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NCT06394999 | NOT YET RECRUITING | Female Contraception

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

Leiden University Medical Center

Information provided by (Responsible Party):


Brief 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.

Condition or disease

Female Contraception


Mifepristone 50 mg



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.

Estimated Enrollment : 1186 participants
Masking : NONE
Primary Purpose : PREVENTION
Official Title : Prospective Phase III Multi-center Open-label Study of the Efficacy, Safety, and Acceptability of Mifepristone 50 mg Once-weekly as a Contraceptive
Actual Study Start Date : 2024-09
Estimated Primary Completion Date : 2028-09
Estimated Study Completion Date : 2029-09

Information not available for Arms and Intervention/treatment

Ages Eligible for Study: 18 Years to 35 Years
Sexes Eligible for Study: FEMALE
Accepts Healthy Volunteers: 1
Inclusion Criteria
  • 1. Age 18-35
  • 2. Live in the Netherlands and speak and understand Dutch or English
  • 3. No desire to become pregnant within the following 12 months, be willing to use mifepristone as the on-ly method of contraception for 12 months.
  • 4. Expecting to have unprotected vaginal heterosexual intercourse with a non-sterilized partner at least once a month.
  • 5. A menstrual cycle of 21-35 days when not using hormonal contraceptives
  • 6. After depo-provera (3 month injectable) at least 3 cycles of 21-35 days
  • 7. BMI \< 35 kg/m2
  • 8. Be able to take oral medication and be willing to adhere to the study protocol.
  • 9. Be willing to fill in a daily dairy
  • 10. Be able to participate in the scheduled visits
  • 11. If 30 years or older, prior Human Papilloma Virus (HPV) or pap-test
  • 12. Be willing to provide signed and dated informed consent about participating in study
Exclusion Criteria
  • 1. Currently pregnant or breast-feeding
  • 2. Signs of current endometritis, incomplete abortion after miscarriage or induced abortion, or retained placental rests after delivery.
  • 3. Undiagnosed post-coital bleeding or unscheduled bleeding (spotting with Combined Oral Contraceptive (COC), patch, vaginal ring, hormonal Intrauterine Device (IUD), implant or hormonal injection allowed)
  • 4. Known subfertility or history of ectopic pregnancy, unless intra-uterine pregnancy afterwards
  • 5. History of gastric bypass
  • 6. Previous or current liver illness, previous or current infection affecting the liver (such as Hepatitis C) or abnormal liver enzymes at screening.
  • 7. Current or previous cancer
  • 8. Family history of endometrial cancer, except BReast CAncer (BRCA) genome mutation
  • 9. Known allergy to mifepristone.
  • 10. Using oral corticosteroids or any drugs that may interact with mifepristone - these include hydantoins (e.g. phenytoin), barbiturates (e.g. phenobarbital), primidone, carbamazepine, rifampicin, oxcarbazepine, topiramate, rifabutin, felbamate, ritonavir, nelfinavir, griseofulvin and products containing St. John's wort (Hypericum perforatum)
  • 11. Treatment with another investigational drug or participating in another intervention study
  • 12. Undiagnosed reason for severe anemia or increased creatinine
  • 13. Abnormal previous Papanicolaou (PAP) smear \> pap II without colposcopic evaluation or untreated High grade Squamous Intraepithelial Lesion (HSIL)
  • 14. Blood pressure 180 or more systolic and/or 110 diastolic or more at screening (hypertension with medical treatment allowed)
  • 15. Intracavitary abnormalities on vaginal ultrasound at screening, including intracavitary polyps or myomas, irregular cystic endometrium, endometrium \> 15 mm, or an obvious sign of hydrosalpinx
  • 16. Unable to comply with the trial protocol

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

Location Details


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Not yet recruiting


Hospital Group Twente

Almelo, Netherlands, 7609 PP

Not yet recruiting


Amsterdam University Medical Centers

Amsterdam, Netherlands, 1105 AZ

Not yet recruiting


Medical Spectrum Twente

Enschede, Netherlands, 7512 KZ

Not yet recruiting


Martini Hospital

Groningen, Netherlands, 9728 NZ

Not yet recruiting


Leiden University Medical Center

Leiden, Netherlands, 2333 FOR

Not yet recruiting


Deaconess House

Utrecht, Netherlands, 3582 KE