Novel compositions and methods are provided for the treatment of cancer employing monoclonal antibodies (MoAbs) conjugated to a toxin. According to the present invention, MoAbs defining epitopes on either a tumor associated glycoprotein antigen of about 72 kD m.w. or on carcinoembryonic antigen conjugated to a ribosomal inhibiting protein, or the like, are employed either alone or in combination as cytotoxic agents in the treatment of various cancers including, but not limited to, colorectal carcinoma, ovarian carcinoma and osteogenic sarcoma. For some of these compositions, an enhanced or potentiated efficacy is observed when the conjugates are administered along with a related, unconjugated monoclonal antibody.
Hybridomas XMMCO-791 and XMMCO-228 were deposited with the A.T.C.C. on Aug. 14, 1986 and given A.T.C.C. Accession Nos. HB 9173 and HB 9174, respectively. Hybridoma XMMBR-B14 was deposited with the A.T.C.C. on Jan. 14, 1987 and given A.T.C.C. Accession No. HB 9308.