Moderna and Merck announce that their personalized mRNA vaccine, Intismeran (intismeran autogene), combined with Merck’s immunotherapy Keytruda, meets key goals in a late-stage Phase 3 melanoma trial. The companies report improved outcomes versus Keytruda alone, including a reduction in the risk of melanoma recurrence and a secondary improvement related to cancer spread.

The trial enrolled 1,137 patients with high-risk stage IIB to IV melanoma that has been surgically removed. Patients received up to nine doses of the personalized vaccine plus Keytruda for about one year, or Keytruda alone. Multiple outlets report the companies have not disclosed specific numbers for the latest Phase 3 results, and the study remains ongoing, with further details expected at a medical meeting.

Outlets also emphasize the context for the companies and markets. Reports describe the results as the first positive Phase 3 outcome for a personalized cancer vaccine, and as the first showing that adding an mRNA vaccine to Keytruda outperforms Keytruda alone. Financial coverage highlights sharp gains in Moderna shares in premarket or early trading, and notes Merck’s more modest rise, while other reporting points to potential regulatory discussions and possible approval timing.