Ribosomal inhibiting protein-immunoglobulin conjugates with specificity for tumor cell surface antigens, and mixtures thereof

A pharmaceutical composition comprising an immunotoxin consisting essentially of a ribosomal inhibiting toxin conjugated to a monoclonal antibody that binds to an epitone on a carcinoembryonic antigen of about 180 kD m.w. present on human colon carcinoma cells, and which has the binding specificity of antibodies produced by hybridoma XMMCO-228 having A.T.C.C. Accession No. HB 9174.

A cytotoxic therapeutic cocktail comprising a mixture of:

• a first immunotoxin consisting essentially of a ribosomal inhibiting toxin conjugated to a monoclonal antibody that binds to an epitope on a non-shedding human osteogenic sarcoma tumor associated antigen of about 72 kD m.w., which has the binding specificity of antibodies produced by hybridoma XMMCO-791 having A.T.C.C. Accession No. HB 9173;
• and
• a second immunotoxin consisting essentially of a ribosomal inhibiting toxin conjugated to monoclonal antibody that binds to an epitope on a carcinoembryonic antigen of 180 kD m.w. present on human colon carcinoma cells, and which has the binding specificity of antibodies produced by hybridoma XMMCO-228 having A.T.C.C. Accession No. HB 9174.

Hybridoma XMMCO-228 having A.T.C.C. Accession No. HB 9174 which produces an immunoglobulin that defines an epitope on carcinoembryonic antigen.