Specific imaging of VEGF-A expression with radiolabeled anti-VEGF monoclonal antibody

Contains fulltext : 70965.pdf (Publisher’s version ) (Closed access) Vascular endothelial growth factor-A (VEGF-A) is one of the most important angiogenic factors. Here, we studied in a nude mouse model whether the expression of VEGF-A in a tumor could be imaged with a radiolabeled anti-VEGF antibody. The humanized anti-VEGF-A antibody A.4.6.1. (bevacizumab), which is reactive with all VEGF-A isoforms, was radiolabeled with In-111 or with I-125. The accumulation of the radiolabeled antibodies in VEGF-A expressing tumors (LS174T) in nude mice was examined in biodistribution studies and by gamma camera imaging. The uptake of the In-111-bevacizumab in the tumor at 3 days p.i. was significantly higher than that of I-125-bevacizumab (19.4 +/- 7.0 %ID/g vs. 9.6 +/- 3.3 %ID/g, p = 0.04). Coinjection of an excess unlabeled antibody resulted in a significant decrease in radioactivity concentration in the tumor (