Correlating Early FDG PET/CT and ctDNA in Immune Checkpoint Inhibitor (ICI)-Treated Melanoma Patients

Correlation Between Early Interval 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (PET/CT) and Circulating Tumor DNA (ctDNA) in Advanced Melanoma Patients Treated With Immune Checkpoint Inhibitors

The purpose of this research study is to determine if analysis of PET/CT scans and testing of blood samples in people with melanoma that has spread in their body can help researchers determine which patients are more or less likely to respond to immunotherapy and are more or less likely to have side effects. 24 participants will be enrolled and be on study until approximately 4 weeks after their first dose of Immune Checkpoint Inhibitor therapy.

This is a pilot, prospective, observational study to estimate the degree to which baseline and early interval 18F-FDG PET/CT imaging within 3-4 weeks of ICI therapy initiation can accurately correlate with ctDNA level trends, predict clinical response, onset of immune-related adverse events, and survival outcomes in advanced stage melanoma patients.

Primary Objective

• To determine if early interval response assessment with 18F-FDG PET/CT during initial treatment with ICI therapy at 3-4 weeks correlates with ctDNA level changes in advanced melanoma patients.

Secondary Objectives

• To determine if early interval response assessment with 18F-FDG PET/CT during initial treatment with ICI therapy at 3-4 weeks predicts clinical efficacy at standard disease assessment time points in advanced melanoma patients.
• To assess if early interval response assessment with 18F-FDG PET/CT predicts development of clinical irAEs in advanced melanoma patients.
• To assess if early interval response assessment with 18F-FDG PET/CT and ctDNA level predicts progression-free survival (PFS) in advanced melanoma patients.
• To assess if early interval response assessment with 18F-FDG PET/CT and ctDNA level predicts overall survival (OS) in advanced melanoma patients.

Inclusion Criteria:

• Willing to provide informed consent.
• Must have an advanced stage III or stage IV melanoma diagnosis for which treatment with ipilimumab, nivolumab, and/or pembrolizumab, either alone or in combination with other ICI therapy, is planned.
• Must be planning to participate in Signatera™ (ctDNA level) monitoring with standard of care laboratory testing routinely obtained for treatment with ICI therapy.
• Individuals at least 18 years of age.
• Women of childbearing potential must be willing to use effective contraception as discussed with their oncologist while participating in this study.
• Willing to comply with all study procedures and be available for the duration of the study.

Exclusion Criteria:

• Not able to receive treatment with ICI therapy
• Use of investigational drugs, biologics, or devices within 30 days prior to enrollment.
• Women who are pregnant, lactating, or planning on becoming pregnant during the study.
• Not suitable for study participation due to other reasons at the discretion of the investigators.