Tucatinib (Tukysa)

Mechanism of action

From the NCI Drug Dictionary: An orally bioavailable inhibitor of the human epidermal growth factor receptor tyrosine kinase ErbB-2 (also called HER2) with potential antineoplastic activity. Tucatinib selectively binds to and inhibits the phosphorylation of ErbB-2, which may prevent the activation of ErbB-2 signal transduction pathways, resulting in growth inhibition and death of ErbB-2-expressing tumor cells.

Diseases for which it is established

• HER2+ breast cancer

Diseases for which it is used

• HER2+ colorectal cancer

History of changes in FDA indication

• 2020-04-17: Initial approval in combination with trastuzumab and capecitabine, for adult patients with advanced unresectable or metastatic HER2-positive breast cancer, including patients with brain metastases, who have received one or more prior anti-HER2-based regimens in the metastatic setting. (Based on HER2CLIMB)
• 2023-01-19: Granted accelerated approval in combination with trastuzumab for RAS wild-type HER2-positive unresectable or metastatic colorectal cancer that has progressed following fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy. (Based on MOUNTAINEER)

History of changes in EMA indication

• 2021-02-11: Initial marketing authorization as Tukysa.

Also known as

• Code name: ARRY-380, ONT-380
• Generic name: irbinitinib
• Brand name: Tukysa