| Year | Detail |
| 2005 |
The company was established. |
| 2007 |
Astellas acquired Agensys Inc., a biotechnology company. |
| 2010 |
Astellas acquired OSI Pharmaceuticals Inc. |
| 2012 |
Astellas launched Gonax |
| 2013 |
Astellas and UCB Japan launched Cimzia |
| 2016 |
Astellas acquired Ocata Therapeutics Inc. |
| 2016 |
Astellas acquired Ganymed Pharmaceuticals AG |
| 2017 |
Astellas acquired Ogeda SA |
| 2018 |
Astellas acquired Mitobridge Inc. |
| 2018 |
Astellas acquired Universal Cells Inc. |
| 2019 |
Astellas acquired Xyphos Biosciences Inc. |
| 2020 |
Astellas acquired Audentes Therapeutics Inc. |
| 2020 |
Astellas acquired Nanna Therapeutics Ltd |
| 2024 |
Astellas collaborates with Mass General Brigham |