A Phase 2a, Single-dose, Open-label Study to Evaluate Diagnostic Performance and Safety of Pegsitacianine, an Intraoperative Fluorescence Imaging Agent for the Detection of Cancer, in Patients With Unknown Primary Head and Neck Cancer (ILLUMINATE STUDY)

This study is evaluating a new fluorescent imaging agent called pegsitacianine that surgeons can use during operations to better identify cancer tissue in real time. It is being tested in patients with head and neck cancer, including those with an unknown primary cancer site. **You may be eligible if...** - You are 18 or older - You have been diagnosed (or there is high clinical suspicion) of head and neck squamous cell carcinoma (HNSCC), stage 1–4 - OR you have a type of head and neck cancer where the primary tumor location is unknown, but cancer has spread to a lymph node in the neck - Your blood, kidney, and liver function are acceptable for surgery **You may NOT be eligible if...** - You have known allergies to the imaging agent - Your organ function does not meet surgical safety requirements - You cannot undergo surgery for other medical reasons Talk to your doctor to see if this trial is right for you.