Monoclonal antibody F(ab')2 fragment labeled with N-succinimidyl 2,4-dimethoxy-3-halobenzoates: in vivo comparison of iodinated and astatinated fragments.
N-Succinimidyl 3-[211At]astato-2, 4-dimethoxybenzoate (SADMB) was prepared from a trialkylstannyl precursor in about 70-75% yield. With either trimethyl or tri-n-butylstannyl precursor, no temporal effect was found in the astatodestannylation yield. However, the methyl analog gave slightly better yield which was found to be not statistically significant. A monoclonal antibody (MAb) fragment, Mel-14 F(ab')2, could be labeled using SADMB in 28% coupling efficiency. The specific binding of this labeled fragment to tumor homogenates in vitro was 61.0 +/- 0.5% (62.8 +/- 0.9% for the 131I labeled fragment). Paired-label tissue distribution in normal mice showed similar uptake of 131I and 211 At in many tissues. However, by 14.5 h selectivity of spleen, lungs and stomach for Mel-14 F(ab')2 labeled with 211At compared to 131I was 4.1, 3.8 and 6.4, respectively.
Vaidyanathan
G
G
Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
Affleck
D
D
Zalutsky
M R
MR
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000493:pharmacokinetics; D001246:Astatine / Q000737:chemistry* / Q000493:pharmacokinetics; D001565:Benzoates / Q000737:chemistry* / Q000493:pharmacokinetics; D019817:Benzoic Acid; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry*; D007457:Iodine Radioisotopes / Q000737:chemistry* / Q000493:pharmacokinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D001565:Benzoates; D007140:Immunoglobulin Fab Fragments; D007457:Iodine Radioisotopes; D019817:Benzoic Acid; D001246:Astatine