Comparison of five bifunctional chelate techniques for 90Y-labeled monoclonal antibody CO17-1A.

Monoclonal antibody CO17-1A was radiolabeled with 90Y by five bifunctional chelate techniques. Radiation absorbed dose estimates for normal organs and tumor were calculated for each preparation based on timed tissue distribution studies in nude mice bearing SW 948 human colorectal carcinoma xenografts. The cyclic DTPA anhydride technique was inferior to the four other techniques studied. Data for SCN-Bz-DTPA and SCN-Bz-Mx-DTPA, which were conjugated to epsilon-lysyl amino groups, were similar to those for NH2-Bz-DTPA and NH2-Bz-Mx-DTPA, which were conjugated site specifically to oligosaccharides.