| | | | | |
| Name | Jurisdiction of Incorporation |
| Cascadian Therapeutics, LLC | Delaware |
| East Coast Ventures, Inc. | Delaware |
| Seagen Australia Pty Limited | Australia |
| Seagen Austria GmbH | Austria |
| Seagen B.V. | Netherlands |
| Seagen Canada Inc. | Canada |
| Seagen Denmark ApS | Denmark |
| Seagen France SAS | France |
| Seagen Germany GmbH | Germany |
| Seagen International GmbH | Switzerland |
| SeaGen International Holdings, LLC | Delaware |
| SeaGen Ireland Limited | Ireland |
| Seagen Italy S.r.l. | Italy |
| Seagen Spain, S.L. | Spain |
| Seagen Sweden AB | Sweden |
| Seagen U.K. Ltd. | England and Wales |
| Seagen U.S. Inc. | Delaware |
| SeaGen US Holdings, LLC | Delaware |