MS drug withdrawn
NEWS IN BRIEF — Posted March 28, 2005
Tysabri, or natalizumab, approved last fall to treat multiple sclerosis, was taken off the market on Feb. 28 after one patient died and another possibly developed progressive multifocal leukoencephalopathy.
Tysabri had been granted accelerated approval by the Food and Drug Administration based on promising first-year results from a two-year trial. The drug had shown signs of being effective in treating relapsing MS, the most common form. About 400,000 people have been diagnosed with MS.
The patient death and possible illness occurred during a clinical trial using Tysabri in combination with Avonex, or interferon beta-1a. Both patients had received more than two years of treatment with Tysabri and Avonex. A total of 3,000 patients have been treated with Tysabri in clinical trials of MS, Crohn's disease and rheumatoid arthritis.
Manufacturer Biogen Idec sent out Dear Doctor letters recommending that patients be evaluated for signs and symptoms of PML and that any potential cases be reported.
Note: This item originally appeared at http://www.ama-assn.org/amednews/2005/03/28/hlbf0328.htm.