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How does Tykerb work?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Jan 10, 2023.

Official answer


Tykerb (lapatinib) is a dual tyrosine kinase inhibitor and works by blocking both Epidermal Growth Factor Receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2). This helps stop or slow the spread of breast cancer cells. Tykerb is a targeted drug therapy used in the treatment of HER-2 positive metastatic breast cancers.

Tykerb blocks EGFR and HER2 receptors that encourage cancer cell growth. Some cells have too many of these proteins which can lead to uncontrolled cell growth and cancer. Tykerb interferes with specialized proteins called kinases that can stimulate cell division.

Tykerb is an oral tablet used with capecitabine (Xeloda) or letrozole (Femara) to treat certain types of HER2-positive breast cancer that are advanced or have spread (metastasized).

Is Tykerb considered a chemotherapy drug?

Tykerb is not a traditional chemotherapy drug. It is an oral targeted drug therapy used in the treatment of advanced breast cancer. It is considered a targeted drug therapy because it works on specific proteins on breast cancer to help slow or stop the spread of cancer cells. Tykerb is classified as a dual tyrosine kinase inhibitor (TKI).

Tykerb is given as an oral tablet with other medicines. You will normally continue treatment until the cancer continues to grow or you have unacceptable side effects from treatment.

Will I lose my hair with Tykerb?

Tykerb is not a traditional chemotherapy drug but you may still experience hair-thinning or hair loss with this medicine. In studies, hair loss (alopecia) was reported in about 10% to 13% of patients receiving Tykerb plus other medicines. In most patients, hair loss is a reversible side effect if treatment is stopped.

Other side effects, including serious or life-threatening adverse effects, may occur.

Learn more: Tykerb (lapatinib) dosing and side effects (in detail)

Related questions

What is HER2-positive breast cancer?

HER2-positive breast cancer is one type of breast cancer that has an excess of HER2 genes or receptors. HER2 stands for human epidermal growth factor receptor 2.

HER2 receptors are specialized proteins found on breast cancer cells that help control cell growth. The test for HER2 determines the risk of breast cancer returning and can help your healthcare provider decide on the best treatment to direct against the cancer.

The HER2 protein is found in about 1 out of every 5 (20%) with breast cancer. All women are screened for this protein when they are first diagnosed.

HER2-positive breast cancers can be more aggressive than some other types of breast cancer. HER2-targeted therapy, called HER2 inhibitors, are a standard treatment for HER2-positive breast cancers and are often combined with other treatments.

HER2 therapy is not used for HER2-negative breast cancer.

This is not all the information you need to know about Tykerb (lapatinib) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.

  • Castellino S, O'Mara M, Koch K, et al. Human metabolism of lapatinib, a dual kinase inhibitor: implications for hepatotoxicity. Drug Metab Dispos. 2012 Jan;40(1):139-50. doi: 10.1124/dmd.111.040949
  • Tykerb (lapatinib) prescribing information. 3/2022. Novartis. Accessed Jan. 10, 2023 at

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