Merck and Moderna Say Their Tumor-Tailored mRNA Therapy Met Its Goals in a Melanoma Trial
A Phase 3 trial of Merck and Moderna's individualized mRNA cancer therapy, intismeran autogene, has met its primary endpoint of recurrence-free survival and a key secondary endpoint of distant metastasis-free survival, the companies announced Aug. 19. The therapy was given with Merck's Keytruda (pembrolizumab) to patients whose melanoma had been removed by surgery, and compared with Keytruda alone.
The companies released no results. Their statement reports "statistically significant and clinically meaningful improvements" in both measures at a pre-specified interim analysis, and gives no hazard ratio, no survival figure and no confidence interval. The data will be presented at "an upcoming international medical meeting" and shared with regulators.
The trial, INTerpath-001, enrolled 1,137 patients with completely resected stage IIB-IV cutaneous melanoma. It assigned them at random, 2-to-1 and double-blind, to intismeran at 1 mg every three weeks for up to nine doses plus Keytruda at 400 mg every six weeks, or to Keytruda alone, for about a year. The trial continues to measure overall survival and other secondary endpoints, with safety matching what earlier studies of the combination showed.
Each course is built for one person: synthetic mRNA coding for up to 34 neoantigens, protein fragments specific to that patient's tumor.
Merck and Moderna describe the result as the first positive Phase 3 readout for an individualized neoantigen therapy and for an mRNA cancer therapy.
The companies point to five-year results from an earlier, smaller trial, the Phase 2b KEYNOTE-942, presented at the 2026 ASCO meeting: a 49% lower risk of recurrence or death (hazard ratio 0.51; 95% CI, 0.294-0.887) and a 59% lower risk of distant metastasis or death (hazard ratio 0.411; 95% CI, 0.200-0.843) for the combination against Keytruda alone. Those numbers are that trial's, not this one's.
