Comparative biodistributions of yttrium- and indium-labeled monoclonal antibody B72.3 in athymic mice bearing human colon carcinoma xenografts.
The biodistribution of yttrium- and indium-labeled monoclonal antibody (MAb) B72.3 IgG using three different chelate conjugates (SCN-Bz-EDTA, CA-DTPA, and SCN-Bz-DTPA) was compared in athymic mice bearing LS-174T tumors. The 88Y-SCN-Bz-DTPA-B72.3 yielded 40% ID/g at 5-7 days in the tumors, while the 88Y-SCN-Bz-EDTA-B72.3 and 88Y-CA-DTPA-B72.3 showed only 6-8% ID/g. The yttrium uptake in the bone with the SCN-Bz-EDTA and CA-DTPA conjugated IgG was over 14 and 11% ID/g, respectively, while 88Y-SCN-Bz-DTPA-B72.3 showed only 3% ID/g. In contrast, the 111In-labeled B72.3 uptake in the bone with all three chelate conjugates was 2-3% ID/g. The differences in yttrium- versus indium-labeled MAb biodistributions demonstrate the difficulty in using 111In-labeled MAbs to predict the biodistribution and dosimetry of 90Y-labeled MAbs unless chelate conjugates such as SCN-Bz-DTPA are used.
Roselli
M
M
Laboratory of Tumor Immunology and Biology, National Cancer Institute, Bethesda, Maryland 20892.
Schlom
J
J
Gansow
O A
OA
Raubitschek
A
A
Mirzadeh
S
S
Brechbiel
M W
MW
Colcher
D
D
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism* / Q000627:therapeutic use; D002277:Carcinoma / Q000378:metabolism* / Q000532:radiotherapy; D002614:Chelating Agents / Q000493:pharmacokinetics / Q000627:therapeutic use; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000532:radiotherapy; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism / Q000627:therapeutic use; D000922:Immunotoxins / Q000378:metabolism* / Q000627:therapeutic use; D007205:Indium Radioisotopes / Q000378:metabolism* / Q000627:therapeutic use; D051379:Mice; D008819:Mice, Nude / Q000378:metabolism*; D009368:Neoplasm Transplantation; D014018:Tissue Distribution; D014183:Transplantation, Heterologous; D015021:Yttrium Radioisotopes / Q000378:metabolism* / Q000627:therapeutic use
D000911:Antibodies, Monoclonal; D002614:Chelating Agents; D007074:Immunoglobulin G; D000922:Immunotoxins; D007205:Indium Radioisotopes; D015021:Yttrium Radioisotopes