Seattle Genetics Inc. and Cascadian Therapeutics Inc. announced the signing of a definitive merger agreement under which Seattle Genetics has agreed to acquire Cascadian Therapeutics. Under the terms of the agreement, Seattle Genetics will pay $10.00 per share in cash, or approximately $614 million. The transaction was unanimously approved by the Boards of Directors of both companies. The transaction is anticipated to close in the first quarter of 2018.