Phase 1 vaccine against mutant KRAS produced a T-cell response in 18 of 20 people at hereditary risk of pancreatic cancer

In a first-in-human phase I trial, the peptide vaccine mKRAS-VAX induced a mutant-KRAS-specific T cell response in 18 of 20 individuals (90%) with hereditary predisposition to pancreatic cancer, and the vaccine-induced clonotypes persisted for up to 2 years; the trial was single-arm and assessed safety and immunogenicity, not efficacy. Adverse events were grade 1-2 only. No participant developed pancreatic cancer over a median follow-up of 16.5 months, but with 20 participants and no control group this cannot be read as evidence of prevention. Commentary in Nature Reviews Cancer; source trial in Cancer Discovery 2026, NCT05013216.