What is the mechanism of action of tucatinib?

The mechanism of action of Tucatinib is based on its properties as an oral tyrosine kinase inhibitor (TKI), which mainly acts on the human epidermal growth factor receptor 2 (HER2) signaling pathway. HER2 is overexpressed in certain cancer cells and promotes cancer cell proliferation, survival and metastasis. Tucatinib can selectively bind to the HER2 receptor and block its downstream signaling, thus inhibiting the growth and division of cancer cells.

Tucatinib inhibits the kinase activity of HER2 receptor and blocks its downstream signaling. HER2 is an important transmembrane receptor tyrosine kinase involved in regulating cell growth, differentiation and survival. In HER2 positive breast cancer, HER2 receptors are often overexpressed or abnormally activated, leading to malignant proliferation and metastasis of tumor cells. Tucatinib effectively prevents the growth of diseased cells by inhibiting the kinase activity of the HER2 receptor.

Tucatinib not only inhibits the activation of HER2 receptors, but also blocks the proliferation and phosphorylation of its downstream effector Akt, thereby further inhibiting the growth and metastasis of tumor cells. At the same time, its inhibitory effect on other receptors such as EGFR is weak, reducing the toxic reactions caused by inhibiting other receptors.

Tucatinib has a high degree of target selectivity forHER2, which increases the targeting effect on lesions, reduces the impact on normal cells, and improves the tolerability and safety of the treatment.

The small molecule design of tucatinib enables it to better cross the blood-brain barrier and inhibit cancer cells in the brain. This makes it particularly effective in the treatment of HER2-positive breast cancer with brain metastasis.

Tucatinib is often used as part of a combination treatment regimen that includes combinations with trastuzumab and capecitabine. This combination treatment regimen is widely used in patients with HER2-positive advanced or metastatic breast cancer and can significantly improve patient survival and progression-free survival.

References:

https://www.drugs.com/medical-answers/mechanism-action-tucatinib-3557652/