Antiangiogenic monoclonal antibodies in combination with therapeutic radionuclides are potential targeted therapy agents in
cancer. In this study, bevacizumab was successively labeled with [166Ho]HoCl3 after conjugation with DOTA-NHS-ester with a radiochemical purity of higher than 95% (RTLC). The conjugates were purified
by molecular filtration, the average number of DOTA conjugated per mAb was calculated and total concentration was determined
by spectrophotometric method and the average chelate to antibody ratio (c/a) for the conjugate used in this study was 5.8:1
and protein integrity experiments (SDS-PAGE). The biodistribution studies in wild-type rats demonstrate a similar pattern
to the other radiolabeled anti-vascular endothelial growth factor A (VEGF-A) immunoconjugates. 166Ho-DOTA-bevacizumab is a potential compound for therapy/imaging of VEGF-A expression in oncology.