New Frontiers in Adjuvant Care: Evaluating Elacestrant in the ELEGANT Trial

For patients with high-risk, estrogen receptor—positive, HER2-negative early breast cancer, the standard of care has long relied on adjuvant endocrine therapy (ET) to mitigate the risk of late recurrence. However, despite these interventions, a significant subset of patients remains at risk for metastatic relapse. At the 2026 American Association for Cancer Research (AACR) Annual Meeting, Sara M. Tolaney, MD, MPH, chief of the Division of Breast Oncology at Dana-Farber Cancer Institute and associate professor of medicine at Harvard Medical School, highlighted the ELEGANT trial (NCT06492616), a global, randomized phase 3 study designed to investigate whether switching to a next-generation oral selective estrogen receptor degrader (SERD) can offer superior protection over current standards.¹

The trial specifically focused on patients who have already completed between 24 and 60 months of initial adjuvant endocrine therapy. The rationale behind the study stemmed from the unique mechanism of elacestrant (Oserdu), which is currently FDA-approved for metastatic breast cancer harboring ESR1 mutations.² By comparing elacestrant head-to-head against continued aromatase inhibitors or tamoxifen, the ELEGANT trial seeks to determine if this sequential exposure to a SERD can more effectively degrade the estrogen receptor and prevent the recurrence of breast cancer in a high-risk population.

Transcript:

The ELEGANT study is a randomized phase 3 trial that is looking at the oral SERD elacestrant in patients who have received at least 2 years of adjuvant endocrine therapy for their lymph node positive breast cancer. Patients could have received somewhere between 24 to 60 months of adjuvant endocrine treatment, and then they get [randomly assigned] to receive elacestrant or to receive their current endocrine therapy that they continue on the control arm of the study, and the study is looking to see if elacestrant helps prevent recurrence better than standard endocrine treatment. The rationale here is that elacestrant is an oral SERD, so a selective estrogen receptor degrader. There is some thought that these drugs may be superior to standard endocrine therapy. Elacestrant is already FDA approved for metastatic hormone receptor—positive breast cancer, specifically in patients who have tumors that harbor an ESR1 mutation. The trial is looking at what I think of as sequential exposure to endocrine therapy, because these patients have already had a couple years of their standard, mostly aromatase inhibition, and then they’re getting either switched to get a SERD or continuing on their aromatase inhibitor, with the idea being that maybe the SERD is a better endocrine drug head-to-head compared with their [aromatase inhibitor]. So [that] could help prevent recurrence of their breast cancer.

References

1. Bardia A, Kaklamani V, Oshaughnessy J, et al. ELEGANT: elacestrant versus standard endocrine therapy (ET) in women and men with node-positive, estrogen receptor-positive (ER+), HER2-negative (HER2-), early breast cancer (eBC) with high risk of recurrence in a global, multicenter, randomized, open-label phase 3 study. Presented at the 2026 American Association for Cancer Research (AACR) Annual Meeting, San Diego, CA; April 17-22, 2026. Poster CT225.
2. FDA approves elacestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer. News release. FDA. January 27, 2023. Accessed April 22, 2026. bit.ly/3kQrxHq