Preparation Of Clinical-Grade Zr-89-Panitumumab As A Positron Emission Tomography Biomarker For Evaluating Epidermal Growth Factor Receptor-Targeted Therapy

Panitumumab is a fully human monoclonal antibody approved for the treatment of epidermal growth factor receptor (EGFR) positive colorectal cancer. Recently, panitumumab has been radiolabeled with Zr-89 and evaluated for its potential to be used as immuno-positron emission tomography (PET) probe for EGFR positive cancers. Interesting preclinical results published by several groups of researchers have prompted us to develop a robust procedure for producing clinical-grade Zr-89-panitumumab as an immuno-PET probe to evaluate EGFR-targeted therapy. In this process, clinical-grade panitumumab is bio-conjugated with desferrioxamine chelate and subsequently radiolabeled with Zr-89 resulting in high radiochemical yield (>70%, n=3) and purity (>98%, n=3). All quality control (QC) tests were performed according to United States Pharmacopeia specifications. QC tests showed that Zr-89-panitumumab met all specifications for human injection. Herein, we describe a step-by-step method for the facile synthesis and QC tests of Zr-89-panitumumab for medical use. The entire process of bioconjugation, radiolabeling, and all QC tests will take about 5h. Because the synthesis is fully manual, two rapid, in-process QC tests have been introduced to make the procedure robust and error free. Copyright (c) 2013 John Wiley & Sons, Ltd.