| Top Institutional Holders |
|---|
| Holder | Shares | % Out | Value* | Reported |
|---|
| FMR, LLC | 7,920,168 | 9.70 | 71,677,520 | Mar 31, 2013 | | Primecap Management Company | 5,643,289 | 6.91 | 51,071,765 | Mar 31, 2013 | | Sectoral Asset Management, Inc. | 4,782,622 | 5.86 | 43,282,729 | Mar 31, 2013 | | Vanguard Group, Inc. (The) | 4,389,346 | 5.38 | 39,723,581 | Mar 31, 2013 | | QVT Financial LP | 4,137,144 | 5.07 | 37,441,153 | Mar 31, 2013 | | Price (T.Rowe) Associates Inc | 3,889,000 | 4.76 | 35,195,450 | Mar 31, 2013 | | State Street Corporation | 3,231,890 | 3.96 | 29,248,604 | Mar 31, 2013 | | S.A.C. Capital Advisors, LLC | 3,078,962 | 3.77 | 27,864,606 | Mar 31, 2013 | | BlackRock Fund Advisors | 3,013,189 | 3.69 | 27,269,360 | Mar 31, 2013 | | Visium Asset Management | 3,000,000 | 3.68 | 27,150,000 | Mar 31, 2013 |
|
| Holder | Shares | % Out | Value* | Reported |
|---|
| Primecap Odyssey Aggressive Growth Fund | 3,616,289 | 4.43 | 32,727,415 | Mar 31, 2013 | | Fidelity Select Portfolios - Biotechnology | 3,172,913 | 3.89 | 28,714,862 | Mar 31, 2013 | | Fidelity Blue Chip Growth Fund | 2,356,200 | 2.89 | 21,323,610 | Mar 31, 2013 | | Price (T.Rowe) Health Sciences Fund | 2,139,300 | 2.62 | 19,360,665 | Mar 31, 2013 | | Columbia Acorn Fund | 2,025,000 | 2.48 | 19,622,250 | Dec 31, 2012 | | SPDR (R) Ser Tr-SPDR (R) S&P (R) Biotech ETF | 1,865,472 | 2.29 | 16,882,521 | Mar 31, 2013 | | Parnassus Small-Cap Fund | 1,750,000 | 2.14 | 15,837,500 | Mar 31, 2013 | | Fidelity Growth Company Fund | 1,373,117 | 1.68 | 12,426,708 | Mar 31, 2013 | | iShares Russell 2000 Index Fund | 1,311,179 | 1.61 | 11,866,169 | Mar 31, 2013 | | First Trust NYSE Arca Biotechnology Index Fund | 1,261,975 | 1.55 | 12,228,537 | Dec 31, 2012 |
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View Transactions for Insiders & Institutional Holders Value shown is computed using the security's price on the report date given. Currency in USD. |
1.06%