The drug fampridine improves walking ability in some patients with multiple sclerosis (MS) and seems to be well-tolerated in patients with all disease course types of MS. The results of this Phase III study are published in an Article in this week's edition of The Lancet.
A progressive decline in mobility is a key feature of MS but there are currently few therapeutic options available to patients to complement physiotherapy. It has been suggested that treatment with fampridine may improve visual function, strength, walking ability, fatigue, and endurance in people with MS. But the safety and efficacy of fampridine in MS patients is still not clear.
To provide further evidence, Professor Andrew Goodman from the University of Rochester Medical Center, in New York, USA and colleagues from the USA, did a randomised trial to assess the efficacy and safety of slow-release fampridine on walking ability and leg strength in MS patients, at 33 centres in the USA and Canada. Patients were eligible if they had any disease course of MS and were able to complete two trials of the timed 25-foot walk (T25FW).
In total, 301 patients aged 18 years were randomised to receive either fampridine (10mg twice daily) or placebo (twice daily) for 14 weeks. Patients were assessed for walking speed measured with the T25FW at 2 weeks, and then every 4 weeks for 14 weeks. The 12-item multiple sclerosis walking scale (MSWS-12) was also used to measure the patients' perception of the effect that difficulties in walking were having on them.
Findings showed that the number of timed walk responders (patients who achieved a faster walking speed in at least three of the four assessments when they were on treatment compared with the fastest when they were not on treatment) was significantly higher in the fampridine treatment group (78/224 or 35%) compared to the placebo group (6/72 or 8%).
In addition, among the responders taking fampridine, improvement in walking speed compared to placebo was 25.5% vs 4.7%. Improvement in leg strength was also greater in fampridine-treated patients than in people on placebo. Further, timed walk responders reported a greater improvement in all 12 items on the MSW scale compared to timed walk non-responders—so responder did translate into an improvement in patients' perception.
The authors report that 11 patients in the fampridine group (5%) were withdrawn from the study due to adverse events, with eight of those (4%) involving treatment-emergent events. Only two serious adverse events (focal seizure and severe anxiety) were considered as being connected with the drug. However, they point out that risk of seizure shown in previous studies seems to increase in a dose-dependent way with fampridine.
The authors conclude: "Treatment with fampridine produces clinically meaningful improvement in walking ability in some people with multiple sclerosis, irrespective of disease course type or concomitant treatment with immunomodulators."
In an accompanying Comment, Alan Thompson from University College London, UK, and Chris Polman from the VU Medical Centre in Amsterdam, welcome the findings but add that: "Better understanding of the treatment profile, in terms of the full functional treatment effect and identification of those most likely to respond, is needed to allow for effective implementation in treatment regimens for multiple sclerosis."
Professor Andrew Goodman, University of Rochester Medical Center, New York, USA. T) +1 585 319 7140 E) Andrew_goodman@urmc.rochester.edu
Professor Alan Thompson, University College London, Institute of Neurology, London, UK. T) +44 (0) 207 692 2362 E) a.thompson@ion.ucl.ac.uk
For full Article and Comment see: http://press.thelancet.com/fampridine.pdf
Journal
The Lancet