A personalized cancer vaccine from Moderna, intismeran (an mRNA neoantigen approach developed with Merck), met its pivotal Phase 3 endpoint and reduced the risk of recurrence or death by 42% versus pembrolizumab alone, according to readouts discussed around ESMO. The result positions neoantigen mRNA vaccination as a late-stage, efficacy-demonstrated oncology modality. The reporting also framed a near-term regulatory push, with expectations that submission activity for U.S. approval could begin in 2027. Moderna and Merck are preparing to extend the strategy beyond melanoma, with additional testing planned across other cancer types. From an industry standpoint, the readout tightens the competitive bar for therapeutic cancer vaccines—shifting the conversation from feasibility to clinical package completeness, including manufacturing scale, patient selection, and combination sequencing.