Sustained-release fampridine for symptomatic treatment of multiple sclerosis

Abstract

Objective: To review the pharmacology, pharmacokinetics, clinical trials, and adverse effects of sustained-release (SR) fampridine in patients with multiple sclerosis (MS).

Data sources: An English-language human data search was done using PubMed/MEDLINE (1966-August 2008) to retrieve relevant material using the search terms fampridine-SR, 4-aminopyridine, and multiple sclerosis. References of selected articles and information from the drug developer were used to further identify pertinent trials.

Study selection and data extraction: Article selection was based primarily on studies that evaluated the pharmacokinetics, safety, and efficacy of fampridine-SR in patients with MS. Relevant meeting abstracts were also included as part of the analysis.

Data synthesis: Fampridine-SR is a sustained-release, orally administered potassium-channel blocker acting in the central nervous system to enhance conduction in demyelinated axons. Several small trials have evaluated the safety and efficacy of fampridine-SR in patients with MS to improve their walking ability. Data from a recent large Phase 3 trial indicated that walking speed improved in 42.9% of patients with MS who were treated with fampridine-SR compared with 9.3% of those who received placebo (p < 0.001). Treatment-related adverse events associated with the use of fampridine-SR include dizziness, insomnia, nausea, and paresthesia. More severe adverse events, such as seizure, have occurred in patients receiving doses higher than those currently recommended.

Conclusions: Positive results from 2 Phase 3 clinical trials have put fampridine-SR on the path toward approval as a medication for improving walking speed and lower extremity strength in patients with MS.