Merck and Moderna's Individualized mRNA Cancer Vaccine Achieves Historic Phase 3 Success in Melanoma
On August 19, 2026, Merck and Moderna announced positive topline results from the Phase 3 INTerpath-001 trial evaluating adjuvant treatment with intismeran autogene (intismeran; V940 or mRNA-4157) in combination with Keytruda (pembrolizumab) in patients with completely resected stage IIB-IV melanoma. The trial successfully met its primary endpoint of recurrence-free survival (RFS) and a key secondary endpoint of distant metastasis-free survival (DMFS) at a pre-specified interim analysis.
This is the first-ever positive Phase 3 readout for an individualized neoantigen therapy (INT) and for an mRNA-based cancer therapy. It is also the first Phase 3 study to demonstrate a clinically meaningful improvement over Keytruda alone, which is currently a standard-of-care immunotherapy.
The treatment is designed by using a patient's tumor sample to identify its unique mutational signature ("fingerprint") and synthesize an mRNA coding for up to 34 neoantigens. This trains and activates the patient's immune system to recognize and attack cancer cells.
The companies plan to present the full dataset at an upcoming international medical meeting and will engage with global regulatory authorities to submit biologics license applications (BLAs).