Merck and Moderna announced a pivotal Phase 3 success for intismeran autogene, a personalized mRNA neoantigen vaccine given with Merck’s Keytruda in resected high-risk melanoma. The companies said the regimen met its primary and key secondary endpoints at an interim analysis, setting up a potential approval push once additional details are disclosed. The trial tested whether the personalized vaccine could reduce recurrence after surgery and improve outcomes including distant metastasis-free survival. Merck and Moderna did not immediately provide full data in the announcement, but their statement framed the readout as both statistically significant and clinically meaningful. The Phase 3 result adds to momentum behind individualized mRNA immunotherapy strategies, where each patient’s tumor sequencing can be used to generate neoantigen targets for the vaccine payload.