Sacituzumab govitecan (IMMU-132) is another treatment option for HR-positive HER2-low metastatic BC, based on the positive results of the TROPICS-02 clinical trial, that showed a PFS (6.4 vs. 4.2 months, HR 0.58, p < 0.01) benefit for sacituzumab govitecan over the CT of physician’s choice (TPC) [112]. Here, ERBB2 is linked to breast cancer.