MULTIPLE SCLEROSIS
Tysabri Returns -- With Caveats
The FDA cleared the way for Tysabri (natalizumab), the multiple sclerosis drug, to go back on the market but under a special restricted distribution program. Tysabri, a monoclonal antibody approved in November 2004 for relapsing forms of MS, was withdrawn by its maker, Biogen Idec, and distributor, Elan, in February 2005.
The drug was yanked after three patients in clinical trials developed progressive multifocal leukoencephalopathy (PML), a rare viral infection of the brain. Two of the cases were fatal.
