Today Biogen Idec (NASDAQ: BIIB) announced that U.S. and EU regulatory authorities have accepted the marketing applications for the review of PLEGRIDY™ (peginterferon beta-1a), the company’s pegylated subcutaneous injectable candidate for relapsing forms of multiple sclerosis (MS). The U.S. Food and Drug Administration (FDA) has accepted Biogen Idec’s Biologics License Application (BLA) for marketing approval of PLEGRIDY in the United States and granted the company a standard review timeline. The Marketing Authorisation Application (MAA) of PLEGRIDY for review in the European Union was also validated by the European Medicines Agency. The regulatory applications included positive one-year results from the two-year global Phase 3 ADVANCE study. The data demonstrated that PLEGRIDY met all primary and secondary endpoints by significantly reducing disease activity including relapses, disability progression and brain lesions compared to placebo, and showed favorable safety and tolerability profiles at one year. “We expect that interferons will remain an important and widely used option for patients with MS. At one-year, PLEGRIDY demonstrated significant reductions in relapses and disability progression, as well as a robust impact on several MRI endpoints,” said Douglas E. Williams, Ph.D., Biogen Idec’s executive vice president of Research and Development. “PLEGRIDY, if approved, could offer a less frequent dosing schedule, a favorable safety profile, and the potential to become the preferred interferon treatment.” About PLEGRIDY 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. PLEGRIDY is a member of the interferon class of treatments, which is often used as a first-line treatment for MS. About ADVANCE The two-year Phase 3 ADVANCE clinical trial is a global, multi-center, randomized, double-blind, parallel-group, placebo-controlled study designed to evaluate the efficacy and safety of PLEGRIDY in 1,516 patients with relapsing-remitting MS. The study investigates two dose regimens of PLEGRIDY, 125 mcg administered subcutaneously every two weeks or every four weeks compared to placebo. The analysis for all primary and secondary efficacy endpoints occurred at one year. After the first year, patients on placebo are re-randomized to one of the PLEGRIDY arms for the duration of the second year of the study. After completing two 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 four years.