Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not yet recruiting

Discontinuation of anti‑HER2 therapy guided by ctDNA in patients with HER2‑positive metastatic breast cancer receiving pertuzumab and trastuzumab

Verified siteRegistered 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

The study focuses on patients with HER2-positive Breast Cancer that has spread to other parts of the body (metastatic). Treatment consists of two targeted medicines, pertuzumab and trastuzumab, which are given through an intravenous infusion and work by attaching to the HER2 protein on cancer cells to block its growth signals.

The purpose is to determine whether stopping anti-HER2 therapy in individuals whose disease shows no detectable MRD by testing for ctDNA can keep them free from cancer progression for up to two years, while allowing treatment to be restarted if molecular signs of disease return.

Participants who have already achieved stable disease will discontinue the infusion treatment and will be followed with regular blood tests that check for the presence of cancer‑related DNA. If the test remains negative, they continue without therapy; if cancer DNA appears, the targeted medicines can be re‑introduced. Follow‑up continues for a period of two years to observe outcomes.

The research process

The trial runs in 8 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Start Anti‑HER2 Therapy

    You receive an intravenous infusion of the study medication. The medication contains pertuzumab (840 mg) alone or a combination product that includes trastuzumab (1200 mg) and pertuzumab (600 mg). The infusion is given according to the schedule defined by the trial protocol.

  2. Step 2

    Baseline ctDNA Test

    A blood sample is taken to measure circulating tumor DNA (ctDNA). This test establishes the initial level of molecular disease before any treatment changes.

  3. Step 3

    Regular ctDNA Monitoring

    At each scheduled visit, another blood sample is collected to assess ctDNA. The results indicate whether minimal residual disease is still present.

  4. Step 4

    Continue Therapy While ctDNA Is Detectable

    If the ctDNA test remains positive, you continue receiving the intravenous anti‑HER2 infusion at the same dose and schedule.

  5. Step 5

    Discontinue Therapy When ctDNA Becomes Undetectable

    When a ctDNA test shows no detectable tumor DNA, the protocol calls for stopping the anti‑HER2 infusion. No further doses are given after this point.

  6. Step 6

    Post‑Discontinuation Monitoring

    After stopping therapy, you continue to have regular blood draws for ctDNA. These tests are performed according to the trial schedule to watch for any molecular signs of disease returning.

  7. Step 7

    Re‑initiation of Therapy If ctDNA Returns

    If a subsequent ctDNA test detects tumor DNA again, the study allows the anti‑HER2 infusion to be restarted at the same dose used previously.

  8. Step 8

    Two‑Year Follow‑Up

    You remain under observation for two years after discontinuation. During this period, clinical assessments and ctDNA testing continue to determine whether metastatic breast cancer progresses.

Who can join the trial?

15 criteria

  • Must be 18 years of age or older; both men and women are eligible.
  • Must have a confirmed diagnosis of HER2‑positive metastatic breast cancer (stage IV), proven by tissue testing.
  • Must have been receiving first‑line anti‑HER2 therapy (trastuzumab alone or with pertuzumab) for at least 36 months, with the most recent dose given within the past 3 weeks.
  • Must have no sign of disease getting worse on physical exam or imaging for the past 3 years; if scans show stable disease or a partial response, there must be at least 12 months of imaging showing no active tumor.
  • Must have had all visible cancer removed by surgery, ablation, or radiotherapy, and at least 2 years must have passed since that treatment with no progression in the last 3 years.
  • Must have a recent PET‑CT or CT scan, bone scan, and mammogram (if applicable) that confirm no active disease at the time of enrollment.
  • If the cancer is only stable or partially responding, a blood test for circulating tumor DNA (ctDNA) must be negative, indicating no measurable minimal residual disease (MRD), and no other clinical signs of active cancer may be present.
  • Patients with a history of brain metastasis must have a brain MRI showing no active disease.
  • Must have adequate heart, kidney, blood, and liver function according to standard medical guidelines.
  • Must be willing and able to attend study visits, follow the treatment plan, and take part in all follow‑up activities.
  • Must sign a written informed consent form before any study procedures begin.
  • Women who could become pregnant must have a negative pregnancy test within the past 28 days and must follow the study’s contraception requirements.
  • Can continue endocrine therapy such as tamoxifen, aromatase inhibitors, or fulvestrant, and can use ovarian suppression (LHRH agonists) if pre‑/perimenopausal.
  • Must stop other targeted endocrine drugs (e.g., CDK4/6 inhibitors, PARP inhibitors, everolimus, PI3K pathway inhibitors) and any anti‑HER2 therapy at the time of enrollment.
  • Bone‑remodeling treatments (medications that strengthen bone) are allowed and may be continued at the doctor’s discretion.

