Therapeutic efficacy as defined by a serodiagnostic test utilizing a monoclonal antibody
DU-PAN-2 is a high molecular weight glycoprotein defined by a murine monoclonal antibody elicited to a pancreatic ductal adenocarcinoma cell line. This monoclonal antibody recognizes an oncofetal antigen present on the surface of pancreatic tumor cells. The antigen has also been detected in the sera of patients with adenocarcinoma of the pancreas by a competition radioimmunoassay (RIA). Ninety-four per cent (31/33) of patients with pancreatic adenocarcinoma in this study had DU-PAN-2 serum antigen levels greater than 300 units/ml by RIA, whereas sera from normal adults had serum levels less than 300 units/ml. Serial studies of DU-PAN-2 serum antigen in pancreatic cancer patients with elevated DU-PAN-2 serum levels (mean: 2873 units/ml) and surgically resectable neoplasms demonstrated a return to the normal range within 1 to 3 weeks after surgery in five of six patients. Five patients in clinical remission had normal DU-PAN-2 serum levels (mean: 110 units/ml). With tumor progression, however, the DU-PAN-2 level increased in all patients (mean: 2835 units/ml) an average of 2 months before evidence of progressive disease by clinical parameters. Serial DU-PAN-2 determinations are sensitive monitors of the progression of pancreatic cancer and may be useful as early indicators of response to therapy.