Phase I-II Study of Interferon-gamma in Patients With HER-2 Positive Breast Cancer

This purpose of this study is to evaluate the safety and to find the optimal dose in participants with human epidermal growth factor receptor 2 (HER2) positive breast cancer who are given the combination of Interferon-gamma with paclitaxel, trastuzumab and pertuzumab. This study will also look at other effects of Interferon-gamma with paclitaxel, trastuzumab and pertuzumab, including its effect on this type of cancer. Interferon-gamma is a biologically manufactured protein that is similar to a protein the body makes naturally. In the body, interferon gamma is produced by immune cells and helps to prevent serious infections.