US pharmaceutical company Merck & Co Inc (NYSE:MRK), known as MSD outside the US and Canada, and biotechnology company Moderna Inc (NASDAQ:MRNA) announced on Wednesday that the Phase 3 INTerpath-001 trial of intismeran autogene (intismeran; V940 or mRNA-4157) plus KEYTRUDA (pembrolizumab) met its primary endpoint of recurrence-free survival and a key secondary endpoint of distant metastasis-free survival in patients with completely resected stage IIB-IV melanoma.

At a pre-specified interim analysis, the combination delivered statistically significant and clinically meaningful improvements in both measures compared with KEYTRUDA alone. The companies said the results represent the first positive Phase 3 readout for an individualised neoantigen therapy and an mRNA-based cancer therapy, as well as the first Phase 3 demonstration of a clinically meaningful benefit over KEYTRUDA alone in the adjuvant setting for resected melanoma.

The study will continue to assess additional secondary endpoints, including overall survival. Safety findings were consistent with previously reported studies of the combination, with no new safety signals identified.

Merck and Moderna plan to present the data at an upcoming international medical meeting and engage with regulators on filing submissions for intismeran autogene in combination with KEYTRUDA.

Intismeran autogene is an investigational mRNA-based individualised neoantigen therapy designed for each patient based on mutations in their tumour.

The companies said the result builds on Phase 2b data showing a 49% reduction in the risk of recurrence or death and a 59% reduction in the risk of distant metastasis or death compared with KEYTRUDA alone.