(Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer
Public ClinicalTrials.gov record NCT05607004. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Phase 2 Trial of (Z)-Endoxifen + Goserelin as Neoadjuvant Treatment for Premenopausal Women With ER+, HER2-, Breast Cancer
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This open-label research study is studying (Z)-endoxifen as a possible treatment for pre-menopausal women with ER+/HER2- breast cancer. (Z)-endoxifen belongs to a group of drugs called selective estrogen receptor modulators or "SERM", which help block estrogen from attaching to cancer cells. This study has two parts: a pharmacokinetic part and a treatment part. The PK part (how the body processes the drug) will enroll about 18 participants. All participants will take (Z)-endoxifen capsules daily. Twelve participants will be randomly assigned (50/50 chance) to take (Z)-endoxifen alone or (Z)-endoxifen with a monthly injection of goserelin a drug that temporarily stops the ovaries from making estrogen. This part will help determine the best dose of (Z)-endoxifen by measuring the drug levels in the blood and how long the body takes to remove it. The Treatment Cohort has been simplified to a single study arm (Z)-endoxifen + goserelin. Up to 20 participants will be enrolled that have a baseline Ki-67 ≤ 10% and 45 participants will be enrolled that have a baseline Ki-67\>10%. A key goal of the study is to see if (Z)-endoxifen can slow down or stop tumor growth as measured by a reduction in Ki-67 levels. Tumor tissue samples will be taken by breast biopsy after about 4 weeks of treatment to check levels of this biomarker. If the tumor shows signs of response, participants can continue treatment for up to 24 weeks or until they have surgery. Study participation is up to 6 months (24 weeks of treatment) followed by surgery and a one-month follow up visit.
Study identification
- NCT ID
- NCT05607004
- Recruitment status
- Active, not recruiting
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 87 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years and older
- Sex
- Female
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Feb 13, 2023
- Primary completion
- Oct 31, 2026
- Completion
- Mar 31, 2027
- Last update posted
- Jul 7, 2026
2023 – 2027
United States locations
- U.S. sites
- 14
- U.S. states
- 13
- U.S. cities
- 14
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Mayo Clinic Arizona | Phoenix | Arizona | 85054 | — |
| University of Arizona | Tucson | Arizona | 85719 | — |
| California Research Institute | Los Angeles | California | 90027 | — |
| Mayo Clinic Florida | Jacksonville | Florida | 32224 | — |
| Northwestern University | Chicago | Illinois | 60611 | — |
| St. Elizabeth Healthcare | Edgewood | Kentucky | 41017 | — |
| Henry Ford Cancer Institute | Detroit | Michigan | 48202 | — |
| Mayo Clinic Rochester | Rochester | Minnesota | 55905 | — |
| Washington University School of Medicine | St Louis | Missouri | 63110 | — |
| Avera Cancer Institute | Sioux Falls | South Dakota | 57105 | — |
| Vanderbilt Ingram Cancer Center | Nashville | Tennessee | 37204 | — |
| Baylor University | Houston | Texas | 77054 | — |
| Bon Secours Cancer Institute | Midlothian | Virginia | 23114 | — |
| Fred Hutchinson Cancer Center | Seattle | Washington | 98109 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT05607004, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Jul 7, 2026 · Synced Sep 2, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT05607004 live on ClinicalTrials.gov.