Study of Sacituzumab Govitecan-hziy Versus Treatment of Physician's Choice in Patients With Previously Untreated Locally Advanced Inoperable or Metastatic Triple-Negative Breast Cancer

Key Inclusion Criteria:

• Individuals, regardless of race and ethnic group, with previously untreated locallyadvanced, inoperable or metastatic triple-negative breast cancer (TNBC)

• Individuals whose tumors are programmed cell death ligand 1 (PD-L1) negative atscreening or individuals whose tumors are PD-L1 positive at screening if theyhave received an anti-PD-(L)1 inhibitor in the (neo) adjuvant setting or ifthey cannot be treated with a checkpoint inhibitor due to a comorbidity

• Centrally confirmed TNBC and PD-L1 status on fresh or archival tissue

• Individuals must have completed treatment for Stage I-III breast cancer, ifindicated, and ≥ 6 months must have elapsed (with the exception of endocrinetherapy) between completion of treatment with curative intent and firstdocumented local or distant disease recurrence

• Individuals presenting with de novo metastatic TNBC are eligible

• Measurable disease based on computed tomography (CT) or magnetic resonance imaging (MRI) in accordance with per Response Evaluation Criteria in Solid Tumors (RECIST)Version 1.1. as evaluated locally

• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

• Demonstrates adequate organ function

• Male individuals and female individuals of childbearing potential who engage inheterosexual intercourse must agree to use protocol-specified method(s) ofcontraception

• Individuals with human immunodeficiency virus (HIV) must be on antiretroviraltherapy (ART) and have a well-controlled HIV infection/disease

Key Exclusion Criteria:

• Positive serum pregnancy test or women who are lactating

• Received systemic anticancer treatment within the previous 6 months or radiationtherapy within 2 weeks prior to enrollment

• Have not recovered from adverse events (AEs) due to a previously administered agentat the time study entry

• May not be participating in a study with an investigational agent or investigationaldevice within 4 weeks prior to randomization. Individuals participating inobservational studies are eligible

• Previously received topoisomerase 1 inhibitors or antibody drug conjugatescontaining a topoisomerase inhibitor

• Active second malignancy

• Active serious infection requiring antibiotics

• Positive for HIV-1 or 2 with a history of Kaposi sarcoma and/or MulticentricCastleman Disease

• Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection

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