Sacituzumab Govitecan +/- Pembrolizumab In HR+ / HER2 - MBC

Study Summary

This research study is evaluating the safety and effectiveness of Sacituzumab Govitecan with or without Pembrolizumab in metastatic HR+/HER2- breast cancer. The names of the study interventions involved in this study are: * Sacituzumab govitecan (IMMU-132) * Pembrolizumab (Keytruda®; MK-3475)