Metastatic Breast CancerACT-MBCNCT05662345
ACT-MBC: A Study of Circulating Tumor Cells (CTCs) in Metastatic Breast Cancer (MBC)
An observational study of Metastatic Breast Cancer, run by Menarini Silicon Biosystems, INC at 4 sites in United States.
Trial summary
ACT-MBC prospectively assesses the impact of CTCs on treatment decisions, response assessment and prognosis in MBC patients. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Metastatic Breast Cancer
- What is being tested?
- CellSearch Circulating Tumor Cells
- How many people
- 65 participants
- Where
- 4 sitesUnited States
- Study dates
- 12 Dec 2022to Oct 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Advanced/metastatic breast cancer of following subtypes/lines of systemic therapy in metastatic setting: * Estrogen Receptor (ER)+/Human Epidermal growth factor Receptor 2 (HER2) - patients prior to starting 2nd line or later therapy * Triple Negative (TN) patients prior to starting any line of systemic therapy
Who may be able to join
- Invasive breast cancer with radiographic and/or clinical evidence of advanced metastatic or unresectable disease
- ER+/HER2- patients prior to starting 2nd line therapy or beyond OR ER/Progesterone Receptor (PR)/HER2-negative (Triple Negative) patients prior to starting any line of therapy
- Measurable and/or non-measurable disease is allowed
- Male or female breast cancer is allowed
- Age > 18 years
- Willingness to provide mandatory blood specimens
- Willing to return to enrolling institution for follow up imaging at least once
Who cannot join
- Life expectancy of ≤ 6 months
- Inability to provide blood samples based on the judgment of the treating provider
Trial locations and contacts
4 sites in 1 country.
United States4 sites
Mayo Clinic Health System Albert Lea
Albert Lea, Minnesota, 56007
MCHS Eau Claire
Eau Claire, Wisconsin, 54703
Mayo Clinic Health System Mankato
Mankato, Minnesota, 56001
Mayo Clinic
Rochester, Minnesota, 55905
About this study
Official title: ACT-MBC: A Prospective Observational Impact Study of Circulating Tumor Cells (CTCs) in Metastatic Breast Cancer
ACT-MBC prospectively assesses the impact of CTCs on treatment decisions, response assessment and prognosis in MBC patients.
- Conditions
- Metastatic Breast Cancer
- Being tested
- CellSearch Circulating Tumor Cells
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CellSearch Circulating Tumor CellsDiagnostic test
Serial CTC enumeration
What is being measured
The primary outcome is the main question the study is designed to answer.
To prospectively evaluate the impact of CellSearch CTCs on treatment decisions and response assessment in MBC patients
Assessing proportion of providers that find CellSearch CTCs helpful in determining response to therapy in each unique patient (Questionnaire #2).
Measured: 3 to 4 months
Secondary outcomes (2)
Assess barriers and receptiveness of providers in using CTCs in clinical practice
Assessing provider perception of the general usefulness of CTC in pre and post-intervention surveys (Questionnaire #1 and #3)
Measured: 18 months
Evaluate if CTC results correlate with response assessment and disease progression defined by standard of care imaging
Compare baseline and on treatment serial CTCs assessment to identify correlations with first restaging studies and with progression free survival
Measured: 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Dec 2022
- Study start12 Dec 2022
- Primary completion14 Nov 2025
- Study completionOct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Breast CancerStudies 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
- Case only
- Time perspective
- Prospective
- Enrolment
- 65 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Menarini Silicon Biosystems, INC
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Medex15
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05662345
- Sponsor's protocol ID
- ACT-MBC
- Acronym
- ACT-MBC
- Status last verified
- Mar 2026
- First submitted
- 14 Dec 2022
- Last updated
- 17 Mar 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 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ACT-MBC: A Prospective Observational Impact Study of Circulating Tumor Cells (CTCs) in Metastatic Breast Cancer
- ClinicalTrials.gov ID
- NCT05662345
- Acronym / sponsor ID
- ACT-MBC / ACT-MBC
- Conditions
- Metastatic Breast Cancer
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 65 participants (estimated)
- Lead sponsor
- Menarini Silicon Biosystems, INCIndustry (pharma, biotech, devices)
- Collaborators
- Medex15
- Study start
- 12 Dec 2022 (actual)
- Primary completion
- 14 Nov 2025 (actual)
- Study completion
- Oct 2026 (estimated)
- First posted
- 22 Dec 2022 (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.
ACT-MBC prospectively assesses the impact of CTCs on treatment decisions, response assessment and prognosis in MBC patients.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Advanced/metastatic breast cancer of following subtypes/lines of systemic therapy in metastatic setting: * Estrogen Receptor (ER)+/Human Epidermal growth factor Receptor 2 (HER2) - patients prior to starting 2nd line or later therapy * Triple Negative (TN) patients prior to starting any line of systemic therapy
Key inclusion criteria (7 listed)
- Invasive breast cancer with radiographic and/or clinical evidence of advanced metastatic or unresectable disease
- ER+/HER2- patients prior to starting 2nd line therapy or beyond OR ER/Progesterone Receptor (PR)/HER2-negative (Triple Negative) patients prior to starting any line of therapy
- Measurable and/or non-measurable disease is allowed
- Male or female breast cancer is allowed
- Age > 18 years
Key exclusion criteria (2 listed)
- Life expectancy of ≤ 6 months
- Inability to provide blood samples based on the judgment of the treating provider
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 |
|---|---|---|
| CellSearch Circulating Tumor CellsSerial CTC enumeration | Diagnostic test | – |
Primary outcome
To prospectively evaluate the impact of CellSearch CTCs on treatment decisions and response assessment in MBC patients
Time frame: 3 to 4 months
Assessing proportion of providers that find CellSearch CTCs helpful in determining response to therapy in each unique patient (Questionnaire #2).
2 secondary outcomes
Assess barriers and receptiveness of providers in using CTCs in clinical practice
Time frame: 18 months
Evaluate if CTC results correlate with response assessment and disease progression defined by standard of care imaging
Time frame: 18 months
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 17 Mar 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 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Metastatic Breast Cancer, run by Menarini Silicon Biosystems, INC at 4 sites in United States.
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 7 inclusion and 2 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 17 Mar 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 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?
To prospectively evaluate the impact of CellSearch CTCs on treatment decisions and response assessment in MBC patients (time frame: 3 to 4 months). 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 17 Mar 2026.