Shares of Biogen Idec Inc. jumped more than 5 percent following an announcement late on Wednesday that the FDA approved Tecfidera (dimethyl fumarate) for relapsing forms of multiple sclerosis (MS). The drug was approved with a label in line with expectations with no black box warnings, just recommendations for baseline and annual white blood cell count monitoring. The greatest remaining question is pricing, which has not yet been announced, but which could affect how the drug performs upon entering in the market.