A Randomized, Open-label, Phase 3 Study of Sacituzumab Govitecan Versus Treatment of Physician’s Choice in Patients With Previously Untreated, Locally Advanced, Inoperable or Metastatic Triple-Negative Breast Cancer Whose Tumors Do Not Express PD-L1 or in Patients Previously Treated With Anti-PD-(L)1 Agents in the Early Setting Whose Tumors Do Express PD-L1

The primary objective of this study is to compare the progression-free survival (PFS) between
sacituzumab govitecan-hziy (SG) versus treatment of physician's choice (TPC) in participants
with previously untreated, locally advanced, inoperable or metastatic triple-negative breast
cancer whose tumors do not express programmed cell death ligand 1 (PD-L1) or in participants
previously treated with anti-programmed cell death (ligand or protein) 1 (Anti-PD-(L)1)
Agents in the early setting whose tumors do express PD-L1.

Key Inclusion Criteria:

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

- Individuals whose tumors are programmed cell death ligand 1 (PD-L1) negative at
screening or individuals whose tumors are PD-L1 positive at screening if they
have received an anti-PD-(L)1 inhibitor in the (neo) adjuvant setting or if they
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, if
indicated, and ≥ 6 months must have elapsed (with the exception of endocrine
therapy) between completion of treatment with curative intent and first
documented 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 in
heterosexual intercourse must agree to use protocol-specified method(s) of
contraception

- Individuals with human immunodeficiency virus (HIV) must be on antiretroviral therapy
(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 radiation
therapy within 2 weeks prior to enrollment

- Have not recovered from adverse events (AEs) due to a previously administered agent at
the time study entry

- May not be participating in a study with an investigational agent or investigational
device within 4 weeks prior to randomization. Individuals participating in
observational studies are eligible

- Previously received topoisomerase 1 inhibitors or antibody drug conjugates containing
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 Multicentric Castleman
Disease

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

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