Study of CAP1-6D in Patients With Locally Advanced or Surgically Resected Pancreatic Adenocarcinoma

PC has a dismal prognosis. Despite surgery, chemotherapy, and radiation, most patients with PC will die of distant metastatic disease. Peptide vaccine approaches offer an attractive potential treatment option. Since CEA is expressed in \>90% of PC, it would make an attractive target for a vaccination approach. Several different vaccination approaches have been tested using CEA as a TAA. Although some investigators suggest that DC-based approaches are the most active, they are limited by the need to obtain patient-specific DCs. One attractive approach would be to add GM-CSF to the peptide to recruit endogenous DC to the site of vaccination. There are data on the use of tumor vaccines in advanced PC. Gjerertsen et al. used a K Ras peptide and GM-CSF in 48 patients with advanced PC. 50% of patients showed a peptide specific CTL response (Gjertsen, Buanes et al. 2001). Those that had an immune response had an increased overall survival, The data from phase I and II clinical trials was based on heavily pretreated patients with metastatic disease. The majority of clinical responses have been disease stabilization. The data in B cell lymphoma vaccines suggests that immune responses are more likely to be generated in minimum disease states (Bendandi, Gocke et al. 1999). For patients that have had a complete resection and treatment with adjuvant chemoradiation, and for patients with locally advanced nonresectable disease treated with standard chemoradiation, there is presently no therapy available to decrease the chance of disease reoccurrence. Our hypothesis is that immunization with a modified CEA peptide in Montanide/GM-CSF can lead to expansion of CEA-reactive CTL and result in control of CEA expressing pancreatic carcinomas.