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

NCT06394999 | Recruiting Phase 3

• 1 other identifier: 2022-502694-41-00
• Study Type: interventional
• Target: 1,186
• Locations: 1 country
• Sites: 14

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.

Conditions

Female Contraception

Keywords

Oral; Weekly; Non-hormonal

Outcome Measures

Primary Outcomes (3)

• Overall Pearl Index

  Nominator Number of pregnancies with conception during treatment period from the first day of pill intake to the last day of pill intake + 7 days Denominator The time period from the first day of pill intake to the last day of pill intake + 7 days. Cycles with documentation of no unprotected intercourse will be subtracted from this period, unless in the unlikely case that a pregnancy occurred in such a cycle.

  0-12 months

• Pearl Index by Method failure

  Nominator Number of pregnancies with conception during cycles as defined in the denominator Denominator The number of cycles with perfect use times 1300. A cycle is defined as (at least) 28 days after the first day of mifepristone 50 mg intake. Cycles with documentation of no unprotected intercourse will be subtracted from this time period, unless in the unlikely case that a pregnancy occurred in such a cycle. Also, cycles with non-perfect use, i.e. without mifepristone 50 mg intake at least once every 7 days will be excluded. Diary charts and counting of remaining tablets will provide dosing information to determine (non-) perfect use.

  0-12 months

• Assess the contraceptive safety of once-weekly mifepristone 50 mg

  Proportion of women with endometrial thickness \>15 mm, endometrium with irregular cystic appearance on US; with ALT, AST elevation three times above normal levels or bilirubin two times above normal levels; with adverse events / serious adverse events

  3, 6 and 12 months

Secondary Outcomes (9)

• Depression

  baseline, 3, 6 and 12 months

• Sexual functioning

  baseline, 3, 6 and 12 months

• Use of antidepressants

  baseline, 3, 6 and 12 months

• Weight [kg]

  baseline, 3, 6 and 12 months

• Bleeding profile

  0-365 days

Study Arms (1)

mifepristone 50 mg

EXPERIMENTAL

mifepristone 50 mg once weekly

Drug: Mifepristone 50 mg

Interventions

Mifepristone 50 mg DRUG

Once-weekly oral mifepristone 50 mg

mifepristone 50 mg

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-35 at the moment of signing the informed consent.
• In case of 30 years or older, prior HPV or pap-test.
• Understand and speak Dutch or English.
• Willing to use mifepristone as the only method of contraception for 12 months.
• Able to take oral medication and willing to adhere to the study protocol.
• Have unprotected vaginal heterosexual intercourse with a non-sterilized partner at least once a month.
• BMI \< 35 kg/m2.
• Willing to fill in a daily diary on the smartphone or computer and five times an on-line questionnaire.
• Able to participate in the scheduled visits and comply with the study protocol.
• Provide informed consent about participating in study and provide permission to request medical data in the event of complications or pregnancy.
• In case of not using hormonal contraceptives, menstrual cycle of 21-35 days.
• In case of Depo-Provera (3 month injectable) at least 3 cycles of 21-35 days after stop.
• In case of necessary progesterone treatment, be willing to use condoms temporarily.

You may not qualify if:

• Currently pregnant or breast-feeding.
• Desire to become pregnant within the following 12 months.
• Signs of current endometritis, incomplete abortion after miscarriage or induced abortion, or retained pla-cental rests after delivery.
• Undiagnosed post-coital bleeding or unscheduled bleeding (spotting with COC, patch, vaginal ring, hormo-nal IUD, implant allowed).
• Known subfertility or history of ectopic pregnancy, unless intra-uterine pregnancy afterwards, or grade 3-4 endometriosis proven by laparoscopy.
• History of gastric reduction or gastric bypass or use of weight-loss medicines.
• Previous or current liver illness, previous or current infection affecting the liver (such as Hepatitis) or mod-erately abnormal liver enzymes at screening (ALAT, ASAT or bilirubin \> 2 ULN).
• Current or previous cancer or DCIS.
• Family history of endometrial cancer, except BRCA genome mutation.
• Known allergy to mifepristone.
• Using non-dermal corticosteroids or any drugs that may interact with mifepristone. These include hydan-toins (e.g. phenytoin), barbiturates (e.g. phenobarbital), primidone, carbamazepine, rifampicin, oxcarbaze-pine, topiramate, rifabutin, felbamate, ritonavir, nelfinavir, griseofulvin and products containing St. John's wort (Hypericum perforatum).
• Treatment with another investigational drug or participating in another intervention study, unless the prin-cipal investigators agree.
• Undiagnosed reason for severe anemia or increased creatinine.
• Abnormal previous PAP smear \> pap II without colposcopic evaluation or untreated HSIL.
• Systolic blood pressure ≥ 180 mmHg and/or diastolic ≥ 110 mmHg (hypertension with medical treatment allowed).

Sponsors & Collaborators

• Leiden University Medical Center: lead
• Karolinska Institutet: collaborator
• Women on Waves: collaborator
• Children's Investment Fund Foundation: collaborator

Study Sites (14)

Noordwest Ziekenhuisgroep

Alkmaar, 1815 JD, Netherlands

RECRUITING

Ziekenhuisgroep Twente

Almelo, 7609 PP, Netherlands

NOT YET RECRUITING

Flevoziekenhuis

Almere Stad, 1315 RA, Netherlands

NOT YET RECRUITING

Amsterdam Universitair Medische Centra

Amsterdam, 1105 AZ, Netherlands

NOT YET RECRUITING

Medisch Spectrum Twente

Enschede, 7512 KZ, Netherlands

RECRUITING

Admiraal De Ruyter Ziekenhuis

Goes, 4462 RA, Netherlands

RECRUITING

Martini Ziekenhuis

Groningen, 9728 NZ, Netherlands

RECRUITING

Medisch Centrum Leeuwarden

Leeuwarden, 8934 AD, Netherlands

RECRUITING

Leiden University Medical Center

Leiden, 2333 ZA, Netherlands

RECRUITING

Maastricht Universitair Medisch Centrum

Maastricht, 6229 HX, Netherlands

NOT YET RECRUITING

Canisius Wilhelmina Ziekenhuis

Nijmegen, 6532 SZ, Netherlands

NOT YET RECRUITING

Franciscus Gasthuis

Rotterdam, 3045 PM, Netherlands

RECRUITING

Diakonessenhuis

Utrecht, 3582 KE, Netherlands

NOT YET RECRUITING

Maxima Medisch Centrum

Veldhoven, 5504 DB, Netherlands

RECRUITING

MeSH Terms

Interventions

Mifepristone

Intervention Hierarchy (Ancestors)

Estrenes; Estranes; Steroids; Fused-Ring Compounds; Polycyclic Compounds

Study Officials

• Rebecca Gomperts, PhD

  Leiden University Medical Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Rebecca Gomperts, PhD

CONTACT

+31652052561; r.gomperts@lumc.nl

Elma Meershoek, MSc

CONTACT

+31715263500; clinicalresearchcenter@lumc.nl

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Researcher

Study Record Dates

• First Submitted: April 29, 2024
• First Posted: May 1, 2024
• Study Start: May 2, 2025
• Primary Completion (Estimated): April 1, 2029
• Study Completion (Estimated): April 1, 2030
• Last Updated: September 16, 2025

Record last verified: 2025-09

Locations

NL (14)