| FMR LLC | 8,199,893 | $799.3m | 0.0% |
| BlackRock, Inc. | 4,123,822 | $402.0m | 0.0% |
| T. Rowe Price Investment Management, Inc. | 3,888,456 | $379.0m | 0.2% |
| WELLINGTON MANAGEMENT GROUP LLP | 3,229,882 | $314.8m | 0.1% |
| Fairmount Funds Management LLC | 2,537,191 | $247.3m | 16.3% |
| PRICE T ROWE ASSOCIATES INC /MD/ | 2,514,946 | $245.2m | 0.0% |
| STATE STREET CORP | 2,357,440 | $229.8m | 0.0% |
| VANGUARD CAPITAL MANAGEMENT LLC | 2,159,568 | $210.5m | 0.0% |
| Avidity Partners Management LP | 2,104,184 | $205.1m | 32.8% |
| Octagon Capital Advisors LP | 1,841,667 | $179.5m | 16.1% |
| TCG Crossover Management, LLC | 1,676,624 | $163.4m | 3.9% |
| FRED ALGER MANAGEMENT, LLC | 1,302,493 | $127.0m | 0.4% |
| GEODE CAPITAL MANAGEMENT, LLC | 1,258,502 | $122.7m | 0.0% |
| Venrock Adviser, LLC | 1,180,000 | $115.0m | 3.5% |
| UBS Group AG | 1,140,260 | $111.2m | 0.0% |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 1,125,313 | $109.7m | 1.1% |
| JENNISON ASSOCIATES LLC | 1,021,763 | $99.6m | 0.1% |
| Polar Capital Holdings Plc | 1,018,726 | $99.3m | 0.2% |
| CITADEL ADVISORS LLC | 974,911 | $95.0m | 0.0% |
| FRANKLIN RESOURCES INC | 968,983 | $94.5m | 0.0% |
| BAKER BROS. ADVISORS LP | 852,164 | $83.1m | 0.4% |
| Logos Global Management LP | 800,000 | $78.0m | 3.4% |
| Cormorant Asset Management, LP | 750,000 | $73.1m | 3.7% |
| ALLIANCEBERNSTEIN L.P. | 834,150 | $70.0m | 0.0% |
| BRAIDWELL LP | 594,562 | $58.0m | 2.1% |