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Study of oral TherO2-01S22 with anti-HER2 therapy in patients with metastatic breast cancer

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on patients with HER2-positive metastatic breast cancer. The research evaluates a new treatment approach that combines standard anti-HER2 therapy with an experimental medication called TherO2-01S22. The standard treatment includes established medications such as trastuzumab, pertuzumab, docetaxel, paclitaxel, and vinorelbine.

The main purpose of this research is to determine if adding TherO2-01S22 syrup to the standard anti-HER2 treatment can improve treatment outcomes for patients with metastatic breast cancer. During the study, participants will receive either TherO2-01S22 or placebo in addition to their regular cancer treatment.

The treatment period lasts up to 18 months, during which patients will receive medication through both oral intake and intravenous infusion. Throughout the study, doctors will monitor patients' response to treatment, overall health status, and any potential side effects. Regular assessments will include heart function monitoring and quality of life evaluations.

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

    Initial treatment phase

    You will receive anti-HER2 targeted treatment through intravenous infusion. This includes trastuzumab and pertuzumab.

    Additionally, you will be randomly assigned to receive either TherO2-01S22 syrup or a placebo syrup (inactive substance) to take by mouth.

    Neither you nor your doctor will know which syrup you are receiving (this is called double-blinded).

  2. Step 2

    Treatment cycles

    Your treatment will be organized in cycles.

    Blood samples will be collected before taking the syrup and at specific times (15, 30, 45, 60, 120, 240, and 300 minutes after) during cycle 1 and cycle 2.

    Additional blood samples will be taken before receiving trastuzumab/pertuzumab on day 1 of cycle 2 and day 43 (cycle 3).

  3. Step 3

    Monitoring and assessments

    Your response to treatment will be evaluated on day 43.

    Your heart function will be checked every 3 months using imaging tests.

    You will complete quality of life questionnaires at the start of treatment and on day 43.

    Regular check-ups will occur every 3 months for up to 24 months to monitor your progress.

  4. Step 4

    Safety monitoring

    Any side effects will be monitored and recorded throughout the treatment period until the final safety visit on day 64.

    Your heart function will be regularly monitored through specific tests to ensure your safety during treatment.

  5. Step 5

    Long-term follow-up

    Your progress will be monitored for up to 24 months from the start of treatment.

    Regular assessments will track how long the treatment remains effective and your overall health status.

Who can join the trial?

9 criteria

  • Must be at least 18 years old (men or women can participate)
  • Must have normal calcium levels in blood tests and normal blood sugar levels when fasting
  • Must have breast cancer that has spread to other parts of the body (metastatic breast cancer)
  • Must have a specific type of breast cancer that has high levels of a protein called HER2 (confirmed by special laboratory tests)
  • Must be well enough to perform daily activities, with some limitations allowed (performance status of 0, 1, or 2)
  • Must be starting their first treatment for metastatic breast cancer that includes HER2-targeted therapy
  • Must have a life expectancy of at least 3 months
  • Must have good heart function (heart ejection fraction greater than 50%), tested within 7 days before starting the study
  • Must be willing and able to sign an informed consent form to participate in the study

Who cannot join the trial?

15 criteria

  • History of severe allergic reactions to any monoclonal antibody (type of targeted therapy) treatments
  • Active or untreated brain metastases (cancer that has spread to the brain)
  • Serious heart conditions including heart failure or uncontrolled high blood pressure
  • Pregnant or breastfeeding women
  • Current participation in other clinical trials
  • Major surgery within 4 weeks before starting the study
  • Significant liver problems or abnormal liver function tests
  • Active or chronic infections including hepatitis B, hepatitis C, or HIV
  • Other active cancers requiring treatment (except for certain skin cancers or cervical cancer in situ)
  • Any condition that, in the opinion of the study doctor, would make participation unsafe
  • Unable to swallow oral medications
  • Severe kidney problems or abnormal kidney function
  • History of other cancers within the past 5 years
  • Mental conditions that could interfere with study participation
  • Life expectancy less than 6 months
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Investigated drugs

  • TherO2-01S22

    is an experimental oral medication being studied for treating HER2-positive metastatic breast cancer. It is designed to work together with existing anti-HER2 targeted treatments. The medication is being tested to see if adding it to standard breast cancer therapy can improve how well tumors respond to treatment. This is a new drug that is still known by its development code name.

  • Anti-HER2 targeted treatments

    are established medications that specifically target breast cancer cells that have high levels of a protein called HER2. These treatments are already approved and commonly used as the first line of therapy for HER2-positive breast cancer. They work by blocking the HER2 protein that helps cancer cells grow.

What is already known about the treatment

TherO2-01S22 - An oral medication currently being investigated in clinical trials for treating HER2-positive metastatic breast cancer. This drug is designed to be used as an add-on therapy alongside first-line anti-HER2 targeted treatments. It is being evaluated in a Phase II/III clinical trial to determine its effectiveness in improving objective response rates in breast cancer patients. While the exact molecular mechanism is still under investigation through clinical studies, the drug is administered orally and is being tested specifically for its potential to enhance the effectiveness of existing HER2-targeted therapies in treating metastatic breast cancer.

Investigated diseases

Metastatic Breast Cancer - A form of breast cancer that has spread beyond the breast and nearby lymph nodes to other parts of the body. The cancer cells break away from the original tumor and travel through the bloodstream or lymphatic system to form new tumors in other organs such as the bones, liver, lungs, or brain. This stage of breast cancer occurs when cancer cells have developed the ability to move and grow in other locations. The disease typically develops gradually, with cancer cells first spreading to nearby tissues before reaching distant organs. The progression and pattern of spread can vary among different patients.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IVTrial ID2024-516576-15-00Protocol code2022-009Estimated enrolment224 patientsSponsorCentre Regional Lutte Contre Le Cancer

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