Breast Cancer, MetastaticHER2 CRNCT06663787
Personalized Detection of ctDNA for Patients With HER2-Positive Metastatic Breast Cancer Patients Who Achieved Durable Response to Anti-HER2 Treatment
An observational study of Breast Cancer, Metastatic and HER2 + Breast Cancer, run by Nagoya City University at 4 sites in 2 countries.
Trial summary
Anti-HER2 therapy, such as trastuzumab and pertuzumab, has significantly improved long-term survival in HER2-positive breast cancer. The updated data of the CLEOPATRA trial showed significant Kaplan-Meier curves, suggesting the potential for a cure. Read more about this study
- Who is it for?
- Ages 20 years and older, women only
- Conditions the study is for
- Breast Cancer, Metastatic, HER2 + Breast Cancer
- What is being tested?
- Trastuzumab (Herceptin) and SIgnatera
- How many people
- 50 participants
- Where
- 4 sitesin 2 countries
- Study dates
- 1 Apr 2024to 31 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Study population: The eligibility criteria for this study include patients who have been diagnosed with histologically confirmed invasive breast cancer and unresectable HER2-positive breast cancer. Eligible cases are those in which drug therapy, including anti-HER2 therapy, was initiated between January 1, 2000, and December 31, 2021. Additionally, patients must have maintained a partial or complete response to drug therapy, including anti-HER2 therapy, for more than two years. Finally, the study is limited to female patients aged 20 years or older.
Who may be able to join
- HER2 + metastatic breast cancer
- Pre / post menopausal
- Previously treated with anti-HER2 therapy
- Continuing CR or PR for more than 2 year
Who cannot join
- Patients who were deemed inappropriate as research subjects based on the physician's judgment, such as those possibly receiving inappropriate treatment.
Trial locations and contacts
4 sites in 2 countries.
4 sites in 2 countries
Japan3 sites
Aichi Cancer Center
Nagoya, Aichi-ken, 4678601
Nagoya City University
Nagoya, Aichi-ken, 4678601
The Cancer Institute Hospital of Japanese Foundation for Cancer Research
Tokyo, Tokyo, 135-8550
About this study
Official title: Personalized Detection of ctDNA for Patients With HER2-Positive Metastatic Breast Cancer Who Achieved Durable Response by Anti-HER2 Treatment
Anti-HER2 therapy, such as trastuzumab and pertuzumab, has significantly improved long-term survival in HER2-positive breast cancer. The updated data of the CLEOPATRA trial showed significant Kaplan-Meier curves, suggesting the potential for a cure. However, the efficacy of maintenance therapy in long-term responders remains unexplored. This study will assess MRD in unresectable HER2-positive breast cancer cases with long-term response using the Signatera™ ctDNA assay, which could contribute to future treatment strategy development.
Read the detailed description
More than 20 years have passed since the introduction of trastuzumab as a treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The additive effect of trastuzumab, an anti-HER2 antibody, was evaluated in combination with chemotherapy (paclitaxel or anthracycline plus cyclophosphamide) in previously untreated, unresectable HER2-positive breast cancer. The number of cases achieving long-term survival with anti-HER2 therapy has been increasing, and this trend is also observed in our institution.
The treatment for unresectable breast cancer is systemic therapy, which is typically continued as long as it remains effective and side effects are tolerable. However, in cases of long-term response in HER2-positive breast cancer, the impact of continuing anti-HER2 therapy alone as maintenance therapy on prognosis and the safety of treatment discontinuation remains unclear.
In recent years, the clinical application of circulating tumor DNA (ctDNA) has attracted attention for early diagnosis and detection of minimal residual disease. Signatera™, an assay developed by Natera Inc., detects minimal residual disease. It is a personalized ctDNA test for individual patients, and a study targeting breast cancer patients post-surgery reported a detection sensitivity exceeding 90% for variant allele frequencies (VAF) as low as 0.01%. This high sensitivity has been reported not only in breast cancer but also in other cancer types. However, there have been no reports of Signatera analysis in unresectable breast cancer.
In this study, investigators will use Signatera™ to evaluate and analyze ctDNA status (ctDNA positive or negative) in cases of unresectable HER2-positive breast cancer that have achieved long-term response. By assessing ctDNA in such cases, this study may lead to new therapeutic strategies, such as de-escalating anti-HER2 therapy in ctDNA-negative cases.
- Conditions
- Breast Cancer, Metastatic, HER2 + Breast Cancer
- Being tested
- Trastuzumab (Herceptin), SIgnatera
- Keywords
- ctDNA monitoring, MRD, minimal residual disease, HER2+ breast cancer, Dual response
- Medical subject headings
- Breast Neoplasms, Neoplasm Metastasis, Neoplasm, Residual
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Trastuzumab (Herceptin)Drug
Also called Trastuzumab Emtansine, Trastuzumab Deruxtecan
Continuing anti-HER2 treatment
SIgnateraDiagnostic test
A personalized, tumor-informed test.
| Study group | Role | What they receive |
|---|---|---|
| Continuing anti-HER2 treatment | Breast cancer patients who are continuing complete response (CR) or partial response (PR) for more than two years of anti-HER2 treatment (trastuzumab, pertuzumab, T-DM1, and T-DXd) Receives: Drug: Trastuzumab (Herceptin); Diagnostic Test: SIgnatera | |
| Follow up (stop anti-HER2 treatment) | Breast cancer patients who stopped anti-HER2 treatment with complete response (CR) or partial response (PR) after more than two years of anti-HER2 treatment(trastuzumab, pertuzumab, T-DM1, and T-DXd) Receives: Diagnostic Test: SIgnatera |
What is being measured
The primary outcome is the main question the study is designed to answer.
