| 5.12% | % of Shares Held by All Insider |
| 95.64% | % of Shares Held by Institutions |
| 100.80% | % of Float Held by Institutions |
| 127 | Number of Institutions Holding Shares |
| Holder | Shares | Date Reported | % Out | Value |
|---|---|---|---|---|
| RTW Investments LP | 16,037,486 | Mar 30, 2019 | 31.89% | 281,297,504 |
| Tang Capital Management, LLC | 2,965,485 | Mar 30, 2019 | 5.90% | 52,014,606 |
| Adage Capital Partners GP L.L.C. | 2,400,000 | Mar 30, 2019 | 4.77% | 42,096,000 |
| Blackrock Inc. | 2,116,343 | Mar 30, 2019 | 4.21% | 37,120,656 |
| Cormorant Asset Management, LP | 1,700,000 | Mar 30, 2019 | 3.38% | 29,818,000 |
| Bridger Management LLC | 1,529,032 | Mar 30, 2019 | 3.04% | 26,819,221 |
| Boxer Capital, LLC | 1,466,051 | Mar 30, 2019 | 2.92% | 25,714,534 |
| FMR, LLC | 1,465,099 | Mar 30, 2019 | 2.91% | 25,697,836 |
| Vanguard Group, Inc. (The) | 1,266,938 | Mar 30, 2019 | 2.52% | 22,222,092 |
| Citadel Advisors LLC | 1,096,474 | Mar 30, 2019 | 2.18% | 19,232,153 |
| Holder | Shares | Date Reported | % Out | Value |
|---|---|---|---|---|
| Fidelity Select Portfolios - Biotechnology | 1,464,787 | Apr 29, 2019 | 2.91% | 27,186,446 |
| Vanguard Total Stock Market Index Fund | 631,991 | Dec 30, 2018 | 1.26% | 9,366,106 |
| iShares Russell 2000 ETF | 482,481 | Apr 29, 2019 | 0.96% | 8,954,847 |
| iShares NASDAQ Biotechnology ETF | 450,115 | Apr 29, 2019 | 0.90% | 8,354,134 |
| Invesco Health Care Fund | 427,394 | Mar 30, 2019 | 0.85% | 7,496,490 |
| SPDR (R) Ser Tr-SPDR (R) S&P (R) Biotech ETF | 418,353 | Apr 29, 2019 | 0.83% | 7,764,631 |
| Price (T.Rowe) Health Sciences Fund | 397,702 | Mar 30, 2019 | 0.79% | 6,975,693 |
| Mutual Fund Ser Tr-Eventide Healthcare & Life Sciences Fund | 394,585 | Sep 29, 2018 | 0.78% | 9,714,682 |
| Price (T.Rowe) New Horizons Fund | 374,812 | Mar 30, 2019 | 0.75% | 6,574,202 |
| Vanguard Extended Market Index Fund | 354,879 | Dec 30, 2018 | 0.71% | 5,259,306 |