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Study of Milademetan and Fulvestrant for Patients with Advanced or Metastatic Breast Cancer with GATA3 Mutation, ER-Positive, HER2-Negative

Verified siteRegistered drugNo placebo
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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 GATA3-mutant, ER-positive, HER2-negative advanced or metastatic breast cancer. The study involves two treatments: Milademetan, which is taken as a capsule, and Fulvestrant, which is given as an injection. The purpose of the study is to determine how effective these treatments are when used together in patients with this specific type of breast cancer.

Participants in the study will receive either the combination of Milademetan and Fulvestrant or a placebo. The study will last for several months, during which time participants will take the medication and have regular check-ups to monitor their health and the progress of the treatment. The study aims to see if the combination of these treatments can help control the cancer for at least six months.

Throughout the study, doctors will assess the participants' response to the treatment, looking for any changes in the cancer's size or spread. They will also monitor for any side effects that may occur. The study will help researchers understand if this combination of treatments can provide a clinical benefit to patients with this type of breast cancer.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Beginning of treatment

    Upon joining the study, the treatment phase begins. The study involves the use of two medications: milademetan and fulvestrant. Milademetan is taken orally in the form of capsules, while fulvestrant is administered as an intramuscular injection.

    The specific dosage and frequency of these medications will be determined by the study team based on individual health conditions and responses to treatment. The treatment aims to assess the clinical benefit rate at six months.

  2. Step 2

    Medication administration

    Milademetan is provided in capsule form for oral use. The exact dosage and schedule will be communicated by the healthcare provider overseeing the trial.

    Fulvestrant is given as a 250 mg solution for injection. This is administered intramuscularly, meaning it is injected into a muscle. The frequency of these injections will be specified by the healthcare team.

  3. Step 3

    Monitoring and assessments

    Throughout the trial, regular monitoring and assessments will be conducted to evaluate the effectiveness of the treatment and to check for any side effects. This includes physical examinations, blood tests, and imaging studies as needed.

    Participants will be asked to report any side effects or changes in their health to the study team promptly. This information is crucial for ensuring safety and adjusting treatment as necessary.

  4. Step 4

    End of treatment evaluation

    At the end of the treatment period, a comprehensive evaluation will be conducted. This will include a review of the participant's response to the treatment and any side effects experienced.

    The study team will discuss the results and any further steps or follow-up care that may be needed. Participants will be informed about the findings related to their health and the overall study outcomes.

Who can join the trial?

16 criteria

  • The breast cancer must have a GATA3 mutation, which is a specific change in the DNA of the cancer cells.
  • Must be 18 years or older.
  • Must have a performance status of 0 or 1, which means being fully active or restricted in physically strenuous activity but able to carry out light work.
  • Must have Stage IV metastatic breast cancer, meaning the cancer has spread to other parts of the body.
  • The cancer must be estrogen receptor-positive (ER+) and HER2-negative (HER2-), which are specific characteristics of the cancer cells.
  • Must have received at least one prior treatment with hormone therapy and a CDK4/6 inhibitor, but no more than two hormone therapies for metastatic disease.
  • No more than two prior chemotherapy treatments for metastatic disease.
  • Must have disease that can be measured by the doctor.
  • Must be willing to provide a sample of the tumor tissue for testing.
  • Must have a life expectancy of at least 3 months.
  • Must have adequate organ function, which includes specific blood and liver function tests.
  • If female and able to have children, must have a negative pregnancy test and agree to use effective birth control methods.
  • Must be postmenopausal, surgically infertile, or willing to use effective birth control methods for at least 2 years after the study.
  • Must be able to swallow capsules.
  • Must be willing to participate for the duration of the study and follow study procedures.
  • Must be able to give signed informed consent, which means agreeing to participate after understanding the study details.

Who cannot join the trial?

4 criteria

  • Patients with any other type of cancer that is not GATA3-mutant, ER-positive, HER2-negative advanced or metastatic breast cancer cannot participate.
  • Patients who are not within the specified age range for the study cannot participate.
  • Patients who are not female or male cannot participate.
  • Patients who are considered part of a vulnerable population cannot participate. A vulnerable population includes groups like children, pregnant women, or people with certain disabilities.
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Investigated drugs

  • Milademetan

    is a medication being studied for its potential to treat certain types of breast cancer. It works by targeting specific proteins in cancer cells that help them grow and survive. By interfering with these proteins, milademetan aims to slow down or stop the growth of cancer cells, which may help in managing the disease.

  • Fulvestrant

    is a therapy used to treat breast cancer that is hormone receptor-positive. It works by blocking the effects of estrogen, a hormone that can promote the growth of breast cancer cells. Fulvestrant helps to slow down or stop the growth of these cancer cells by reducing their ability to use estrogen, which is important for their survival and proliferation.

What is already known about the treatment

  • Milademetan

    Milademetan is administered orally in the form of tablets. It is currently being studied in clinical trials for its effectiveness in treating certain types of breast cancer, specifically GATA3-mutant, ER-positive, HER2-negative advanced or metastatic breast cancer. The medication works by targeting and inhibiting a specific protein that helps cancer cells grow, thereby slowing down or stopping the progression of the disease. Milademetan is classified as an investigational drug, meaning it is still under research and not yet approved for general medical use.

  • Fulvestrant

    Fulvestrant is given as an injection into the muscle, typically in the buttocks. It is an established medication used in the treatment of hormone receptor-positive metastatic breast cancer, particularly in postmenopausal women. Fulvestrant works by blocking and degrading estrogen receptors on cancer cells, which are necessary for their growth and survival. It is classified as an estrogen receptor antagonist and is widely recognized in medical literature for its role in breast cancer therapy.

Investigated diseases

GATA3-mutant, ER-positive, HER2-negative advanced or metastatic breast cancer – This type of breast cancer is characterized by mutations in the GATA3 gene, which plays a role in regulating the development and function of certain cells. It is estrogen receptor-positive (ER-positive), meaning that the cancer cells grow in response to the hormone estrogen. The cancer is also HER2-negative, indicating that it does not have an excess of the HER2 protein on its surface. This form of breast cancer is considered advanced or metastatic, meaning it has spread beyond the original site to other parts of the body. The progression of the disease involves the growth and spread of cancer cells, which can invade nearby tissues and organs. Over time, the cancer may become more aggressive and resistant to certain treatments.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2022-502360-21-00Protocol codeIC 2022-05Estimated enrolment48 patientsSponsorInstitut Curie

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