BISPECIFIC MONOCLONAL ANTI-CA125 X ANTIPEROXIDASE ANTIBODIES IN THE MEASUREMENT OF THE OVARIAN-CARCINOMA ANTIGEN

The CA125 antigen is the most important tumor marker for the managemen t of ovarian cancer. It is a large glycoprotein aggregate in its nativ e form and the serum concentration is generally measured by a sandwich assay to provide valuable information on the clinical status of the o varian cancer patient. We had previously developed two monospecific mo noclonal antibodies B43.13 and B27.1, which react against non-overlapp ing epitopes of the CA125 antigen. In this report we describe the deve lopment of second generation bispecific monoclonal antibodies produced by fusing the anti-CA125 secreting hybridomas to an anti-horseradish peroxidase secreting hybridoma. The resulting hybrid-hybridomas or qua dromas were selected and the bispecific antibody purified to develop a sandwich assay. This assay exhibited superior characteristics in term s of kinetics, sensitivity and reproducibility when compared to the ra dioimmunoassay with monospecific reagents.