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(Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer
NCT05607004 · View on ClinicalTrials.gov ↗
Study Summary
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.
Conditions Studied
Interventions
- DRUG (Z)-endoxifen
- DRUG goserelin
Study Locations (15)
Arizona
- Mayo Clinic Arizona — Phoenix
- University of Arizona — Tucson
Texas
- Baylor University — Houston
- Tranquility Research — Webster
California
- California Research Institute — Los Angeles
Florida
- Mayo Clinic Florida — Jacksonville
Illinois
- Northwestern University — Chicago
Kentucky
- St. Elizabeth Healthcare — Edgewood
Michigan
- Henry Ford Cancer Institute — Detroit
Minnesota
- Mayo Clinic Rochester — Rochester
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 87 participants |
| Start Date | 2023-02-14 |
| Est. Completion | 2027-04 |
| Phase | Phase 2 |
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Full Details on ClinicalTrials.gov ↗What the Registry Record Tells You About NCT05607004
The ClinicalTrials.gov registry entry for NCT05607004 describes a study currently listed as recruiting. It is categorized as Phase 2, which is the standard way researchers label where a study sits along the investigational pathway from early safety work through later efficacy and post-marketing evaluation. The registered enrollment target is 87 participants, a figure that helps gauge the scale of data the investigators plan to collect. The listed sponsor is Atossa Therapeutics, which has 1 total studies on file at ClinicalTrials.gov, and sponsors are the parties responsible for study design, oversight, and regulatory filings.
The record links to 4 conditions, with Breast Neoplasms appearing as the primary indexed condition, and to 2 interventions — of which (Z)-endoxifen is the first listed. Interventions can include drugs, devices, procedures, behavioral programs, or observational arms, and each is tracked as a separate registry field so that downstream queries can filter accurately. When a trial lists multiple interventions, it usually reflects a multi-arm design or a comparison protocol rather than a single treatment being tested in isolation. The brief summary published in the registry is the clearest source of protocol intent and should be read before drawing conclusions from any sidebar tags.
Geographic footprint matters for practical reasons: NCT05607004 reports 15 study locations spanning 13 distinct geographic areas — top geographies include Arizona, Texas, California. A larger site network tends to correlate with broader recruitment capacity, but it does not imply anything about study quality, and site-level enrollment status can diverge from the overall registry status shown above. Every data point on this page comes from the public ClinicalTrials.gov dataset and is reproduced here for reference only; it is not a medical recommendation, an endorsement of the sponsor, or an invitation to enroll. Verify current status, eligibility criteria, and contact details directly at ClinicalTrials.gov, and discuss any participation decision with your own healthcare provider.
Frequently Asked Questions
What is clinical trial NCT05607004 about?
NCT05607004 is a clinical study titled "(Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer". 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 st...
What is the current status of trial NCT05607004?
This trial is currently recruiting. It is a Phase 2 study. The enrollment target is 87 participants. The study started on 2023-02-14. Estimated completion is 2027-04.
What conditions does trial NCT05607004 study?
This clinical trial studies the following conditions: Breast Neoplasms, HER2-negative Breast Cancer, Invasive Breast Cancer, Estrogen-receptor-positive Breast Cancer. These conditions were identified from the trial registry and reflect the primary focus areas of the research.
What interventions are being tested in trial NCT05607004?
The interventions under investigation include: (Z)-endoxifen (DRUG), goserelin (DRUG). Each intervention is being evaluated for safety and efficacy as part of this clinical study.
Who is sponsoring clinical trial NCT05607004?
This trial is sponsored by Atossa Therapeutics, which has 1 total clinical trials registered on ClinicalTrials.gov. The sponsor is responsible for the study's design, funding, and regulatory compliance.
Where is trial NCT05607004 being conducted?
This trial has 15 study locations across Arizona, California, Florida, Illinois, Kentucky. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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