Global pharmaceutical giant AbbVie announced on Monday that it has entered into a definitive agreement to acquire clinical-stage biotech company Apogee Therapeutics in an all-cash transaction valued at approximately $10.9 billion, marking AbbVie’s largest acquisition since its $63 billion purchase of Allergan, the maker of Botox, in 2019.

Under the terms of the agreement, AbbVie will acquire all outstanding shares of Apogee for $135.11 per share in cash, representing an equity value of roughly $10.9 billion. The offer reflects a premium of about 49% to Apogee’s closing price on June 18.

The announcement sent Apogee shares soaring nearly 47%, while AbbVie gained almost 5% in early trading. The transaction has been unanimously approved by the boards of directors of both companies and is expected to close in the third quarter of 2026.