On Oct. 28, 2020, Seagen announced the closing of a $1.0 billion equity investment by Merck in 5.0 million newly-issued shares of Seagen common stock at a price of $200 per share. The investment was made in connection with a global collaboration with Merck to co-develop and commercialize ladiratuzumab vedotin, an investigational antibody-drug conjugate (ADC) targeting LIV-1, which is currently in clinical trials for breast cancer and other solid tumors.