Using 18FFTT PET Imaging to Measure PARP Expression in Adults With Metastatic Breast Cancer Receiving Standard PARP Inhibitor and Immune Checkpoint Treatments

What this Trial Is About

Researchers are evaluating how well fluorine F 18 fluorthanatrace 18FFTT positron emission tomography PET works in imaging patients with metastatic breast cancer who are receiving standard treatments using PARP inhibitors, with or without immune checkpoint inhibitors ICI. This study focuses on detecting how tumors respond clinically to these treatments by targeting and visualizing PARP1 expression in tumor cells using the 18FFTT tracer during PET scans. PARP inhibitors block an enzyme involved in repairing cell damage, potentially causing tumor cells to die, while ICIs may assist the immune system in attacking cancer and slowing tumor growth. Participants are assigned to one of two groups. In Arm I, patients receive 18FFTT intravenously and undergo PET scans 60-75 minutes later on the first day of starting PARP inhibitor treatment with or without ICI, and again at 12 weeks. Following this, they have standard FDG PETCT scans and follow-ups at 12 weeks and 6 months, with optional tissue biopsies during screening and follow-up. In Arm II, patients receive 18FFTT and PET scans similarly on day 1 but only have follow-up FDG PETCT scans and may have biopsies during screening. After initial imaging, patients are monitored for up to 6 months or until disease progression. During the study, participants undergo several assessments including 18FFTT PET scans, FDG PETCT scans, tissue biopsies, and health record reviews. Researchers measure the overall response rate up to 6 months to evaluate tumor response to treatment. Safety and progression are monitored throughout, with multiple imaging and biopsy timepoints to track changes. Participation involves scheduled visits for imaging and scans, with treatment and evaluations following standard care protocols.

[18F]FTT Positron Emission Tomography for the Measurement of PARP Tumor Expression in Patients With Metastatic Breast Cancer