ELACESTRANT in Women and Men With CDK4/6 Inhibitor-Naive Estrogen Receptor Positive, HER-2 Negative Metastatic Breast Cancer Study

Inclusion criteria

• ✓. Patient has signed the informed consent before all study specific activities are conducted.
• ✓. Women or men aged ≥18 years (or the minimum age of consent as per local law), at the time of informed consent signature. Female patients may be either postmenopausal or premenopausal/perimenopausal.
• ✓. Premenopausal or perimenopausal women and men must be concurrently given a luteinizing hormone-releasing hormone (LHRH) agonist starting at least 4 weeks before the start of trial therapy and is planning to continue LHRH during the study.
• ✓. For perimenopausal women to be considered of non-childbearing potential, follicle-stimulating hormone (FSH) levels must be \>40 milli-international units per milliliter (mIU/mL).
• ✓. Documentation of histopathologically or cytologically confirmed ER+, HER2-breast cancer, per local laboratory, as per the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. Note: In the context of this trial, ER status will be considered positive if ≥10% of tumor cells demonstrate positive nuclear staining by immunohistochemistry.
• ✓. Radiological disease progression during or after the most recent therapy in the advanced/metastatic setting
• ✓. Patient has received at least one (and up to two) prior hormonal therapy in the advanced/metastatic setting.
• ✓. Patients with disease relapse while on adjuvant endocrine therapy after the 2 first years, or with disease relapse within 12 months of completing adjuvant endocrine therapy are allowed (i.e., patients with secondary-resistant breast cancer according to the 5th European School of Oncology (ESO)-European Society for Medical Oncology (ESMO) international consensus guidelines for advanced breast cancer, Cardoso et al 2020). This therapy will be considered as first line treatment for eligibility purposes.

Exclusion criteria