ctDNA Guided Adjuvant Treatment With Elacestrant: TBCRC-068

Eligibility Criteria

• 1. Women or men aged 18 years and older.
• 2. Previous diagnosis of anatomic stage IIB or anatomic stage III histopathologically or cytologically confirmed ER+, HER2-, breast cancer per local laboratory as per ASCO/CAP guidelines. In the context of this trial, ER status will be considered positive if \>10% of tumor cells demonstrate positive nuclear staining by immunohistochemistry, with or without progesterone receptor positivity. Patients who are PR positive but ER-negative are not eligible.
• 3. Participants must have been diagnosed with ER+HER2- breast cancer at least five years ago and no more than 15 years ago and must have completed adjuvant endocrine therapy.
• 4. Participants must be off endocrine therapy for at least six months prior to screening.
• 1. Known current metastatic disease.
• 2. Known contraindication to receiving elacestrant as per FDA package insert.
• 3. Current treatment with endocrine therapy.
• 4. Prior treatment with elacestrant or other investigational SERDs.
• 5. Current or past invasive cancer other than breast cancer, except:
• 1. Adequately treated basal or squamous cell carcinoma of the skin.
• 2. Cancer survivors of previously diagnosed invasive cancer who were treated with curative intent and have no evidence of disease recurrence for five years or more and are considered low risk for future recurrence by the treating physician.
• 6. Patients in the screening phase, or in the randomized trial (treatment phase), cannot start receiving therapy on another therapeutic clinical trial.