Specific in vitro and in vivo drug localisation to tumour cells using a hybrid-hybrid monoclonal antibody recognising both carcinoembryonic antigen (CEA) and vinca alkaloids.

By using a bispecific monoclonal antibody recognising both carcinoembryonic antigen (CEA) and the cytostatic vinca alkaloid drugs we have been able to show specific tumour localisation of vinca alkaloids. In vitro studies with sections of human colorectal tumours have demonstrated that the hybrid-hybrid 28.19.8 monoclonal is able to specifically localise vindesine to cells expressing CEA. Furthermore, the hybrid-hybrid 28.19.8 localises in vivo preferentially to tumour tissues in nude mice bearing the MAWI human xenograft tumour. This tumour-bound hybrid-hybrid monoclonal antibody induces profound changes in the bio-distribution of vinca alkaloid drugs, targeting them specifically to tumour tissues.