Evaluation of 177Lu-CHX-A′′-DTPA-Bevacizumab as a radioimmunotherapy agent targeting VEGF expressing cancers

This study aimed at the preparation and evaluation of 177Lu-CHX-A′′-DTPA-Bevacizumab for targeting VEGF over-expressing cancers. Bevacizumab conjugated to p-NCS-Bn-CHX-A′′-DTPA was radiolabeled with 177Lu. The radioimmunoconjugate characterized by SE-HPLC exhibited radiochemical purity of 98.0±0.6%. In vitro stability was retained upto 4 days at 37 °C. In vitro cell binding studies showed good uptake by VEGF expressing U937 tumor cells. Biodistribution studies in melanoma model showed significant uptake and retention of 177Lu-CHX-A′′-DTPA-Bevacizumab in tumor with reduction in uptake in presence of cold Bevacizumab confirming its specificity to VEGF.