WEDNESDAY, March 8, 2006 (HealthDay News) -- A U.S. Food and Drug Administration advisory panel voted unanimously Wednesday to allow the promising but controversial multiple sclerosis drug Tysabri back on the market.
However, the panel then placed certain restrictions on use of the drug, which has been linked to a rare but potentially fatal brain infection. The panel members agreed to a manufacturer's plan to set up a mandatory patient registry, and they recommended that its use be limited to individuals who have the relapsing form of the disease. They also recommended that it be administered as a solo therapy only, and that individuals who take the drug have periodic assessments to look for side effects.
In a 7-5 vote, the experts did allow the use of Tysabri as a first-line treatment for certain multiple sclerosis (MS) patients. The drug had been previously recommended only for especially tough-to-treat cases where the patients had failed other therapies.
While the FDA generally follows the recommendations of its advisory panels, it is not required to do so. The agency is expected to render its final decision on the drug by the end of the month.
"It's a drug that's obviously important to the MS community, and the committee advised us to help get it out there," Robert Temple, director of the FDA's Center for Drug Evaluation and Research, said at a press conference following the meeting. "What we need to do is take into account all of the committee's recommendations, and reach our own conclusions about what various critical components of a risk-management program will have to be included. There are a number of details to be worked out, and we will have to do that very rapidly."
Biogen Idec Inc. and Elan Corp., the makers of Tysabri, issued a statement Wednesday that said the companies will work closely with FDA officials on a safety-monitoring plan.
"Biogen Idec and Elan will continue to work closely with the FDA in the weeks ahead with the goal of making TYSABRI available. Discussions with FDA will include, among other things, finalizing the details of the TYSABRI risk-management plan. The companies anticipate action by the FDA by March 29, 2006," the statement read.
Physicians and MS patients alike were heartened by Wednesday's panel decision, which came during the second day of two days of deliberations.
"Tysabri is a very important step forward despite the fact that there are some concerns and limitations concerning its safety, but the safety risk at the moment, in the range of about one in 1,000, is probably well worth taking for patients with more severe or unstable disease," said Dr. Joseph Herbert, director of the Multiple Sclerosis Care Center and chief of neurology at New York University/Hospital for Joint Diseases in New York City.
"Patients with rapidly progressive or aggressive MS are probably at far greater risk because of the disease than they are from a potential rare side effect of the drug," Herbert said.
MS patient and attorney Karen Miller, 49, told the committee that Tysabri "is as close as it comes" to a miracle drug. Miller credited the drug with a renewed ability to ride her bike, wash her windows and run daily errands, the AP said.
"I am at the end of my road, in terms of what I can take. I want it to be my choice," another MS patient, Barbara Crooks, 48, told the news service.
Biogen and Elan pulled the drug off the market in February 2005 after three patients taking it developed PML, a progressive neurodegenerative disease. Two of those patients died.
The removal took place just three months after the FDA had granted accelerated approval of the drug for the treatment of relapsing forms of MS.
Last month, the FDA announced that Biogen and Elan could resume clinical trials for MS patients who were previously treated with the drug under an investigational study.
According to the National Institute of Neurological Disorders and Stroke, MS is an unpredictable disease of the central nervous system that can range from relatively benign to somewhat disabling to devastating. Most MS patients experience their first symptoms between the ages of 20 and 40, and most suffer muscle weakness in their extremities and difficulty with coordination and balance. These symptoms may be bad enough to hamper walking or even standing; in worst cases, MS can produce partial or complete paralysis.
Tysabri is a monoclonal antibody, engineered to attach itself to white blood cells called lymphocytes and prevent them from entering the brain, where they do damage that causes the disabling symptoms of MS. Tysabri had also been used to treat Crohn's disease.
One of the biggest issues in bringing the drug back to market is what kind of risk-management plan should be implemented. An initial plan submitted to the FDA by the manufacturers was considered insufficient.
"There's no question with this kind of essentially lethal risk that there is going to have to be some kind of risk-management program," Temple said at a Tuesday news conference.
"The three cases that did develop PML were all patients who were on other immune modulator drugs," Herbert noted. "If we use Tysabri judiciously and as a monotherapy, it is possible that the risk will turn out to be lower than we imagine."
Tysabri is only the second prescription drug to be returned to the market after being taken off. The other was Lotronex, used for irritable bowel syndrome, which was withdrawn in 2000 but allowed back on the market two years later.
"Lotronex was a unique drug with value for some people," Temple said. "The drugs that disappear permanently tend to be drugs that tend to have substitutes."
More information
Find out more about Tysabri at the U.S. Food and Drug Administration.
