S. Kinuya et al., Experimental radioimmunotherapy with Re-186-MAG3-A7 anti-colorectal cancermonoclonal antibody: Comparison with I-131-counterpart, ANN NUCL M, 15(3), 2001, pp. 199-202
A murine IEG(1) against a Mr 45 kD tumor-associated glycoprotein in human c
olorectal cancer, A7, was radiolabeled with Re-186 by a chelating method wi
th a mercaptoacetyltriglycine (MAG3). Its specific activity was 119 MBq/mg,
which would be high enough for a therapeutic purpose, and its immunoreacti
vity was preserved well as was I-131-A7 labeled by the chloramine-T method.
Growth of human colon cancer xenografts, 9.14 +/- 0.44 mm in diameter, in
nude mice was significantly suppressed by an intravenous dose of 4.48 MBq o
f Re-186-A7. The therapeutic outcome with (186)ReA7 was better than that wi
th 4.63 MBq of I-131-A7. Toxicity of treatments assessed by body weight cha
nge was similar with both conjugates. These results are likely caused by th
e tumor size and more favorable physical properties of Re-186 than those of
I-131.