Recent positive Phase 3 data from Moderna and Merck’s personalized mRNA vaccine, intismeran autogene (mRNA-4157), combined with Keytruda (pembrolizumab) drove trader sentiment. The August 2026 INTerpath-001 trial met its primary recurrence-free survival endpoint and key secondary distant metastasis-free survival goal in resected high-risk stage IIB-IV melanoma, building on earlier Phase 2 results with no new safety signals. Companies plan regulatory filing within months, positioning potential approval in late 2026 or 2027 depending on review timelines. This contrasts with the FDA’s August 2026 accelerated approval of Replimune’s oncolytic viral therapy Tudriqev plus nivolumab for PD-1 refractory cases, which is not an mRNA vaccine. Key catalysts ahead include full data presentation and any breakthrough therapy or priority review designations that could accelerate the process.