Tumour localization using monoclonal antibodies. II. Biodistribution of A5B7/111indium chelates.

The anti-CEA antibody A5B7 has been conjugated with the chelating agents DTPA and DHDE. Radioimmunoassay and FPLC studies have shown that the conjugation procedure has not impaired the CEA binding ability of the antibody or induced aggregate formation. Biodistributions of the 111In-labelled conjugates have been carried out in nude mice bearing the human colon carcinoma xenograft LS174T. The results show favourable tumour-to-tissue ratios for the DTPA conjugate.