Description and Target

Tucatinib was added to our pipeline in March 2018 with the acquisition of Cascadian Therapeutics. It is an orally bioavailable, small molecule tyrosine kinase inhibitor (TKI) that is highly selective for HER2, a growth factor receptor that is over-expressed in multiple cancers, including breast, colorectal, esophageal, gastric, lung and ovarian cancers. It is over-expressed in approximately 20% of breast cancers.

Tucatinib has been evaluated as a single agent and in combination with both chemotherapy and other HER2-directed agents including Herceptin® (trastuzumab) and Kadcyla® (trastuzumab emtansine). Results from phase 1b trials showed that the combination of tucatinib, capecitabine and trastuzumab was generally well-tolerated and demonstrated clinical activity in patients with and without brain metastases.

See the Pipeline section for information on the ongoing clinical studies evaluating tucatinib in breast and colorectal cancer.


Tucatinib is an investigational agent, and its safety and efficacy have not yet been established.