Why Biogen's Better-Than-Expected Q1 Results Weren't Good Enough

It's fair to say that Biogen (NASDAQ:BIIB) is at a pivotal point. The company built a strong multiple sclerosis franchise that's now facing intense competition. It hopes to achieve success in treating Alzheimer's disease but must first jump a major hurdle by winning U.S. Food and Drug Administration (FDA) approval.

Biogen announced its first-quarter results before the market opened on Thursday with these factors in the minds of many investors. Those results apparently didn't give investors a warm and fuzzy feeling, though: The biotech stock slipped 4% in early trading. Here are the highlights from Biogen's Q1 update.