Brand Name: Herceptin 
Generic Name: trastuzumab

Medication Class: monoclonal antibody
Similar Drugs: pertuzumab (Perjeta), ado-trastuzumab emtansine (Kadcyla)
Manufacturer: Genentech
FDA Approval date: September 1998

What is Herceptin and its mechanism of action?

Herceptin is a man-made injectable protein that blocks Human epidermal growth factor receptor 2 protein (HER2) in breast and gastric cancer cells. HER2 is a type of receptor found on normal cells and inside breast or gastric cancer cells. Women with HER2-positive breast cancer or people with HER2 gastric cancer have too many HER2 receptors in their cancer cells. When HER2 receptors are activated, they cause cancer cells to grow and divide. Herceptin is a humanized monoclonal antibody that mimics the antibodies the body naturally produces as part of the immune system’s response to viruses, bacteria, and other invaders. Herceptin works by attaching itself to HER2 receptors on breast or gastric cancer cells, preventing them from receiving the signals they need to grow. This slows or stops the spread of breast or gastric cancer.

What is Herceptin used for treating?

Herceptin is used for adjuvant treatment of breast cancer that has an abundance of HER2 receptors.

• As part of a regimen including doxorubicin, cyclophosphamide, paclitaxel or docetaxel
• With docetaxel and carboplatin
• As a single agent after anthracycline-based therapy

It is also effective in treating HER2-positive metastatic breast cancer (cancer that has spread out from the site where it started)

• In combination with paclitaxel
• As a single agent in patients who have received one or more chemotherapy regimens

Herceptin can also be used in combination with cisplatin and capecitabine (Xeloda) or 5-fluorouracil to treat HER2-positive metastatic gastric or gastroesophageal junction adenocarcinoma in people who have not received prior treatment.

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