Recruiting
Phase 2

Ulipristal Acetate

Sponsor:

OHSU Knight Cancer Institute

Code:

NCT07434128

Conditions

Mammography Screening

Breast Density

Eligibility Criteria

Sex: Female

Age: 18 - 50

Healthy Volunteers: Not accepted

Interventions

Biospecimen Collection

Magnetic Resonance Imaging

Mammogram

Survey Administration

Ulipristal Acetate

Study Details

Brief summary:

This phase II trial tests whether taking ulipristal acetate prior to a mammogram decreases breast density for people with a history of dense breast tissue. One limitation to breast cancer screening with mammography is dense breast tissue, which decreases the sensitivity of screening as breast density masks cancer and precancerous lesions. Ulipristal acetate lowers the amount of progesterone made by the body which may temporarily decrease the density of the breast tissue, allowing for a more accurate mammogram for people with dense breast tissue.

Conditions

Mammography Screening

Breast Density

Study ID

NCT07434128

Start date

Aug 21, 2026

Status verified date

Sep, 2026

Completion date

Dec 31, 2027

Anticipated

Primary completion date

Dec 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 50

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Participant must provide written informed consent before any study-specific procedures or interventions are performed
  • Ages 18-50 years. The maximum age cut off is due to the intervention only applying to premenopausal physiology only
  • Assigned female at birth with at least one ovary in situ. Members of all races and ethnic groups will be included
  • Presenting for a screening mammogram
  • Has an antecedent mammogram within 24 months with a Breast Imaging Reporting and Data System (BI-RADS) breast composition score of Category C (heterogeneously dense) or D (extremely dense) for which images are available for analysis
  • Report no history of breast cancer or symptoms concerning for breast cancer such as a self-palpated mass
  • Reasonably assumed to be premenopausal by history of regular menses. For individuals who do not menstruate (due to hysterectomy or endometrial ablation), premenopausal status will be determined clinically by the absence of symptoms of menopause including weekly hot flashes which is consistent with clinical care

Exclusion Criteria:

  • Having a mammogram as part of a diagnostic process
  • Current breast implants in one or both breasts
  • Pregnant, less than 1 year postpartum or breastfeeding within last 6 months at the time of their antecedent mammogram or their current mammogram. This exclusion is due to known changes in mammograms during pregnancy and postpartum that would preclude comparative analyses
  • Using hormonal medications including estrogens or progestins
  • History of allergy to UPA
  • A history of liver disease (including but not limited to viral or autoimmune hepatitis, non-alcoholic fatty liver disease, hemochromatosis or Wilson's disease), alcoholism or a history of liver function tests such as aspartate aminotransferase (AST)/alanine aminotransferase (ALT) greater than 3 x the upper limit of normal without known etiology
  • Seeking pregnancy during study duration or a positive urine pregnancy for people at risk of pregnancy who cannot be reasonably assumed not to be pregnant at the beginning of the intervention
  • Use of CYP3A4 inducer or inhibitors which may alter plasma concentrations of study drug (See Appendix A for list of common drugs/herbs). Regarding recent use of CYP3A4 inducers or inhibitors, a washout period will be deemed sufficient if at least 14 days or 5 half lives of the drug have elapsed prior to initiation of the study drug, whichever is longer. Participants will be advised to abstain from CYP3A4 inducers or inhibitors during the study and will only be ineligible if unable to
  • Contraindication to MRI including: pacemakers, wires, stents, defibrillator, implanted hear values, aneurysm clips, metal pin, join, or prosthesis, electric devices (stimulator or pump), mental fragments, hearing aids, middle/inner ear prosthesis or dentures

Study Design

Enrollment

26 participants

Anticipated

Intervention Model

Single group

Primary purpose

Diagnostic

Interventions and Outcome Measures

Arms

experimental: Diagnostic (ulipristal acetate)

Patients receive ulipristal acetate PO every 5 days for 4 doses in the absence of unacceptable toxicity. Patients then undergo a mammogram. Patients also undergo MRI and blood sample collection throughout the study.

Interventions

Biospecimen Collection

Undergo blood sample collection

Magnetic Resonance Imaging

Undergo MRI

Mammogram

Participants will undergo their standard of care mammogram.

Survey Administration

Ancillary studies

Ulipristal Acetate

Given orally

Primary outcome measure

  • Difference in percent dense area [ Time Frame: From baseline mammogram to study day 20 mammogram ]

Central Contacts and Locations

Locations

OHSU Knight Cancer Institute

Recruiting

Portland, Oregon, United States, 97239

Contacts

Abigail Liberty

503-494-3666liberty@ohsu.edu

Principal Investigator:

Abigail Liberty

More Information

Sponsor

OHSU Knight Cancer Institute

Last update posted

Sep 3, 2026

Last verified

Sep, 2026

Keywords

  • Progesterone receptor modulators

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by OHSU Knight Cancer Institute on 2026-09-03.