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

Few in vitro tests currently available are able to accurately predict the in vivo localization of monoclonal antibodies (Mabs) to cancer. We report on a fresh tissue incubation assay (FTIA) and compare the results of this assay to the in vivo localization of renal cell carcinoma (RCC)-reactive Mab A6H and control Mab AFP-22 to RCC and non-RCC xenografts implanted in nude mice. Both the FTIA and in vivo localization study demonstrated highly selective uptake of A6H in RCC but not in non-RCC xenografts. Radioimmunoscintigraphy using A6H clearly visualized RCC xenografts in every attempt, while AFP-22 did not highlight any of the tumor xenografts. The results demonstrate that FTIA may be a useful in vitro assay for selecting Mabs for in vivo application, and that radioimmunoscintigraphy is a potentially useful tool in detecting cancer sites