Biogen Idec's (NASDAQ:BIIB) latest earnings report is the envy of the industry as Tecfidera keeps marching toward its multi-billion dollar potential. Beyond multiple sclerosis collaboration revenue from Roche's best-selling cancer therapy Rituxan continues to fill Biogen's coffers, and a recent approval opened the door to the $6 billion hemophilia A market. 

Of course, these gains come at a price. Analysts have been rightfully concerned that Tecfidera might cannibalize previous MS blockbusters. Also, gaining market share in an increasingly crowded hemophilia space isn't going to be easy. Watch the slideshow below to see whether or not these concerns are materializing.

Biogen Idec Q2 2014 Earnings: Firing on All Cylinders from The Motley Fool