[89Zr]Zr-DFO-R8B4

[89Zr]Zr-DFO-R8B4 is a zirconium-89-labeled monoclonal antibody-based radiopharmaceutical designed for immunoPET imaging. The compound consists of the R8B4 monoclonal antibody conjugated to the chelator desferrioxamine (DFO), which securely binds the positron-emitting radionuclide zirconium-89 ([89Zr]). This agent is administered intravenously and used in immunoPET/CT imaging to noninvasively visualize and quantify CD70-expressing malignant tumors in patients. The long half-life of zirconium-89 (approximately 78.4 hours) allows for optimal imaging windows that match the pharmacokinetics of antibodies, enabling high-sensitivity detection of tumor lesions over several days post-injection. In clinical studies, patients receive a single dose (1–3 mCi; 1–2 mg antibody mass) followed by multiple PET/CT scans to assess biodistribution and tumor targeting[9]. The primary indication under investigation is cancer diagnosis through molecular imaging.