Researchers at Johns Hopkins University reported early clinical proof-of-concept for a peptide-based pancreatic cancer vaccine targeting the six most common mutant KRAS variants. In a Cancer Discovery-published Phase 1 trial in high-risk participants with confirmed pancreatic lesions that had not progressed to cancer, the vaccine induced protective, antigen-specific T cell responses. The study reported mild, self-resolving side effects and described slowed progression of lesions toward pancreatic cancer in the enrolled participants. Investigators used four immunization timepoints with a booster dose after the final prime, assessing immune responses through peripheral blood mononuclear cells. The dataset supports further development in larger studies focused on lesion outcomes and durability of immune activation, particularly in genetically predisposed groups.