#7 Biogen Idec
Ticker: BIIB
YTD performance: 41%
Market cap: $22.8 billion

Biogen Idec (BIIB), a maker of specialized treatments for neurological diseases like multiple sclerosis, benefited from two positive developments in its drug pipeline this year.

In April, the company announced positive results from a Phase 3 clinical trial for a new MS treatment called BG-12. Phase 3 trials are often the last step in a drug's development before it heads to market.

Later that month, the Food and Drug Administration approved the drug Rituxan, which Biogen co-developed with Roche's (RHBBY) Genentech, for use in treating two extremely rare diseases -- Wegener's Granulomatosis and Microscopic Polyangiitis.The combination of those two events sent shares of Biogen up more than 30% in April alone.

All data current as of June 17, 2011.
Last updated June 29 2011: 7:39 AM ET
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