TY - JOUR
T1 - Improved tumor targeting and decreased normal tissue accumulation through extracorporeal affinity adsorption in a two-step pretargeting strategy
AU - Mårtensson, Linda
AU - Nilsson, Rune
AU - Ohlsson, Tomas G
AU - Sjögren, Hans Olof
AU - Strand, Sven-Erik
AU - Tennvall, Jan
PY - 2007
Y1 - 2007
N2 - Purpose: Evaluation of the possibilities of reducing the accumulation of radiolabeled streptavidin in radiosensitive organs by extracorporeal affinity adsorption (ECAT). Experimental Design: Rats were injected with biotinylated antibody and subjected to removal of the antibodies from the circulation by ECAT 24 h after injection (avidin column). Animals were then injected with In-111-1,4,7,10-tetra-azacylododecane N,N',N '',N'''-tetraacetic acid (DOTA) streptavidin. In a third step, animals were subjected to a second ECAT 8 h after injection to remove the DOTA-streptavidin from the circulation (biotin column). Biodistribution and tumor targeting of DOTA-streptavidin 24 h after injection was determined. Results: Elimination of biotinylated antibody by ECAT before injection of DOTA-streptavidin increased the tumor targeting by 50%. In addition, the levels of DOTA-streptavidin in liver and lymph nodes were reduced by 60%, which implied a 4.3- and 3.8-fold increase of tumor-to-liver and tumor-to-lymph node ratios, respectively. By doing a second ECAT to remove DOTA-streptavidin from the circulation, accumulation in normal tissues was reduced. However, this latter ECAT also reduced tumor accumulation by 25% (mostly corresponding to radioactivity in the circulation). Conclusions: ECAT was efficient as a means of removing biotinylated antibodies and would probably also be efficient for the clearance of streptavidin-conjugated antibodies. Conversely, the use of ECAT for removal of radiolabeled streptavidin seems not to offer any advantage.
AB - Purpose: Evaluation of the possibilities of reducing the accumulation of radiolabeled streptavidin in radiosensitive organs by extracorporeal affinity adsorption (ECAT). Experimental Design: Rats were injected with biotinylated antibody and subjected to removal of the antibodies from the circulation by ECAT 24 h after injection (avidin column). Animals were then injected with In-111-1,4,7,10-tetra-azacylododecane N,N',N '',N'''-tetraacetic acid (DOTA) streptavidin. In a third step, animals were subjected to a second ECAT 8 h after injection to remove the DOTA-streptavidin from the circulation (biotin column). Biodistribution and tumor targeting of DOTA-streptavidin 24 h after injection was determined. Results: Elimination of biotinylated antibody by ECAT before injection of DOTA-streptavidin increased the tumor targeting by 50%. In addition, the levels of DOTA-streptavidin in liver and lymph nodes were reduced by 60%, which implied a 4.3- and 3.8-fold increase of tumor-to-liver and tumor-to-lymph node ratios, respectively. By doing a second ECAT to remove DOTA-streptavidin from the circulation, accumulation in normal tissues was reduced. However, this latter ECAT also reduced tumor accumulation by 25% (mostly corresponding to radioactivity in the circulation). Conclusions: ECAT was efficient as a means of removing biotinylated antibodies and would probably also be efficient for the clearance of streptavidin-conjugated antibodies. Conversely, the use of ECAT for removal of radiolabeled streptavidin seems not to offer any advantage.
U2 - 10.1158/1078-0432.CCR-07-0891
DO - 10.1158/1078-0432.CCR-07-0891
M3 - Article
C2 - 17875791
SN - 1078-0432
VL - 13
SP - 5572S-5576S
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 18
ER -