NEW DRUGS Perjeta, an Antibody For Metastatic Breast Cancer

NEW DRUGS Perjeta, an Antibody For Metastatic Breast Cancer HER-2, a protein involved in normal cell growth, is found in increased amounts on some types of cancer cells, including some breast cancers. In HER-2–positive breast cancer, the increased amount of the HER-2 protein contributes to cancer cell growth and survival. About 20% of breast cancers have increased amounts of HER-2. The FDA recently approved a new anti– HER-2 therapy, pertuzumab (Perjeta, Genentech), to treat patients with HER-2– positive late-stage breast cancer. The drug is intended for patients who have not been treated for metastatic breast cancer with an anti–HER-2 drug or chemotherapy. Perjeta is combined with trastuzumab (Herceptin, Genentech), another anti– HER-2 agent, and docetaxel (Taxotere, Sanofi), a type of chemotherapy. Perjeta is a humanized monoclonal antibody manufactured through biotechnology methods. Administered intravenously, it is believed to work by targeting a different part of the HER protein than is targeted by trastuzumab, resulting in further reduction in the growth and survival of HER-2–positive breast cancer cells. The labeling for Perjeta includes a boxed warning regarding the potential risk for severe fetal injury or fetal death. Source: FDA, June 8, 2012