Merck and Moderna reported sustained benefit from their personalized melanoma vaccine when added to Merck’s Keytruda, showing a continuing reduction in risk of recurrence or death at five years. The long‑term follow‑up reinforces earlier efficacy signals from the combination program. The five‑year durability data bolster the companies’ strategy to advance mRNA immunotherapy approaches in oncology and strengthen the case for further registrational activity. Investors and partners will watch how the data shape regulatory discussions and combinations across other cancer types.