The status of ctDNA
To assess the status of ctDNA in CR patients with/without continuing treatment, or PR patients with continuing treatment
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2024
- Study start1 Apr 2024
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast Cancer, MetastaticStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Nagoya City University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kazuki Nozawa, Nagoya City University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06663787
- Sponsor's protocol ID
- HER2 CR
- Other IDs
- 80-24-0057
- Acronym
- HER2 CR
- Status last verified
- May 2026
- First submitted
- 24 Oct 2024
- Last updated
- 13 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 13 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Personalized Detection of ctDNA for Patients With HER2-Positive Metastatic Breast Cancer Who Achieved Durable Response by Anti-HER2 Treatment
- ClinicalTrials.gov ID
- NCT06663787
- Acronym / sponsor ID
- HER2 CR / HER2 CR
- Conditions
- Breast Cancer, Metastatic, HER2 + Breast Cancer
- Keywords
- ctDNA monitoring, MRD, minimal residual disease, HER2+ breast cancer, Dual response
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Nagoya City UniversityUniversity, hospital or other
- Study start
- 1 Apr 2024 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 29 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Anti-HER2 therapy, such as trastuzumab and pertuzumab, has significantly improved long-term survival in HER2-positive breast cancer. The updated data of the CLEOPATRA trial showed significant Kaplan-Meier curves, suggesting the potential for a cure. However, the efficacy of maintenance therapy in long-term responders remains unexplored. This study will assess MRD in unresectable HER2-positive breast cancer cases with long-term response using the Signatera™ ctDNA assay, which could contribute to future treatment strategy development.
Detailed description
More than 20 years have passed since the introduction of trastuzumab as a treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The additive effect of trastuzumab, an anti-HER2 antibody, was evaluated in combination with chemotherapy (paclitaxel or anthracycline plus cyclophosphamide) in previously untreated, unresectable HER2-positive breast cancer. The number of cases achieving long-term survival with anti-HER2 therapy has been increasing, and this trend is also observed in our institution.
The treatment for unresectable breast cancer is systemic therapy, which is typically continued as long as it remains effective and side effects are tolerable. However, in cases of long-term response in HER2-positive breast cancer, the impact of continuing anti-HER2 therapy alone as maintenance therapy on prognosis and the safety of treatment discontinuation remains unclear.
In recent years, the clinical application of circulating tumor DNA (ctDNA) has attracted attention for early diagnosis and detection of minimal residual disease. Signatera™, an assay developed by Natera Inc., detects minimal residual disease. It is a personalized ctDNA test for individual patients, and a study targeting breast cancer patients post-surgery reported a detection sensitivity exceeding 90% for variant allele frequencies (VAF) as low as 0.01%. This high sensitivity has been reported not only in breast cancer but also in other cancer types. However, there have been no reports of Signatera analysis in unresectable breast cancer.
In this study, investigators will use Signatera™ to evaluate and analyze ctDNA status (ctDNA positive or negative) in cases of unresectable HER2-positive breast cancer that have achieved long-term response. By assessing ctDNA in such cases, this study may lead to new therapeutic strategies, such as de-escalating anti-HER2 therapy in ctDNA-negative cases.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Continuing anti-HER2 treatment | – | Drug: Trastuzumab (Herceptin), Diagnostic Test: SIgnateraBreast cancer patients who are continuing complete response (CR) or partial response (PR) for more than two years of anti-HER2 treatment (trastuzumab, pertuzumab, T-DM1, and T-DXd) |
| Follow up (stop anti-HER2 treatment) | – | Diagnostic Test: SIgnateraBreast cancer patients who stopped anti-HER2 treatment with complete response (CR) or partial response (PR) after more than two years of anti-HER2 treatment(trastuzumab, pertuzumab, T-DM1, and T-DXd) |
Who may qualify
- Ages
- 20 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The eligibility criteria for this study include patients who have been diagnosed with histologically confirmed invasive breast cancer and unresectable HER2-positive breast cancer. Eligible cases are those in which drug therapy, including anti-HER2 therapy, was initiated between January 1, 2000, and December 31, 2021. Additionally, patients must have maintained a partial or complete response to drug therapy, including anti-HER2 therapy, for more than two years. Finally, the study is limited to female patients aged 20 years or older.
Key inclusion criteria (4 listed)
- HER2 + metastatic breast cancer
- Pre / post menopausal
- Previously treated with anti-HER2 therapy
- Continuing CR or PR for more than 2 year
Key exclusion criteria (1 listed)
- Patients who were deemed inappropriate as research subjects based on the physician's judgment, such as those possibly receiving inappropriate treatment.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Trastuzumab (Herceptin)Also: Trastuzumab Emtansine, Trastuzumab DeruxtecanContinuing anti-HER2 treatment | Drug | Continuing anti-HER2 treatment |
| SIgnateraA personalized, tumor-informed test. | Diagnostic test | Continuing anti-HER2 treatment, Follow up (stop anti-HER2 treatment) |
Primary outcome
The status of ctDNA
Time frame: 1 year
To assess the status of ctDNA in CR patients with/without continuing treatment, or PR patients with continuing treatment
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 May 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
4 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Breast Cancer, Metastatic and HER2 + Breast Cancer, run by Nagoya City University at 4 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 13 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Japan, United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The status of ctDNA (time frame: 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 May 2026.