Johns Hopkins researchers reported Phase 1 results for a mutant KRAS peptide vaccine (mKRAS-VAX) aimed at intercepting pancreatic ductal adenocarcinoma in high-risk cohorts. In a study published in Cancer Discovery, vaccination was well tolerated and elicited KRAS-specific T-cell responses in 90% of 20 participants. Across a median 16.5 months of follow-up, none of the vaccinated participants developed pancreatic cancer, and some precancerous lesions shrank or stopped progressing. The work used a six-mutation vaccine design to target common KRAS variants and demonstrated persistence of vaccine-induced T-cell clonotypes for up to two years. The findings provide early human proof-of-concept that immune-based vaccination could move preventive oncology beyond surveillance—an area where detection sensitivity remains a key limitation and surgical intervention often carries high recurrence risk.