A Phase 2 interventional study of 18F-fluorofuranylnorprogesterone and Positron Emissions Tomography / Magnetic Resonance Imaging in Breast Cancer, sponsored by University of Wisconsin, Madison. Recruiting at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-31.
Sponsored by University of Wisconsin, Madison · Phase 2, Interventional, and Diagnostic
This clinical trial will investigate an estrogen-regulated parameter as an early measure of endocrine therapy response: progesterone receptor (PR) protein with a progestin-based radioligand, 18F-fluorofuranylnorprogesterone (18F-FFNP). The overall purpose of this research is to test the efficacy of 18F-FFNP PET/MRI for predicting response to presurgical endocrine therapy and to determine the quantitative reliability of 18F-FFNP breast PET/MRI in patients with newly diagnosed PR+ primary breast cancer.
Primary Objective
Secondary Objectives
Exploratory Objectives
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This study's planned enrollment of 53 is below the median of 72 across 9,303 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →University of Wisconsin, Madison is the lead sponsor of 1,161 studies on the registry; 182 are open to participants now.
Of its 151 completed or terminated interventional studies of FDA-regulated products, 114 (75%) have results posted.
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Postmenopausal status defined by either
Exclusion Criteria:
Patients requiring conscious sedation for imaging are not eligible; patients requiring mild, oral anxiolytics for the clinical MRI scan will be allowed to participate as long as the following criteria are met:
participants will undergo venous blood sampling during the PET/MRI scan
Drug: 18F-fluorofuranylnorprogesterone · Device: Positron Emissions Tomography / Magnetic Resonance Imaging · Other: Blood Sampling · Drug: FDA-approved gadolinium-based intravenous contrast agent
participants will undergo PET/MRI scans before and after 2 weeks treatment with anastrozole
Drug: 18F-fluorofuranylnorprogesterone · Device: Positron Emissions Tomography / Magnetic Resonance Imaging · Drug: Anastrozole · Drug: FDA-approved gadolinium-based intravenous contrast agent
participants will undergo baseline and repeat PET/MRI scans without intervening treatment to determine repeatability
Drug: 18F-fluorofuranylnorprogesterone · Device: Positron Emissions Tomography / Magnetic Resonance Imaging · Drug: FDA-approved gadolinium-based intravenous contrast agent
18F-FFNP will be given by a slow infusion (approximately 2 minutes), and the dose administered will be approximately 7 mCi.
Also known as: FFNP
Breast specific PET/MRI data will be acquired using a 3T simultaneous PET/MRI scanner (Signa PET/MR, GE Healthcare)
Also known as: PET/MRI
hormone based chemotherapy that reduces estrogen, 1 mg anastrozole once daily by mouth for a minimum of 14 days
Venous blood samples will be collected at multiple timepoints (e.g., 5, 10, 20, 30, and 45 min after 18F-FFNP injection to determine parent and metabolite fractions
FDA-approved gadolinium-based intravenous contrast agent used for the MRI portion of this study
Also known as: gadopiclenol, gadobenate dimuglumine
Percentage change in 18F-FFNP uptake between baseline and follow-up PET/MRI scans
Tumor uptake values of 18F-FFNP will be obtained from the attenuation corrected PET component of the simultaneous breast 18F-FFNP PET/MRI research scan according to the procedures detailed in the imaging manual and the FDA IND.
Time frame: up to 4 weeks on study and up to 7 weeks on study
Percentage change in tumor Ki67 proliferation score, as a surrogate measure of endocrine sensitivity
Baseline Ki67 proliferation immunohistochemistry score will be obtained from the existing clinical standard-of-care breast biopsy. Post-treatment K67 proliferation immunohistochemistry score will be obtained from the surgical specimen after excision. Treatment response is defined as a reduction in Ki67 score of greater than or equal to 60 percent. Treatment nonresponse is defined as a reduction of less than 60 percent.
Time frame: up to 4 weeks on study and up to 7 weeks on study
Qualitative Analysis of 18F-FFNP uptake
18F-FFNP uptake will be visually evaluated qualitatively with the following grading scale: no uptake (tumor \< background), minimal uptake (tumor = background), mild (tumor slightly \> background), moderate uptake (tumor \>\> background), and intense uptake (tumor \>\>\> background). Tumor uptake will also be dichotomized as increased (mild, moderate, or intense uptake) or absent (no uptake, minimal).
