Primary results from EMILIA, a phase III study of trastuzumab emtansine (T-DM1) versus capecitabine (X) and lapatinib (L) in HER2-positive locally advanced or metastatic breast cancer (MBC) previously treated with trastuzumab (T) and a taxane

SUMMARY:The HER or erbB family of receptors consist of HER 1,HER 2,HER 3 and HER 4. Overexpression of HER 2 in breast cancer has been associated with higher risk for relapse as well as overall survival. Trastuzumab is a humanized monoclonal antibody targeting HER 2. It binds to the extracellular domain of the receptor and blocks the downstream cell signaling pathways. Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate (ADC) comprised of the antibody trastuzumab and the chemotherapy agent DM1 linked together and inhibits HER2 signaling and destroys the HER2-positive tumor cells by delivering the chemotherapy agent DM1 directly inside the tumor cells. The EMILIA trial is a phase III study in which 978 patients with HER2-positive locally advanced or metastatic breast cancer who had previously received treatment with HERCEPTIN® (Trastuzumab) and a taxane chemotherapy, were enrolled. Patient received either trastuzumab emtansine (T-DM1) or XELODA® (Capecitabine) and TYKERB® (Lapatinib) doublet. The primary endpoints were Progression Free Survival (PFS), Overall Survival (OS) and safety. Patients receiving T-DM1 had an improved PFS compared to XELODA® and TYKERB® (9.6 months vs 6.4 months, HR=0.65, P <0.0001). A final OS analysis will be available at a later date. Blackwell KL, Miles D, Gianni L, et al. J Clin Oncol 30, 2012 (suppl; abstr LBA1)