← Back to Clinical Trials
Recruiting Phase 2 NCT05716516

NCT05716516 STUDY02001740;22SCH740: Estradiol For ER+ Advanced Breast Cancer (ESTHER)

◆ AI Clinical Summary
Plain-language summary for patients
Clinical Trial Summary
NCT ID NCT05716516
Status Recruiting
Phase Phase 2
Sponsor Dartmouth-Hitchcock Medical Center
Condition Metastatic Breast Cancer
Study Type INTERVENTIONAL
Enrollment 36 participants
Start Date 2023-05-04
Primary Completion 2027-05

Eligibility & Interventions

Sex Female only
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
Estradiol

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 36 participants in total. It began in 2023-05-04 with a primary completion date of 2027-05.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

Determine whether subjects harboring ESR1-mutant/amplified breast cancer have a higher rate of clinical benefit from 17b-estradiol therapy than subjects with ESR1-wild-type breast cancer

Eligibility Criteria

Inclusion Criteria: * Post-menopausal women with ER+ breast cancer. * Metastatic or locoregional recurrence not amenable to treatment with curative * intent. * Received ≥1 prior line of endocrine-based therapy (e.g., including tamoxifen, aromatase inhibitors, fulvestrant, or combinations) in the advanced/metastatic setting Exclusion Criteria: * During the study Treatment Phase with 17b-estradiol, no concurrent anti-cancer therapies are allowed with the following exceptions: * Exception: Trastuzumab is allowed for the treatment of subjects with a history of HER2+ disease, and will be used at the physician's discretion. * Exception: Anti-resorptive bone therapies (e.g., bisphosphonates, denosumab) are permitted. * Any investigational cancer therapy in the last 3 weeks. * Known CNS disease, unless clinically stable for ≥ 3 months. * History of any of the following: * Deep venous thrombosis. * Pulmonary embolism. * Stroke. * Acute myocardial infarction. * Congestive heart failure. * Previous malignancy not treated with curative intent, or with an estimated recurrence risk ≥30%.

Contact & Investigator

Central Contact

Research Nurse

✉ Cancer.Research.Nurse@dartmouth.edu

📞 1-800-639-6918

Principal Investigator

Muhammad Azfal, MD

PRINCIPAL INVESTIGATOR

Dartmouth-Hitchcock Medical Center

Frequently Asked Questions

Who can join the NCT05716516 clinical trial?

This trial is open to female participants only, aged 18 Years or older, studying Metastatic Breast Cancer. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT05716516 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT05716516 currently recruiting?

Yes, NCT05716516 is actively recruiting participants. Contact the research team at Cancer.Research.Nurse@dartmouth.edu for enrollment information.

Where is the NCT05716516 trial being conducted?

This trial is being conducted at Lebanon, United States.

Who is sponsoring the NCT05716516 clinical trial?

NCT05716516 is sponsored by Dartmouth-Hitchcock Medical Center. The principal investigator is Muhammad Azfal, MD at Dartmouth-Hitchcock Medical Center. The trial plans to enroll 36 participants.

Related Trials

Related Intelligence Guides

In-depth guides covering this condition's trials, eligibility, and what to expect.

ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: April 2026  ·  Data Methodology