Durvalumab With Trastuzumab and Pertuzumab in HER2-Enriched Breast Cancer

The purpose of this research study is to test the safety and effectiveness of using durvalumab with trastuzumab and pertuzumab in participants with HER2-enriched breast cancer. The standard or usual pre-surgery treatment for this type of disease are drugs called trastuzumab and pertuzumab that target HER2. Studies have shown that trastuzumab and pertuzumab treatment can stimulate the body's own immune system to attack cancer cells. Durvalumab is a drug that also activates the immune system. The use of durvalumab together with trastuzumab and pertuzumab treatment may allow the immune system to work harder to kill cancer cells.