Oct 14, 2009
Panel Recommends that FDA Approve Fampridine-SR (proposed name Amaya) for Symptomatic Treatment of MS -- Found to improve walking speed for all types of MS
A U.S. Food and Drug Administration advisory committee today recommended that the agency approve marketing of Fampridine-SR (Acorda Therapeutics, with a proposed name change to Amaya) for its ability to improve walking speed in people with any type of multiple sclerosis. While the FDA is not required to follow the recommendations of its advisory committees, it usually does. The agency is expected to make a final decision about whether to approve the drug for market on or before the target date of October 22, 2009.
During an all-day meeting held October 14, 2009, the FDA advisory committee considered Acorda Therapeutics’ application for approval of Fampridine-SR, reviewing data about the drug’s effectiveness and safety. The committee also heard public testimony from individuals and patient advocacy groups, including the National MS Society, which testified to the unmet need for therapies to improve walking for people with MS.
Among its discussions, the advisory committee recommended that the FDA require the sponsor to evaluate the effects of doses lower than originally studied, but that these studies would not be required to be done prior to the drug’s marketing approval. In addition, the FDA is likely to require a plan to mitigate potential risks. During its presentation to the committee, Acorda representatives outlined such a plan -- the Risk Evaluation Mitigation Strategies (REMS).
Background on Unmet Need: Problems with gait (difficulty in walking) are among the most common limitations in MS. While there are six FDA-approved disease-modifying therapies that are at least partially effective against some forms of the disease, as well as rehabilitation and symptomatic treatments for some symptoms, at present there is no pharmacologic treatment specifically available for MS-related difficulty walking. This disability has wide-ranging effects on people’s lives, even in its milder manifestations.A recent survey among more than 1,000 individuals with MS and many of their family members examined the impact of mobility issues, such as difficulty walking, on quality of life among patients with MS and their families. Some two-thirds of patients reported difficulty walking and of these, 70% reported that such difficulty was the most challenging part of their MS, and most reported that difficulty walking restricts their daily activities significantly, including their ability to travel. (Read more about survey results)
About the Drug: Fampridine-SR is a sustained-release formula of 4-aminopyridine, which blocks tiny pores, or potassium channels, on the surface of nerve fibers. This blocking ability may improve the conduction of nerve signals in nerve fibers whose insulating myelin coating has been damaged by MS. The first studies of this potassium-blocking approach in people with MS were supported by the National MS Society.
What Clinical Trials Found: Acorda Therapeutics sponsored two phase 3 clinical trials of the drug. In the first, involving 301 people with any type of MS, walking speed increased by 25%. Results of this study have been published (February 28, 2009 issue of The Lancet (2009 373;732-738), summarized here). Results from a later, second phase 3 study involving 240 people with MS confirmed the benefits seen in the first, finding that a significantly greater proportion of people on the therapy had a consistent improvement in walking speed compared to those who took placebo. Among those taking Fampridine-SR who improved in walking speed, there was a statistically significant improvement in leg strength.
In the first study, common adverse events (side effects) experienced more often by those on active treatment included back pain, dizziness, insomnia, fatigue, nausea and balance disorder. Two serious adverse events led participants to discontinue taking the drug (one case of anxiety and one seizure in a person who developed sepsis from a urinary tract infection). In the second study, additional common adverse events in those on therapy included urinary tract infection, falls, and headache.
Comment: “The clinical trial results suggest that for a substantial percentage of people with MS, Fampridine has the potential to restore some significant function and make a real difference in people’s quality of life,” said John R. Richert, MD, Executive Vice President of Research & Clinical Programs for the National MS Society. “If the FDA agrees that Fampridine is safe and effective, this would bring a welcome symptomatic therapy that has potential utility for a large number of people with different types of MS.”
Further study and clinical practice may help determine the extent to which the drug may impact other functions not measured in the clinical trials, and provide hints as to which patients are most likely to respond.