NCT05941520 · National Cancer Institute (NCI)
Acolbifene Versus Low Dose Tamoxifen for the Prevention of Breast Cancer in Premenopausal Women at High Risk for Development of Breast Cancer
What this study is about
This phase IIA trial compares the effect of acolbifene versus low dose tamoxifen in preventing breast cancer in premenopausal women at high risk for developing breast cancer. The usual approach for patients at increased risk for breast cancer is to undergo yearly breast magnetic resonance imaging or ultrasound in addition to yearly mammogram.
View original scientific description
This phase IIA trial compares the effect of acolbifene versus low dose tamoxifen in preventing breast cancer in premenopausal women at high risk for developing breast cancer. The usual approach for patients at increased risk for breast cancer is to undergo yearly breast magnetic resonance imaging or ultrasound in addition to yearly mammogram. Premenopausal women at very high lifetime risk for breast cancer (greater than 50%) can consider preventive removal (mastectomy) of both breasts.
Interventions
DRUG
Acolbifene Hydrochloride
Given PO
PROCEDURE
Biospecimen Collection
Undergo collection of blood
PROCEDURE
Mammography
Undergo 3D mammography
OTHER
Questionnaire Administration
Ancillary studies
PROCEDURE
Random Periareolar Fine-Needle Aspiration
Undergo RPFNA
DRUG
Tamoxifen
Given PO
Primary outcome measures
Change in the relative abundance of the specific sequence of messenger ribonucleic acid that codes for AGR2
Time frame: Baseline up to 6 months
Will be assessed in benign breast tissue acquired by random periareolar fine-needle aspiration. Change over the intervention period is expressed as the ratio of the relative abundance values (6-month value: baseline value) and then this fold change value is log transformed (base 2) for analysis. For this variable, values of zero indicate no change in the relative abundance of AGR2; positive values indicate an increase in the relative abundance; and negative values a decrease in the relative abundance.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age \>= 35 years
- Considered clinically premenopausal
- Having regular menstrual cycles (between 21 and 35 days) unless a contraceptive device such as progestin containing intrauterine device (IUD) (e.g., Mirena IUD) is being used which suppresses menstrual periods, or premenopausal women who have undergone a hysterectomy, but ovaries are intact
- Not considering pregnancy for at least 12 months
- Women of child-bearing potential capacity must be willing to have used effective birth control precautions for 8 weeks prior to fine needle aspiration and be willing to continue for 8 weeks after study completion as tamoxifen may have teratogenic effects on the developing fetus. Reproductive and developmental toxicity studies have not been conducted with acolbifene. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must stop study drug and inform her study physician immediately.
- For women not using oral contraceptive
Where
- Duarte, California
- Chicago, Illinois
- Kansas City, Kansas
- Columbus, Ohio
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 7, 2026 · Source of record for eligibility and locations