–Less Frequent Injections would be a Significant Advancement for People Living with MS–

Biogen Idec (NASDAQ: BIIB) today announced enrollment of the first patient in a Phase III, randomized, double-blind, placebo-controlled trial designed to evaluate the efficacy and safety of PEGylated interferon beta-1a (BIIB017) in patients with relapsing multiple sclerosis (RMS). The trial, called ADVANCE, will determine the efficacy of PEGylated interferon beta-1a in reducing relapse rates in patients with RMS.

“A major issue with patient adherence to injectable therapies for MS is the frequency of injections,” said Peter Calabresi, M.D., principal investigator of the ADVANCE trial and professor of neurology and director of The Johns Hopkins Multiple Sclerosis Center, Baltimore, MD. “Examined in Phase I studies, PEGylated interferon beta-1a was shown to be much longer acting than intramuscular interferon beta-1a and thus offers the possibility of every two or four week dosing without compromising efficacy. This could greatly increase the convenience of this first line class of therapy."

Interferon beta-1a has been successfully used to treat patients with relapsing-remitting multiple sclerosis for more than 10 years. PEGylation protects the interferon beta-1a molecule from being degraded, extending the amount of time the drug remains in a patient's system. The process has been used in other therapeutic areas, and Biogen Idec is studying this innovation in interferon therapy for MS. Administered via subcutaneous injection, PEGylated interferon beta-1a is being studied to evaluate its potential to reduce the frequency of treatment injections and provide patients with an effective and more convenient dosing option.

“Bringing PEGylation to the interferon-class of MS treatments would be an innovation welcomed by the MS community,” said Michael Panzara, M.D., M.P.H., vice president, chief medical officer of neurology, Biogen Idec. “Biogen Idec is committed to improving the lives of MS patients by delivering first-in-class treatments, unparalleled patient support, and cutting-edge research as we continue to work towards a cure and redefine success in the treatment of this debilitating disease.”

About the ADVANCE Phase III Clinical Trial

The ADVANCE trial is a two-year multicenter, randomized, double-blind, parallel-group, placebo-controlled trial designed to evaluate the efficacy and safety of PEGylated interferon beta-1a in patients with RMS.