Preclinical pharmacokinetics and localization studies of the radioiodinated anti-ovarian carcinoma MAb MOv18

The in vivo behavior of the monoclonal antibody (MAb) MOv18, with a restricted specificity for human ovarian carcinoma was analyzed on normal and tumor-bearing animals. The pharmacokinetics of the iodine-labeled MAb carried out in BALB/c mice fits an open two-compartment model. The t _{1 2} alpha was found not to be influenced by the different iodine isotopes used (¹²⁵I vs ¹³¹I) and by the time between labeling procedures and administration. The t _{1 2} beta were found to be longer after i.p. than i.v. administration and influenced by the time lapse between preparation and administration. A radiolocalization study was carried out in CD1 nu/nu mice bearing i.p. xenotransplant of the human ovarian carcinoma cell line IGROV1. Tumor/non tumor ratios were higher when the time between administration and sacrifice was short and, for ¹³¹I-MOv18, with a short interval between labeling and injection. Even if longer half lives were obtained using ¹²⁵I-MOv18 and i.p. administration a fairly rapid decrease in the values of the percentage of the injected dose per gram of tumor during the time was noted. These data indicate that this MAb could be considered a good candidate for radiotherapeutic approaches.