MSD, Moderna’s mRNA cancer vaccine lowers recurrence risk in phase 3 trial

A personalized mRNA cancer vaccine jointly developed by Merck (MSD) and Moderna successfully reduced the risk of recurrence in a large clinical trial. The results represent the first positive phase 3 findings in personalized neoantigen therapies and the mRNA cancer field.

On the 19th, the companies announced that the phase 3 INTerpath-001 trial, which evaluated the combination of the personalized mRNA neoantigen therapy intismeran autogene (development code V940/mRNA-4157) and the PD-1 inhibitor Keytruda (pembrolizumab), simultaneously met its primary endpoint of recurrence-free survival (RFS) and key secondary endpoint of distant metastasis-free survival (DMFS).

The trial enrolled 1137 patients with stage IIB to IV cutaneous melanoma who had undergone complete surgical resection.

Personalized mRNA cancer vaccines identify tumor mutations through rapid sequencing, select candidate neoantigens, encode them as mRNA, and then administer them to the body to train the immune system to attack the tumor. Combining the vaccine with a PD-1 inhibitor is expected to relieve the suppression of T cells by the tumor microenvironment.

However, identifying neoantigens alone is not sufficient. To verify actual efficacy, researchers must determine whether vaccine-induced T cells have reached the tumor tissue, retained sustained killing capacity, and avoided functional exhaustion.

MGI’s spatial proteomics instruments are used in this process. The PMIF-20 pathology slide staining scanner and the Path-P96 WF fully automated staining and imaging system rapidly analyze the spatial location, functional status, and interactions of vaccine-induced immune cells in situ within tumor tissue.

Based on cyclic multiplex immunofluorescence technology, the PMIF-20 automates the entire staining, imaging, and washing process and supports detection of up to 24-plex. As the first automated instrument in the country to integrate multiplex immunofluorescence staining and scanning, it has been registered with China’s National Medical Products Administration (NMPA), as have both the instrument and its reagents.

The Path-P96 WF can simultaneously detect more than 100 protein markers on a single slide and process 32 slides at once, making it suitable for large-scale cohort studies. MGI said the system can be used to compare differences in the tumor microenvironment between treatment responders and nonresponders.

MGI also provides the FluoXpert Vision image analysis solution, which supports cell segmentation, phenotype identification, coexpression, and spatial proximity analysis. The company said the solution can shift analysis of vaccine-induced immune responses from qualitative observation to quantitative interpretation.