Comparison of seven iodine-labelled monoclonal antibodies in nude mice with human colon carcinoma xenografts.
The biokinetics of seven 131I-labelled monoclonal antibodies (MAbs), directed against human colon carcinoma and one 125I-labelled unspecific MAb have been examined. The study in nude mice, carrying human colon carcinoma, was intended to be a step in the selection of the most suitable antibody for clinical scintigraphy. The biological half-life in blood was found to be between 1.3 and 7.4 days for the different MAbs. Chromatography of plasma samples showed that the radioiodine was mainly bound to IgG-sized molecules. The (normal tissue)/blood ratios were similar for all the MAbs. The tumour/blood ratio was 0.41 for the unspecific MAb and 0.49-1.1 for the specific MAbs, and the tumour/muscle ratio was between 3.2 and 6.8 for the specific MAbs 6 days after injection. For one MAb tumour/blood and tumour/muscle ratios were 3.9 and 9.8 respectively 9 days after injection. Localization indices were at their highest 2.6 6 days after injection. For at least two of the monoclonal antibodies the tumour/blood and tumour/muscle ratios found are high enough to justify clinical trials regarding their usefulness for scintigraphy of colon cancer in man.
Forssell Aronsson
E
E
Department of Radiation Physics, University of Göteborg, Sahlgrenska Hospital, Sweden.
Grétarsdóttir
J
J
Jacobsson
L
L
Mattsson
S
S
Holmberg
S B
SB
Hafström
L O
LO
Karlsson
B
B
Lindholm
L
L
D000230:Adenocarcinoma / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics*; D003110:Colonic Neoplasms / Q000378:metabolism*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes