Open label, multi-centre, Phase Ia/b adaptive design study with an initial 2-stage Dose Escalation Phase followed by a Dose Expansion Phase.
(Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer
This is not medical advice. AI-assisted translation — inaccuracies may occur. Always verify the original and consult your oncologist before taking any steps.
This trial is no longer recruiting — here are similar active trials
Matched by cancer type/biomarker, currently recruiting.
The purpose of this study is to investigate the efficacy, safety, and tolerability of camizestrant in combination with ribociclib in patients with ER+ HER2- BC who have not received any other systemic treatment for advanced disease. Participants will be treated within the trial until they discontinue the study treatment for any reason.
The primary objective of the study is to measure efficacy of saruparib (AZD5305) plus camizestrant compared with physician's choice CDK4/6i plus ET in patients with BRCA1, BRCA2, or PALB2m, HR-positive, HER2-negative (defined as IHC 0, 1+, 2+/ ISH non-amplified) advanced breast cancer
This study will evaluate the efficacy and safety of the combination of inavolisib plus a cyclin-dependent kinase 4 and 6 inhibitor (CDK4/6i) and letrozole versus placebo plus a CDK4/6i and letrozole in the first-line setting in participants with endocrine-sensitive PIK3CA-mutated hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), advanced breast cancer (ABC).
About the trial
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.
Original English text from ClinicalTrials.gov
Who can (and can't) join
✓ Qualifies
- •Kobieta (urodzenie biologiczne jako kobieta)
- •Wiek 18 lat lub więcej
- •Nie w ciąży, nie karmiąca piersią i nie planująca ciąży w następnym roku; zgodna na używanie antykoncepcji przez 9 miesięcy po ostatniej dawce leku
- •Stosowanie co najmniej jednej niezawodnej metody antykoncepcji niezawierającej hormonów przez cały czas badania
- •W wieku przed menopauzą - menstruująca lub ze stężeniem estradiolu we właściwym zakresie
- •Potwierdzony nowotwór piersi dodatni do receptora estradiolu (≥67% lub wynik Allred 6-8)
- •Stan ogólny zdrowia 0-2 wg skali ECOG (może być lekko ograniczona aktywność)
- •Guz T2 lub T3 (średni lub duży) bez przerzutów odległych, z przerzutami maksymalnie w węzłach chłonnych pacjorowych
✗ Disqualifies
- •Nowotwór w obu piersiach jednocześnie lub zapalny nowotwór piersi
- •Wcześniejsza diagnoza lub leczenie raka piersi, lub inny aktywny nowotwór w ostatnich 2 latach (z wyjątkiem leczonych zmian przedrakowych)
Simplified criteria — AI translation
Trial details
- Minimum age
- 18 Years
- Last updated (source)
- July 8, 2026
- Sex
- Female only
Therapies / drugs in trial
Locations (14)
Mayo Clinic Arizona
Phoenix, United States
University of Arizona
Tucson, United States
California Research Institute
Los Angeles, United States
Mayo Clinic Florida
Jacksonville, United States
Northwestern University
Chicago, United States
St. Elizabeth Healthcare
Edgewood, United States
Henry Ford Cancer Institute
Detroit, United States
Mayo Clinic Rochester
Rochester, United States
Washington University School of Medicine
St Louis, United States
Avera Cancer Institute
Sioux Falls, United States
Vanderbilt Ingram Cancer Center
Nashville, United States
Baylor University
Houston, United States
Bon Secours Cancer Institute
Midlothian, United States
Fred Hutchinson Cancer Center
Seattle, United States
Share this trial
Data from ClinicalTrials.gov. AI-assisted translation, last sync: 7/1/2026.
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