Biogen Idec ($BIIB) picked up U.S. approval for its oral multiple sclerosis drug, Tecfidera, or BG-12, already touted as a sure blockbuster. At least two other oral MS drugs--Sanofi's ($SNY) Aubagio and Novartis' ($NVS) Gilenya--have reached the market, but they don't come with the credentials or safety rating Tecfidera brings to the table. Late-stage clinical trials showed the drug could cut MS relapse rate by about half, and the FDA said in a release that, because there is no cure for MS, it is important to have a variety of treatment options. Multiple sclerosis is one of the most common causes of neurological disabilities in young adults, and analysts think Tecfidira could earn more than $3 billion a year for Biogen Idec out of a $12 billion market. FierceBiotech's story | More