Study of Sacituzumab Govitecan (SG) in Japanese Participants With Advanced Solid Tumors

Key Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1

• Measurable disease by computed tomography (CT) or magnetic resonance imaging (MRI)as per RECIST Version 1.1 criteria

• Adequate hematologic counts without transfusional or growth factor support within 2weeks of study drug initiation

• Adequate hepatic function (bilirubin ≤ 1.5 upper limit of normal (ULN)), alanineaminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 ULN

• Creatinine clearance ≥ 30 mL/min

• Male and female individuals of childbearing potential who engage in heterosexualintercourse must agree to use protocol-specified method(s) of contraception.

• Phase 1 only: Histologically or cytologically confirmed advanced solid tumor that isrefractory to or intolerant of all standard therapy or for which no standard therapyis available.

• Phase 2 metastatic triple-negative breast cancer (mTNBC) Cohort: Histologically orcytologically confirmed TNBC per American Society of Clinical Oncologists/College ofAmerican Pathologists (ASCO/CAP) criteria, based on the most recent analyzed biopsyor other pathology specimen. Refractory to or relapsed after at least 2 priorstandard-of-care chemotherapy regimens for unresectable, locally advanced ormetastatic breast cancer.

• Phase 2 hormone receptor-positive/human epidermal growth factor receptor 2-negativemetastatic breast cancer (HR+/HER2- mBC) Cohort: Documented evidence of HR+/HER2-mBC confirmed by a local laboratory and defined per ASCO/CAP criteria.

• Refractory to or relapsed after 2 prior systemic chemotherapy regimens forlocally advanced unresectable or metastatic disease.

• Phase 2 metastatic urothelial cancer (mUC) Cohort: Histologically documented UC thatis metastatic or locally advanced unresectable.

• Progressed or recurred following receipt of platinum-containing regimen andanti-PD-1/PD-L1 therapy for metastatic or locally advanced unresectable disease

Key Exclusion Criteria:

• Positive serum pregnancy test, or females who may possibly be pregnant

• Known Gilbert's disease

• Have previously received antibody drug conjugate containing topoisomerase Iinhibitors

• Presence of bulky disease (defined as any single mass > 7 cm in greatest dimension).

• Known to be HIV positive, or hepatitis B virus (HBV) surface antigen positive orhepatitis C virus (HCV) antibody positive at screening

• Known history of significant cardiac disease

• Known history of clinically significant active chronic obstructive pulmonarydisease, or other moderate-to-severe chronic respiratory illness

• History of interstitial lung disease

• History of clinically significant gastrointestinal (GI) bleeding, have activechronic inflammatory bowel disease (ulcerative colitis, Crohn's disease) or GIperforation

• Individuals with a history of anaphylactic reaction to irinotecan.

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