mRNA-1608, an mRNA-Based Therapeutic Genital Herpes Vaccine Candidate: Interim Safety, Immunogenicity and Clinical Endpoint Results from a Phase 1/2 Trial
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A conference abstract (IDWeek 2025) reporting interim safety, immunogenicity, and clinical-endpoint results from the Phase 1/2 dose-ranging trial of Moderna's therapeutic candidate mRNA-1608. The results are interim and from a conference abstract. Trade press reported in November 2025 that Moderna will not advance the program to Phase 3, framing it as a portfolio decision rather than a reported safety failure; we have not confirmed this against a Moderna release or filing.
This IDWeek 2025 abstract reports interim data from the Phase 1/2 dose-ranging trial (NCT06033261) of mRNA-1608, Moderna’s therapeutic candidate — one aimed at reducing recurrences in people who already have HSV-2, rather than preventing infection.
Read it alongside what has been reported since: trade press reported in November 2025 that Moderna will not advance mRNA-1608 to Phase 3, as part of a pipeline prioritization. We have not confirmed this against a Moderna release or filing. The trial itself reached completion and this abstract is its public interim read-out; the reporting frames the decision as a portfolio choice, not a reported safety or efficacy failure. The distinction matters, and the candidate page keeps both facts side by side.