Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study on Zanidatamab and Chemotherapy for Patients with Metastatic HER2-Positive Breast Cancer After Trastuzumab Deruxtecan Treatment

Fast replyRegistered drugNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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 metastatic HER2-positive breast cancer. This is a condition where cancer cells have spread beyond the breast to other parts of the body and have a specific protein called HER2 on their surface. The study is comparing two treatments to see which is more effective. One treatment involves a medication called zanidatamab combined with chemotherapy, and the other involves a medication called trastuzumab combined with chemotherapy. Chemotherapy is a type of cancer treatment that uses drugs to destroy cancer cells. The chemotherapy options in this study include eribulin, gemcitabine, vinorelbine, and capecitabine.

The purpose of the study is to compare the effectiveness of these two treatment combinations in patients who have already been treated with another medication called trastuzumab deruxtecan but have not responded well or cannot tolerate it. Participants in the study will receive one of the two treatment combinations, and their progress will be monitored over a period of time. The study will look at how long patients live without the cancer getting worse and other important health outcomes.

During the study, participants will receive their assigned treatment and will be regularly monitored by healthcare professionals. The study aims to provide valuable information about which treatment combination might be more beneficial for patients with this type of breast cancer. The study is expected to continue for several years to gather enough data to make a clear comparison between the two treatment options.

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

    Joining the study

    Upon joining the study, the participant will be randomly assigned to one of two treatment groups. One group will receive zanidatamab in combination with a chemotherapy chosen by the physician, while the other group will receive trastuzumab with a physician's choice of chemotherapy.

    The choice of chemotherapy may include eribulin, gemcitabine, vinorelbine, or capecitabine.

  2. Step 2

    Treatment administration

    Participants will receive their assigned treatment through intravenous (IV) injection or infusion for zanidatamab, trastuzumab, eribulin, gemcitabine, and vinorelbine. Capecitabine will be administered orally.

    The specific dosage and frequency of administration will be determined by the physician based on the participant's condition and the chosen chemotherapy.

  3. Step 3

    Monitoring and assessments

    Throughout the study, participants will undergo regular monitoring to assess the effectiveness and safety of the treatment. This includes measuring progression-free survival and overall survival.

    Participants will also be evaluated for any side effects or adverse events, and adjustments to the treatment may be made if necessary.

  4. Step 4

    Completion of the study

    The study is expected to continue until April 2031. Participants will be followed up regularly to monitor their health and any long-term effects of the treatment.

    Upon completion, the data collected will be analyzed to determine the efficacy and safety of the treatments compared.

Who can join the trial?

15 criteria

  • Must be at least 18 years old or the legal adult age in your area when signing the consent form.
  • Must have a **creatinine clearance** of at least 30 mL/minute. This is a measure of how well your kidneys are working.
  • Must have a **LVEF** (Left Ventricular Ejection Fraction) of at least 55%. This is a measure of how well your heart is pumping blood.
  • Must have an **ECOG performance status** of 0 or 1, which means you are fully active or have some symptoms but can still do light work.
  • Male participants must agree to use contraception during the study and for at least 7 months after the last dose of the study drug.
  • Female participants must not be pregnant or breastfeeding and must use effective contraception during the study and for at least 7 months after the last dose if they are of childbearing potential.
  • Must be able to give signed informed consent, meaning you understand and agree to participate in the study.
  • Must have **HER2-positive breast cancer** confirmed by a laboratory test.
  • Must have **unresectable** or **metastatic HER2-positive breast cancer** that has worsened after previous treatment with T-DXd or if you cannot tolerate it.
  • Must have measurable disease according to specific guidelines (RECIST version 1.1).
  • Must be eligible to receive one of the chemotherapy options chosen by your doctor (eribulin, gemcitabine, vinorelbine, or capecitabine).
  • Participants with a history of treated or inactive **CNS metastases** (cancer spread to the brain) are eligible.
  • Must have a life expectancy of at least 6 months, as judged by the study doctor.
  • Must have adequate **hematologic parameters**, meaning your blood counts are within a safe range.
  • Must have adequate **hepatic function**, meaning your liver is working well enough.

Who cannot join the trial?

10 criteria

  • Patients who have a different type of cancer that is not **HER2-positive breast cancer**.
  • Patients who have not been diagnosed with **metastatic** cancer, which means cancer that has spread to other parts of the body.
  • Patients who are not within the specified age range for the study.
  • Patients who are not able to receive chemotherapy for any reason.
  • Patients who have other serious health conditions that might interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who are unable to follow the study procedures or attend the required visits.
  • Patients who have participated in another clinical trial recently.
  • Patients who have allergies or reactions to the study medications.
  • Patients who are not willing to provide informed consent, which means agreeing to participate after understanding the study details.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • Zanidatamab

    is a medication being studied for its effectiveness in treating metastatic HER2-positive breast cancer. It is used in combination with chemotherapy to see if it can help patients who have not responded well to previous treatments.

  • Trastuzumab

    is a medication commonly used to treat HER2-positive breast cancer. In this study, it is combined with chemotherapy to compare its effectiveness against the combination of zanidatamab and chemotherapy.

What is already known about the treatment

  • Zanidatamab

    Zanidatamab is administered intravenously and is currently being studied in clinical trials for its effectiveness in treating metastatic HER2-positive breast cancer. It is designed to be used in combination with chemotherapy and is being compared to trastuzumab, another medication used for the same condition. Zanidatamab works by targeting the HER2 protein on cancer cells, helping to inhibit their growth and survival. It is classified as a monoclonal antibody, which is a type of targeted cancer therapy.

  • Trastuzumab

    Trastuzumab is given through an intravenous infusion and is a well-established treatment for HER2-positive breast cancer, including metastatic cases. It is often used in combination with chemotherapy to enhance its effectiveness. The medication works by binding to the HER2 protein on the surface of cancer cells, blocking signals that promote cell growth and survival. Trastuzumab is classified as a monoclonal antibody, which specifically targets cancer cells with minimal impact on normal cells.

Investigated diseases

Metastatic HER2-positive breast cancer – This is a type of breast cancer characterized by the overexpression of the HER2 protein, which promotes the growth of cancer cells. In its metastatic form, the cancer has spread beyond the breast to other parts of the body, such as the bones, liver, lungs, or brain. The disease progresses as cancer cells continue to grow and invade other tissues, often leading to the formation of new tumors in distant organs. The presence of HER2-positive cancer cells can make the disease more aggressive compared to other types of breast cancer. The progression of the disease can vary, with some patients experiencing rapid spread while others may have a slower progression. Understanding the specific characteristics of HER2-positive cancer is crucial for determining the most effective treatment strategies.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-508960-31-00Protocol codeJZP598-303Estimated enrolment555 patientsSponsorJazz Pharmaceuticals Ireland Limited

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.