Simvastatin Plus Dual Anti-HER2 Therapy for Metastatic Breast Cancer

This study is recruiting participants with metastatic breast cancer that is HER2 positive. "Metastatic" means that cancer has spread to areas of the body outside of the breast. "HER2 positive" means that a cancer cell has too many HER2 receptors on its surface. HER2 receptors act like copy machines, and help tell cancer cells to grow and multiply. Drugs known as HER2-targeted therapies are often used to treat HER2-positive cancers. HER2-targeted therapies work by blocking the HER2 protein from telling the cell to grow and divide. Once the protein stops working, the cancer cells can no longer make copies of themselves. Once a cancer cell becomes unable to make copies of itself, the tumor will start to shrink. However, some tumors are able to find other ways to make copies of themselves, even when the HER2 protein is blocked. When this happens, the cancer will start to grow again. Researchers believe that adding a drug called simvastatin to an anti-HER2 therapy regimen may cause the cancer to start responding again to your HER2-medications. Simvastatin is a drug that is approved by the Food and Drug Administration (FDA) to treat high cholesterol. Laboratory research has shown that simvastatin together with dual HER2-targeted therapy slows the growth of breast cancer tumors that had been growing on dual HER2-targeting therapy alone.