A personalized mRNA vaccine for pancreatic cancer kept 7 of 8 trial patients who responded to treatment alive for six years, a striking outcome for a disease where fewer than 13% of patients survive five years. The Phase 1 trial from Memorial Sloan Kettering involved just 16 patients total, so scientists emphasize larger studies are needed before this becomes standard treatment—but the immune response generated was unusually potent for pancreatic cancer, which has historically resisted immunotherapy. The vaccine works by using genetic material from each patient's tumor to train their immune system to attack remaining cancer cells after surgery.