Experimental Immunotherapy of Colorectal Carcinoma by Monoclonal Antibody ND4

Abstract

The potential for experimental immunotherapy of colorectal cancers by mouse IgG2a monoclonal antibody (MAb) ND4 is investigated. The MAb ND4 recognizes a 160 kd cell surface glycoprotein that is strongly expressed in 58% of colorectal carcinomas. The antibody is internalizable by MIP-101 colorectal carcinoma cells. Biodistribution studies in nude mice bearing MIP-101 subcutaneous tumors showed accumulation of ¹²⁵I-ND4 MAb in tumors from 5% at 18 hours to 14% of the injected dose per gram tissue at 14 days after intraperitoneal (IP) injection. Experimental immunotherapy studies using ¹²⁵I-ND4 in MIP-101 tumor-bearing nude mice showed 64% inhibition of tumor growth 2 weeks after two IP injections at 7-day intervals. The MAb ND4 may be useful as a therapeutic reagent for colorectal tumors.