Ulipristal Acetate for Breast Density

This trial tests whether the drug ulipristal acetate can reduce breast density before a mammogram. Extremely dense breast tissue can make it difficult for mammograms to detect cancer. By lowering the body's progesterone, ulipristal acetate might temporarily reduce breast tissue density, resulting in more accurate mammograms. This trial is for individuals assigned female at birth, who are premenopausal with extremely dense breast tissue, and have no history of breast cancer. As a Phase 2 trial, the research focuses on measuring the treatment's effectiveness in an initial, smaller group of participants.

Yes, you will need to stop taking hormonal medications like estrogens or progestins. If you are using drugs that affect CYP3A4 enzymes, you must stop them at least 14 days before starting the trial or wait for 5 half-lives of the drug, whichever is longer.

Research has shown that ulipristal acetate is generally safe for people. One study found that its use in patients with uterine fibroids did not harm normal breast tissue and had manageable side effects. Another study reported no moderate to severe side effects when ulipristal acetate was used on breast cells that might lead to cancer. These findings suggest that ulipristal acetate is safe for humans, with few reports of serious side effects.¹²³⁴⁵

Ulipristal acetate is unique because it targets breast density in a way that current options don't. While most treatments for breast density, like hormonal therapies, focus on altering estrogen levels, ulipristal acetate works as a selective progesterone receptor modulator. This means it can potentially reduce breast density by modulating the effects of progesterone, offering a new angle of attack. Researchers are excited because this could lead to a faster and possibly more effective reduction in breast density, which is a key factor in breast cancer risk.

Studies have shown that ulipristal acetate can slow the growth of breast cells and reduce the number of cells at higher risk. Ulipristal acetate likely achieves this by lowering progesterone levels, temporarily making breast tissue less dense. Research suggests this effect might lead to clearer mammogram results. Additionally, ulipristal acetate has lowered markers linked to breast cancer risk. These findings suggest it could benefit individuals with very dense breast tissue. Participants in this trial will receive ulipristal acetate to evaluate its effects on breast density and related outcomes.²³⁶⁷⁸