Merck and Moderna Announce Historic First Phase 3 Win for Personalized mRNA Cancer Vaccine
On August 19, 2026, Merck and Moderna announced positive topline results from the Phase 3 INTerpath-001 trial evaluating the adjuvant treatment of intismeran autogene (V940 or mRNA-4157) in combination with Keytruda (pembrolizumab) in patients with completely resected stage IIB-IV melanoma.
This landmark milestone represents the first positive Phase 3 readout for an individualized neoantigen therapy (INT) and for an mRNA-based cancer therapy. The trial met its primary endpoint of Recurrence-Free Survival (RFS) and its key secondary endpoint of Distant Metastasis-Free Survival (DMFS), showing a statistically significant and clinically meaningful improvement over Keytruda alone (the current standard-of-care immunotherapy).
Intismeran autogene is a patient-specific therapy customized by sampling a patient's tumor to profile its unique mutational signature, providing mRNA instructions to help the patient's immune system target up to 34 distinct cancer-specific neoantigens. The Phase 3 success builds on previously reported Phase 2b data, which showed a 49% reduction in the risk of recurrence or death over five years when intismeran was added to Keytruda. The companies are actively preparing for global regulatory submissions.