Trastuzumab (Herceptin) is a drug widely used to treat women with breast cancers that produce high levels of the HER2 protein. It is very effective, but in some women the cancer returns. In this study, researchers are evaluating the addition of pertuzumab (Perjeta), another drug that targets HER2, to treatment with chemotherapy and trastuzumab in women with HER2-positive breast cancer when given after surgery, to see if this combination is more effective than chemotherapy and trastuzumab alone for slowing cancer growth and improving survival.
Patients in this study will be randomly assigned to receive chemotherapy, trastuzumab, and pertuzumab or chemotherapy, trastuzumab, and a placebo. The treatment is given intravenously (by vein).