NCT06502691 · University of Washington
[18F]FTT Positron Emission Tomography for the Measurement of PARP Tumor Expression in Patients With Metastatic Breast Cancer
What this study is about
This clinical trial studies how well fluorine F 18 fluorthanatrace (\[18F\]FTT) positron emission tomography (PET) works in imaging patients with breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic) who are receiving the usual treatment (SOC) poly (ADP-ribose) polymerase (PARP) inhibitors with or without immune checkpoint inhibitors (ICI) to be able to detect clinical response to PARP inhibitor ± ICI treatment. \[18F\]FTT is a radiotracer that targets and binds to PARP1 which can potentially be used for the imaging of PARP1 expression using PET. Once administered, \[18F\]FTT targets and binds to PARP1. Upon PET, PARP1-expressing tumor cells can be visualized. PET is an established imaging technique that utilizes small amounts of radioactivity attached to very minimal amounts of tracer, in the case, \[18F\]FTT. Because some cancers take up \[18F\]FTT it can be seen with PET. PARP inhibitors work as a targeted therapy by blocking an enzyme involved in repairing cell damage. It may cause tumor cells to die. ICI may help the body's immune system attack the cancer and may interfere with the ability of tumor cells to grow and spread. Combining \[18F\]FTT with a PET scan may help detect tumor cells better in patients with metastatic breast cancer who are receiving the usual treatment PARP inhibitors with our without ICI treatment.
View original scientific description
This clinical trial studies how well fluorine F 18 fluorthanatrace (\[18F\]FTT) positron emission tomography (PET) works in imaging patients with breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic) who are receiving standard of care (SOC) poly (ADP-ribose) polymerase (PARP) inhibitors with or without immune checkpoint inhibitors (ICI) to be able to detect clinical response to PARP inhibitor ± ICI treatment. \[18F\]FTT is a radiotracer that targets and binds to PARP1 which can potentially be used for the imaging of PARP1 expression using PET. Once administered, \[18F\]FTT targets and binds to PARP1. Upon PET, PARP1-expressing tumor cells can be visualized. PET is an established imaging technique that utilizes small amounts of radioactivity attached to very minimal amounts of tracer, in the case, \[18F\]FTT. Because some cancers take up \[18F\]FTT it can be seen with PET. PARP inhibitors work as a targeted therapy by blocking an enzyme involved in repairing cell damage. It may cause tumor cells to die. ICI may help the body's immune system attack the cancer and may interfere with the ability of tumor cells to grow and spread. Combining \[18F\]FTT with a PET scan may help detect tumor cells better in patients with metastatic breast cancer who are receiving standard of care PARP inhibitors with our without ICI treatment.
Interventions
OTHER
Best Practice
Receive of standard care
PROCEDURE
Biopsy of Breast
Undergo breast biopsy
PROCEDURE
Computed Tomography
Undergo FDG PET/CT
OTHER
Electronic Health Record Review
Ancillary studies
OTHER
Fludeoxyglucose F-18
Given FDG
RADIATION
Fluorine F 18 Fluorthanatrace
Given IV
DRUG
Immune Checkpoint Inhibitor
Receive ICI treatment
DRUG
Poly (ADP-Ribose) Polymerase Inhibitor
Receive PARP inhibitor treatment
PROCEDURE
Positron Emission Tomography
Undergo \[18F\]FTT PET
PROCEDURE
Positron Emission Tomography
Undergo FDG PET/CT
Primary outcome measures
Overall response rate (ORR)
Time frame: Baseline up to 6 months
Will be assessed using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria on poly (ADP-ribose) polymerase (PARP) inhibitor ± immune checkpoint inhibitor (ICI) treatment. Will use a boxplot to illustrate the difference of standard uptake value (SUV)max and SUVmean between responders and non-responders.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Patients must have histologically confirmed invasive breast cancer with metastatic disease
- Patients must be candidates for treatment with PARP inhibitor as a single agent or for PARP inhibitor in combination with an ICI per treating physician discretion
- Patients must have evaluable disease or at least one measurable lesion that can be assessed at baseline by CT (or magnetic resonance imaging \[MRI\]) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1
- Age \>= 18 years
- Karnofsky performance status (KPS) \>= 50% or Eastern Cooperative Oncology Group (ECOG) performance status 0-2
- Archival tissue (formalin-fixed paraffin-embedded \[FFPE\]) from at least one metastatic site biopsy should be available prior to study enrollment; if archival tissue is not available, then a metastatic site biopsy will be required during the study screening period
- Patient must be willing to proceed with an on-treatment biopsy of metastatic site if an on-treatment \[18F\]FTT PET will be performed (at 12 ± 4 weeks after starting PARP inhibitor ± ICI treatment)
- For women of childbearing potential, a negative serum pregnancy test is required within 7 days prior to \[18F\]FTT PET imaging on day 1. For women who obtain on-treatment (12-week) \[18F\]FTT imaging, a negative serum pregnancy test will be required within 7 days prior to \[18F\]FTT PET imaging
- Men and women of reproductive potential need to agree to employ two highly effective and acceptable forms of contraception throughout their participation in the study
- Patient is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations
- Ability to understand and the willingness to sign a written informed consent document. Informed consent must be provided prior to any study specific procedures
Exclusion criteria
- Patients with prior myelodysplastic syndrome or acute myeloid leukemia due to rare risk associated with PARP inhibitor therapy
- Pregnant or breastfeeding women
- Patient with a known hypersensitivity to the proposed PARP inhibitor product
- Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
- Patients unable to swallow orally administered medication and patients with gastrointestinal disorders likely to interfere with absorption of PARP inhibitor therapy (per investigator's discretion)
Where
- Seattle, Washington
Collaborators
Breast Cancer Research Foundation
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 19, 2026 · Source of record for eligibility and locations