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Study on the Effects of Atezolizumab, Trastuzumab, and Pertuzumab in Patients with Early-Stage Triple-Negative or HER2+ 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 the effects of a new treatment approach for patients with early-stage breast cancer, specifically those with triple-negative or HER2-positive types. The treatment involves using a combination of medications, including Atezolizumab (also known by its code name RO5541267), Trastuzumab, Pertuzumab, and Bevacizumab. These medications are given as solutions for infusion, which means they are administered directly into the bloodstream through a vein.

The purpose of the study is to explore whether a short course of immunotherapy, which is a type of treatment that helps the immune system fight cancer, can increase the activity of certain immune cells in the body. The study will compare the effects of these medications on the immune system before and after treatment. Participants will receive the treatment before their standard cancer therapy, and the study will involve taking samples from the tumor to analyze changes in immune cell activity.

Throughout the study, participants will receive the medications intravenously, and their health will be monitored closely. The study aims to understand how these medications affect the immune system and whether they can improve the body's ability to fight cancer. The trial will also look at any side effects that may occur during the treatment period and up to four weeks after surgery. This research could provide valuable insights into new ways to treat early-stage breast cancer.

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 begin with a series of initial assessments to confirm eligibility. This includes a review of medical history and a physical examination.

    The patient will provide informed consent, acknowledging understanding of the study's procedures and requirements.

  2. Step 2

    Initial treatment phase

    The patient will receive a combination of medications administered through an intravenous infusion. These medications include atezolizumab, pertuzumab, trastuzumab, and bevacizumab.

    The specific dosage and frequency of each medication will be determined by the study protocol and the patient's specific condition.

  3. Step 3

    Monitoring and assessments

    Throughout the treatment phase, the patient will undergo regular monitoring to assess the response to the medications. This includes blood tests and imaging studies.

    Biopsies will be performed to evaluate changes in the tumor and immune cell activity.

  4. Step 4

    Surgery preparation

    Following the initial treatment phase, the patient will be prepared for surgery. This involves additional assessments to ensure readiness for the procedure.

    The timing of the surgery will be based on the patient's response to the treatment and the study's schedule.

  5. Step 5

    Surgery

    The patient will undergo surgery to remove the tumor. The surgical procedure will be performed according to standard medical practices.

    Post-surgery, the patient will be monitored for recovery and any potential complications.

  6. Step 6

    Post-surgery follow-up

    After surgery, the patient will continue to be monitored for any changes in health status. This includes regular follow-up visits and assessments.

    The study will evaluate the long-term effects of the treatment and the patient's overall recovery.

Who can join the trial?

12 criteria

  • The patient must understand, sign, and date a written consent form before any study-specific procedures are done. They should be willing to attend study visits and follow procedures as outlined in the study plan.
  • Women who can have children must agree to use a very effective birth control method, along with a barrier method like a condom, or choose not to have sexual activity during the study and for a certain period after stopping treatment. This is to prevent pregnancy during the study.
  • Men who are sexually active must agree to use a condom during the study and for a certain period after stopping treatment. It is also recommended that their female partners use a highly effective birth control method during this time.
  • The patient must be part of a social security system or have similar benefits.
  • Both female and male patients must be 18 years or older.
  • The patient should have a good general health status, which is measured by a scale called ECOG performance status, with a score of 0-1 indicating they are fully active or have some symptoms but do not need to stay in bed.
  • The patient must have breast cancer confirmed by a tissue sample, with no signs that the cancer has spread to other parts of the body.
  • The patient should be a candidate for surgery or need standard pre-surgery treatment, with treatment starting after the pre-surgery immunotherapy and biopsies done before starting the treatment.
  • The tumor must be at least 11 mm in size as measured by an ultrasound of the breast.
  • The cancer type must be assessed locally according to specific guidelines: for the triple-negative breast cancer group, certain hormone levels should be low, and for the HER2-positive group, there should be an overexpression of HER2.
  • The patient must have adequate blood and organ function, which includes specific levels of blood cells, proteins, and liver and kidney function tests.
  • Women who can have children must have a negative pregnancy test before starting the study treatment and agree to use effective birth control or abstain from sex during the study and for a certain period after the last dose of treatment.

Who cannot join the trial?

10 criteria

  • Patients with a different type of breast cancer than the one specified in the study.
  • Patients with breast cancer that has spread to other parts of the body (metastatic).
  • Patients who have already received treatment for their breast cancer.
  • Patients who are not within the specified age range for the study.
  • Patients who are not able to provide informed consent.
  • Patients with other serious health conditions that might interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who are participating in another clinical trial.
  • Patients with a known allergy to the study drugs.
  • Patients who have had a recent major surgery.
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Investigated drugs

  • Atezolizumab

    is an immunotherapy medication used in this trial to treat early-stage breast cancer. It works by helping the immune system recognize and attack cancer cells more effectively. In this study, it is used to see if it can increase the activity of certain immune cells in the tumor.

  • Trastuzumab

    is a targeted therapy used for treating HER2-positive breast cancer. It works by attaching to the HER2 protein on cancer cells, which can help slow or stop the growth of the tumor. In this trial, it is combined with other treatments to evaluate its effectiveness in increasing immune cell activity.

  • Pertuzumab

    is another targeted therapy used alongside trastuzumab for HER2-positive breast cancer. It also targets the HER2 protein but works in a slightly different way to help prevent cancer cells from growing. The trial aims to assess its role in enhancing the immune response when used with other therapies.

What is already known about the treatment

  • Atezolizumab

    Atezolizumab is administered intravenously and is currently being studied in clinical trials for its effectiveness in treating early-stage triple-negative breast cancer. It is an immunotherapy drug that works by blocking the PD-L1 protein, which helps the immune system recognize and attack cancer cells. Atezolizumab is classified as a monoclonal antibody and is being evaluated for its ability to increase the activity of specific immune cells in the tumor environment.

  • Trastuzumab

    Trastuzumab is given through an intravenous infusion and is widely used in the treatment of HER2-positive breast cancer. It targets the HER2 protein on cancer cells, inhibiting their growth and survival. Trastuzumab is a monoclonal antibody and is well-established in medical practice for its role in improving outcomes in HER2-positive breast cancer patients.

  • Pertuzumab

    Pertuzumab is administered intravenously and is used in combination with trastuzumab for treating HER2-positive breast cancer. It works by binding to a different part of the HER2 protein, preventing cancer cell growth. Pertuzumab is also a monoclonal antibody and is recognized for its effectiveness in enhancing the therapeutic effects of trastuzumab in HER2-positive breast cancer treatment.

Investigated diseases

  • Triple-Negative Breast Cancer

    This is a type of breast cancer that lacks three common receptors known to fuel most breast cancer growth: estrogen, progesterone, and HER2. It is considered more aggressive and has fewer treatment options compared to other breast cancer types. The cancer cells do not respond to hormonal therapy or medicines that target HER2 receptors. It often occurs in younger women and is more likely to spread and recur. The progression can be rapid, and it requires different treatment strategies than other breast cancer types.

  • HER2-Positive Breast Cancer

    This form of breast cancer is characterized by the overexpression of the HER2 protein, which promotes the growth of cancer cells. It tends to grow and spread more quickly than other types of breast cancer. HER2-positive breast cancer can be more aggressive, but it often responds well to targeted therapies that specifically attack the HER2 protein. The disease can affect women of any age, but it is more common in younger women. The progression of the disease can vary, but targeted treatments have improved outcomes significantly.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-512826-26-00Protocol code2020-004696-41Estimated enrolment185 patientsSponsorInstitut Gustave Roussy

sourced from the EU Clinical Trials Register and site verification

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