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Comparative tumor localization of whole immunoglobulin g anticarcinoembryonic antigen monoclonal antibodies immu‐4 and immu‐4 f(ab′) 2 in colorectal cancer patients
Author(s) -
Murray James L.,
Rosenblum Michael G.,
Zhang HuaZhong,
Podoloff Donald A.,
Kasi Leela P.,
Curley Steven A.,
Chan James C.,
Roh Mark,
Hohn David C.,
Brewer Hannah,
Cunningham Joan E.,
Thompson Lora B.,
Bhadkamkar Viju,
Pinsky Carl M.,
Fogler William E.
Publication year - 1994
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/1097-0142(19940201)73:3+<850::aid-cncr2820731316>3.0.co;2-s
Subject(s) - medicine , antibody , lymph node , colorectal cancer , monoclonal antibody , cancer , antigen , lymph , pathology , immunology
Background . Previous studies in the literature have suggested that radiolabeled F(ab′) 2 fragments might be superior to whole immunoglobulin G (IgG) for imaging and therapy of cancer because of their greater penetration in tumors. To test this hypothesis, the authors compared tumor and normal tissue uptake along with plasma clearance of 125 I‐labeled monoclonal antibody (MoAb) IMMU‐4 whole IgG with its 131 I‐labeled F(ab′) 2 fragment. Methods . Five patients with either liver metastases from colorectal cancer (n = 4) or intact primary tumors (n = 1) received a combination of 125 I‐IMMU‐4 IgG (2 mCi/1 mg) plus 131 I‐IMMU‐4 F(ab′) 2 (10 mCi/1 mg) as a single 1‐hour intravenous infusion on day 1. Serial blood samples were taken for up to 72 hours postinfusion to determine plasma clearance of each MoAb. On days 3–9, patients underwent exploratory laparotomy in which biopsies of tumor as well as normal tissues (liver, normal colon, lymph node, and blood) were obtained. Tissues were weighed and counted in a gamma counter, and the percent of injected dose per kilogram (%ID/kg) of each antibody, along with the radiolocalization index (RI), was computed (RI = %ID/kg tumor. %ID/kg normal tissue). Results . Tumor uptake of both antibodies (2.3 ± 0.53 %ID/kg) was significantly higher than that of normal tissues (0.56 ± 0.12; P < 0.001), except for blood (2.8 ± 0.83), resulting in an RI ≥ 3. There were no significant differences in uptake (%ID/g) between F(ab′) 2 and IgG (F[ab′] 2 = 2.0 ± 0.57; IgG = 2.6 ± 0.94). The mean ± SD of plasma T½ was slightly shorter for F(ab′) 2 (28.8 ± 7.2 hours) than for IgG (45.9 ± 16.7; P = 0.08). Conclusion . In short, the biodistribution and pharmacokinetics of IMMU‐4 F(ab′) 2 were comparable to those of IMMU‐4‐IgG. Cancer 1994; 73:850–7.