Ampriva Helps Improve Nervous System Function in Multiple Sclerosis Patients
Daniel J. DeNoon
WebMD Health News
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Reviewed By Louise Chang, MD
Oct. 16, 2009 -- A new drug for multiple sclerosis truly helps some patients walk better, says an FDA advisory panel.
The finding, by a panel of outside experts, makes it more likely that full FDA approval will come soon. If approved, the drug -- tentatively named Ampriva -- would be the first to improve nervous system function in people suffering from the devastating disease.
Current treatments slow MS progression and target symptoms, but they do not affect the damage the disease already has done. Nerves frayed of their protective myelin sheath lose their ability to send electrical signals. Ampriva improves conduction of nerve signals.
Nerve damage from MS often makes it very difficult for patients to walk. It's among the symptoms that most bother people with MS.
In clinical trials, over 35% of MS patients taking Ampriva were able to walk faster, says Andrew D. Goodman, MD, director of the multiple sclerosis center at the University of Rochester and the lead investigator in the clinical studies.
"Those who responded improved walking speed on average by 25%," Goodman tells WebMD. "This can mean things like getting to the bathroom on time before having an accident, or getting across the street before the light changes."
Ampriva is not a miracle cure. While it can help even patients with relentlessly progressive MS, patients do continue to get worse over time. And the improvements seen with the drug are rather modest. In fact, the central question the advisory panel was asked to decide was whether the improvements were truly significant to patients.
At the hearing, people with MS and their family members told the panel that they would welcome the kind of improvements seen in the clinical trials. Goodman says he hears the same thing from his patients.
"The kinds of things that people have described to me are, 'Look, I can get around the supermarket without having to hold on to the cart all the time,' or 'Just getting up that step between the garage and the house gives me independence,'" he says.
The drug is by no means risk-free. Ampriva is a new formulation of a drug called fampridine, which was originally used as a bird poison.
Some 20 years ago, test tube studies suggested that fampridine could improve nerve conduction. Since then, some neurologists -- Goodman is not one of them -- have ordered the drug from compounding pharmacies for their MS patients.
Fampridine causes seizures and convulsions at doses not much higher than the dose thought to be therapeutic. The sustained-release formulation of fampridine used in Ampriva lessens the chance of this side effect, but the drug cannot be used by MS patients with a history of seizures.
The FDA advisory panel voted 10-2, with one abstention, that -- for some MS patients -- they would consider the benefits of Ampriva to outweigh the risks.
The FDA is scheduled to consider Acorda Therapeutics' application for approval of Ampriva next week, although that schedule is not set in stone. Acorda had intended to call the drug Amaya, but the FDA rejected that brand name.
SOURCES: Email from Karen Mahoney, spokeswoman Acorda Therapeutics.
News release, Acorda Therapeutics.
FDA Advisory Committee briefing documents, accessed online Oct. 16, 2009.
WebMD Health News: "Experimental MS Drug May Aid Walking."
Andrew D. Goodman, MD, professor of neurology; director, Multiple Sclerosis Center; chief, Neuroimmunology Unit, University of Rochester Medical Center, N.Y.
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