Who cannot join the trial?

6 criteria

  • If your ability to perform daily activities is limited (ECOG performance status 2 or higher), you cannot join the study. ECOG performance status is a simple scale doctors use to see how well a person can move around and take care of themselves.
  • If there is any sign that your breast cancer has gotten worse (progressed) in the past three years or at the start of the study, you are excluded. Progression means the cancer is growing or spreading.
  • If you are currently taking other cancer medicines besides the study drugs, you cannot participate. This includes any approved or experimental antineoplastic agents (drugs that treat cancer) such as PARP inhibitors, CDK4/6 inhibitors, everolimus, or PI3K pathway inhibitors. These drugs must be stopped before you can join.
  • If you have had another type of cancer in the last five years, you are not eligible, except for certain skin cancers (basal cell carcinoma or squamous cell carcinoma) or an early‑stage cervical cancer called carcinoma in situ. These are considered less serious skin or cervical lesions.
  • If you have serious other health problems that would give you a life expectancy of less than about two years even if the cancer does not return, you cannot take part. Life expectancy refers to the expected length of time a person may live.
  • If you are already enrolled in another ongoing prospective study that is testing the first‑line treatment with TP (the initial combination of drugs used for breast cancer), you must wait until that study is closed for active follow‑up before joining.
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.

Not yet 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

  • Pertuzumab

    is a medicine given through an IV infusion that targets the HER2 protein on cancer cells. By attaching to HER2, it blocks signals that tell the cancer cells to grow and helps the immune system recognize and attack the tumor. In this study it is used as a single‑agent anti‑HER2 therapy.

  • Trastuzumab + Pertuzumab

    (combined in one injectable solution) are two different antibodies that both bind to the HER2 protein, but at slightly different places. Together they provide a stronger block of the HER2 signals that drive cancer growth. This combination is given by IV infusion and serves as a more intensive anti‑HER2 treatment in the trial.

What is already known about the treatment

  • Perjeta 420 mg concentrate for solution for infusion

    This medication is given by intravenous infusion, meaning it is slowly injected into a vein through a drip. It is an approved drug that is widely used and described in medical literature for treating HER2‑positive breast cancer. The main use is to help control the growth of cancer cells that have too much HER2 protein on their surface. It works by attaching to the HER2 protein and blocking the signals that tell the cancer cells to grow, and it belongs to the class of HER2‑targeted monoclonal antibodies.

  • Phesgo 1200 mg/600 mg solution for injection

    This product is also administered by intravenous infusion, delivering the medicine directly into the bloodstream. It is an approved combination therapy that is well documented for HER2‑positive breast cancer treatment. The combination is used to more effectively stop cancer cells that over‑express HER2 from growing and spreading. It contains two monoclonal antibodies, trastuzumab and pertuzumab, which both bind to different parts of the HER2 protein to block its activity, placing it in the HER2‑targeted antibody class.

Investigated diseases

Breast Cancer - Breast cancer is a condition in which cells of the breast begin to grow and divide without normal control. It usually starts in the milk‑producing ducts or the lobules that supply them. As the abnormal cells multiply, they can invade nearby tissue and travel to regional lymph nodes. Over time the disease may spread to distant organs such as bone, liver, lung, or brain, a stage known as metastatic breast cancer. When the cancer remains limited to the breast, it is considered early‑stage disease.
Trial detailsLast updated 21 Oct 2026
Age18+ yearsPhasePhase IITrial ID2026-526268-18-00Protocol codeFIS-HER2-EMR-26Estimated enrolment239 patientsSponsorFundacion Para El Fomento De La Investigacion Sanitaria Y Biomedica De La Comunitat Valenciana

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.