@article {Schoffelen1570, author = {Rafke Schoffelen and Robert Sharkey and William McBride and Gerben Franssen and Annemarie Eek and Winette van der Graaf and Wim Oyen and David Goldenberg and Otto Boerman}, title = {Pretargeted radioimmunotherapy effectively inhibits growth of subcutaneous colon carcinoma xenografts in nude mice}, volume = {50}, number = {supplement 2}, pages = {1570--1570}, year = {2009}, publisher = {Society of Nuclear Medicine}, abstract = {1570 Objectives The therapeutic efficacy of radioimmunotherapy is limited due to the long circulatory half-life of radiolabeled antibodies. Pretargeted radioimmunotherapy (PT-RAIT) with bispecific antibodies and a radiolabeled peptide could be more effective. In this study the therapeutic efficacy of PT-RAIT of colon cancer was determined in athymic mice with s.c. CEA-expressing tumors. Methods Groups of nine BALB/c nude mice with subcutaneous LS174T tumors were treated with TF2 (bispecific anti-CEA x anti-HSG antibody) and 177Lu-labeled IMP-288 (DOTA-Gly-Lys(HSG)-Tyr-Lys(HSG)-NH2) (26 MBq/mouse/cycle) or with carrier only. PT-RAIT was administered either in 1, 2, or 3 successive cycles, with an interval of 2 days. Primary endpoint was survival; secondary endpoints were tumor growth, bone marrow toxicity and kidney toxicity. Results PT-RAIT resulted in prolonged survival (median survival after treatments with 1, 2, and 3 cycles PT-RAIT and carrier-only: 24 (range 24-31), 45 (range 38-69), 65 (range 48-66) and 13 (range 6-20) days, with significant difference between all survival curves (P\<0.001), except for 2 cycles PT-RAIT compared to 3 cycles (P=0.22)). Bone marrow and kidney toxicity in the PT-RAIT groups was minimal. Conclusions This study suggests that PT-RAIT can be an effective treatment modality of colon cancer with limited toxicity.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/50/supplement_2/1570}, eprint = {https://jnm.snmjournals.org/content}, journal = {Journal of Nuclear Medicine} }