UNLABELLED: A33, a monoclonal antibody that targets colon carcinomas, was labeled with (125)I or (131)I and the relative therapeutic efficacy of the 2 radiolabeled species was compared in a human colon cancer xenograft system. METHODS: Nude mice bearing human SW1222 colon carcinoma xenografts were administered escalating activities of (125)I-A33 (9.25-148 MBq) or (131)I-A33 (0.925-18.5 MBq), (125)I- and (131)I-labeled control antibodies, unlabeled antibody, or no antibody. The effects of treatment were assessed using the endpoints of tumor growth delay and cure. RESULTS: Tumor growth delay increased with administered activity for all radiolabeled antibodies. Approximately 4.5 times more activity was required for (125)I-A33 to produce therapeutic effects that were equivalent to those of (131)I-A33. This ratio was approximately 7 for a nonspecific, noninternalizing isotype-matched, radiolabeled control antibody. Unlabeled A33 antibody had no effect on tumor growth. Approximately 10 times more activity of (125)I-A33 produced toxicity similar to that of (131)I-A33, and this ratio fell to approximately 6 for radiolabeled control antibody. CONCLUSION: Treatment with (125)I-A33 resulted in a relative therapeutic gain of approximately 2 compared with (131)I-A33 in this experimental system.
UNLABELLED: A33, a monoclonal antibody that targets colon carcinomas, was labeled with (125)I or (131)I and the relative therapeutic efficacy of the 2 radiolabeled species was compared in a humancolon cancer xenograft system. METHODS:Nude mice bearing human SW1222 colon carcinoma xenografts were administered escalating activities of (125)I-A33 (9.25-148 MBq) or (131)I-A33 (0.925-18.5 MBq), (125)I- and (131)I-labeled control antibodies, unlabeled antibody, or no antibody. The effects of treatment were assessed using the endpoints of tumor growth delay and cure. RESULTS:Tumor growth delay increased with administered activity for all radiolabeled antibodies. Approximately 4.5 times more activity was required for (125)I-A33 to produce therapeutic effects that were equivalent to those of (131)I-A33. This ratio was approximately 7 for a nonspecific, noninternalizing isotype-matched, radiolabeled control antibody. Unlabeled A33 antibody had no effect on tumor growth. Approximately 10 times more activity of (125)I-A33 produced toxicity similar to that of (131)I-A33, and this ratio fell to approximately 6 for radiolabeled control antibody. CONCLUSION: Treatment with (125)I-A33 resulted in a relative therapeutic gain of approximately 2 compared with (131)I-A33 in this experimental system.
Authors: Sarah M Cheal; Edward K Fung; Mitesh Patel; Hong Xu; Hong-Fen Guo; Pat B Zanzonico; Sebastien Monette; K Dane Wittrup; Nai-Kong V Cheung; Steven M Larson Journal: J Nucl Med Date: 2017-07-13 Impact factor: 10.057
Authors: Sai Kiran Sharma; Serge K Lyashchenko; Hijin A Park; Nagavarakishore Pillarsetty; Yorann Roux; Jiong Wu; Sophie Poty; Kathryn M Tully; John T Poirier; Jason S Lewis Journal: Nucl Med Biol Date: 2019-05-03 Impact factor: 2.408
Authors: Lawrence T Dauer; Daniel C Boylan; Matthew J Williamson; Jean St Germain; Steven M Larson Journal: Health Phys Date: 2009-05 Impact factor: 1.316
Authors: Sarah M Cheal; Hong Xu; Hong-Fen Guo; Sang-Gyu Lee; Blesida Punzalan; Sandhya Chalasani; Edward K Fung; Achim Jungbluth; Pat B Zanzonico; Jorge A Carrasquillo; Joseph O'Donoghue; Peter M Smith-Jones; K Dane Wittrup; Nai-Kong V Cheung; Steven M Larson Journal: Eur J Nucl Med Mol Imaging Date: 2015-11-24 Impact factor: 9.236