Impact of interferon-alpha in combined chemoradioimmunotherapy for pancreatic adenocarcinoma (CapRI): First data from the immunomonitoring

Data from a phase II trial combining chemoradiotherapy with IFN-a (CapRI scheme) for adjuvant treatment of pancreatic carcinoma are very encouraging. Therefore, a phase III trial comparing chemotherapy with the chemoradiotherapy with IFN-a scheme has been initiated in August 2004. Translational research with a focus on immunomodulation is performed in parallel to the study. Blood and serum samples are taken at various time points. Patients in arm A (chemoradioimmunotherapy) receive a single low-dose-Interferon injection before therapy to investigate the direct effect of IFN-a. So far samples from 44 patients have been investigated for surface molecule expression, cytokine levels, natural killer cell cytotoxicity, and antigen-specific Granzyme B release. Patients in arm A showed 1 day after IFN-a injection a significant increase in spontaneous cytotoxicity; this effect was fading after repeated injections. Furthermore, cells releasing Granzyme B after stimulation with CA 19.9 and MUC-1 protein increased under therapy. Five days after the first IFN-a injection, IL-12 and TNF-a serum levels peak. We observed significant increases of monocytes, peripheral dendritic cells, CD40 cells, central and effector memory T cells, and CD8 cells, CD4 cells decreased during therapy. All these effects were only observed in arm A patients and none of them in arm B patients. In conclusion, in a translational research project accompanying a challenging multimodality treatment trial including IFN-a, we observed an immediate activation of antigen-presenting cells and natural killer cells followed later on by antigen-specific activation. It will be most interesting if the immunologic data will show a correlation with the clinical course of the patients.