Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) have announced results from an ongoing, one-year longitudinal health outcomes study (n=1275) in which patients who received three infusions of TYSABRI® (natalizumab) reported reduced fatigue, as well significant improvements in general and disease-specific measurements of quality of life (QoL) and cognitive function. Findings from the study, which was performed in conjunction with HealthCore Inc., a health-outcomes research company, are the first attempt to assess patient experiences with TYSABRI in usual-care settings. The results from this study were presented in two separate posters at the 61st Annual Meeting of the American Academy of Neurology.

"MS is a debilitating disease that significantly reduces the quality of patients' lives. In this study, a majority of patients said they were less tired, thought more clearly, and had a better overall quality of life," said Dr. William Stuart, M.D., medical director of the Multiple Sclerosis Center of Atlanta. "Data from the pivotal trial has shown that TYSABRI not only results in a significant reduction in relapses, but also showed an improvement in quality of life. These new patient-reported outcomes expand our understanding of the real-world impact of TYSABRI on different aspects of the lives of MS patients."

The ongoing one-year follow-up study will assess health outcomes from patients' perspectives before starting TYSABRI and after the third, sixth, and 12th infusions of TYSABRI, respectively. A majority of the patients in the study are female (78.4%) with mean age of 45.3 years and mean disease duration of 10 years.

Quality of Life Study Results

As early as after the third infusion of TYSABRI, patients reported statistically significant improvement in: general health-related QoL, as measured by the 12-item Short Form Scale (SF-12), with higher scores indicating better QoL

MS-specific QoL, as measured by the 29-item Multiple Sclerosis Impact Scale (MSIS-29), with lower scores indicating better QoL Both scales report the physical and psychological aspects of QoL in two summary scores. SF-12 physical component summary (baseline 34.03 vs. 36.02 at the 3rd infusion; p