Trial of Sacituzumab Govitecan in Participants With Refractory/Relapsed Metastatic Triple-Negative Breast Cancer (TNBC)

Key Inclusion Criteria:

Histologically or cytologically confirmed TNBC based on the most recent analyzed biopsy or other pathology specimen. Triple negative is defined as <1% expression for estrogen receptor (ER) and progesterone receptor (PR) and negative for human epidermal growth factor receptor 2 (HER2) by in-situ hybridization.
Refractory to or relapsed after at least two prior standard therapeutic regimens for advanced/metastatic TNBC.
Prior exposure to a taxane in localized or advanced/metastatic setting.
Eligible for one of the chemotherapy options listed as TPC (eribulin, capecitabine, gemcitabine, or vinorelbine) as per investigator assessment.
Eastern Cooperative Oncology Group (ECOG) performance score of 0 or 1.
Measurable disease by computed tomography (CT) or magnetic resonance imaging (MRI) as per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). Bone-only disease is not permitted.
At least 2 weeks beyond prior anti-cancer treatment (chemotherapy, endocrine therapy, radiotherapy, and/or major surgery), and recovered from all acute toxicities to Grade 1 or less (except alopecia and peripheral neuropathy).
At least 2 weeks beyond high dose systemic corticosteroids (however, low dose corticosteroids < 20 mg prednisone or equivalent daily are permitted provided the dose is stable for 4 weeks).
Adequate hematology without ongoing transfusional support (hemoglobin > 9 g/dL, absolute neutrophil count (ANC) > 1,500 per mm^3, platelets > 100,000 per mm^3).
Adequate renal and hepatic function (creatinine clearance [CrCL] > 60 mL/min, bilirubin ≤ 1.5 institutional upper limit of normal [IULN], aspartate aminotransferase [AST] and alanine aminotransferase [ALT] ≤ 2.5 x IULN or ≤ 5 x IULN if known liver metastases and serum albumin ≥3 g/dL).
Recovered from all toxicities to Grade 1 or less by National Cancer Institute common terminology criteria for adverse events (NCI CTCAE) v4.03 (except alopecia or peripheral neuropathy that may be Grade 2 or less) at the time of randomization. Participants with Grade 2 neuropathy are eligible but may not receive vinorelbine as TPC.
Participants with treated, non-progressive brain metastases, off high-dose steroids (>20 mg prednisone or equivalent) for at least 4 weeks can be enrolled in the trial.

Key Exclusion Criteria:

Women who are pregnant or lactating.
Women of childbearing potential or fertile men unwilling to use effective contraception during study and up to three months after treatment discontinuation in women of child-bearing potential and six months in males post last study drug.
Participants with Gilbert's disease.
Participants with non-melanoma skin cancer or carcinoma in situ of the cervix are eligible, while participants with other prior malignancies must have had at least a 3-year disease-free interval.
Participants known to be human immunodeficiency (HIV) positive, hepatitis B positive, or hepatitis C positive.
Infection requiring antibiotic use within one week of randomization.
Other concurrent medical or psychiatric conditions that, in the Investigator's opinion, may be likely to confound study interpretation or prevent completion of study procedures and follow-up examinations.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.