Prospective Study to Evaluate the Clinical Utility of ctDNA Tumor Fraction (TF) for Detection of Estrogen Receptor 1 (ESR1) Mutations in (Human Epidermal Growth Factor Receptor) HR+/HER2- Metastatic Breast Cancer (MBC)

November 2, 2026 updated by: Yale University

Prospective Study to Evaluate the Clinical Utility of ctDNA Tumor Fraction (TF) for Detection of ESR1 Mutations in HR-positive HER2-negative Metastatic Breast Cancer (MBC)

This is a prospective, single center, single-arm interventional study to evaluate the clinical utility of protocol-mandated diagnostic testing algorithm incorporating liquid biopsy and reflex tissue biopsy NGS for detection of ESR1 mutations in HR+/HER- metastatic breast cancer.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Participants are prospectively assigned to undergo ctDNA testing with FoundationOne® Liquid CDx (F1LCDx) at protocol-defined clinical decision points. Participants with an indeterminate negative F1LCDx result (ctDNA TF <1% and negative for ESR1mut) are assigned to undergo reflex tissue biopsy NGS unless deemed medically unsafe. The protocol does not mandate treatment selection; treating clinicians retain full discretion regarding therapy.All research-related procedures will be performed at the time of standard of care clinical visits. No extra visits outside of routine care are required. For participants with algorithm-detected ESR1 mutations, serial Electronic Medical Record review will be performed for up to 2 years to track subsequent treatment patterns, progression events, and survival status to assess other clinical outcomes associated with subsequent SERD-based regimens compared with historical clinical trial benchmarks.

This study will guide clinical decision-making for acquiring new tissue specimens following an indeterminate negative ESR1mut result from liquid biopsy, which is a critical step to ensure accurate detection of actionable mutations and enable the selection of the most appropriate targeted therapy

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
155

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Connecticut
      • New Haven, Connecticut, United States, 06520
        • Yale New Haven Hospital - Yale Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Diagnosis of metastatic breast cancer that is hormone receptor-positive (ER≥10%), HER2 low or negative (defined as HER2 Imunohistochemistry (IHC) 0, 1+ or IHC 2+/In Situ Hybridization (ISH)-).
  • Progression of metastatic breast cancer that is hormone receptor-positive (ER≥10%), HER2 low or negative (defined as HER2 IHC 0, 1+ or IHC 2+/ISH-) while on systemic therapy.
  • Currently receiving or have previously received aromatase inhibitor therapy.

Exclusion Criteria:

  • Patients with locally or regionally recurrent breast cancer without evidence of metastatic disease.
  • De novo metastatic breast cancer.
  • Presence of symptomatic metastatic visceral crisis.
  • Participants with inflammatory breast cancer.
  • Intact uterus with a history of endometrial intraepithelial neoplasia (atypical endometrial hyperplasia or higher-grade lesion).
  • Diagnosis of any other malignancy within 5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix, or second primary breast cancer.
  • Other conditions that, in the opinion of the treating investigator, would preclude the patient from meeting the study requirements or interfere with interpretation of study results.
  • Pregnant and breastfeeding women are excluded from the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: HR+/HER- metastatic breast cancer at diagnosis or experiencing disease progression

Participants with ESR1 mutations in HR+/HER- metastatic breast cancer undergoing tissue biopsy for ctDNA Tumor Fraction (TF) testing using next-generation sequencing (NGS) after an indeterminate negative result in liquid biopsy (F1LCDx).
Diagnostic test: FoundationOne® Liquid CDx (F1LCDx)

Blood test that analyzes cancer-related genes from a single blood draw

Diagnostic test: Reflex tissue biopsy

Reflex tissue biopsy using an Next-generation sequencing (NGS) test

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of participants with ESR1 mutations detected by reflex tissue NGS
Time Frame: From enrollment through study completion (up to 5 years)

Among participants with an indeterminate-negative liquid biopsy result (negative for ESR1 mutations and ctDNA tumor fraction below 1%), measure the number of participants with an ESR1 mutation detected by reflex tissue NGS performed according to the study algorithm.
From enrollment through study completion (up to 5 years)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Progression-free survival (PFS)
Time Frame: Up to 2 years after positive ESR1 mutation detection

Time from initiation of the first selective estrogen receptor degrader (SERD) after ESR1 mutation detection until objective disease progression, assessed using RECIST version 1.1 when available, or death from any cause, whichever occurs first.
Up to 2 years after positive ESR1 mutation detection
Rate of ESR1 mutation detection by liquid biopsy and ctDNA tumor fraction
Time Frame: Throughout the study, up to 5 years

Rate of ESR1 mutation detection by FoundationOne Liquid CDx (F1LCDx), stratified by ctDNA tumor fraction below 1% versus 1% or greater.
Throughout the study, up to 5 years
Reflex Tissue NGS testing rate
Time Frame: Within the reflex testing time frame during the study, up to 5 years

Number of participants with an indeterminate-negative liquid biopsy result who undergo reflex tissue biopsy and NGS within the protocol-defined timeframe.
Within the reflex testing time frame during the study, up to 5 years
Number participants initiating Selective Estrogen Receptor Degraders (SERD) therapy
Time Frame: Throughout the study, up to 5 years

Number participants initiating SERD therapy after ESR1 mutation detection
Throughout the study, up to 5 years
Number participants SERD therapy by SERD agent
Time Frame: Throughout the study, up to 5 years

Number participants initiating SERD therapy after ESR1 mutation detection. Report counts by SERD agent, with FDA-approved SERDs grouped by class as applicable.
Throughout the study, up to 5 years
Actionable genomic alterations detected by liquid biopsy and tissue NGS.
Time Frame: Throughout the study, up to 5 years

Rtes of actionable genomic alterations detected by F1LCDx and tissue NGS.
Throughout the study, up to 5 years
Other genomic alterations detected at disease progression
Time Frame: At disease progression during the study, up to 5 years

Rates of driver and acquired genomic alterations detected at progression by F1LCDx or tissue NGS that were absent from prior tissue comprehensive genomic profiling (CGP). Acquired alterations are those absent from tissue CGP at diagnosis but newly detected at progression.
At disease progression during the study, up to 5 years
Correlation of HRR gene findings with variant origin and germline confirmation
Time Frame: During the study, when the relevant genomic and confirmatory testing results are available, up to 5 years

Assess the relationship between homologous recombination repair (HRR) gene detection, variant origin prediction, germline banner classification when F1LCDx is performed, and confirmation of germline alterations by orthogonal testing.
During the study, when the relevant genomic and confirmatory testing results are available, up to 5 years
Correlation of HER2 status with ERBB2 copy number
Time Frame: During the study, when the relevant HER2 status and genomic results are available, up to 5 years

Assess the relationship between HER2-low or HER2-negative status and ERBB2 copy number results when F1CDx is performed.
During the study, when the relevant HER2 status and genomic results are available, up to 5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Yale University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Foundation Medicine

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jing Du, MD, Yale University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2031

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 26, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 2, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2000038562

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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