FAP PET/CT for Staging Patients With Breast Cancer

[⁶⁸Ga]Ga-FAP-2286 PET/CT for Staging and Restaging Patients With Newly Diagnosed Primary Breast Cancer: a Phase II Study (FAPILOUS)

This study aims to evaluate the clinical utility of [68Ga]Ga-FAP-2268 PET/CT for disease staging and assessment in patients with high-risk primary breast cancer. By targeting fibroblast activation protein (FAP), this novel imaging approach may offer improved tumor visualization compared to conventional imaging, which may help improve treatment planning.

Study Overview

• Status: Not yet recruiting
• Conditions: Breast Cancer Detection
• Intervention / Treatment: Drug: 68Ga-FAP-2286

• Study Type: Interventional
• Enrollment (Estimated): 65
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Sara E Dahlsgaard-Wallenius, MD; Phone Number: +45 53 57 45 55; Email: sara.elisabeth.wallenius@rsyd.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Male and females ≥ 18 years
• Biopsy-verified newly diagnosed breast cancer
• Can read and understand Danish
• Capable of providing written and informed consent
• Undergoing a routine [¹⁸F]FDG PET/CT scan as part of the clinical standard diagnostic workup

Exclusion Criteria:

• Pregnant or lactating women
• Not able to participate in the conduct of the scan due to any reason ( e.g., claustrophobia or inability to lie still for entire imaging time)
• Ongoing oncological treatment for another cancer
• History of allergic reactions / hypersensitivity attributed to [⁶⁸Ga]Ga-FAP-2286.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 68Ga-FAP-2286 PET/CT Imaging; Patients undergo intravenous administration (200 MBq) of 68Ga-FAP-2286 followed by PET/CT imaging for staging of high-risk primary breast cancer. A baseline scan is performed prior to initiation of therapy. Patients receiving neoadjuvant chemotherapy undergo an additional scan prior to surgery.	Drug: 68Ga-FAP-2286; One scan at baseline staging, and for those reciving NACT : one scan before surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients with nodal and distant metastases detected by [⁶⁸Ga]Ga-FAP-2286 PET/CT at baseline (pre-treatment staging)	Nodal and distant metastases will be identified on a per-patient and per-lesion basis using [⁶⁸Ga]Ga-FAP-2286 PET/CT in 65 patients undergoing baseline staging. PET/CT images will be read blinded. The reference standard is histopathology where available; if histopathology is not available, a composite of clinical and imaging follow-up will be used. Sensitivity and specificity with 95% confidence intervals will be calculated per patient and per lesion.	Baseline (pre-treatment). Inclusion period 1 year.
Concordance of [⁶⁸Ga]Ga-FAP-2286 PET/CT with surgical pathology for axillary lymph node status after neoadjuvant therapy (restaging)	In approximately 50 patients undergoing post-neoadjuvant therapy PET/CT prior to surgery, axillary lymph node status will be classified as (a) uptake on PET/CT with histologically confirmed residual disease, or (b) no uptake on PET/CT with pathological complete response (pCR). PET/CT images will be read blinded, with surgical pathology as the gold standard. Concordance (proportion correctly classified) and appropriate concordance statistics will be calculated.	Post-therapy/ pre-surgery scan, about 6 month after baseline scan.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients with TNM stage or MDT treatment decision changes after [⁶⁸Ga]Ga-FAP-2286 PET/CT	For baseline staging (approximately 65 patients), TNM stage and MDT treatment decisions will be compared before and after availability of [⁶⁸Ga]Ga-FAP-2286 PET/CT results. Proportions of patients with changes will be reported with 95% confidence intervals (Wilson-score method). Data will be extracted from eCRF documentation.	Baseline (pre-PET/CT) and up to 7 days post-PET/CT at MDT review
Inter-reader agreement of [⁶⁸Ga]Ga-FAP-2286 PET/CT lesion detection, BI-RADS-like scoring, and SUV/TBR quantification	All baseline scans will be independently read by two blinded physicians. Lesions will be scored using a standardized Likert-type scale for presence, risk of malignancy, and clinical relevance on a per-patient and per-lesion basis. Quantitative uptake will be measured using SUVmax, SUVmean, and lesion-to-background ratio (LBR). Interobserver agreement for categorical measures will be quantified with (linearly weighted) Cohen's kappa; for continuous measures, Bland-Altman analysis and intraclass correlation coefficients (ICC) will be used.	Baseline (initial reading) and up to 18 months post-baseline for blinded second reading
Incidence, severity, and causality of AEs, SAEs, and SUSARs after [⁶⁸Ga]Ga-FAP-2286 administration	Adverse events will be recorded for 48 hours post-injection, assessed per CTCAE v6.0. Data will include incidence, severity, and causality of AEs, SAEs, and SUSARs. Descriptive statistics will summarize findings by type, severity, and relation to the tracer.	From tracer injection to 48 hours post-injection
Lesion-level [⁶⁸Ga]Ga-FAP-2286 uptake patterns (SUVmax, SUVmean, LBR) across tumor subtypes and anatomical sites	ROI-based quantification will be performed for primary tumors, axillary lymph nodes, and suspected distant lesions. Uptake metrics (SUVmax, SUVmean, LBR) will be summarized per lesion, stratified by histological and molecular subtype, and anatomical site using descriptive statistics.	Baseline and up to approximately 6 months post-baseline.
Frequency, type, and clinical impact of incidental findings on [⁶⁸Ga]Ga-FAP-2286 PET/CT	Incidental findings will be documented per patient at baseline , and for patients receiving neoadjuvant chemotherapy, on pre-surgery scans. This will include numbers of incidental findings, type, and clinical consequences. Proportions of incidental findings leading to additional diagnostic procedures (e.g., biopsy, MRI, CT) or clinical intervention will be reported descriptively.	Baseline and up to approximately 6 months post-baseline (Pre-surgery, for patients receiving NACT)

Collaborators and Investigators

• Sponsor: Odense University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): January 1, 2029

Study Registration Dates

• First Submitted: March 9, 2026
• First Submitted That Met QC Criteria: April 8, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 8, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: PET/CT; Breast cancer; FAP; FAPI
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms
• Other Study ID Numbers: 2025-521324-29-00

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No