Moderna and Merck have released updated results from a clinical trial evaluating their experimental mRNA cancer vaccine, mRNA-4157 (V940). The study focuses on patients with high-risk stage III or IV melanoma who have undergone surgery to remove the cancer. According to the companies, the combination of the mRNA vaccine and Merck’s immunotherapy drug, Keytruda, resulted in a 42% reduction in the risk of recurrence or death compared to treatment with Keytruda alone.

This announcement follows earlier reports from the companies confirming that the trial had met its primary goals. The vaccine is designed to be personalized; it is created by analyzing a patient’s specific tumor samples to identify unique mutations, which then allows the mRNA to instruct the body’s immune system to recognize and attack those specific cancer cells. By combining this targeted approach with Keytruda, which helps the immune system identify and fight cancer more broadly, the companies aim to prevent the disease from returning after surgical intervention.

While the results are considered a significant milestone in the field of mRNA technology—which gained widespread attention during the COVID-19 pandemic—the companies have not yet released the full peer-reviewed data. The medical community is currently awaiting the complete study results to better understand the long-term efficacy and potential side effects of the treatment. The companies intend to use these findings to support further clinical development and potential regulatory discussions for the vaccine's use in various cancer types.