This is an international, multi-center, open-label, randomized, Phase III study in patients with metastatic TNBC refractory or relapsing after at least 2 prior chemotherapies (including a taxane) for their metastatic disease. Patients meeting eligibility will be randomized 1:1 to receive either sacituzumab govitecan or treatment of physician choice (TPC), which needs to be selected prior to randomization from one of the 4 allowed regimens. Randomization will be stratified by number of prior chemotherapies for advanced disease (2-3 vs > 3) and geographical location (North America vs Europe).
Patients will be treated until progression, unacceptable toxicity, study withdrawal, or death, whichever comes first. Tumor progression leading to treatment withdrawal will be assessed by the investigator. Starting with the initial dose of sacituzumab govitecan or TPC, CT scans (or MRI if contrast allergic) will be obtained at least every 8 weeks until the occurrence of progression of disease requiring discontinuation of further treatment.All patients, including those prematurely terminating study participation, will be followed every 4 weeks during the first year and every 8 weeks thereafter for survival follow-up.