Preparation and evaluation of Re-labeled antibody (A7) for radioimmunotherapy with rhenium(I) tricarbonyl core as a chelate site

Ogawa, Kazuma*; Kawashima, Hidekazu*; Kinuya, Seigo*; Shiba, Kazuhiro*; Onoguchi, Masahisa*; Kimura, Hiroyuki*; Hashimoto, Kazuyuki; Odani, Akira*; Saji, Hideo*

Annals of Nuclear Medicine, 23(10), p.843 - 848, 2009/12

https://doi.org/10.1007/s12149-009-0319-4

Rhenium is one of the most valuable elements for internal radiotherapy because Re have favorable physical characteristics. However, there are problems when proteins such as antibodies are used as carriers of Re. Labeling methods require the complicated processes. Therefore, we planned the preparation by a simple method and evaluation of a stable Re-labeled antibody. For this purpose, we selected Re(I) tricarbonyl complex as a chelating site. A7 was used as a model protein. Re-labeled A7 was prepared by directly reacting a Re(I) tricarbonyl precursor with A7. Re-(CO)-A7 were prepared with radiochemical yields of 23-28%. After purification, Re-(CO)-A7 showed a radiochemical purity of over 95%. In biodistribution experiments, Re-labeled A7 showed high uptakes in the tumor.