Elacestrant for Breast Cancer

Overseen By Stephanie Ladd

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: Yale University

Must not be taking: Endocrine therapy, SERDs

Disqualifiers: Metastatic disease, Invasive cancer, others

Stay on Your Current Meds You can continue your current medications while participating

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 7

Duration: 12 months

50 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests elacestrant, a medication for individuals with ER+ (estrogen receptor-positive) breast cancer. The goal is to determine if elacestrant can benefit patients who have undergone breast cancer treatment but still have cancer DNA in their blood. This trial targets those who had ER+ breast cancer at least five years ago, have completed endocrine therapy, and are not currently receiving cancer treatment. Participants must not have any other active cancers or previous exposure to elacestrant. As a Phase 2 trial, the research focuses on assessing the treatment's effectiveness in an initial, smaller group of participants.

Will I have to stop taking my current medications?

The trial requires that participants must have stopped endocrine therapy at least six months before screening. Other current medications are not specified in the protocol.

Is there any evidence suggesting that elacestrant is likely to be safe for humans?

Research shows that elacestrant is generally well-tolerated by people with breast cancer. Studies indicate that its side effects are usually mild and manageable. Patients with ER+ metastatic breast cancer have used the drug without encountering unexpected safety problems. Reports from both real-world use and clinical trials have not revealed any new risks.

Elacestrant has already received FDA approval for treating certain types of advanced breast cancer, indicating it has passed important safety checks for that purpose. In summary, while some side effects can occur, they are usually expected and manageable. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for breast cancer?

Elacestrant is unique because it targets estrogen receptors in a new way, as a selective estrogen receptor degrader (SERD). Unlike traditional hormone therapies for ER+ metastatic breast cancer, which often just block estrogen receptors, elacestrant actively breaks them down. This could potentially overcome resistance that develops with current treatments like aromatase inhibitors or tamoxifen. Researchers are excited because elacestrant’s oral administration offers a more convenient option compared to some other SERDs that require injections, making it an appealing alternative for patients.

What evidence suggests that elacestrant might be an effective treatment for ER+ breast cancer?

Research has shown that elacestrant can help treat certain types of breast cancer. In studies, it reduced the risk of cancer progression or death by 30% compared to standard treatments. Another study found a 45% lower risk for individuals with specific tumor mutations. Elacestrant also significantly extended the time during which the cancer does not worsen, compared to standard hormone therapies. These findings suggest that elacestrant could be a promising option for treating estrogen receptor-positive (ER+) breast cancer. Participants in this trial will receive elacestrant according to the FDA-approved dose and schedule. ^{3 4 6 7 8}

Who Is on the Research Team?

Mariya Rozenblit, MD

Principal Investigator

Yale University

Are You a Good Fit for This Trial?

This trial is for men and women over 18 who had a certain type of breast cancer (ER+, HER2-) diagnosed between 5 to 15 years ago. They must have finished hormone therapy at least six months before the study starts and show positive signs of cancer in their blood.

Inclusion Criteria

My breast cancer was stage IIB or III, ER positive and HER2 negative.

I was diagnosed with ER+HER2- breast cancer between 5 and 15 years ago and finished hormone therapy.

I haven't taken hormone therapy for at least 6 months.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

Up to 12 months

1 visit (in-person)

Treatment

Participants receive elacestrant treatment for one year with ctDNA testing and imaging every three months

12 months

4 visits (in-person) for imaging and ctDNA testing

Follow-up

Participants are monitored for safety and effectiveness after treatment, with ctDNA testing every six months

12 months

2 visits (in-person) for ctDNA testing

Open-label extension (optional)

Participants may continue on elacestrant for an additional year or resume standard endocrine therapy

12 months

What Are the Treatments Tested in This Trial?

Interventions

• Elacestrant

Trial Overview

The trial is testing Elacestrant, a drug given after initial breast cancer treatment. It's for those with ER+ breast cancer who still have traces of cancer DNA in their blood. The study has no comparison group; all participants receive Elacestrant.

How Is the Trial Designed?

Group I: Single Arm Experimental Treatment 1 Intervention

Administration of elacestrant will follow the FDA approved dose and schedule for patients with ER+ metastatic breast cancer. Elacestrant 345 mg will be administered orally once daily for 12 cycles or until disease progression or unacceptable toxicity

Who Is Running the Clinical Trial?

Yale University

Lead Sponsor

Trials

1,963

Recruited

3,046,000+

Johns Hopkins University

Collaborator

Trials

2,366

Recruited

15,160,000+

Stemline Therapeutics, Inc.

Industry Sponsor

Trials

24

Recruited

6,500+

Published Research Related to This Trial

Elacestrant, an oral selective estrogen receptor downregulator, was approved by the FDA in January 2023 for treating hormone receptor positive (HR+) HER2- advanced breast cancer, showing improved progression-free survival in patients with ESR1 mutations who had previously failed treatment with CDK 4/6 inhibitors and endocrine therapy.

Clinical trials indicate that elacestrant has a safety profile comparable to existing endocrine therapies and provides an effective alternative treatment option, especially for patients who have not responded to standard therapies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Elacestrant for ER-Positive HER2-Negative Advanced Breast Cancer. Hageman, E., Lussier, ME.[2023]

In a phase III trial involving 477 patients with ER-positive/HER2-negative advanced breast cancer, elacestrant significantly improved progression-free survival (PFS) compared to standard-of-care endocrine therapy, with a hazard ratio of 0.70 for all patients and 0.55 for those with ESR1 mutations.

