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Biomarkers to Detect Endocrine Therapy Resistance

Integrating Minimally Invasive Biomarkers of Estrogen Signaling to Detect Endocrine Therapy Resistance in Metastatic Invasive Lobular Breast Cancer

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06067503
Enrollment
8
Registered
2023-10-05
Start date
2024-04-30
Completion date
2026-08-31
Last updated
2025-04-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metastatic Cancer, Breast Cancer, Lobular Breast Carcinoma

Keywords

Endocrine Therapy Resistance, circulating tumor cell, liquid biopsy

Brief summary

This pilot observational study is being done to identify possible biomarkers of response to endocrine therapy in patients with ER/PR+ metastatic lobular breast cancer (LBC) starting new endocrine therapy. 18F-fluorofuranylnorprogesterone Positron Emission Tomography/Computed Tomography (FFNP-PET/CT) and liquid biopsies will be performed at baseline and after 4 weeks of treatment. Baseline levels and dynamic on-treatment changes in estrogen signaling as measured by FFNP-PET/CT and circulating tumor cell (CTC) liquid biopsy will be correlated with clinical response to endocrine therapy and progression-free survival in the above cohort of patients.

Interventions

The dose of the investigational imaging agent, FFNP, is approximately 7 millicurie (mCi) (259 megabecquerels (MBq)), IV slow infusion over approximately two minutes followed by saline flush.

DEVICELiquid Biopsy

20ml of whole blood will be collected into two Ethylenediaminetetraacetic acid (EDTA) tubes at each timepoint, CTCs are isolated using the microfluidic Versatile Exclusion-based Rare Sample Analysis (VERSA) platform that integrates CTC capture with RNA extraction on a single chip using Exclusion-Based Sample Preparation (ESP) technology

FFNP drug in combination with PET/CT scans to image participant

Sponsors

University of Wisconsin, Madison
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Willing to provide informed consent 2. Individuals at least 18 years of age 3. Have biopsy-proven ER/PR-positive (defined as ER ≥1 percent and PR ≥1 percent by IHC) and HER2-negative advanced or metastatic LBC starting new standard of care endocrine therapy 4. Adequate organ function as indicated by standard laboratory tests (CBC, liver function tests or CMP) allowing for systemic breast cancer treatment per treating oncologist 5. Patients with evaluable bone-only disease that is lytic or mixed lytic-sclerotic are eligible 6. Willing to comply with all study procedures and be available for the duration of the study 7. Disease may be measurable by RECIST 1.1 criteria or non-measurable. Lesion size must be at least 1cm. If only bone lesions present, they should be lytic or mixed lytic-sclerotic. If only liver lesions present, patient is not eligible.

Exclusion criteria

1. Patients with active brain metastases 2. Patients with liver-only disease are not eligible due to high background liver activity related to the radiopharmaceutical's hepatobiliary route of elimination 3. Unable to lie flat during or tolerate PET/CT 4. Patients with a history of allergic reaction attributable to compounds of similar chemical or biologic composition to FFNP 5. Presence of liver failure as judged by patient's treating physician 6. Individuals who are pregnant, lactating, or planning on becoming pregnant during the study 7. Not suitable for study participation due to other reasons at the discretion of the investigators 8. Patients with progesterone-receptor negative disease defined as PR \<1 percent by IHC

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants who have decreased FFNP uptake on PET/CT in response to endocrine therapybaseline, 4 weeks
Number of Participants who have decrease in circulating tumor cell estrogen signaling in response to endocrine therapybaseline, 4 weeksBaseline level and on-treatment CTC ESR1 and estrogen regulated gene expression will be evaluated as well as endocrine-resistance associated mutations including ESR1 (though rare in this patient population) and PGR.
Number of Participants who have a decrease in concentration of Circulating Tumor DNA in response to endocrine therapybaseline, 4 weeks

Secondary

MeasureTime frameDescription
Progression Free Survival (PFS) for 6 monthsup to 6 months
Correlation coefficientsup to 6 monthsCorrelate baseline levels and dynamic on treatment changes in estrogen signaling as measured by FFNP-PET/CT and CTC liquid biopsy with clinical response to endocrine therapy and progression-free survival in patients with ER/PR+ metastatic LBC.
Adverse Events within 24 hours of FFNP infusiona 24 hour period up to 7 days pre-treatment, a 24 hour period 4 weeks after the first infusion

Countries

United States

Contacts

Primary ContactCancer Connect
clinicaltrials@cancer.wisc.edu800-622-8922

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026