QuantifyHER: Quantitative Immunofluorescence and/or RT-qPCR for Measuring HER2 in HER2-low Metastatic Breast Cancer

April 2, 2026 updated by: Abramson Cancer Center at Penn Medicine
This study will assess whether a quantitative, HER2 assay can accurately and reliably discriminate between responders and non-responders among patients with HER2 IHCI+ metastatic breast cancer who are receiving T-Dxd.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

200

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 Locations

  • United States
    • California
      • San Francisco, California, United States, 94143
        • Recruiting
        • University of California San Francisco Medical Center
        • Contact:
    • Connecticut
      • Derby, Connecticut, United States, 06418
        • Recruiting
        • Smilow Cancer Hospital-Derby Care Center
        • Contact:
      • Fairfield, Connecticut, United States, 06824
      • Glastonbury, Connecticut, United States, 06033
        • Recruiting
        • Smilow Cancer Hospital at Glastonbury
        • Contact:
      • Greenwich, Connecticut, United States, 06830
        • Recruiting
        • Smilow Cancer Hospital Care Center at Greenwich
        • Contact:
      • Guilford, Connecticut, United States, 06437
      • Hartford, Connecticut, United States, 06105
        • Recruiting
        • Smilow Cancer Hospital at Saint Francis
        • Contact:
      • New Haven, Connecticut, United States, 06511
        • Recruiting
        • Yale Cancer Center
        • Principal Investigator:
          • Adriana Kahn, MD
        • Contact:
      • New Haven, Connecticut, United States, 06473
        • Recruiting
        • Yale-New Haven Hospital North Haven Medical Center
        • Contact:
      • Stamford, Connecticut, United States, 06901
        • Recruiting
        • Smilow Cancer Hospital Care Center at Long Ridge
        • Contact:
      • Torrington, Connecticut, United States, 06790
        • Recruiting
        • Smilow Cancer Hospital-Torrington Care Center
        • Contact:
      • Trumbull, Connecticut, United States, 06611
      • Waterbury, Connecticut, United States, 06708
        • Recruiting
        • Smilow Cancer Hospital-Waterbury Care Center
        • Contact:
      • Waterford, Connecticut, United States, 06385
        • Recruiting
        • Smilow Cancer Hospital Care Center - Waterford
        • Contact:
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20016
        • Recruiting
        • Sibley Memorial Hospital
        • Contact:
      • Washington D.C., District of Columbia, United States, 20010
      • Washington D.C., District of Columbia, United States, 20007
    • Illinois
    • Indiana
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • Recruiting
        • John's Hopkins Hospital
        • Contact:
    • New Jersey
      • Plainsboro, New Jersey, United States, 08536
    • New York
      • The Bronx, New York, United States, 10467
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
      • Pittsburgh, Pennsylvania, United States, 15213
        • Recruiting
        • University of Pittsburgh Medical Center
        • Contact:
      • Pittsburgh, Pennsylvania, United States, 15232
    • Rhode Island
      • Westerly, Rhode Island, United States, 02891
    • Texas
      • Houston, Texas, United States, 77030
      • Houston, Texas, United States, 77030
      • Houston, Texas, United States, 77079
      • Houston, Texas, United States, 77054
        • Recruiting
        • Baylor College of Medicine/Dan L Duncan Comprehensive Cancer Center
        • Contact:
      • League City, Texas, United States, 77573
      • Sugar Land, Texas, United States, 77478
      • Woodland, Texas, United States, 77384
    • Washington
      • Seattle, Washington, United States, 98109
        • Recruiting
        • University of Washington - Fred Hutchinson Cancer Center
        • Contact:

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients with HER2 IHC1+ metastatic breast cancer, histologically confirmed

Description

Inclusion Criteria:

  • Women and men age > 18 years
  • Metastatic breast cancer, histologically- confirmed. Any estrogen receptor (ER) status is allowed. ER status will be determined by local laboratory assessment utilizing ASCO/CAP guidelines.
  • Primary and/or metastatic tumor with 1+ level of expression of HER2 by immunohistochemistry as determined by local laboratory assessment utilizing ASCO/CAP guidelines.
  • Measurable disease by cross-sectional imaging at the start of treatment. Patients with measurable bone-only disease or active brain metastases are eligible.
  • Archival tissue available for biomarker assessment. One specimen should be the most recent metastatic biopsy. If HER2 1+ status was determined on a different specimen (either primary or metastatic tissue), that specimen is also required. Samples obtained from bone metastases that were processed via decalcification methods are not eligible.
  • Intention to initiate therapy with T-DXd (Enhertu) at FDA-approved dose and schedule as next line of therapy. If T-DXd was already initiated, patients must be registered within 30 days of initiation.
  • Ability to provide informed consent

Exclusion Criteria:

  • Concurrent Her2-overexpressing metastatic breast cancer (as confirmed by a metastatic biopsy with IHC 3+ or IHC 2+ with FISH amplified as per standard ASCO/CAP guidelines)

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
HER2 Assay
Analysis of HER2 expression via QIF and mRNA assays
Diagnostic test: CE-10-IVD
Leftover tumor tissue from a routine biopsy will be sent for analysis.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Real-World Objective Response Rate
Time Frame: from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months
Association between quantitative HER2 expression (as a continuous variable) and real-world objective response rate
from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Real-World Progression Free Survival
Time Frame: from date of first dose of T-DXd to date of last dose of T-DXd for each.Up to 100 months
Association between quantitative HER2 expression (as a continuous variable) and real world Progression Free Survival
from date of first dose of T-DXd to date of last dose of T-DXd for each.Up to 100 months
Real-World Progression Free Survival and Objective Response Rate by estrogen receptor expression
Time Frame: from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months
Association between HER2 expression by quantitative immunofluorescence and mRNA in HER2 IHC 1+ tumors and both rwORR and rwPFS, stratified by mRNA ER expression
from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months
Threshold for HER2 QIF and/or mRNA levels
Time Frame: from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months
cut-off value for HER2 QIF, mRNA and the combination below which patients will not respond to T-DXd."
from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months
Association between combined mRNA + QIF and real-world Objective Response Rate
Time Frame: from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months
Comparison, based on rwORR, of a linear combination of HER2 QIF and mRNA, versus either alone in ability to discriminate T-DXd responders from non- responders
from date of first dose of T-DXd to date of last dose of T-DXd for each. Up to 100 months

Collaborators and Investigators

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

Sponsor

Abramson Cancer Center at Penn Medicine

Collaborators

Translational Breast Cancer Research Consortium
Danaher Inc.

Investigators

  • Principal Investigator: Angela DeMichele, MD, Abramson Cancer Center at Penn Medicine

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 (Actual)

October 10, 2024

Primary Completion (Estimated)

September 1, 2029

Study Completion (Estimated)

September 1, 2029

Study Registration Dates

First Submitted

July 29, 2024

First Submitted That Met QC Criteria

August 9, 2024

First Posted (Actual)

August 13, 2024

Study Record Updates

Last Update Posted (Actual)

April 7, 2026

Last Update Submitted That Met QC Criteria

April 2, 2026

Last Verified

May 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UPCC 09124
  • 855924 (Other Identifier: University of Pennsylvania IRB)

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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