Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study on Elacestrant and Everolimus for Patients with Advanced ER+/HER2- Breast Cancer Resistant to Endocrine Therapy and CDK4/6 Inhibitors

Verified siteRegistered drug
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 a type of breast cancer known as estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer. This specific type of cancer has a mutation called ESR1 and has progressed despite previous treatments with hormone therapy and medications called CDK4/6 inhibitors. The study aims to compare the effectiveness of a combination of two medications, elacestrant and everolimus, against elacestrant alone. Elacestrant is a medication that targets hormone receptors, while everolimus is used to slow down the growth of cancer cells. The study will also include a group receiving a placebo, which is a substance with no active medication, to help understand the effects of the treatment.

Participants in the study will be randomly assigned to receive either the combination of elacestrant and everolimus, elacestrant with a placebo, or another treatment as part of the study. The study will be conducted in a way that neither the participants nor the researchers know which treatment each participant is receiving, a method known as "double-blind." This helps ensure that the results are not influenced by expectations about the treatment. The main goal is to see if the combination of elacestrant and everolimus can help patients live longer without their cancer getting worse, which is referred to as "progression-free survival."

The study will take place over several years, with regular check-ups and assessments to monitor the participants' health and the progression of their cancer. Participants will receive their assigned treatment for a set period, and their response to the treatment will be closely monitored through various tests and evaluations. The study will also look at the overall survival of participants, the response of the cancer to the treatment, and any side effects experienced. This research is important for understanding how to better treat this specific type of breast cancer and improve outcomes for patients in the future.

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

    Joining the study

    Upon joining the study, the patient will be randomly assigned to one of two groups. One group will receive a combination of elacestrant and everolimus, while the other group will receive elacestrant and a placebo.

    The study is designed to be double-blind, meaning neither the patient nor the researchers will know which group the patient is in.

  2. Step 2

    Medication administration

    The patient will take elacestrant orally. The dosage will be either 86 mg or 345 mg, depending on the specific requirements of the study.

    If assigned to the combination group, the patient will also take everolimus orally at a dosage of 2.5 mg.

    The medications will be taken daily, and the duration of administration will continue as long as the patient remains in the study.

  3. Step 3

    Monitoring and assessments

    Regular monitoring will occur to assess the patient's health and the effectiveness of the treatment. This includes imaging tests to evaluate the progression of the disease.

    The patient's response to the treatment will be evaluated using criteria known as RECIST v.1.1, which helps determine changes in tumor size.

  4. Step 4

    Safety evaluations

    The study will include assessments of safety and tolerability. This involves monitoring for any adverse effects or changes in health status.

    Regular check-ups will include laboratory tests, electrocardiograms (ECGs), and assessments of vital signs.

  5. Step 5

    Quality of life assessments

    The patient's quality of life will be evaluated using specific questionnaires designed to measure health-related quality of life in cancer patients.

    These assessments will help understand the impact of the treatment on the patient's daily life and well-being.

  6. Step 6

    Completion of the study

    The study is expected to continue until December 2027. The patient will remain in the study until disease progression, unacceptable side effects, or other criteria for discontinuation are met.

    Upon completion, the patient will undergo a final assessment to evaluate the overall outcomes of the treatment.

Who can join the trial?

