

Ampyra is a potassium channel blocker, marketed by Acorda Therapeutics and Biogen, which is

approved to improve walking ability in multiple sclerosis patients. Although Ampyra’s active molecule

fampridine (4-aminopyridine) is readily available, by using Elan’s Intestinal Protective Drug Absorption

System, Acorda has developed a sustained-released oral tablet formulation allowing twice-daily

dosing. Acorda hopes this is a significant improvement on fampridine because there is a narrower

toxic to therapeutic range and the most debilitating side effects occur at high plasma concentrations.

In January 2010, following advisory panel concerns that the drug showed an increased risk of seizures,

the US Food and Drug Administration (FDA) approved Ampyra with a Risk Evaluation and Mitigation

Strategy (REMS) program comprising of a medication guide and communication plan (BioMedTracker,

Copyright 2015, reprinted with permission). This made Ampyra the first drug to gain FDA approval as a

treatment to improve walking in patients with multiple sclerosis, for which it has orphan drug status.

The drug was later approved in the EU in July 2011 with the brand name Fampyra, where it is

marketed by Biogen.