Experimental tumoricidal effects of monoclonal antibody against solid breast tumors.

Two distinct monoclonal antibodies (mAbs) were effective in the therapy of breast carcinomas of human origin established and growing in nude mice. Passive administration of either of the antibodies produced very rapid (less than 1 week) and significant reduction of in vivo tumor volume. Each of the mAbs showed in vivo targeting of the tumors. Histological analysis of mAb-treated tumors revealed extensive cellular necrosis. Each of the antibodies in vitro was effective in complement-mediated cytolysis at a concentration less than 1 ng/ml. The tumoricidal responses show that this is a useful model for passive human immunotherapy using mAbs.