19 criteria

  • The patient or their legal representative must understand the study's purpose and sign a written consent form before starting any study procedures.
  • The patient must not have had chemotherapy for advanced disease before.
  • The patient must have measurable disease, which means the cancer can be measured by doctors using specific criteria, or have a type of disease that can be evaluated, including certain bone diseases.
  • The patient must be willing and able to provide a sample of their tumor tissue, either from a recent biopsy or an older sample.
  • The patient's fasting cholesterol levels must be 300 mg/dL or lower, and fasting triglycerides must be 2.5 times the normal limit or lower.
  • The patient must have adequate bone marrow and organ function, which includes specific levels of blood cells, liver function, and kidney function.
  • The patient must have recovered from any side effects of previous cancer treatments to a mild level, except for hair loss, which can be more severe.
  • Women who can have children and are sexually active must have a negative pregnancy test and agree to use effective birth control before and during the study, and for a period after the study ends.
  • Men with partners who can have children must be sterile or use effective birth control before and during the study, and for a period after the study ends. They must also not donate sperm during this time.
  • The patient must have an ECOG performance status of 0-1, which means they are fully active or have some symptoms but can still carry out light work.
  • The patient must have a life expectancy of at least 12 weeks at the time of screening.
  • The patient must be 18 years or older at the time of signing the consent form.
  • Pre- or perimenopausal women and men must be receiving a specific type of hormone treatment for at least 28 days before the study and plan to continue it during the study. Postmenopausal women must meet certain criteria, such as age or hormone levels.
  • The patient must have a confirmed diagnosis of a specific type of breast cancer that cannot be surgically removed or has spread to other parts of the body.
  • The patient's cancer must be estrogen receptor-positive (ER[+]) and human epidermal growth factor receptor 2-negative (HER2[-]), confirmed by specific tests.
  • The patient must have a specific mutation called ESR1, confirmed by a specific test before joining the study.
  • The patient must show evidence of disease progression after previous treatment with a CDK4/6 inhibitor and endocrine therapy for advanced disease.
  • The patient must have received at least one and no more than two lines of endocrine therapy for advanced breast cancer.
  • The patient must not have received certain investigational drugs or treatments for advanced disease before, except for a specific drug called fulvestrant if it was given at least 28 days before joining the study.

Who cannot join the trial?

7 criteria

  • Patients who have not been diagnosed with **estrogen receptor-positive**/**human epidermal growth factor receptor 2-negative** breast cancer. This means the cancer cells grow in response to the hormone estrogen and do not have a protein called HER2 on their surface.
  • Patients whose cancer does not have a specific change in the **ESR1 gene**. This gene is related to how the body responds to estrogen.
  • Patients who have not received **endocrine therapy**. This is a treatment that blocks or lowers the amount of hormones in the body to slow down or stop cancer growth.
  • Patients who have not been treated with **CDK4/6 inhibitors**. These are medicines that help stop cancer cells from growing by blocking certain proteins.
  • Patients who are not experiencing cancer that is getting worse despite previous treatments.
  • Patients who are not within the specified age range for the study.
  • Patients who are part of a vulnerable population, which means they 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

  • Elacestrant

    is a medication used in this study to treat advanced breast cancer that is estrogen receptor-positive and human epidermal growth factor receptor 2-negative. It is being tested to see if it can help slow down the progression of cancer in patients who have already been treated with endocrine therapy and CDK4/6 inhibitors.

  • Everolimus

    is another medication used in this study. It is being combined with elacestrant to see if the combination is more effective in prolonging the time before the cancer progresses compared to using elacestrant alone. Everolimus works by interfering with cancer cell growth and spread.

What is already known about the treatment

  • Elacestrant

    Elacestrant is administered orally and is currently being studied in clinical trials for its effectiveness in treating advanced breast cancer. It is specifically used for patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, ESR1-mutated breast cancer that has progressed after endocrine therapy and CDK4/6 inhibitors. Elacestrant works by binding to estrogen receptors, blocking their activity, and reducing cancer cell growth. It is classified as a selective estrogen receptor degrader (SERD).

  • Everolimus

    Everolimus is taken orally and is being evaluated in combination with elacestrant for its potential to improve outcomes in advanced breast cancer. It is used for patients with specific types of breast cancer that have not responded to other treatments. Everolimus acts by inhibiting the mTOR pathway, which is involved in cell growth and proliferation. It belongs to the class of drugs known as mTOR inhibitors.

Investigated diseases

Advanced Breast Cancer – This type of cancer occurs when breast cancer cells have spread beyond the breast to other parts of the body. It is characterized by the presence of estrogen receptor-positive (ER+) and human epidermal growth factor receptor 2-negative (HER2-) cells, which means the cancer cells grow in response to estrogen but do not have excess HER2 protein. In some cases, mutations in the ESR1 gene can occur, which may affect how the cancer responds to hormone therapies. The disease progresses as cancer cells continue to grow and spread, often becoming resistant to standard endocrine therapies and CDK4/6 inhibitors. This resistance can lead to further progression of the disease, requiring alternative treatment strategies to manage growth and spread.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-512926-27-00Protocol codeMEDOPP545Estimated enrolment240 patientsSponsorMedica Scientia Innovation Research S.L.

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.