Clinical Research Directory

Inclusion Criteria: * Diagnosis of metastatic breast cancer that is hormone receptor-positive (ER≥10%), HER2 low or negative (defined as HER2 IHC 0, 1+ or IHC 2+/ISH-). * Progression of metastatic breast cancer that is hormone receptor-positive (ER≥10%), HER2 low or negative (defined as HER2 IHC 0, 1+ or IHC 2+/ISH-) while on systemic therapy. * Currently receiving or have previously received aromatase inhibitor therapy. Exclusion Criteria: * Patients with locally or regionally recurrent breast cancer without evidence of metastatic disease. * De novo metastatic breast cancer. * Presence of symptomatic metastatic visceral crisis. * Participants with inflammatory breast cancer. * Intact uterus with a history of endometrial intraepithelial neoplasia (atypical endometrial hyperplasia or higher-grade lesion). * Diagnosis of any other malignancy within 5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix, or second primary breast cancer. * Other conditions that, in the opinion of the treating investigator, would preclude the patient from meeting the study requirements or interfere with interpretation of study results. * Pregnant and breastfeeding women are excluded from the study