CAMBRIDGE, Mass. & DUBLIN, Ireland--(BUSINESS WIRE)--Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) today announced the two-year anniversary of TYSABRI® (natalizumab) as a treatment for relapsing forms of multiple sclerosis (MS), marking the reintroduction of the product in the United States (US) and the first international approval. The companies estimate that as of the end of June 2008, more than 31,800 patients worldwide are receiving TYSABRI treatment.
