Zirconium Zr 89-DFO-YS5

**Zirconium Zr 89-DFO-YS5** is a CD46-targeted immunoPET radiopharmaceutical also known as FG-3180. It consists of the human anti-CD46 IgG1 monoclonal antibody YS5 conjugated to desferrioxamine and radiolabeled with zirconium-89. Following intravenous administration, it binds a tumor-selective CD46 epitope and accumulates in CD46-expressing lesions, enabling PET-based visualization, lesion detection, biodistribution assessment, and dosimetry rather than direct antitumor treatment. The agent is being clinically evaluated in CD46-positive multiple myeloma and metastatic castration-resistant prostate cancer, including as a potential imaging biomarker to support CD46-directed therapy selection. ([cancer.gov](https://www.cancer.gov/research/participate/clinical-trials-search/v?id=NCI-2023-04068))

Other names

89Zr-DFO-YS5Zirconium Zr 89-DFO-YS5[89Zr]DFO-YS5[89Zr]Zr-DFO-YS5