Moderna and Merck's Cancer Vaccine Halves Melanoma Recurrence in Five-Year Study
Chicago, Monday, 1 June 2026.
Five-year trial data reveals Moderna and Merck’s personalized mRNA cancer vaccine cuts the risk of severe melanoma recurrence by 49% and distant metastasis by 59%.
A Milestone in Personalized Oncology
Today, June 1, 2026, at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Moderna (NASDAQ: MRNA) and Merck (NYSE: MRK) formally presented highly anticipated five-year data for their investigational individualized neoantigen therapy, intismeran autogene (also known as mRNA-4157 or V940) [1][2][GPT]. Administered in combination with Merck’s blockbuster immunotherapy KEYTRUDA (pembrolizumab), the treatment targets patients with high-risk stage III/IV melanoma who have undergone complete surgical resection [1]. The presentation, part of a broader shift toward individualized mRNA treatments showcased at this year’s ASCO conference, underscores the maturing landscape of personalized medicine [2].
Safety Profile and Clinical Significance
The safety profile of the combination therapy has remained consistent over the five-year observation period. The most frequently reported adverse events were fatigue and injection site pain, both occurring in 59.6% of patients, followed by chills in 51.0% [1]. The majority of these reactions were classified as low-grade, with immune-related adverse events occurring at a comparable rate, showing a difference of just 1.2 percentage points between the combination arm (45.2%) and the KEYTRUDA-alone arm (44%) [1]. This tolerability is crucial given the high toxicity often associated with advanced oncological regimens [GPT]. For context, clinical data for KEYTRUDA across various trials shows that severe adverse reactions frequently lead to permanent treatment discontinuation, such as the 14% discontinuation rate observed in the KEYNOTE-054 trial for stage III melanoma [1].
Expanding the mRNA Oncology Pipeline
Beyond melanoma, Moderna and Merck are aggressively expanding their oncology footprint. The pharmaceutical giants are currently conducting nine Phase 2 and Phase 3 clinical trials to evaluate the intismeran autogene and KEYTRUDA combination across different tumor types [1]. This includes fully enrolled Phase 3 trials for adjuvant melanoma (INTerpath-001) and renal cell carcinoma (INTerpath-004), as well as actively enrolling studies targeting non-small cell lung cancer (NSCLC) and bladder cancer [1]. Dr. David Berman, Chief Development Officer of Moderna, noted that the five-year data bolsters confidence in the potentially transformative impact of utilizing mRNA technology for cancer care [1].