An experimental personalized mRNA vaccine, developed by Merck and Moderna, has shown significant promise in reducing the risk of melanoma recurrence when combined with the immunotherapy drug Keytruda (pembrolizumab), according to data from a Phase 2b clinical trial.
The trial, which involved patients with high-risk stage III/IV melanoma who had undergone surgical removal of their tumors, found that the combination of the vaccine (mRNA-4157/V940) and Keytruda reduced the risk of recurrence or death by 44% compared to Keytruda alone. The results were presented at the American Association for Cancer Research (AACR) annual meeting in April 2023 and published in The Lancet.
The vaccine is designed to target up to 34 neoantigens specific to each patient's tumor, training the immune system to recognize and attack cancer cells that may remain after surgery. The therapy is currently being evaluated in a Phase 3 trial, with the companies planning to expand into other cancer types.
Experts have called the approach a potential watershed moment in cancer treatment, as it represents a personalized, precision-medicine strategy that could be adapted for various cancers. However, the vaccine is not yet approved for general use, and further studies are needed to confirm its long-term benefits and safety.
