A chimeric monoclonal antibody against human colorectal and pancreatic carcinoma-associated antigens (CPAAs) with potential immunomodulating and anti-tumor activities. Ensituximab binds to CPAAs, which may activate the immune system to exert a cytotoxic T-lymphocyte (CTL) response and an antibody-dependent cellular cytotoxicity (ADCC) response against CPAA-expressing tumor cells. CPAAs, cell surface proteins, are upregulated on colon and pancreatic tumor cells. Ensituximab contains the variable region of the heavy and light chain of murine NPC-1 and linked in-frame to constant regions of a human IgG1 isotype.