Comparison of fresh tissue incubation assay and the in vivo localization of monoclonal antibodies to renal cell carcinoma

Biodistribution of monoclonal antibody A7 and its F(ab')2 fragment in athymic nude mice bearing human pancreatic carcinoma

Xenografts of a human pancreatic carcinoma cell line, HPC-YS, which reacted with the monoclonal antibody (MAb) A7, were used to investigate the in vivo localization of radioiodinated MAb A7 after intraperitoneal injection. MAb A7 localized to the tumor 4 days and 8 days after injection with a tissue/blood ratio of 1.45 +/- 0.18 and 2.04 +/- 0.20, respectively. The accumulation of MAb A7 in the tumor was 5%/g and 3.3%/g of the injected dose on day 4 and on day 8, respectively. In contrast, the F(ab')2 fragment of MAb A7 localized to the tumor 4 days after intravenous injection with a tissue/blood ratio of 14.2. The accumulation of the F(ab')2 fragment in the tumor was 1.2%/g of the injected dose. These results suggested that MAb A7 might be a suitable carrier of anticancer drugs for immunotargeting chemotherapy and that the F(ab')2 fragment might be potentially useful for the immunodetection of human pancreatic carcinomas.

Rationale for immunotherapy of renal cell carcinoma

Metastasis to distant organs is the principal cause of death from renal cell carcinoma (RCC). No commonly accepted therapy is available for disseminated RCC at present. Immunotherapy is a mode of therapy that either interferes with the immune system or makes use of drugs that have been derived from soluble mediators of the immune system. Several lines of evidence suggest that combinations of genetically engineered cytokines (e.g. interleukin-2 and interferon alpha) may be particularly active in the treatment of advanced RCC. There are two major rationales for considering immunotherapy for RCC: (1) there is currently no other therapy available, and (2) there is hardly any innovative approach besides immunotherapy. Still, immunotherapy is far from being a standard therapy for disseminated RCC.