A recent study showed that trastuzumab emtansine (T-DM1), a new treatment for HER2-positive metastatic breast cancer, worked better to control the cancer growth than the current standard treatment of chemotherapy with capecitabine (Xeloda) and lapatinib (Tykerb). HER2-positive means that the breast cancer has too much of a protein called human epidermal growth factor receptor 2 (HER2).
T-DM1, the new drug found to be more effective in controlling the cancer growth, is a combination of a drug that targets HER2 and one that is similar to chemotherapy. The study of nearly 1,000 patients with metastatic HER2-positive breast cancer showed that cancer worsened three months later in patients receiving T-DM1 than in patients receiving the standard therapy. In addition, T-DM1 has few side effects, namely low levels of platelets and signs of liver function problems. These side effects went away with a break in treatment.
More information on the study can be found here.