Study of Sacituzumab Govitecan-hziy Versus Treatment of Physician's Choice in Participants With HR+/HER2- Metastatic Breast Cancer

Open to people ages 18 years and up

• Documented evidence of hormone receptor-positive human epidermal growth factor receptor 2 negative (HER2-negative) (hormonal receptor-positive (HR+)/HER2-) metastatic breast cancer (MBC) confirmed
• Refractory to or relapsed after at least 2, and no more than 4, prior systemic chemotherapy regimens for MBC including:
• At least 1 prior anticancer hormonal treatment.
• At least 1 cyclin-dependent kinase inhibitor 4/6 in the metastatic setting.
• Eligible for one of the chemotherapy options listed in the TPC arm
• Documented disease progression after the most recent therapy

• Adequate bone marrow function (hemoglobin ≥ 9 g/dL, absolute neutrophil count (ANC) ≥ 1,500 per mm³, platelets ≥ 100,000 per mm³).

• Adequate renal function: calculated creatinine clearance ≥ 30 mL/minute according to the Cockcroft and Gault formula
• Adequate hepatic function (bilirubin ≤ 1.5 institutional upper limit of normal (IULN), aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) ≤ 2.5 x IULN or 5.0 x IULN)
• Females must not be lactating or pregnant at Screening or Baseline (as documented by a negative beta human chorionic gonadotropin (ß-hCG))

• Previous treatment with topoisomerase 1 Inhibitors as a free form or as other formulations
• History of significant cardiovascular disease or clinically significant electrocardiogram (ECG) abnormality
• Individuals with Gilbert's disease.
• Active serious infection requiring antibiotics
• Individuals with a history of an anaphylactic reaction to irinotecan
• 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.
• Locally advanced MBC (stage IIIc) in individuals who are candidates for curative intent therapy at the time of study enrollment

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