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks and up to 6 weeks for the test-retest Group 3
Intra- and Inter-Observer Variability of Quantitative Assessment of Tumor 18F-FFNP uptake
For the test-retest portion of the clinical trial, the mixed effects model framework will be utilized to determine the intra- and interobserver variability of quantitative assessment of tumor 18F-FFNP uptake via a parametric bootstrapping approach.
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks and up to 6 weeks for the test-retest Group 3
Quantitative Assessment of Tumor 18F-FFNP: Standardized Uptake Values (SUV)
Differences in repeatability of the different SUV measures (SUVmax, SUVpeak, and SUVmean) and their respective methods of normalization will be assessed by comparing the variances of the relative test-retest differences, using the Pitnam-Morgan test for correlated variances.
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks and up to 6 weeks for the test-retest Group 3
Test-Retest Variability of Quantitative Assessment of Tumor 18F-FFNP uptake
For the test-retest portion of the clinical trial, the mixed effects model framework will be utilized to determine the test-retest variability of quantitative assessment of tumor 18F-FFNP uptake via a parametric bootstrapping approach.
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks and up to 6 weeks for the test-retest Group 3
NCIC Adverse Events Version 5.0 Frequency Tables
Safety and tolerability of 18F-FFNP by NCIC Adverse Events Version 5.0 will be assessed by frequency tables and possible relationship to study drug as assessed by the investigators.
Time frame: up to 7 weeks
Summary of Parent and Metabolite Fractions of 18F-FFNP over the course of the scan
Median and interquartile ranges will be calculated for metabolized and unmetabolized (parent) 18F-FFNP obtained from subjects undergoing venous blood sampling in the metabolite study and plotted against time.
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks on study for Group 1
Statistical Correlation between tumor 18F-FFNP uptake with serum progesterone, 17-OH progesterone, estradiol, and corticosteroid binding globulin levels
Pearson's or Rank correlation analysis will be performed to assess the association between tumor 18F-FFNP uptake with serum progesterone, estradiol, and corticosteroid binding globulin levels. Scatter plots, correlation coefficients (rho), 95% confidence intervals, and p values will be reported.
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks on study for Group 1
Statistical correlation between 18F-FFNP breast PET/MRI parameters and changes in PR immunohistochemistry in therapy responders and non-responders
An ANCOVA model, which will include treatment as a fixed effect and the corresponding baseline value as a covariate, and a paired t-test will be utilized to compare the change in tumor 18F-FFNP update after window treatment with change in PR immunostaining from the biopsy to surgical specimen. Means and standard errors will be presented. Least-squares means and 95% CI will be reported. Furthermore, correlation analyses will be performed to describe these associations.
Time frame: imaging takes up to 2 hours during a visit and will take place up to 4 weeks on study for Group 1, up to 4 weeks and up to 7 weeks for Group 2, and up to 4 weeks and up to 6 weeks for Group 3
Statistical correlation between tumor 18F-FFNP uptake with disease recurrence
If there is sufficient follow-up data for disease recurrence, the Kaplan-Meier method will be used to analyze time to disease recurrence, defined as date of imaging day until disease recurrence. Patients who do not experience disease recurrence will be censored at the date of last available follow-up. A Cox proportional hazards model will be used to evaluate the association of tumor 18F-FFNP uptake with time to disease recurrence. If there is insufficient follow-up data, descriptive statistics will be used to summarize tumor 18F-FFNP uptake for those patients with disease recurrence
Time frame: up to 5 years (long term follow up)
Statistical determination of whether MRI parameters improve the predictive value of FFNP PET alone
The investigators will explore whether adding MRI parameters improves the AUC of 18F-FFNP PET alone. Regression models will be performed on the following parameters: quantitative tumor perfusion (signal enhancement ratio, functional tumor volume), quantitative tumor diffusion (apparent diffusion coefficient), qualitative morphologic phenotype (categories I, II, III, IV), and qualitative background parenchymal enhancement (categories are minimal, mild, moderate, marked).
Time frame: up to 5 years (long term follow up)
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University of Wisconsin, Madison