Perjeta is a medicine that targets the HER2 receptor, which is designed specifically to prevent the HER2 receptor from pairing with other HER receptors on the surface of cancer cells. Binding of Perjeta to HER2 may also signal the body’s immune system to destroy the cancer cells. The mechanisms of action of Perjeta and Herceptin (trastuzumab) are believed to complement each other and provide a more comprehensive dual blockade of HER signalling pathways, thus preventing tumour cell growth and survival.

In the US, Europe and other countries Perjeta is approved in combination with Herceptin and chemotherapy for the neoadjuvant (pre-surgery) treatment of people with HER2-positive, locally advanced, inflammatory, or early stage breast cancer and as a first-line treatment of advanced HER2-positive breast cancer. In the US, Perjeta in combination with Herceptin and chemotherapy is also indicated for the adjuvant (post-surgery) treatment of people with HER2-positive early breast cancer at high risk of recurrence.