Brand Name: Tykerb 
Generic Name: lapatinib

Medication Class:  tyrosine kinase inhibitor
Similar Drugs: imatinib (Gleevec), gefitinib (Iressa), erlotinib (Tarceva)
Manufacturer: Novartis
Approval date: 2007

What is Tykerb and its mechanism of action?

Tykerb is an oral drug used for treating breast cancer. It is a tyrosine kinase inhibitor. HER2 is a type of receptor found on normal cells and inside breast cancer cells. Women with HER2-positive breast cancer have too many HER2 receptors in their cancer cells. When HER2 receptors are activated, they make the cancer cell grow and divide. Tykerb is a molecule small enough to penetrate the cancer cell membrane and bind to the part of the HER2 receptor that is inside the cell. This stops the cell from growing.

What is Tykerb used for treating?

Tykerb is used to treat HER2-positive metastatic breast cancer. Metastatic means the cancer that has spread beyond its site of origin. Tykerb is used in combination with capecitabine when prior therapy, including anthracycline (such as doxorubicin), a taxane (such as  paclitaxel) and Herceptin (trastuzumab) fail.

How effective is Tykerb?

Tykerb was studied in 399 women with advanced or metastatic HER2-positive breast cancer whose disease progressed after treatment with anthracycline, a taxane, and trastuzumab. Patients were randomized into two groups. The first group received Tykerb 1250 mg orally daily with capecitabine 2000 mg/m² orally in 2 divided doses, days 1 to 14 in a repeating 21-day cycle. The second group received capecitabine 2500 mg/m² a day orally in 2 divided doses on days 1 to 14 in a repeating 21-day cycle.

Two years following therapy, women who received Tykerb had a lower mortality  rate of 76% compared to  women who did not take Tykerb with a mortality rate of  82%. Tykerb with capecitabine lowered risk of disease progression by 43% compared with capecitabine alone. (Data cutoff was 100 days after  randomization)

A second study looked at the efficacy of Tykerb in combination with Femara (letrozole) in 1,286 postmenopausal women with metastatic breast cancer. Of those women, 219 had HER2-positive cancer. In this group, women had an average of 35.4 weeks of progression-free survival following treatment with Tykerb plus letrozole versus 13 weeks in women who were treated with letrozole only.

Interesting Facts about Tykerb

• Tykerb is taken as five tablets by mouth once daily.
• Tykerb can be taken at home.
• It should be taken on an empty stomach.
• Some people may develop severe liver damage while taking Tykerb.

What are side effects of Tykerb?

Common side effects:

• Diarrhea
• Red, painful hands and feet
• Nausea/vomiting
• Rash
• Fatigue

Severe side effects:

• Heart problems
• Liver problems
• Severe diarrhea
• Lung problems
• Severe skin reactions

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