Abstract

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer-related deaths in women worldwide. Approximately 1 in 5 women diagnosed with BC will have HER2-positive disease, an aggressive subset of breast cancer.   Trastuzumab, a monoclonal antibody that targets the HER2 receptor on breast cancer cells. It has improved survival in breast cancer patients. However, resistance to therapy arises especially in patients with advanced disease. Trastuzumab emtansine (T-DM1) is a HER2-targeted ADC, composed of trastuzumab, a stable thioether linker, and the potent cytotoxic agent, emtansine (DM1, derivative of maytansine). T-DM1 has been approved for use in patients with metastatic who have failed prior therapy with trastuzumab and a taxane chemotherapy.  The Phase III randomized EMILIA and TR3RESA trials demonstrated that T-DM1 significantly improves progression-free and overall survival in pretreated HER2-positive metastatic breast cancer patients and currently under evaluation for use in early stage breast cancers. It will be very interesting to listen to case of an ADC, T-DM1 which has established globally an effective therapeutic option for the management of metastatic HER2-positive breast cancer patients.