Description:

This study in 20 patients is designed as a monocentric, open-label and uncontrolled, exploratory pilot study. Patients diagnosed with advanced melanoma (stage III-IV) and scheduled for anti-PD-1 immunotherapy will be recruited for this project. Patients will receive IV 250 µg Tilmanocept, labelled with 370 MBq of Tc-99m (bolus injection) according to the Navidea's protocol in our GMP certified radiopharmaceutical unit, before the first cycle of clinically scheduled immunotherapy. Scintigraphy images will be acquired dynamically from time of injection to +30 minutes. Quantitative SPECT/CT (xSPECT/CT, Siemens Symbia Intevo, Erlangen, Germany) imaging will be performed up to 1 hour p.i. to evaluate hyperaemia, and up to 3 hours p.i. to image and measure the CD206 receptor uptake. The data of the scans will be compared to immunohistochemistry results from biopsy staining for TAMs and M2-like TAMs and retrospectively with response to the immunotherapy to determine any correlation between M2-like TAMs and treatment response. For the planned retrospective comparison we will use the FDG - PET/CT data that is done after the immunotherapy as standard of care. We will analyse the lesion size and FDG - uptake in standard of care PET/CT of CD206+ and CD206 negative lesions in Tilmanocept SPECT/CT before and after immunotherapy to determine any correlation between CD206 related uptake and treatment response.