NCT06394999

Efficacy, Safety, and Acceptability of Mifepristone 50 mg Once-weekly as a Contraceptive

Prospective Phase III Multi-center Open-label Study of the Efficacy, Safety, and Acceptability of Mifepristone 50 mg Once-weekly as a Contraceptive

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 1,186 (estimated)
• Sponsor: Leiden University Medical Center · Academic / Other
• Sex: Female
• Age: 18 Years – 35 Years
• Healthy volunteers: Accepted

Summary

Participants in the study will use mifepristone 50 mg once-a-week for one year as a contraceptive. With this, we want to confirm that the chances of getting pregnant while using this contraceptive are very small. We also want to demonstrate that the use of mifepristone is safe, and it does not lead to any severe health problems. We expect fewer side effects compared to other frequently used contraceptives with hormones. Mifepristone does not contain these hormones. It is important to know how people experience that use of one tablet a week.

Detailed description

Mifepristone 50 mg, a progesterone receptor modulator, is a proven safe emergency contraceptive and a promising new weekly contraceptive. As mifepristone does not contain estrogens or progestogens, we anticipate users will not experience the undesirable side effects and health risks of current hormonal contraceptives. Furthermore, pills are a highly desired formulation approach and a weekly regimen instead of daily administration will likely contribute to a high acceptability and adherence among users. Based on promising early stage clinical data, we expect the use of weekly mifepristone 50 mg as a contraceptive will be safe, effective, and acceptable.

Conditions

• Female Contraception

Interventions

Type	Name	Description
DRUG	Mifepristone 50 mg	Once-weekly oral mifepristone 50 mg

Timeline

• Start date: 2025-05-02
• Primary completion: 2029-04-01
• Completion: 2030-04-01
• First posted: 2024-05-01
• Last updated: 2025-09-16

Locations

14 sites across 1 country: Netherlands