MS drug TYSABRI to be highlighted at 62nd AAN Annual Meeting

Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) today announced 15 company-sponsored platform and poster presentations at the American Academy of Neurology's (AAN) 62^nd Annual Meeting in Toronto, April 10 - 17, 2010. The AAN Annual Meeting is the world's largest gathering of neurologists. The presented data, based on post-hoc analyses and patient-reported outcomes studies, highlights the ability of TYSABRI (natalizumab), in some multiple sclerosis (MS) patients, to improve sustained visual function, disability, overall quality of life (QoL), cognition and fatigue.

“Visual problems are often the first symptom of MS, and for many patients, the knowledge that vision may be compromised adds a level of anxiety about future quality of life and activities of daily living”

"TYSABRI continues to change the way neurologists and patients define success in the treatment of MS," said Alfred Sandrock, M.D., Ph.D., Senior Vice President of Neurology Research and Development at Biogen Idec. "The data presented at AAN contribute to the growing body of scientific evidence supporting TYSABRI's strong efficacy profile."

Multiple sclerosis is one of the most common neurological disorders, affecting more than 400,000 people in the United States each year. Physical disabilities such as the loss of vision and difficulty walking are among the common symptoms associated with the disease and can have a devastating impact on quality of life for many MS patients. TYSABRI's strong efficacy profile in treating MS demonstrated in clinical trials continues to be enhanced further with data such as those being presented at AAN.

Data from the 15 company-sponsored presentations at the conference show that TYSABRI, in some patients, improves sustained visual function, disability, overall QoL, cognition and fatigue. The presentations also include results from two studies related to the JC virus (JCV) and a follow-up study in pregnant women.