The FDA has approved Biogen Idec’s Plegridy (peginterferon beta-1a), a new treatment for people with relapsing forms of multiple sclerosis (RMS). Plegridy, the only pegylated beta interferon approved for use in RMS, is dosed once every two weeks and can be administered subcutaneously with the Plegridy Pen, a new, ready-to-use autoinjector, or a prefilled syringe.

“Plegridy offers people with MS robust efficacy, a safety profile consistent with the established interferon class, and significantly fewer injections than other beta interferon treatments,” said George A. Scangos, Ph.D., chief executive officer of Biogen Idec.

The FDA approval of Plegridy is based on results from one of the largest pivotal studies of beta interferon conducted, Advance, which involved more than 1,500 MS patients. Advance was a two-year, phase III, 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.

In the first year of the Advance clinical trial, PLEGR Plegridy IDY dosed once every two weeks significantly reduced annualized relapse rate (ARR) at one year by 36% compared to placebo (p=0.0007). Plegridy reduced the risk of 12-week confirmed disability progression, as measured by the Expanded Disability Status Scale, by 38% (p=0.0383) compared to placebo. Plegridy also significantly reduced the number of new gadolinium-enhancing [Gd+] lesions by 86% (p<0.0001) and reduced new or newly enlarging T2-hyperintense lesions by 67% (p<0.0001) compared to placebo.

The most common adverse reactions were injection site reaction, flu-like illness, fever, headache, muscle pain, chills, injection site pain, weakness, injection site itching and joint pain. The Advance two-year safety data were consistent with safety results observed in year one.

MS is a chronic, often disabling disease that attacks the central nervous system. Symptoms may be mild or severe, ranging from numbness in the limbs to paralysis or loss of vision. The progression, severity and specific symptoms of MS are unpredictable and vary from one person to another. MS affects more than 2.3 million people worldwide. Best current estimates indicate that there are at least 400,000 people with MS in the U.S.

Plegridy also recently has been approved by the European Commission.