| FMR LLC | 4,993,906 | $65.2m | 0.0% |
| BlackRock, Inc. | 4,281,425 | $55.9m | 0.0% |
| Foresite Capital Management IV, LLC | 1,943,682 | $25.4m | 8.7% |
| Merck & Co., Inc. | 1,666,666 | $21.7m | 4.1% |
| T. Rowe Price Investment Management, Inc. | 1,595,274 | $20.8m | 0.0% |
| Foresite Capital Management V, LLC | 1,318,983 | $17.2m | 4.8% |
| Capital World Investors | 1,175,944 | $15.3m | 0.0% |
| PRICE T ROWE ASSOCIATES INC /MD/ | 1,005,035 | $13.1m | 0.0% |
| VANGUARD CAPITAL MANAGEMENT LLC | 922,707 | $12.0m | 0.0% |
| EcoR1 Capital, LLC | 732,606 | $9.6m | 0.5% |
| GEODE CAPITAL MANAGEMENT, LLC | 556,955 | $7.3m | 0.0% |
| BAKER BROS. ADVISORS LP | 555,555 | $7.2m | 0.0% |
| ALLIANCEBERNSTEIN L.P. | 641,888 | $6.8m | 0.0% |
| SOROS CAPITAL MANAGEMENT LLC | 484,672 | $6.3m | 1.1% |
| StepStone Group LP | 395,340 | $5.2m | 0.2% |
| CANADA PENSION PLAN INVESTMENT BOARD | 379,024 | $4.9m | 0.0% |
| STATE STREET CORP | 354,093 | $4.6m | 0.0% |
| FRANKLIN RESOURCES INC | 350,000 | $4.6m | 0.0% |
| General Catalyst Group Management, LLC | 305,233 | $4.0m | 2.1% |
| UBS Group AG | 263,932 | $3.4m | 0.0% |
| Parkman Healthcare Partners LLC | 256,053 | $3.3m | 0.3% |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 182,105 | $2.4m | 0.0% |
| Schonfeld Strategic Advisors LLC | 179,775 | $2.3m | 0.0% |
| NORTHERN TRUST CORP | 175,927 | $2.3m | 0.0% |
| Ensign Peak Advisors, Inc | 170,490 | $2.2m | 0.0% |