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Study on Giredestrant and Everolimus for Patients with Estrogen Receptor-Positive, HER2-Negative Advanced or Metastatic Breast Cancer

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 Estrogen Receptor-Positive, HER2-Negative, Locally Advanced or Metastatic Breast Cancer. This type of cancer has spread beyond the breast and is not suitable for surgery aimed at curing it. The study will explore the effectiveness and safety of a new treatment combination. The treatment involves a medication called Giredestrant, which is taken as a capsule, combined with another medication called Everolimus, which is taken as a tablet. The study will compare this combination to the usual hormone therapy chosen by doctors, also combined with Everolimus.

The purpose of the study is to see how well the new treatment works in slowing down the progression of the cancer and to assess its safety. Participants will be randomly assigned to receive either the new treatment combination or the standard hormone therapy with Everolimus. The study will last for a period of up to 42 days, during which participants will take the medications orally. The study will also involve regular check-ups and monitoring to track the progress of the disease and any side effects that may occur.

By participating in this study, researchers aim to gather important information that could help improve treatment options for patients with this type of breast cancer. The study will focus on patients who have previously been treated with a type of medication called a CDK4/6 inhibitor and hormone therapy. The results will help determine if the new treatment combination is more effective than the current standard options available for managing this condition.

The research process

The trial runs in 5 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, eligibility is confirmed based on specific criteria, including the type of breast cancer and previous treatments.

    A blood sample is required to determine specific genetic markers related to the cancer.

  2. Step 2

    Randomization

    Participants are randomly assigned to one of two groups: one receiving giredestrant plus everolimus, and the other receiving a physician's choice of endocrine therapy plus everolimus.

  3. Step 3

    Treatment administration

    For those receiving giredestrant, it is administered orally in capsule form.

    The dosage and frequency of everolimus depend on the specific product used, with options including 2.5 mg, 5 mg, and 10 mg tablets taken orally.

    Participants in the physician's choice group may receive medications such as tamoxifen (20 mg tablets), fulvestrant (250 mg injection), or exemestane (25 mg tablets), depending on the physician's decision.

  4. Step 4

    Monitoring and assessments

    Regular assessments are conducted to monitor the progression of the disease and the body's response to the treatment.

    These assessments include imaging tests and evaluations of symptoms and side effects.

  5. Step 5

    Follow-up

    Participants continue to be monitored for progression-free survival, which is the time during and after treatment that the patient lives with the disease without it getting worse.

    Additional follow-up includes monitoring overall survival and quality of life measures.

Who can join the trial?

7 criteria

  • The patient must have **locally advanced** or **metastatic breast cancer** that cannot be treated with the aim of curing it. This means the cancer has spread beyond the breast and nearby areas and cannot be completely removed or cured.
  • The cancer must be **estrogen receptor-positive (ER+)**, which means the cancer cells grow in response to the hormone estrogen. This is determined by a test showing that at least 1% of the cancer cells have this characteristic.
  • The cancer must be **HER2-negative**, meaning it does not have high levels of a protein called HER2, which can promote the growth of cancer cells.
  • The patient must be able to provide a blood sample to check for a specific change in the cancer's DNA, known as the **ESR1 mutation**.
  • The patient must have **measurable disease**, which means the cancer can be measured by scans or tests. If the cancer has spread to the bones, there must be at least one area in the bones that can be seen and measured on a CT or MRI scan.
  • Any side effects from previous cancer treatments or surgeries must have improved to a mild level, as defined by a specific medical guideline.
  • The study is open to both **female and male** patients.

Who cannot join the trial?

5 criteria

  • Patients who have not been previously treated with a CDK4/6 inhibitor and endocrine therapy. A CDK4/6 inhibitor is a type of medication used to treat certain breast cancers, and endocrine therapy is a treatment that blocks or lowers the amount of hormones in the body to slow down or stop cancer growth.
  • Patients with breast cancer that is not Estrogen Receptor (ER)-Positive or HER2-Negative. ER-Positive means the cancer cells grow in response to the hormone estrogen. HER2-Negative means the cancer does not have high levels of the protein HER2.
  • Patients who do not have locally advanced or metastatic breast cancer. Locally advanced means the cancer has spread to nearby tissues or lymph nodes, and metastatic means the cancer has spread to other parts of the body.
  • Patients who are not part of the ESR1m subpopulation. This refers to a specific group of patients with a mutation in the estrogen receptor 1 gene.
  • Patients who are not part of the intent-to-treat (ITT) population. This means all patients who are intended to be treated in the study, regardless of whether they complete the treatment.
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Investigated drugs

  • Giredestrant

    is a medication being studied for its potential to treat breast cancer. It works by targeting and blocking the estrogen receptor, which can help slow down or stop the growth of cancer cells that rely on estrogen to grow.

  • Everolimus

    is a medication used in this trial to help treat breast cancer. It works by interfering with the cancer cells' ability to grow and divide. It is often used in combination with other treatments to enhance its effectiveness.

  • Endocrine Therapy

    refers to a group of treatments that aim to block or lower the amount of hormones in the body, particularly estrogen, to slow down or stop the growth of hormone-sensitive tumors. In this trial, the specific type of endocrine therapy is chosen by the physician based on the patient's needs.

What is already known about the treatment

  • Giredestrant

    Giredestrant is administered orally and is currently being studied in clinical trials for its effectiveness in treating certain types of breast cancer. It is specifically being evaluated for use in patients with estrogen receptor-positive, HER2-negative, locally advanced or metastatic breast cancer that has previously been treated with a CDK4/6 inhibitor and endocrine therapy. Giredestrant works by selectively binding to estrogen receptors, blocking the effects of estrogen, which can promote the growth of cancer cells. It is classified as a selective estrogen receptor degrader (SERD).

  • Everolimus

    Everolimus is taken orally and is an established medication used in various cancer treatments, including breast cancer. In the context of the clinical trial, it is being combined with giredestrant to assess its efficacy in treating estrogen receptor-positive, HER2-negative breast cancer. Everolimus works by inhibiting the mTOR pathway, which is involved in cell growth and proliferation, thereby slowing down or stopping the growth of cancer cells. It is classified as an mTOR inhibitor.

Investigated diseases

Estrogen Receptor (ER)-Positive, HER2-Negative, Locally Advanced or Metastatic Breast Cancer – This type of breast cancer is characterized by the presence of estrogen receptors on the surface of the cancer cells, which means the cancer cells may receive signals from estrogen that could promote their growth. It is HER2-negative, indicating that the cancer cells do not have an excess of the HER2 protein on their surfaces. The disease can be locally advanced, meaning it has spread beyond the breast to nearby tissues, or metastatic, indicating it has spread to other parts of the body. Patients with this type of cancer have typically been previously treated with a CDK4/6 inhibitor and endocrine therapy. The progression of the disease involves the growth and spread of cancer cells, which can lead to various symptoms depending on the areas affected. The focus of ongoing studies is to evaluate the effectiveness of different treatment combinations in managing the progression of this cancer.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-506821-12-00Protocol codeML43171Estimated enrolment367 patientsSponsorGenentech Inc.

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