ASCENT-07: This study is evaluating whether targeted therapy is more effective than standard treatment in people with HR+, HER2- metastatic or advanced breast cancer who have had prior treatment with endocrine therapyA Randomized, Open-label, Phase 3 Study of Sacituzumab Govitecan Versus Treatment of Physician's Choice in Patients With Hormone Receptor-Positive (HR+)/Human Epidermal Growth Factor Receptor 2 Negative (HER2-) (HER2 IHC0 or HER2-low [IHC 1+, IHC 2+/ISH-]) Inoperable, Locally Advanced, or Metastatic Breast Cancer and Have Received Endocrine Therapy

Inclusion

• Able to understand and give written informed consent.
• Must have adequate tumor tissue sample from locally recurrent or metastatic site.
• Documented evidence of HR+ metastatic breast cancer (mBC) confirmed with the most recently available tumor biopsy from a locally recurrent or metastatic site.
• Documented evidence of HER2- status.
• Documented PD by computed tomography (CT) or magnetic resonance imaging during or after the most recent therapy per RECIST v1.1 criteria.
• Candidate for the first chemotherapy in the locally advanced or metastatic setting.
• Eligible for capecitabine, nab-paclitaxel, or paclitaxel.

• Individuals must have one of the following:

  • Disease progression on at least 2 or more previous lines of endocrine therapy (ET) with or without a targeted therapy in the metastatic setting.

    • Disease recurrence while on the first 24 months of starting adjuvant ET will be considered a line of therapy; these individuals will only require 1 line of ET in the metastatic setting.
  • Disease progression within 6 months of starting first-line ET with or without a cyclin-dependent kinase (CDK) 4/6 inhibitor in the metastatic setting.
  • Disease recurrence while on the first 24 months of starting adjuvant ET with CDK 4/6 inhibitor and if the individual is no longer a candidate for additional ET in the metastatic setting.
• Individuals may have received prior targeted therapies, including but not limited to phosphatidylinositol 3-kinase (PI3K) inhibitors (for those with PIK3CA mutations) or mammalian target of rapamycin (mTOR) inhibitors. However, individuals can no longer be candidates for additional endocrine treatment with or without targeted therapies.
• Individuals with HIV must be on antiretroviral therapy (ART) and have a well-controlled HIV infection/disease.
• 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.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.