Merck and Moderna say cancer vaccine shows promise in preventing recurrence of melanoma

Merck and Moderna released interim Phase 3 results showing their personalized mRNA cancer vaccine Intismeran, combined with Merck's immunotherapy Keytruda, reduced melanoma recurrence in high-risk patients following surgery. The trial enrolled 1,137 patients and found no new safety concerns, though full data have not yet been published in a peer-reviewed journal. Earlier research from a 157-patient study, published in June in the Journal of Clinical Oncology, showed the combination halved the risk of melanoma returning over five years. Moderna shares surged up to 147% on the news, with Merck rising approximately 13%. The trial will continue to track overall survival outcomes.