CAMBRIDGE, Mass. & DUBLIN, Ireland--(BUSINESS WIRE)--Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) announced that data to be presented today at the Academy of Managed Care Pharmacy’s (AMCP) 2006 Educational Conference in Chicago, IL show that in Phase III studies TYSABRI® (natalizumab) therapy significantly reduced corticosteroid use and hospitalizations, and increased the proportion of MS patients with no disease activity. Findings will also be presented that demonstrate the positive impact of TYSABRI on a number of health-related quality of life of measures (QoL) and the cost-effectiveness of MS therapies.