Moderna and Merck reported Phase 3 results for their personalized mRNA melanoma vaccine, intismeran autogene, after the topline data appeared to leak ahead of schedule. The combination with pembrolizumab reduced the risk of relapse or death by 42% versus pembrolizumab alone after a median follow-up of about two years. According to trial reporting, the therapy also lowered the risk of distant spread or death by 38%. While overall survival and quality-of-life findings were not yet included in the released dataset, oncologists cited the disease-control signal as a key milestone for individualized neoantigen vaccines. The companies said they plan to engage regulators for approval, and analysts flagged the market reaction as a sell-the-news response despite the clinical signal. The dataset also sharpened the operational question around manufacturing customization and scalability compared with standard adjuvant pembrolizumab delivery.