Institutional Ownership

Top Holders

Holder Shares Held % O/S Share Change Filing Date
QVT Financial LP 75,000,000 69.63 -- 9/30/17
PRIMECAP Management Company 3,410,800 3.17 73,598 9/30/17
Fidelity Management & Research Company 3,227,057 3.00 -4,008,575 9/30/17
PointState Capital LP 2,321,100 2.15 1,970,900 9/30/17
T. Rowe Price Associates, Inc. 1,971,438 1.83 -908,460 9/30/17
Franklin Advisers, Inc. 1,363,634 1.27 -99,948 9/30/17
BlackRock Institutional Trust Company, N.A. 1,306,643 1.21 140,027 9/30/17
Citadel LLC 1,285,810 1.19 984,336 9/30/17
IPL Advisers, LLC 1,207,958 1.12 437,011 9/30/17
Sio Capital Management, LLC 1,118,894 1.04 1,118,894 9/30/17

Top Holders: Mutual Funds

Fund Shares Held % O/S Share Change Filing Date
PRIMECAP Odyssey Aggressive Growth Fund 3,049,806 2.83 84,806 9/30/17
Fidelity Contrafund 2,089,476 1.94 -1,778,832 9/30/17
Fidelity Select Biotechnology Portfolio 1,090,369 1.01 -92,700 9/30/17
T. Rowe Price Health Sciences Fund 940,844 0.87 -754,638 9/30/17
Franklin Templeton Invest-Biotechnology Discovery 928,500 0.86 -- 8/31/17
Janus Henderson Global Life Sciences Fund 750,987 0.70 -40,834 3/31/17
iShares Russell 2000 ETF 681,205 0.63 33,579 10/31/17
Franklin Biotechnology Discovery Fund 509,834 0.47 -25,248 9/30/17
Fidelity Advisor New Insights Fund 402,495 0.37 -312,095 9/30/17
T. Rowe Price Small Cap Stock Fund 364,660 0.34 -4,700 9/30/17

* Insider values reflect direct beneficial ownership.