Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study on Mifepristone and Letrozole for Treating Ectopic Pregnancy in Comparison to Methotrexate

Fast replyRegistered drugNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the treatment of ectopic pregnancy, a condition where a fertilized egg implants outside the uterus, often in a fallopian tube. The study will compare two treatment options: a combination of the medications mifepristone and letrozole, and the medication methotrexate. Mifepristone, also known by its code name RU-486, is typically used to terminate early pregnancies, while letrozole is often used in breast cancer treatment. Methotrexate is a medication that can treat certain types of cancer and autoimmune diseases, and it is also used to treat ectopic pregnancies.

The purpose of this study is to determine if the combination of mifepristone and letrozole is as effective as methotrexate in treating ectopic pregnancy. Participants in the study will be randomly assigned to receive either the combination of mifepristone and letrozole or methotrexate. The study will monitor the participants over a period to see how well the treatments work in resolving the ectopic pregnancy without the need for additional medical or surgical intervention.

Throughout the study, researchers will also observe any side effects or adverse events related to the treatments. The study aims to provide valuable information on the effectiveness and safety of these treatment options for ectopic pregnancy, potentially offering new insights into managing this condition. Participants will be closely monitored by healthcare professionals to ensure their safety and well-being during the trial.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit and consent

    Upon joining the study, the first step involves an initial visit where the condition of ectopic pregnancy is confirmed or highly suspected. This is determined by an empty uterus and specific hormone levels.

    Participants must be at least 18 years old and able to understand the provided information. Written consent is required to proceed with the trial.

  2. Step 2

    Randomization and treatment assignment

    Participants are randomly assigned to one of two treatment groups. One group receives a combination of mifepristone and letrozole, while the other group receives methotrexate.

    The purpose is to evaluate if the combination of mifepristone and letrozole is as effective as methotrexate in treating ectopic pregnancy.

  3. Step 3

    Treatment administration

    For those receiving methotrexate, the medication is administered as an intramuscular injection. The dosage and frequency are determined by the study protocol.

    Participants in the mifepristone and letrozole group take these medications orally. The specific dosage and frequency are provided by the study team.

  4. Step 4

    Monitoring and follow-up

    Participants are monitored regularly to assess the treatment's effectiveness. This includes measuring hormone levels to ensure they decrease to the desired level.

    Follow-up visits occur over a period of up to 60 days to check for successful treatment response and to monitor for any side effects or adverse events.

  5. Step 5

    Evaluation of treatment success

    The primary goal is to achieve a successful treatment response, defined as a decrease in hormone levels to below a specific threshold without needing additional medical or surgical intervention.

    Secondary evaluations include monitoring for any adverse events, the need for further interventions, and the time taken for the ectopic pregnancy to resolve.

  6. Step 6

    Long-term follow-up

    Participants may be asked to attend follow-up appointments at 1 month and 3 months after treatment to assess hormone levels and other health indicators.

    Additional assessments may include time to future pregnancy and pregnancy rates within the first year after treatment.

Who can join the trial?

4 criteria

  • Confirmed ectopic pregnancy, or a high suspicion of it, which means the pregnancy is outside the uterus and needs treatment. This can be indicated by an empty uterus or unusual levels of a pregnancy hormone called hCG.
  • Must be 18 years old or older.
  • Able to understand both spoken and written information about the study.
  • Must have given written consent to participate in the study.

Who cannot join the trial?

4 criteria

  • Participants must not have any other medical conditions that could interfere with the study.
  • Participants should not be pregnant with a normal pregnancy, as the study focuses on ectopic pregnancy, which is a pregnancy that occurs outside the uterus.
  • Participants must not be male, as the study is only for females.
  • Participants should not be part of a vulnerable population, which means groups that might need special protection or care.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

RecruitingNot yet recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • Mifepristone

    is a medication that is often used to end early pregnancies. In this trial, it is being tested to see if it can help treat ectopic pregnancies, which occur when a fertilized egg implants outside the uterus. Mifepristone works by blocking the hormone progesterone, which is necessary for pregnancy to continue. By doing this, it helps stop the growth of the pregnancy tissue.

  • Letrozole

    is a medication that is usually used to treat breast cancer in postmenopausal women. It works by lowering estrogen levels in the body, which can help slow or stop the growth of certain types of breast cancer cells that need estrogen to grow. In this trial, letrozole is being used in combination with mifepristone to see if it can effectively treat ectopic pregnancies.

  • Methotrexate

    is a medication that is commonly used to treat certain types of cancer and autoimmune diseases. It works by slowing down the growth of cells, including those of the pregnancy tissue in an ectopic pregnancy. In this trial, methotrexate is being used as a comparison to see if the combination of mifepristone and letrozole is as effective in treating ectopic pregnancies.

What is already known about the treatment

  • Mifepristone

    Mifepristone is taken orally in pill form and is currently being studied for its effectiveness in treating ectopic pregnancies. It is known in medical literature as a medication that blocks the hormone progesterone, which is necessary for pregnancy to continue. By blocking this hormone, mifepristone helps to stop the growth of the pregnancy tissue. It is classified as an antiprogestogen, meaning it works against the effects of progesterone.

  • Letrozole

    Letrozole is administered orally as a tablet and is being researched for its role in managing ectopic pregnancies. In the medical field, it is recognized for its ability to lower estrogen levels by inhibiting an enzyme called aromatase, which is involved in estrogen production. This reduction in estrogen can help in stopping the growth of pregnancy tissue. Letrozole is classified as an aromatase inhibitor.

  • Methotrexate

    Methotrexate is given as an injection and is a well-established treatment for ectopic pregnancies. It works by interfering with the growth of rapidly dividing cells, such as those found in pregnancy tissue, effectively stopping the pregnancy from progressing. Methotrexate is classified as an antimetabolite, which means it disrupts cell metabolism and growth.

Investigated diseases

Ectopic pregnancy – Ectopic pregnancy occurs when a fertilized egg implants and grows outside the main cavity of the uterus, most commonly in a fallopian tube. This condition can cause the tube to rupture if not addressed, leading to internal bleeding. Initially, symptoms may be similar to a normal pregnancy, such as missed periods and breast tenderness. As it progresses, symptoms can include abdominal pain, vaginal bleeding, and dizziness. The condition can lead to significant complications if the growing tissue causes damage to nearby organs. It requires careful monitoring to prevent further health issues.
Trial detailsLast updated 4 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-503935-16-00Protocol codeWML23Estimated enrolment1 700 patientsSponsorKarolinska Institutet

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.