Biogen Idec's (BIIB -0.48%) Tecfidera wasn't the first oral multiple sclerosis drug, but is sure has gotten off to a much faster start than Novartis' (NVS 2.27%) Gilenya, which was approved by the FDA in 2010 and Sanofi's (SNY 1.15%) Aubagio, which was approved in 2012.

In its third quarter on the market, Biogen registered nearly $400 million in sales, putting it well on its way to achieving blockbuster status. It's not hard to see Tecfidera catching more established injected drugs such as Teva Pharmaceuticals' Copaxone and Biogen Idec's own Avonex.

In the following video, Fool contributor Brian Orelli and health-care bureau chief Max Macaluso discuss why Biogen Idec got off to such a quick start where Novartis and Sanofi couldn't.