Recruiting
Phase 1
Phase 2

\[18F\]FTT

Sponsor:

University of Washington

Code:

NCT06502691

Conditions

Anatomic Stage IV Breast Cancer AJCC v8

Metastatic Breast Carcinoma

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Best Practice

Biopsy of Breast

Computed Tomography

Electronic Health Record Review

Fludeoxyglucose F-18

Study Details

Brief summary:

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.

Conditions

Anatomic Stage IV Breast Cancer AJCC v8

Metastatic Breast Carcinoma

Study ID

NCT06502691

Start date

Feb 26, 2026

Status verified date

May, 2026

Completion date

Dec 31, 2030

Anticipated

Primary completion date

Dec 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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)

Study Design

Enrollment

22 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Diagnostic

Interventions and Outcome Measures

Arms

experimental: Arm I ([18F]FTT PET, FDG PET/CT, PARP inhibitor, ICI)

Patients receive \[18F\]FTT IV and undergo PET scan 60-75 minutes later on day 1 of initiating SOC PARP inhibitor ± ICI therapy and again at 12 weeks. At least 1-7 days later, patients undergo SOC FDG PET/CT and follow up scans at 12 weeks and 6 months. Patients may also undergo tissue biopsy during screening and during follow up.

active comparator: Arm II ([18F]FTT PET, FDG PET/CT, PARP inhibitor, ICI)

Patients receive \[18F\]FTT IV and undergo PET scan 60-75 minutes later on day 1 of initiating SOC PARP inhibitor ± ICI therapy. At least 1-7 days later, patients undergo SOC FDG PET/CT and follow up scans at 12 weeks and 6 months. Patients may also undergo tissue biopsy during screening.

Interventions

Best Practice

Receive of standard care

Biopsy of Breast

Undergo breast biopsy

Computed Tomography

Undergo FDG PET/CT

Electronic Health Record Review

Ancillary studies

Fludeoxyglucose F-18

Given FDG

Fluorine F 18 Fluorthanatrace

Given IV

Immune Checkpoint Inhibitor

Receive ICI treatment

Poly (ADP-Ribose) Polymerase Inhibitor

Receive PARP inhibitor treatment

Positron Emission Tomography

Undergo \[18F\]FTT PET

Positron Emission Tomography

Undergo FDG PET/CT

Primary outcome measure

  • Overall response rate (ORR) [ Time Frame: Baseline up to 6 months ]

Central Contacts and Locations

Central contacts

Jennifer Specht, MD

206-606-6889jspecht@uw.edu

Locations

Fred Hutch/University of Washington Cancer Consortium

Recruiting

Seattle, Washington, United States, 98109

Contacts

Jennifer Specht, MD

206-606-6889jspecht@uw.edu

Principal Investigator:

Jennifer Specht, MD

More Information

Sponsor

University of Washington

Last update posted

May 19, 2026

Last verified

May, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Washington on 2026-05-19.