Biogen Idec's PLEGRIDY™ (peginterferon beta-1a) approved in the US for the treatment of multiple sclerosis Biogen Idec, 15 Aug 2014 Accessed on 19 Aug 2014 from http://www.biogenidec.com/press_release_details.aspx?ID=14712&Action=1&NewsId=2368&M=NewsV2&PID=61997. CommentRecommendBookmarkWatch