PLEGRIDY™ (peginterferon beta-1a) two-year data confirm maintenance of efficacy and safety in multiple sclerosis patients Biogen Idec, 11 Sep 2014 Accessed on 15 Sep 2014 from http://www.biogenidec.com/press_release_details.aspx?ID=14712&Action=1&NewsId=2375&M=NewsV2&PID=61997. CommentRecommendBookmarkWatch