Enhanced radioimmunotherapeutic efficacy of a monoclonal antibody cocktail against SMMC-7721 human hepatocellular carcinoma.

ABSTRACT

The improved tumoricidal effect of the radioantibody mixture ("cocktail") has been reported recently for the treatment of colon tumor. In the present study, we demonstrated the enhanced radioimmunotherapeutic efficacy of a monoclonal antibody (MAb) cocktail against human hepatocellular carcinoma. Therapeutic efficacy was determined by measuring the change in tumor size over a period, determining the percentage of growth inhibition of each treatment at various times after radioantibody therapy. Radioimmunotherapy of SMMC-7721 human hepatoma xenografts in athymic nude mice with combination of 131I-labeled Hepama-1 and 131I-labeled 9403 mouse MAbs was more effective than using either Hepeam-1 or 9403 MAb alone The MAb cocktail could target a greater number of hepatoma cells and increase the magnitude of hepatoma cell uptake of radioantibodies. The in vitro results explain the enhanced effect of the MAb cocktail in in vivo model system.