Available long-term data on Fampyra (fampridine; 4-aminopyridine) suggest the treatment may improve walking speed in patients with multiple sclerosis (MS) for up to one year, but more research is needed, a French study reports.
The study “Multiple Sclerosis and Clinical Gait Analysis before and after Fampridine: A Systematic Review” was published in the journal European Neurology.
MS patients are frequently affected by gait disorders, which can appear early in the disease course. In fact, almost half of all MS patients report gait disorders, which manifest as a decrease in walking abilities, both walking speed and distance.
Fampyra, marketed as Ampyra (dalfampridine) by Acorda Therapeutics in the U.S., is the first symptomatic treatment specifically targeting gait disorders in MS patients. It works as a potassium-channel inhibitor, which improves the formation of action potentials. In other words, it improves signals that go from the brain to the muscles so as to help with the conduction of information within the central nervous system. (Fampyra is the brand name for fampridine in Europe and elsewhere outside of the U.S., marked by Biogen under an agreement with Acorda.)
Clinical trials evaluating Fampyra’s efficacy have shown it has a beneficial therapeutic effect on gait, increasing patients’ walking speed by 25%. But most of these studies have evaluated its use over the short-term, and there is a lack of studies regarding its long-term efficacy and safety.
French researchers conducted a systematic review of studies assessing Fampyra’s use in gait improvement in MS patients. Long-term studies were identified as those that exceeded 28 days. Among 498 studies of the treatment, only 18 studies met that definition of a long-term study, they reported.
Out of those 18 studies, which included 2,200 patients, only three followed patients for more than one year.
One of the three reported a non-significant improvement in gait speed. But, overall, the use of Fampyra improved walking speed in both the short-term and the long-term (up to a year) in patients with MS. Due to the small number of studies and the differing results among them, however, the research team could not draw any conclusions beyond one year.
Fampyra also appears to be well-tolerated as adverse effects were transient and usually mild. The most frequently reported adverse effects were headache and dizziness. Among all the studies analyzed, only four patients experienced serious adverse events.
“This systematic review provides additional evidence that fampridine increases walking speed in the short-term in patients with MS. This treatment is also valid in the longer term, that is to say up to 1 year. However, given the small number of studies and the disparity between them, it is not possible to draw any conclusions on treatment efficacy beyond 1 year” the researchers concluded.
Further long-term studies are needed.
The team also suggested that “it seems necessary to conduct long-term studies that can evaluate other gait parameters, notably objective evaluations in real-life settings of patients taking fampridine. Studies on a return to other activities, whether in rehabilitation or not, could also add to these data.”