| RA CAPITAL MANAGEMENT, L.P. | 28,933,371 | $791.9m | 6.9% |
| FMR LLC | 10,292,735 | $281.7m | 0.0% |
| ARCH Venture Management, LLC | 6,412,780 | $175.5m | 16.0% |
| venBio Partners LLC | 5,266,697 | $144.1m | 27.8% |
| Alphabet Inc. | 4,919,498 | $134.6m | 0.1% |
| Nextech Invest Ltd. | 4,663,176 | $127.6m | 6.1% |
| Cormorant Asset Management, LP | 4,615,612 | $126.3m | 6.5% |
| REGENERON PHARMACEUTICALS, INC. | 4,166,666 | $114.0m | 64.4% |
| Siren, L.L.C. | 2,992,259 | $81.9m | 1.7% |
| FARALLON CAPITAL MANAGEMENT, L.L.C. | 2,368,200 | $64.8m | 0.3% |
| Jupiter Topco LLC | 2,296,547 | $62.7m | 0.0% |
| Frazier Life Sciences Management, L.P. | 1,920,805 | $52.6m | 1.1% |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 1,880,704 | $51.5m | 0.5% |
| General Catalyst Group Management, LLC | 1,600,937 | $43.8m | 23.2% |
| GENERAL ATLANTIC, L.P. | 1,538,461 | $42.1m | 1.4% |
| Soleus Capital Management, L.P. | 1,465,070 | $40.1m | 1.4% |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 1,302,479 | $35.6m | 0.0% |
| VANGUARD CAPITAL MANAGEMENT LLC | 1,156,962 | $31.7m | 0.0% |
| JPMORGAN CHASE & CO | 1,042,772 | $30.4m | 0.0% |
| Foresite Capital Management VI LLC | 999,044 | $27.3m | 4.3% |
| Catalio Capital Management, LP | 824,043 | $22.6m | 4.2% |
| ALLIANCEBERNSTEIN L.P. | 810,279 | $22.2m | 0.0% |
| PRICE T ROWE ASSOCIATES INC /MD/ | 751,947 | $20.6m | 0.0% |
| Casdin Capital, LLC | 645,690 | $17.7m | 0.9% |
| Venrock Adviser, LLC | 625,000 | $17.1m | 0.5% |