Radioimmunotherapy of nude mice with intraperitoneally growing ovarian cancer xenograft utilizing At-211-labelled monoclonal antibody MOv18

The aim of this study was to investigate the therapeutic efficacy of At-211 -labelled monoclonal antibody given intraperitoneally to nude mice with int raperitoneal growth of a human ovarian cancer cell line. Female nude mice w ere inoculated intraperitoneally with I x 10(7) cells of the human ovarian cancer cell line NIH:OVCAR 3. After about two weeks they were injected with the At-211-labelled specific monoclonal antibody MOv18 intraperitoneally. For comparision, other groups of mice were given the same labelled antibody intravenously, At-211-labelled unspecific antibody C242 intraperitoneally or unalbelled MOv18 intraperitoneally. Six weeks later the animals were sac rificed and the occurrence of tumour and ascites was determined. When the m ice were treated with At-211-labelled MOv18 intraperitoneally 9 out of 10 w ere apparently free of both ascites and tumour compared to none of the mice given unlabelled antibody. At-211-labelled MOv18 given intravenously or At -211-labelled unspecific antibody given intraperitoneally were less effecti ve. Regional radioimmunotherapy with the alpa-emitter Astatine seems to be an effective treatment of nude mice with intraperitoneally growing human ov arian cancer. Hopefully this treatment can be given in an adjuvant setting to women with minimal residual ovarian cancer in the future.