Radioiodinated iodobenzoyl conjugates of a monoclonal antibody Fab fragment. In vivo comparisons with chloramine-T-labeled Fab.
A comparative investigation of the biodistributions of radioiodinated p- and m-iodobenzoyl conjugates of a monoclonal antibody Fab fragment, NR-LU-10 Fab, and the same antibody Fab fragment radioiodinated by the chloramine-T (ChT) method has been carried out in mice. Coinjected, dual-isotope studies in athymic mice with tumor xenografts have demonstrated that there are only minor differences in the in vivo distributions of the iodobenzoyl-labeled Fabs, except in the excretory organs, kidneys, and intestines, where major differences were observed. Similarly, coinjection of either the p-iodobenzoyl or m-iodobenzoyl conjugate of NR-LU-10 Fab with the Fab radioiodinated with ChT/radioiodide into BALB/c mice provided additional data that indicated that the two iodobenzoyl conjugates distributed similar in a number of selected tissues. The tissue-distribution differences of the regioisomeric iodobenzoyl conjugates in relation to the ChT-radioiodinated Fab were large for the stomach and neck, consistent with previous studies. The most notable difference between the two iodobenzoyl conjugates was the kidney activity, where the m-iodobenzoyl conjugate was similar to the directly labeled Fab, but the p-iodobenzoyl-conjugated Fab was higher by nearly a factor of 2.
Wilbur
D S
DS
NeoRx Corporation, Seattle, Washington 98119.
Hadley
S W
SW
Grant
L M
LM
Hylarides
M D
MD
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000493:pharmacokinetics; D002700:Chloramines / Q000737:chemistry / Q000276:immunology* / Q000493:pharmacokinetics; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000493:pharmacokinetics; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007462:Iodobenzenes / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D014018:Tissue Distribution; D014105:Tosyl Compounds
D000911:Antibodies, Monoclonal; D002700:Chloramines; D007140:Immunoglobulin Fab Fragments; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D014105:Tosyl Compounds; C016300:chloramine-T