| | | | | |
| Subsidiary | State or Other Jurisdiction of Organization |
| Aphelion LLC | Delaware |
| Cerveau Technologies, Inc. | Delaware |
| Excelsior Life Sciences Ireland Limited | Ireland |
| EXINI Diagnostics AB | Sweden |
| Lantheus Alpha Therapy, LLC | Delaware |
| Lantheus EU Limited | Ireland |
| Lantheus Five, LLC | Delaware |
| Lantheus Medical Imaging, Inc. | Delaware |
| Lantheus MI Canada, Inc. | Canada |
| Lantheus MI Real Estate, LLC | Delaware |
| Lantheus MI UK Limited | United Kingdom |
| Lantheus Omega, LLC | Delaware |
| Lantheus One, LLC | Delaware |
| Lantheus Radiopharmaceuticals UK Limited | United Kingdom |
| Lantheus Three, LLC | Delaware |
| Lantheus Two, LLC | Delaware |
| Meilleur Technologies, Inc. | Delaware |
| MNTX Royalties Sub LLC | Delaware |
| Molecular Insight Pharmaceuticals, Inc. | Delaware |
| Project Hazel Merger Sub, Inc. | Delaware |
| Progenics Pharmaceuticals Nevada, Inc. | Nevada |
| Progenics Pharmaceuticals, Inc. | Delaware |
| PSMA Development Company LLC | Delaware |