FDA Says PML Risk Increases With Tysabri
Tysabri, a favorite medication for relapsing multiple sclerosis (MS), could cause progressive multifocal leukoencephalopathy (PML), a debilitating brain infection, the longer it is used, cautions the U.S. Food & Drug Administration (FDA). The agency announced a label change would update that warning.
The drug, considered one of the most effective MS treatments available, unfortunately, is risky because of its PML affiliation.
Usually fatal, PML attacks the brain and central nervous system; symptoms include loss of memory, coordination and vision concerns. Patients who endure the disease are often permanently disabled. In 2005, Tysabri was pulled from the U.S. market after three clinical trial patients developed PML, but it was reapproved with restrictions in 2006.
The FDA said it has received 31 confirmed case reports of PML as of January 21, 2010, but none in patients treated for less than 12 months since Tysabri was reintroduced in 2006.
The FDA also said incidents of Immune Reconstitution Inflammatory Syndrome (IRIS) have been reported after discontinuing Tysabri because of PML. IRIS can occur after stopping immunosuppressant medications. During immune system recovery, patients sometimes exhibit a severe inflammatory response to an infection. Also, their symptoms can worsen, sometimes after an improvement period. An update to the Warnings and Precautions section of the Tysabri label has been added to indicate this new information.
Posted on Monday, February 8th, 2010 at 9:27 pm under 