Predicting Response to Neoadjuvant Endocrine Therapy (Neo-PREDICT)

February 27, 2026 updated by: Pavani Chalasani, George Washington University

The goal of this clinical trial is to determine how the duration of hormone blocking (endocrine) therapy given prior to surgery (called "neoadjuvant" treatment) affects breast cancer. The main questions the trial aims is answer are:

  1. How breast cancer responds to endocrine therapy given prior to surgery?
  2. To predict tumor pre-operative endocrine prognostic index (PEPI) score for subjects enrolled in cohort B or C

Participants with early-stage breast cancer (Stage I-III) who are eligible for Neoadjuvant Endocrine Therapy (NET) will be enrolled in the study. Participants will:

  • receive endocrine therapy as part of regular care for breast cancer
  • consent to samples of blood and tissue evaluation to determine how endocrine therapy effects the tumor
  • participate in this research anywhere from 2 weeks to 1 year, depending on duration of endocrine therapy and when surgery will be performed

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

90

Phase

  • Phase 2

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
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20037
        • Recruiting
        • George Washington-Medical Faculty Associates
        • 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

Description

Inclusion Criteria:

  • Be capable of understanding the investigational nature of the study and all pertinent aspects of the study
  • Be capable of signing and providing written consent in accordance with institutional and federal guidelines
  • Histologically or cytologically confirmed diagnosis of invasive carcinoma of the breast
  • Clinical stage 1 to 3 breast cancer
  • Candidate for surgical resection
  • Estrogen receptor > 10% positive stained cells based on most recent tumor biopsy and documented by a local laboratory or medical record.
  • HER2 negative or HER2 low breast cancer based on the most recent tumor biopsy and documented by a local laboratory or medical record. HER2 negative tumor is defined per American Society of Clinical Oncology and the College of American Pathologists guidelines, 2018. Patients with HER2 low tumors are eligible as long as patients are not candidates for any HER2 directed therapy.
  • Ability to take oral medication
  • Be willing and able to comply with scheduled visits, treatment plan, and follow up with research staff
  • Age ≥ 21 years

Exclusion Criteria:

  • Inability to comply taking NET
  • Inability to comply to study procedures

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: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Cohort A: Short Duration NET
Patients in this cohort can be treated with NET up to 8weeks (<= 8 weeks)
Drug: Neoadjuvant endocrine therapy
Cohort A: Short duration NET. Patients in this cohort can be treated with NET up to 8weeks (<= 8 weeks)
Drug: Neoadjuvant endocrine therapy
Cohort B: Intermediate duration NET. Patients in this cohort can be treated with NET > 8weeks but <=24 weeks
Drug: Neoadjuvant endocrine therapy
Cohort C: Extended duration NET. Patients in this cohort can be treated with NET >24 weeks but <= 52 weeks
Active Comparator: Cohort B: Intermediate Duration NET
Patients in this cohort can be treated with NET > 8weeks but <=24 weeks
Drug: Neoadjuvant endocrine therapy
Cohort A: Short duration NET. Patients in this cohort can be treated with NET up to 8weeks (<= 8 weeks)
Drug: Neoadjuvant endocrine therapy
Cohort B: Intermediate duration NET. Patients in this cohort can be treated with NET > 8weeks but <=24 weeks
Drug: Neoadjuvant endocrine therapy
Cohort C: Extended duration NET. Patients in this cohort can be treated with NET >24 weeks but <= 52 weeks
Active Comparator: Cohort C: Extended Duration NET
Patients in this cohort can be treated with NET >24 weeks but <= 52 weeks
Drug: Neoadjuvant endocrine therapy
Cohort A: Short duration NET. Patients in this cohort can be treated with NET up to 8weeks (<= 8 weeks)
Drug: Neoadjuvant endocrine therapy
Cohort B: Intermediate duration NET. Patients in this cohort can be treated with NET > 8weeks but <=24 weeks
Drug: Neoadjuvant endocrine therapy
Cohort C: Extended duration NET. Patients in this cohort can be treated with NET >24 weeks but <= 52 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Response to neoadjuvant endocrine therapy (NET)
Time Frame: From enrollment to the end of treatment at <=52 weeks
Response to neoadjuvant endocrine therapy is defined as clear margins (defined as greater than 1mm) measured in the surgical pathology report. The proportion of women in each cohort with response will be estimated with exact 95% binomial confidence intervals. This is a categorical outcome (Success/Failure). Success is defined as clear margins >1mm; Failure is defined as margins ≤1mm.
From enrollment to the end of treatment at <=52 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Physicians will predict Preoperative Endocrine Prognostic Index (PEPI) score after NET for subjects enrolled in cohort B or C
Time Frame: From enrollment to the end of treatment at <=52 weeks
Preoperative Endocrine Prognostic Index (PEPI) score is determined from surgical pathology report. The score ranges from 0 to 12. The score is a composite of tumor size, nodal status, Ki67 level, and ER status. Higher scores indicate a worse outcome (increased risk of relapse), while a score of 0 (PEPI-0) represents a superior prognosis.
From enrollment to the end of treatment at <=52 weeks
Physicians will predict Ki67 after NET: Ki67 Labeling Index (percentage of Ki67-positive tumor cells).
Time Frame: From enrollment to the end of treatment at <=52 weeks
Physicians will make a prediction of what the Ki67 will be in the surgical pathology specimen. It will correlate with the surgical pathology report data recorded by pathologist. Ki67 measures the proportion of actively dividing cancer cells. Higher scores indicate a worse outcome (higher cell proliferation and potentially more aggressive disease). Scores range from 0% to 100%.
From enrollment to the end of treatment at <=52 weeks

Collaborators and Investigators

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

Sponsor

George Washington 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 (Actual)

October 1, 2024

Primary Completion (Estimated)

October 1, 2028

Study Completion (Estimated)

October 1, 2028

Study Registration Dates

First Submitted

January 15, 2025

First Submitted That Met QC Criteria

January 29, 2025

First Posted (Actual)

February 4, 2025

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

February 27, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Neo-PREDICT

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

Subscribe