Localization of the monoclonal antibody HMFG2 after intravenous and intraperitoneal injection into nude mice bearing subcutaneous and intraperitoneal human ovarian cancer xenografts.

Xenografts (s.c. and i.p.) of human ovarian cancer, shown to express the tumor associated antigen defined by the monoclonal antibody HMFG2, were used to investigate in vivo localization of the radioiodinated antibody after i.p. and i.v. injection. Following i.v. injection, maximum uptake (31.4 +/- 3.5%/g s.c. tumor) was seen in s.c. tumors at 48 h after injection. Tumor:normal tissue ratios increased with time to 240 h. Uptake by ascites and i.p. tumors was less, with a maximum of 10.0 +/- 8%/g ascites reached at 16 h and 11.4 +/- 3.2%/g i.p. tumor at 96 h. After i.p. injection uptake in s.c. xenografts was maximal (14.8 +/- 2.0%/g) at 20 h. For ascites, the i.p. route of administration resulted in high uptake (27.7 +/- 5.8%/g) early (2 h) with an ascites:normal tissue ratio of 69.3 and a specific antibody:nonspecific antibody ratio of 30.8. Except for data at one time point, uptake by i.p. solid tumor was similar to that seen for s.c. tumor. These data strongly suggest that large concentration advantages can be achieved in ascites cells by regional i.p. injection, but that i.p. solid tumor may rely on i.v. delivery of antibody before uptake.