Seattle Genetics has agreed to acquire Cascadian Therapeutics in a deal worth US$614 M to gain global rights to tucatinib (ONT-380), which is in Phase II clinical development for the treatment of metastatic human epidermal growth factor 2 positive (HER2+) breast cancer, and some early-stage oncology assets. For Seattle Genetics this is a key deal which has come after an unsuccessful attempt to license sacituzumab govitecan (IMMU-132) from Immunomedics in 2017 and failure of vadastuximab talirine in a late stage clinical trial for leukaemia.