Development of 90 Y-DOTA-nimotuzumab Fab fragment for radioimmunotherapy

Yttrium-90-(90Y) labeled monoclonal antibodies prepared with a chelating agent, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), have been used for radioimmunotherapy of cancer. In the present work, the Fab fragment of anti-EGFR monoclonal antibody nimotuzumab was prepared with high purity, integrity and biological activity. The Fab fragment with high specific recognition of EGFR in NCI-H125 human lung adenocarcinoma cells was derivatized with DOTA-NHS applying a simple procedure. DOTA-nimotuzumab Fab fragment was successfully radiolabeled with 90Y with high radiochemical yield. The in vitro stability of labeled product was optimal over 24 h in buffered solution at 37 °C. Biodistribution and pharmacokinetic studies correctly evaluated the in vivo non-tumor uptake, dosage regimen and excretion pathway in normal Wistar rats.