Phase III Study of Elacestrant Compared to Standard Endocrine Therapy in Adults With ERHER2- Breast Cancer and ctDNA Relapse

What this Trial Is About

Researchers are evaluating elacestrant compared to standard endocrine therapy in patients with estrogen receptor-positive ER and human epidermal growth factor receptor 2-negative HER2- breast cancer who have a relapse detected by circulating tumor DNA ctDNA. This international, multi-center, randomized, open-label phase III trial focuses on patients without distant metastasis who show ctDNA positivity during screening. The study aims to assess whether elacestrant can improve outcomes over the current standard endocrine treatments. The study consists of two phases. First, during the ctDNA screening phase, patients on standard adjuvant endocrine therapy will have plasma samples collected every six months for about 5.7 years to detect ctDNA. Patients who test positive will undergo imaging to confirm no distant metastasis and then be randomized 11 to either continue their current endocrine therapy or receive elacestrant 400 mg orally once daily. Treatment duration depends on prior endocrine therapy length, lasting between 2 to 6 years. Intensive follow-up with ctDNA testing and imaging occurs for up to 3 years after randomization. Participants will be monitored closely with blood tests for ctDNA at weeks 4, 16, and every 16 weeks thereafter, along with yearly mammograms, bone scans, and CT scans every 16 weeks to detect metastases or recurrences. Safety, quality of life, and overall survival are assessed throughout, with follow-up continuing until three years after the last patient enrolls. The primary outcome measured is distant metastasis-free survival at 6.25 years after the first randomization.

Elacestrant for Treating ER+/HER2- Breast Cancer Patients With ctDNA Relapse (TREAT ctDNA)