Trastuzumab emtansine in combination with pertuzumab for HER2-positive early breast cancer - adjuvant therapy

Trastuzumab emtansine in addition to pertuzumab is in clinical development as an adjuvant therapy for HER2-positive early breast cancer. Breast cancer is the most common cancer in the UK. One type of breast cancer is called HER2-positive. HER is a protein that is found in large amounts on the surface of some cancer cells where it stimulates their growth. HER2-positive breast cancer tends to grow faster than HER2-negative breast cancer. Treatment of early stage breast cancer usually involves surgery. Most patients will often receive some treatment both before and after ‘adjuvant’ therapy) the surgery to improve the success rate of the treatment.
Trastuzumab emtansine consists of an anti-HER2 therapy (trastuzumab) and a chemotherapy agent (emtansine or DM1) combined together as an antibody-drug conjugate. Trastuzumab specifically binds to cancer cells that are HER2-positive which provides a targeted delivery of the cytotoxic DM1 inside cancer cells, potentially limiting damage to healthy tissue. Pertuzumab, is designed to attach to HER2, and stop HER2 producing signals that cause the cancer cells to grow. The combination is thought to provide a more comprehensive, dual blockade of HER pathways and prevent tumour cell growth and survival, and if licenced, will offer an additional adjuvant treatment option for patients with HER2- positive early breast cancer.