Circulating Tumor DNA

This is a single-arm, phase II study examining elacestrant in the adjuvant treatment of patients with ER+ breast cancer who test positive for circulating tumor DNA (ctDNA) during the screening period of the trial. Patients with ER+ breast cancer anatomic stage IIB or III at diagnosis who are at least five years from diagnosis and have completed intended course of adjuvant endocrine therapy and are currently off endocrine therapy will be screened with ctDNA testing via the NEXT Personal MRD Detection test from Personalis. Patients who test positive for ctDNA during the screening phase will receive treatment with elacestrant for one year and continue ctDNA testing and imaging with CT scans every three months. During the follow-up period, patients in the study will continue to be ctDNA tested every six months and monitored for one year. If patients remain ctDNA positive at the completion of 12 months of study treatment, since they remain at increased risk of recurrence, they can choose to continue for an additional 12 months for a maximum of 24 months, they may also resume standard endocrine therapy or continue with standard of care surveillance during follow up.