Merck and Moderna said their experimental personalized mRNA vaccine, given with Merck’s Keytruda, met the primary endpoint in a Phase III trial of more than 1,100 high‑risk or advanced melanoma patients, significantly extending recurrence‑free survival versus Keytruda alone and lowering risk of distant metastasis. The result builds on positive Phase II data earlier this year; the trial will continue to evaluate additional endpoints including overall survival. The companies plan to present data a

Merck and Moderna said their experimental personalized mRNA vaccine, given with Merck’s Keytruda, met the primary endpoint in a Phase III trial of more than 1,100 high‑risk or advanced melanoma patients, significantly extending recurrence‑free survival versus Keytruda alone and lowering risk of distant metastasis. The result builds on positive Phase II data earlier this year; the trial will continue to evaluate additional endpoints including overall survival. The companies plan to present data at an upcoming international medical meeting; no timing for a U.S. regulatory submission was disclosed. Merck shares were up about 8% premarket and Moderna shares rose more than 60% premarket.