What is Herceptin and what does it do?

Herceptin “targets” HER2 receptors to fight tumor cell growth.⁠

What is a HER2 receptor?⁠

⁠It’s a type of protein found in everyone. HER2 receptors are on the surface of both normal cells and cancer cells.⁠ This protein tells cells to grow and divide. Too much HER2 is called “HER2 overexpression” or “HER2+.”⁠

What is HER2+ breast cancer?⁠

In breast cancer that is HER2+, the cancer cells have too many HER2 receptors.⁠ Too many HER2 receptors on cancer cells make this type of cancer grow faster⁠

Studies have shown that Herceptin attaches to HER2 receptors. Herceptin may stop a HER2 receptor from telling the cell to grow and divide. Also, Herceptin may signal the body’s immune system to destroy that cancer cell.Herceptin is approved for the treatment of early breast cancer (EBC) that is Human Epidermal growth factor Receptor 2-positive (HER2+) and has spread into the lymph nodes. In the case of HER2+ EBC that has not spread to the lymph nodes, it must meet the following condition: the cancer needs to be estrogen receptor/progesterone receptor (ER/PR)-negative or have one high-risk feature.* Herceptin is also approved for the treatment of HER2+ breast cancer that has spread to other parts of the body (metastatic breast cancer).⁠

*High risk is defined as ER/PR-positive with one of the following features: tumor size >2 cm, age >35 years, or tumor grade 2 or 3.⁠