Biogen to Present Plegridy Data from Phase 3 Study at AAN Annual Meeting

– Two-Year Data Consistent with Positive Efficacy and Safety Observed in Year One – – Additional Analyses of Year-One ADVANCE Results Show High Rates of Freedom from Measured Disease Activity and Recovery from Relapses – Today Biogen Idec BIIB announced two-year data from its Phase 3 ADVANCE clinical trial for PLEGRIDY™ (peginterferon beta-1a) in people with relapsing forms of multiple sclerosis (RMS). These data, which will be presented at the 66th American Academy of Neurology (AAN) annual meeting, indicate PLEGRIDY dosed once every two weeks demonstrated favorable results on relapse rates, magnetic resonance imaging (MRI) findings and disease progression. Over two years, the safety profile of PLEGRIDY was consistent with other multiple sclerosis (MS) interferon therapies. “The two-year data from ADVANCE further establish the efficacy and safety profile of PLEGRIDY demonstrated in the first year of the pivotal trial,” said Gilmore O'Neill, vice president, Global Neurology Clinical Development at Biogen Idec. “If approved, we believe that PLEGRIDY dosed once every two weeks will provide MS patients with one of the most significant developments in the interferon class in over a decade.” ADVANCE was a two-year, Phase 3, placebo-controlled (in year one) study that evaluated the efficacy and safety of PLEGRIDY administered subcutaneously. The analysis for all primary and secondary efficacy endpoints occurred at the end of year one. After the first year, patients on placebo received PLEGRIDY for the duration of the study. New Analysis of ADVANCE Data Showed PLEGRIDY Benefits Maintained Over Two Years A new analysis of data from the second year of ADVANCE presented at AAN demonstrated: The efficacy of PLEGRIDY dosed once every two weeks was maintained throughout year two. Relative to year one, the annualized relapse rate (ARR) was further reduced and the number of new or newly-enlarging T2 lesions was numerically lower in year two The safety and tolerability profile of PLEGRIDY was consistent between years one and two These data will be presented in a platform presentation on Tuesday, April 29 at 2:00 p.m. EDT: Analysis of 2-year Clinical Efficacy and Safety of Peginterferon Beta-1a in Patients with Relapsing-Remitting Multiple Sclerosis: Data from the Pivotal Phase 3 ADVANCE Study (S4.005) “ADVANCE provides us with insight about the efficacy and safety of PLEGRIDY and its every two-week dosing schedule,” said Dr. Bruce L. Hughes, MD, Neurology, Mercy Ruan Neuroscience Center in Des Moines, Iowa. “The reduced dosing regimen of this investigational treatment could be an attractive option for many patients with relapsing forms of MS.” Additional Year-One Analyses Affirmed Efficacy of PLEGRIDY Two new post-hoc analyses from year one of the ADVANCE study will also be presented at the AAN annual meeting: The first analysis showed that PLEGRIDY increased the proportion of patients with RMS who achieved freedom from measured disease activity (FMDA), defined as no relapses, no disability progression, no Gd+ lesions and no new or newly enlarging T2-hyperintense lesions compared to baseline Results show the proportion of patients with overall-, clinical- and MRI-FMDA were significantly higher with PLEGRIDY dosed once every two weeks compared to placebo A second analysis showed treatment with PLEGRIDY was associated with improved recovery from relapses compared to placebo (as measured by the proportion of patients with a relapse associated with sustained disability progression) The first analysis will be presented in a platform presentation on Tuesday, April 29 at 2:30 p.m. EDT: Peginterferon Beta-1a Significantly Increases the Proportion of Patients with Freedom from Measured Disease Activity in Relapsing-Remitting Multiple Sclerosis: Findings from the ADVANCE Study (S4.007) The second analysis will be presented in a platform presentation on Tuesday, April 29 at 1:30 p.m. EDT, followed by a poster presentation on Wednesday, April 30 at 4:30 p.m. EDT: Peginterferon Beta-1a May Improve Recovery Following Relapses: Data from the Pivotal Phase 3 ADVANCE Study in Patients with Relapsing-Remitting Multiple Sclerosis – Platform (S4.003); Poster (I7-1.002) For members of the media interested in more information and additional resources, please visit biogenidec.com/us_media_corner.