TPS226 Background: Patients with resected pancreas cancer treated with standard of care gemcitabine (Gem) have a median recurrence-free survival of 14 months, median overall survival of 22 months, and a survival rate of 20% at 5 years. The postresection patient population represents a compelling model of minimal residual disease for which targeted and active immunotherapy may decrease cancer recurrence and improve survival through elimination of microscopic disease. Activating mutations in ras occur early in the development of pancreas cancer and are subsequently maintained, being found in > 90% of pancreas cancer cases. This trial is designed to evaluate the efficacy, immunogenicity, and safety of GI-4000 plus Gem versus placebo plus Gem in patients with resected pancreas cancer and an activating ras mutation. GI-4000 is a proprietary immunotherapy designed to target cells with activating ras mutations using whole, heat-killed recombinant Saccharomyces cerevisiae yeast (called Tarmogens = targeted molecu...