Skip to main content

What's the mechanism of action for tucatinib?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Jan 25, 2023.

Official answer

by Drugs.com

Tucatinib (Tukysa) is a human epidermal growth factor receptor-2 (HER2) inhibitor that works by blocking the HER2 protein to help slow or stop cancer cell growth in patients with advanced breast cancer or colorectal cancer. Some cancers have an over-expression of the HER2 protein causing increased growth and spread of cancer cells.

Tucatinib, an oral targeted drug therapy, is very selective for the HER2 protein and works inside the cell. Tucatinib binds to tyrosine kinase (an enzyme) of HER2, reducing PI3-kinase and MAP-kinase signaling. Reduced signaling helps to block cell growth and leads to cell death. Tucatinib is classified as a HER2 tyrosine kinase inhibitor.

Related information: List of HER2 Inhibitors

How is tucatinib used?

  • Tucatinib (Tukysa) is used with the medicines trastuzumab (Herceptin) and capecitabine (Xeloda) in adult patients with HER2-positive breast cancer, including cancer that has spread to the brain. It is given to patients who have already received one or more anti-HER2 breast cancer treatments, but are no longer effective.
  • It is also used in combination with trastuzumab to treat adult patients with RAS wild-type HER2-positive unresectable or metastatic colorectal cancer that has progressed following treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy.
  • It is used when the cancer has spread in the body (metastatic) or cannot be removed with surgery (unresectable).

The FDA approved Tukysa for colorectal cancer under an "accelerated approval". This means that continued approval for this use may depend upon results of further clinical studies looking at its effectiveness in colorectal cancer.

This is not all the information you need to know about Tukysa (tucatinib) for safe and effective use and does not take the place of talking to your doctor about your treatment. Review the full product information here, and discuss this information and any questions you have with your doctor or other health care provider.

Related Questions

References
  • Tukysa (tucatinib) product information. Seagen. Bothell, WA. Revised 1/2023. Accessed Jan 25, 2023 at https://docs.seagen.com/TUKYSA_Full_Ltr_Master.pdf
  • Tukysa.com. Mechanism of Action. Seagen Inc. Accessed April 22, 2021 at https://www.tukysahcp.com/videolibrary

Read next

Most side effects of letrozole are mild and temporary, lasting only a few days or weeks until your body gets used to taking the medication. Some other side effects of letrozole take a few months to develop and tend to persist long term until you stop taking letrozole. The half-life of letrozole is 2 days, so once you stop taking letrozole, you might continue to experience side effects for about a week to 10 days after your last dose. Continue reading

When you stop taking letrozole, side effects such as swelling, cough, hot flashes, and nausea, should improve within a week or 10 days. Some, such as high cholesterol, bone loss, and hair thinning may take many months to resolve. As long as you have taken it for at least 5 years, then letrozole should continue to reduce the risk of breast cancer coming back for many years after you stop taking it. Letrozole is usually taken for 5 years, but may be recommended for up to 10 years depending on individual circumstances.  Continue reading

While pain relievers such as acetaminophen and NSAIDs can help relieve the pain, NSAIDs themselves have their side effects and should not be taken long-term unless under a doctor's advice. Continue reading

Related medical questions

Drug information

Related support groups

Medical Disclaimer