Analysis of the mechanism of action of tucatinib/tucatinib

Tucatinib/Tucatinib is an effective treatment for HER2-positive breast cancer and colorectal cancer. It is often used in combination with trastuzumab and capecitabine and is particularly useful in breast cancer patients who have already received one or more anti-HER2 treatments that have not responded well, and can even be effective in cancers that have spread to the brain. In addition, for patients with RAS wild-type HER2-positive unresectable or metastatic colorectal cancer, when chemotherapy regimens based on fluoropyrimidine, oxaliplatin, and irinotecan failed to control the disease, the combination therapy of tucatinib and trastuzumab also showed significant therapeutic effects.

The cells of patients with HER2+ cancer produce excess amounts of the HER2 protein due to the action of a specific gene. This excess HER2 protein promotes rapid and aggressive growth of cancer cells. Tucatinib, as a human epidermal growth factor receptor-2 (HER2) inhibitor, slows or prevents the growth of cancer cells in patients with advanced breast cancer or colorectal cancer by blocking the function of the HER2 protein.

Tucatinib is an oral targeted drug that is highly selective forHER2 protein and works inside cells. It binds tightly to HER2's tyrosine kinase, a key enzyme, thereby reducing signaling by PI3 kinase and MAP kinase. This weakening of signaling helps prevent further growth of cancer cells and ultimately leads to their death. Therefore, tucatinib is classified as a HER2 tyrosine kinase inhibitor.

Tucatinib is an oral tablet that patients need to take twice daily (intervals12 hours apart), with or without food. It is worth noting that tucatinib must be used within 3 months after opening the bottle. After 3 months, any unused tablets should be thrown away.