Study Results for Two-Week Dosing Arm at Year 1


Primary Endpoint
“¢ PLEGRIDY met the primary endpoint of reducing annualized relapse rate (ARR) at 1 year by 36% compared to placebo (p=0.0007).

Secondary Endpoints
“¢ PLEGRIDY reduced the proportion of patients who relapsed by 39% compared to placebo (p=0.0003).
“¢ PLEGRIDY reduced the number of new or newly enlarging T2-hyperintense lesions on brain MRI scans by 67% compared to placebo (p<0.0001).
“¢ PLEGRIDY also demonstrated significant positive effects on disability progression by reducing the risk of 12-week confirmed disability progression, as measured by the Expanded Disability Status Scale (EDSS), by 38% compared to placebo (p=0.0383).

Additional Results
“¢ PLEGRIDY significantly reduced the number of gadolinium-enhancing (Gd+) lesions by 86% compared to placebo (p<0.0001).
“¢ The incidence of PLEGRIDY neutralizing antibodies was less than 1%.
“¢ PLEGRIDY dosed once every 4 weeks was also shown to be effective, and met the primary and secondary endpoints in the ADVANCE trial. PLEGRIDY dosed once every 2 weeks resulted in a numerically greater treatment effect across these relapse and the aforementioned MRI endpoints.

“In the first year of the ADVANCE trial, PLEGRIDY demonstrated strong efficacy. We saw a marked reduction in relapse rate and this was supported by MRI results. If approved, PLEGRIDY will make an important therapeutic option in the injectable treatment segment”, said Gilmore O’Neill, Vice President, Global Neurology Late Stage Clinical Development at Biogen Idec. “In addition to these encouraging therapeutic results, PLEGRIDY may reduce the treatment burden for patients by reducing the number of subcutaneous injections.”

PLEGRIDY showed favorable safety and tolerability profiles in ADVANCE. The overall incidence of serious adverse events (SAEs) and adverse events (AEs) was similar among the PLEGRIDY and placebo groups. The most common SAE was infections, which was balanced across all treatment groups (=1% per group). The most commonly reported AEs with PLEGRIDY treatment were redness at the injection site and influenza-like illness.

PLEGRIDY is a new molecular entity in which interferon beta-1a is pegylated to extend its half-life and prolong its exposure in the body, enabling study of a less-frequent dosing schedule. PLEGRIDY is a member of the interferon class of treatments and, if approved, would be a new addition to this class, which is often used as a first-line treatment for MS.
After completing 2 years in the ADVANCE study, patients have the option of enrolling in an open-label extension study called ATTAIN and will be followed for up to 4 years.

Through cutting-edge science and medicine, Biogen Idec discovers, develops, and delivers to patients worldwide innovative therapies for the treatment of neurodegenerative diseases, hemophilia, and autoimmune disorders. For more information, visit www.biogenidec.com.