Merck and Moderna report Phase 3 success for personalized mRNA cancer vaccine intismeran autogene

Merck and Moderna announced on August 19, 2026 that their personalized mRNA cancer vaccine, intismeran autogene, has completed a successful Phase 3 trial. The collaboration aims to create a patient‑specific immunotherapy that targets unique tumor mutations.

The Phase 3 study evaluated the vaccine in patients with advanced solid tumors and met its primary efficacy endpoints, demonstrating a statistically significant improvement over standard care. Safety data were also consistent with earlier studies, showing the vaccine was well tolerated.

The positive readout is being hailed as a milestone for next‑generation immunotherapy, potentially expanding the role of mRNA technology beyond infectious diseases. Both companies said they will engage regulators and plan further development steps to bring the therapy to market.