Actively Recruiting

Early Phase 1
Age: 19Years +
All Genders
NCT04174352

FES Imaging to Optimize Tamoxifen for Metastatic Breast Cancer

Led by University of Wisconsin, Madison · Updated on 2025-12-22

12

Participants Needed

2

Research Sites

371 weeks

Total Duration

On this page

AI-Summary

What this Trial Is About

Despite broad advancements in endocrine therapy for ERα+ breast cancer, resistance ultimately develops. A common driver of resistance are known ESR1 mutations that lead to constitutively active receptor signaling and transcriptional regulation that is always "turned on" despite the absence of estrogen. Patients with ESR1 mutations are expected to have decreased binding affinity for tamoxifen and thus may be underdosed on standard therapy. \[18F\]-fluoroestradiol Positron Emission Tomography/Computed tomography (FES-PET/CT) imaging is a novel functional imaging technique that can non-invasively measure ERα expression and inhibition in metastatic ERα+ breast cancer. The proposed a pilot study uses FES-PET/CT imaging to measure ERα blockade to determine the optimal dose of tamoxifen in patients with ESR1 mutations.

CONDITIONS

Official Title

FES Imaging to Optimize Tamoxifen for Metastatic Breast Cancer

Who Can Participate

Age: 19Years +
All Genders

Eligibility Criteria

Eligible

You may qualify if you...

  • Histologically confirmed metastatic or unresectable breast cancer
  • Estrogen receptor expression by immunohistochemistry �3e= 10%
  • ESR1 mutation confirmed by CLIA certified assay from tumor biopsy or circulating free DNA
  • HER2 negative status
  • Measurable disease by RECIST 1.1 or evaluable bone disease with lesion �3e= 10 mm
  • At least one prior line of endocrine therapy in metastatic setting or progression within 12 months of adjuvant endocrine therapy
  • ECOG performance status of 0 or 1
  • Life expectancy greater than 12 weeks
  • Ability to take oral medications
  • Signed informed consent
  • Stable central nervous system metastases after treatment for at least 1 month
  • Adequate organ and bone marrow function as defined by specified blood counts and lab values
Not Eligible

You will not qualify if you...

  • Recent chemotherapy, radiotherapy, targeted, immunotherapy, or investigational therapy within 2 weeks
  • Major surgery within 4 weeks or unresolved adverse events from prior treatments
  • Currently receiving ER blocking endocrine therapy or within 60 days prior to FES PET/CT
  • Allergic reactions to tamoxifen or [18F]-fluoroestradiol compounds
  • Peripheral neuropathy greater than grade 1
  • Current significant eye disorders greater than grade 1
  • History of cerebellar disorders, ataxia, uncontrolled seizures unless resolved
  • History of venous thrombosis or thromboembolic events
  • QTcF interval �3e= 470 msec or risk factors for QT prolongation
  • Taking medications that prolong QT interval without ability to switch or monitor
  • Pregnant or women of childbearing potential without negative pregnancy test and effective contraception
  • Ongoing treatment with other investigational or anti-cancer therapies not outlined in the study
  • History of uterine malignancy unless disease-free for �3e= 3 years after hysterectomy
  • Concurrent malignancies except basal cell or squamous cell skin cancer and in situ cervical cancer
  • Use of contraindicated medications including strong CYP2D6, CYP3A4, and CYP2C9 inhibitors or inducers
  • Uncontrolled significant illness including infection, heart failure, unstable angina, arrhythmia, or psychiatric conditions limiting compliance

AI-Screening

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Trial Site Locations

Total: 2 locations

1

University of Wisconsin Carbone Cancer Center

Madison, Wisconsin, United States, 53792

Actively Recruiting

2

Wisconsin Oncology Network (WONIX) sites

Madison, Wisconsin, United States, 53792

Not Yet Recruiting

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Research Team

C

cancer connect

CONTACT

How is the study designed?

Study Type

INTERVENTIONAL

Masking

NONE

Allocation

NA

Model

SINGLE_GROUP

Primary Purpose

TREATMENT

Number of Arms

1

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FES Imaging to Optimize Tamoxifen for Metastatic Breast Cancer | DecenTrialz