Not yet recruiting

Study of tucatinib and trastuzumab for patients with HER3-mutant and HER2-not amplified 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 study focuses on treating patients with metastatic breast cancer that has specific genetic characteristics - HER3-mutant and HER2-not amplified. This type of breast cancer has spread to other parts of the body and has particular genetic changes that may make it respond to targeted treatment.

The study will test a combination of two medications: tucatinib (taken as tablets by mouth) and trastuzumab (given through an intravenous infusion into a vein). The purpose is to show that genetic changes in the HER3 protein can be effectively targeted with this treatment combination in breast cancer patients.

During the study, participants will receive treatment for up to 18 months. Before starting treatment, doctors will test tumor tissue samples to confirm the presence of specific genetic changes. Throughout the treatment period, patients will undergo regular health checks and complete quality of life questionnaires. The study will measure how well the tumor responds to treatment and monitor any side effects that may occur.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Initial assessment
A medical evaluation will confirm if you meet the study requirements, including having metastatic breast cancer that has been treated with at least 2 previous chemotherapy treatments
Your tumor sample will be tested to confirm it has specific genetic changes in the HER3 gene
Your heart function will be checked using an imaging test to ensure your heart is working at 50% or better
Blood tests will be performed to check your liver and kidney function
Step 2
Treatment initiation
You will receive two medications:
Trastuzumab (Ogivri) - given through an intravenous infusion
Tucatinib (TUKYSA) - taken as tablets by mouth
The treatment will continue as long as it is working and you can tolerate it
Step 3
Regular monitoring
Your response to treatment will be checked regularly using imaging scans
Blood tests will be performed to monitor your organ function
You will complete quality of life questionnaires at the start of treatment, during cycles 1 and 3, and when treatment ends
Side effects will be monitored throughout the treatment period
Step 4
Follow-up assessments
Regular check-ups will continue to monitor your health status
Imaging scans will be performed to assess how the cancer is responding to treatment
The study will continue until May 2029

Who can join the trial?

15 criteria

Age 18 years or older
Must have metastatic or unresectable breast cancer (cancer that has spread or cannot be removed by surgery)
Must be HER2-negative breast cancer (confirmed by specific laboratory tests)
Must have received at least 2 previous chemotherapy treatments for advanced breast cancer
Must have a specific type of ERBB3 mutation (a genetic change) in the tumor
Must have a tumor tissue sample that is less than 5 years old with at least 10% tumor content
Must have a physical performance status that allows for daily activities (ECOG score of 2 or less)
Must have measurable disease that can be evaluated by imaging
Heart function must be adequate (pumping strength of at least 50%)
Must have adequate kidney function (creatinine clearance of 50 mL/min or higher)
Must have adequate liver function (within specified limits for liver tests)
Women who can become pregnant must have a negative pregnancy test within 7 days before starting treatment
Both men and women who can have children must agree to use effective birth control during the study and for 3 months after
Must be covered by health insurance
Must be able to understand and sign informed consent documents

Who cannot join the trial?

14 criteria

Prior treatment with any HER2-targeted therapy (medications that target HER2 protein)
Presence of active brain metastases (cancer that has spread to the brain) that are not stable
History of other cancers within the past 3 years, except for successfully treated non-melanoma skin cancer or cervical cancer in situ
Severe heart conditions, including:
- Uncontrolled high blood pressure
- Unstable heart disease
- Heart attack within the past 6 months
- Significant liver problems or abnormal liver function tests
- Severe kidney disease requiring dialysis
- Active, uncontrolled infections
- Known allergic reactions to similar medications
- Pregnancy or breastfeeding
- Unable to swallow oral medications
- Participation in another clinical trial within the past 30 days
- Any condition that, in the opinion of the study doctor, would make participation unsafe

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Verified sites

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

Verified
Centre De Lutte Contre Le Cancer Eugene Marquis
Rennes, France
Verified
Centre Hospitalier Et Universitaire De Limoges
Limoges, France
Responsive
Institut De Cancerologie De Lorraine
Vandoeuvre Les Nancy, France

Trial locations

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Investigated drugs

Tucatinib
is an oral medication that works by blocking a specific protein called HER2. It belongs to a group of drugs called tyrosine kinase inhibitors. This medication specifically targets cancer cells that have mutations in the HER3 gene, helping to slow down or stop cancer growth in breast cancer patients.
Trastuzumab
is an antibody treatment given by infusion that targets the HER2 protein on cancer cells. It works by attaching to HER2 receptors on cancer cells and blocking them from receiving growth signals. This helps to slow down or stop the growth of cancer cells. It has been used for many years as a standard treatment for certain types of breast cancer.

What is already known about the treatment

Tucatinib
An oral tyrosine kinase inhibitor specifically targeting HER2 (human epidermal growth factor receptor 2), administered in tablet form for the treatment of metastatic breast cancer. This medication works by blocking specific cellular signaling pathways that contribute to cancer growth, particularly in patients with HER3 mutations. Tucatinib belongs to the class of targeted cancer therapies and is typically used in combination with other cancer treatments, particularly in cases where the cancer has spread to other parts of the body.
Trastuzumab
A monoclonal antibody medication administered through intravenous infusion that specifically targets HER2 proteins in breast cancer cells. This targeted therapy works by attaching to HER2 receptors on cancer cells, blocking their growth signals and flagging them for destruction by the immune system. Trastuzumab is classified as a biological therapy and has been a cornerstone in the treatment of breast cancer, particularly effective in patients with specific genetic mutations affecting the HER protein family.

Investigated diseases

HER3-mutant and HER2-negative Metastatic Breast Cancer - A specific type of breast cancer that has spread beyond the breast to other parts of the body (metastatic). This condition is characterized by mutations in the HER3 (ERBB3) gene while not showing amplification of the HER2 gene. The cancer cells in this type have developed changes in the HER3 protein, which is involved in cell growth and survival. This form of breast cancer represents a distinct molecular subtype with specific cellular characteristics. The disease progresses as cancer cells continue to grow and spread to distant organs.