Personalized Neoantigen Vaccines Elicit T-Cell Responses in Resected PDAC, With 4.4-Year mOS

Two Phase 1 trials (NCT03956056 and NCT03122106) tested personalized synthetic long-peptide and DNA vaccines designed from each patient’s tumor neoantigens after pancreatic cancer surgery and adjuvant chemotherapy. Twenty patients ultimately received vaccination, with neoantigen-specific T-cell responses detected across vaccinated patients and no grade ≥3 vaccine-related adverse events. Median OS was 4.4 years versus 3.5 years in a contemporaneous propensity-matched control cohort, but the difference was not statistically significant (P=0.23); importantly, median DFS was 1.7 versus 2.2 years (P=0.77), showing no recurrence benefit.