TACSTD2 and breast cancer: Two Phase III studies are comparing sacituzumab govitecan, a Trop-2-directed antibody and topoisomerase inhibitor SN-38 drug conjugate to single agent chemotherapy in HR + BC after the failure of at least 2, and no more than 4, prior chemotherapy regimens (NCT04639986 and NCT03901339). The Phase 2 PACE trial (NCT03147287) is a 3-arm trial that is evaluating synergistic effect of immune checkpoint inhibitor avelumab to combination of fulvestrant and palbociclib.