Merck Stock Skyrockets 8.82% on mRNA Cancer Vaccine Breakthrough

Merck & Co Inc's stock (MRK) surged by 8.82% on August 19, driven by a major clinical breakthrough in partnership with Moderna.

The joint INTerpath-001 trial of intismeran autogene, an individualized mRNA-based cancer vaccine, combined with Keytruda for patients with resected stage IIB to IV melanoma, met its primary endpoint of recurrence-free survival and key secondary endpoint of distant metastasis-free survival.

This landmark result represents the first successful Phase 3 readout for an individualized mRNA-based cancer therapy, validating the platform and establishing strong clinical evidence for combination immunotherapy in early-stage disease.