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Study on the Effectiveness of Abemaciclib, Inavolisib, and Giredestrant in Patients with Early HR-positive/HER2-negative Breast Cancer

Verified siteInvestigationalNo 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 treatments for early-stage, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. The study will explore the effectiveness of different medications, including Verzenios (also known as abemaciclib), Inavolisib (also known as GDC-0077), and Giredestrant (also known as GDC-9545). These medications are being tested to see how well they work in reducing or clearing cancer-related DNA in the blood, known as circulating tumor DNA (ctDNA), in patients with this type of breast cancer.

The purpose of the study is to evaluate how effective these treatments are by monitoring the changes in ctDNA levels. Participants will receive one of the study medications or a placebo, and their ctDNA levels will be checked at various points during the study. The study will last for a period of up to 24 months, during which participants will take the medication orally in the form of tablets or capsules. The study aims to see if there is a significant decrease in ctDNA levels, which could indicate that the treatment is working.

Throughout the study, participants will be monitored for any changes in their ctDNA levels, as well as for any side effects or safety concerns related to the treatments. The study will help researchers understand the potential benefits of these medications for patients with HR-positive, HER2-negative breast cancer and may provide insights into new treatment options for 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, the patient must sign an informed consent form. This is a document that confirms understanding and agreement to participate in the study.

    The patient must have had surgery for their primary breast cancer with clear margins within the past five years and must be able to adhere to study procedures.

  2. Step 2

    Surveillance phase

    During this phase, the patient must not have any signs of metastatic disease, confirmed by recent imaging tests such as CT scans.

    The patient must be on adjuvant treatment with endocrine therapy (ET) for at least two years and no more than four years, with an additional three years planned.

  3. Step 3

    Treatment phase

    The patient must have a positive ctDNA test, indicating the presence of minimal residual disease, but no clinical or radiologic recurrence.

    The patient will receive one of the study treatments, which may include abemaciclib, inavolisib, or giredestrant, all administered orally.

    The treatment aims to achieve a 90% decrease or clearance in baseline ctDNA at three months.

  4. Step 4

    Medication details

    Abemaciclib is provided as 150 mg film-coated tablets.

    Inavolisib and giredestrant are also administered orally, with specific dosages and schedules determined by the study protocol.

  5. Step 5

    Monitoring and follow-up

    The patient's ctDNA levels will be monitored at three, six, nine, and 12 months to assess the treatment's effectiveness.

    The study will evaluate the proportion of patients achieving significant decreases in ctDNA and monitor any potential side effects.

Who can join the trial?

23 criteria

  • For the surveillance phase, you must sign a form agreeing to participate before any study activities begin.
  • For the surveillance phase, you should not have cancer that has spread to other parts of the body, confirmed by recent scans.
  • For the surveillance phase, you must have had surgery for breast cancer with clear margins within the last five years.
  • For the surveillance phase, you need to be able and willing to follow the study procedures.
  • For the treatment phase, you must sign a form agreeing to participate before starting the study.
  • For the treatment phase, you should have a positive ctDNA test without signs of cancer returning, confirmed by standard tests like ultrasound or scans.
  • For the treatment phase, your general health should be good, as measured by a scale called ECOG, with a score of 0, 1, or 2.
  • For the treatment phase, you must have been on the same hormone therapy for at least the last 12 months, with a short break allowed.
  • For the treatment phase, if you are male or pre-menopausal, you should be receiving a specific hormone therapy for at least 90 days before starting the study treatment.
  • For the treatment phase, if you are a woman who can have children or a man with a partner who can have children, you must use effective birth control or abstain from sex during the study and for a certain time after.
  • For the treatment phase, any side effects from previous cancer treatments should be mild or resolved, except for hair loss or other non-risky effects.
  • For the surveillance phase, you must be 18 years or older.
  • For the treatment phase, your blood and organ functions should be within normal limits before starting the study treatment.
  • For the treatment phase, you must be able to swallow and absorb oral medication.
  • For the treatment phase, if you have had a blood clot before, you can participate if you are on stable blood-thinning medication.
  • For the treatment phase, Arm D, you need confirmation of specific genetic markers through a test.
  • For the treatment phase, Arm D, you should not have had previous treatments targeting specific cancer pathways.
  • For the surveillance phase, your general health should be good, as measured by a scale called ECOG, with a score of 0 or 1.
  • For the surveillance phase, your breast cancer should be confirmed as hormone receptor-positive and HER2-negative based on recent tests.
  • For the surveillance phase, you should have high-risk early-stage breast cancer based on specific criteria, such as tumor size or genetic risk scores.
  • For the surveillance phase, you should be on hormone therapy for at least two years and plan to continue for three more years, with specific conditions for pre-menopausal women and men.
  • For the surveillance phase, you should not have had previous treatments with certain cancer drugs like CDK4/6 inhibitors or fulvestrant.
  • For the surveillance phase, you must be willing to provide a sample of your tumor tissue from a previous biopsy or surgery.

Who cannot join the trial?

10 criteria

  • Patients with a different type of breast cancer than the one specified in the study.
  • Patients who have not reached the required age range for the study.
  • Patients who are not able to provide informed consent.
  • Patients who have other serious health conditions that could interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who are currently participating in another clinical trial.
  • Patients who have had a recent major surgery or are planning to have one during the study period.
  • Patients who have a history of allergic reactions to the study medication or similar drugs.
  • Patients who have a history of substance abuse or addiction.
  • Patients who have a mental health condition that could affect their ability to participate in the study.
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Investigated drugs

  • Palbociclib

    is a medication used in this trial to help treat early breast cancer. It works by blocking certain proteins in cancer cells, which can slow down or stop the growth of the cancer.

  • Letrozole

    is another medication involved in the trial. It is used to treat breast cancer by lowering estrogen levels in the body, which can help slow the growth of certain types of breast cancer cells.

  • Fulvestrant

    is also part of the trial. It is used to treat breast cancer by blocking and breaking down estrogen receptors on cancer cells, which can help stop the cancer from growing.

  • Ribociclib

    is included in the trial as well. It works similarly to Palbociclib by inhibiting proteins that are involved in the growth of cancer cells, helping to control the progression of the disease.

What is already known about the treatment

Letrozole – Letrozole is administered orally in tablet form and is primarily used in the treatment of early-stage, hormone receptor-positive, HER2-negative breast cancer. It is currently well-established in medical practice and literature as an effective treatment for this type of breast cancer. The main therapeutic indication for Letrozole is to reduce the risk of cancer recurrence by lowering estrogen levels in the body. At the molecular level, Letrozole works by inhibiting the aromatase enzyme, which is responsible for converting androgens into estrogens, thereby decreasing estrogen production. It is classified as an aromatase inhibitor in pharmacology.

Investigated diseases

Early-stage, Hormone Receptor (HR)-positive / Human Epidermal Growth Factor Receptor 2 (HER2)-negative, breast cancer – This type of breast cancer is characterized by the presence of hormone receptors, meaning the cancer cells grow in response to hormones like estrogen or progesterone. It is also negative for the HER2 protein, which means the cancer does not grow due to the presence of this protein. Typically, this cancer is detected at an early stage, which means it has not spread extensively beyond the breast or nearby lymph nodes. The progression of this cancer can vary, but it generally involves the growth of cancer cells within the breast tissue. Over time, if untreated, it may spread to other parts of the body. The focus in managing this type of cancer is often on controlling hormone levels to slow or stop the growth of cancer cells.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-505661-89-00Protocol codeMedOPP485Estimated enrolment976 patientsSponsorMedica Scientia Innovation Research S.L.

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