Biogen Idec Inc. (NASDAQ:BIIB) added $3.7 billion to its market cap after FDA approved Tecfidera dimethyl fumarate with the cleanest label among oral MS drugs.

Doctors have told BioCentury they like the safety advantage of Tecfidera (BG-12) after Phase III studies showed flushing and abdominal pain as the most common serious adverse events (see BioCentury, April 18, 2011).