Nanobody-Based Pet/Ct Imaging Of Her2 Expression In Breast Carcinoma: Phase I Results And Potential To Assess Tumor Heterogeneity.

e11600 Background: A first-in-human study of 68GaNOTA-Anti-HER2 Nanobody for PET/CT imaging of HER2 expression in breast carcinoma has been completed. Nanobodies are the smallest antigen-binding antibody-fragments derived from heavy-chain-only antibodies. They offer ideal characteristics for imaging: fast blood clearance, high stability, easy labeling. Objectives: Primary: safety, human biodistribution and dosimetry. Secondary: tumor uptake in HER2-expressing lesions. Methods: Anti-HER2 nanobody was labeled with 68Ga via a NOTA derivative. In total, 20 female patients with primary or metastatic breast carcinoma (HER2 IHC 2+ or 3+) were included. Radioactive dose range was 53-174 MBq (average 107 MBq). Patients underwent 3 PET/CT scans (for dosimetry assessment) at 10, 60 and 90 min post administration. Physical evaluation and blood analysis were performed for safety evaluation. Biodistribution was analyzed for 10 organs using MIM software; dosimetry was assessed using OLINDA/EXM. Results: No related adver...