While elacestrant showed promising efficacy, it was associated with a higher rate of treatment-related adverse events, including nausea, and a greater percentage of patients discontinuing treatment due to side effects compared to standard therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Elacestrant (oral selective estrogen receptor degrader) Versus Standard Endocrine Therapy for Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Results From the Randomized Phase III EMERALD Trial. Bidard, FC., Kaklamani, VG., Neven, P., et al.[2023]

Elacestrant (RAD-1901) is a selective estrogen receptor degrader that was approved by the USFDA for treating ER+ HER2-positive breast cancer, demonstrating anticancer activity in both laboratory and animal models.

The review discusses Elacestrant's development, including its medicinal chemistry, mechanism of action, and safety profile based on clinical trial data, highlighting its potential as an effective treatment option.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Elacestrant: a new FDA-approved SERD for the treatment of breast cancer. Bhatia, N., Thareja, S.[2023]

Elacestrant, a selective estrogen receptor degrader, was found to be safe and well tolerated in a study involving 140 postmenopausal women, with doses up to 1000 mg daily not reaching the maximum tolerated dose.

The drug showed good oral bioavailability and a half-life of 27 to 47 hours, allowing for once-daily dosing, while effectively engaging estrogen receptors and demonstrating some ability to cross the blood-brain barrier.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pharmacokinetic and Pharmacodynamic Studies of Elacestrant, A Novel Oral Selective Estrogen Receptor Degrader, in Healthy Post-Menopausal Women. Conlan, MG., de Vries, EFJ., Glaudemans, A., et al.[2021]

Elacestrant was approved by the FDA for treating advanced or metastatic breast cancer in postmenopausal women and adult men with specific estrogen receptor mutations, highlighting its targeted approach for patients who have not responded to prior endocrine therapy.

The summary includes important details about elacestrant's mechanism of action and safety profile, which are crucial for understanding its role in cancer treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

First Approval of Elacestrant as a Selective Estrogen Receptor Degrader for the Treatment of Metastatic Breast Cancer. De, SK.[2023]

Elacestrant is the first oral selective estrogen receptor degrader (SERD) approved by the FDA for treating ER/PR-positive, HER2-negative metastatic breast cancer with ESR1 mutations, showing improved median progression-free survival compared to standard endocrine therapy in the EMERALD trial.

The drug acts as a mixed ER agonist/antagonist and has specific metabolic considerations, being primarily processed by CYP3A4, which can lead to drug interactions; dose adjustments are recommended for patients with moderate hepatic dysfunction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pharmacology and pharmacokinetics of elacestrant. Beumer, JH., Foldi, J.[2023]

The phase I trial assessed the safety and efficacy of elacestrant, a selective estrogen receptor degrader, specifically in patients with breast cancer.

This study represents an important step in evaluating new treatment options for breast cancer, focusing on a novel mechanism of action that targets estrogen receptors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Early Signs of Response to Elacestrant Seen in ER+ HER2- Breast Cancer. [2021]

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC11847623/

Elacestrant in hormone receptor-positive metastatic breast ...

Elacestrant shows promise for improving outcomes in hormone receptor-positive metastatic breast cancer, but further research is needed to confirm its ...

2.

ascopubs.org

ascopubs.org/doi/10.1200/JCO.2025.43.16_suppl.TPS1127

ELCIN: Elacestrant in women and men with CDK4/6 ...

Elacestrant significantly reduced the risk of progression or death vs SOC ET by 30% in the overall population (HR 0.70; 95% CI 0.55-0.88; P= ...

3.

ajmc.com

ajmc.com/view/elacestrant-shows-real-world-effectiveness-in-metastatic-breast-cancers

Elacestrant Shows Real-World Effectiveness in Metastatic ...

The drug targets ESR1-mutated tumors, reducing the overall risk of progression or death by 45% with elacestrant compared with standard-of-care ...

4.

aacrjournals.org

aacrjournals.org/clincancerres/article/30/19/4299/748559/Elacestrant-in-ER-HER2-Metastatic-Breast-Cancer

Elacestrant in ER + , HER2 − Metastatic Breast Cancer with ...

Elacestrant significantly prolonged progression-free survival (PFS) with manageable safety versus standard-of-care (SOC) endocrine therapy (ET)

5.

esmoopen.com

esmoopen.com/article/S2059-7029(24)01470-4/fulltext

Elacestrant in ESR1-mutant, endocrine-responsive ...

Accordingly, the landmark analysis showed 6- and 12-month PFS rates were doubled in the elacestrant arm (6 months: 41% versus 19%; 12 months: 27 ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC12215442/

Evaluation of Safety of Elacestrant in Patients with Breast ...

This study aims to evaluate the safety profile of elacestrant in real-world settings using data from the FDA adverse event (AE) reporting system (FAERS) ...

7.

ascopubs.org

ascopubs.org/doi/10.1200/JCO.2025.43.16_suppl.1079

Elacestrant combinations in patients (pts) with ER+/HER2- ...

Elacestrant combinations continue to demonstrate safety consistent with the known profiles of each drug + SOC ET without increased risk of associated AEs.

8.

bmcpharmacoltoxicol.biomedcentral.com

bmcpharmacoltoxicol.biomedcentral.com/articles/10.1186/s40360-025-00887-2

Post-marketing safety of elacestrant in breast cancer

In 2023, the Food and Drug Administration (FDA) approved elacestrant for patients with advanced or metastatic breast cancer with ESR1 mutation.