Correlation of anti-calreticulin antibody titers with improved overall survival in a phase 2 clinical trial of algenpantucel-L immunotherapy for patients with resected pancreatic cancer.

3029 Background: Algenpantucel-L immunotherapy consists of allogeneic pancreatic cancer cells that have been genetically modified to express the carbohydrate α(1,3)Gal, to which humans have an inherent pre-existing immunity. It is αGal that is primarily responsible for the hyperacute rejection of foreign tissue via this potent immune defense mechanism in humans. Algenpantucel-L leverages this mechanism to educate the immune system towards components of the patients’ own tumor cells. Calreticulin is a calcium-binding chaperone protein that functions in the immune response by folding major histocompatibility complex (MHC) class I molecules and influencing antigen presentation to cytotoxic T cells. In pre-clinical models, drugs that induce cell surface CALR confer enhanced tumor protection. Components of algenpantucel-L express cell surface CALR. Methods: An open-label, 71 patient multicenter phase II study evaluating algenpantucel-L plus standard of care gemcitabine with 5-FU-XRT for resected pancreatic can...