Moderna and Merck said Wednesday that an experimental personalized mRNA cancer vaccine reduced the risk of melanoma recurrence in a phase-3 trial.
This development represents a potential shift in skin cancer treatment by using personalized genetic data to prevent the return of high-risk tumors. If widely adopted, the therapy could significantly extend the period patients live without the disease returning.
The trial involved more than 1,100 high-risk melanoma patients [1]. The experimental mRNA vaccine was administered in combination with Keytruda, an existing immunotherapy drug produced by Merck. Results indicated that the combination treatment lengthened recurrence-free survival, and lowered the overall risk of the cancer returning [2, 3].
Because the vaccine is personalized, it is designed to target the specific mutations found in an individual patient's tumor. This approach aims to prime the immune system to recognize and attack remaining cancer cells that might otherwise lead to a relapse [2].
The announcement triggered a significant reaction in the financial markets. Reports on Moderna's stock price varied following the news, with CNBC reporting an approximately 90% rise [4], while IBTimes said the stock more than doubled [5].
Researchers focused on high-risk patients because these individuals face the greatest challenge with cancer spread after initial treatment. The phase-3 trial is the final stage of testing required before a company can seek regulatory approval for public use [3].
“The experimental mRNA vaccine was administered in combination with Keytruda.”
The success of this phase-3 trial suggests that mRNA technology, which gained global prominence during the pandemic, can be effectively pivoted toward oncology. By combining a personalized vaccine with a checkpoint inhibitor like Keytruda, the treatment targets cancer through two different mechanisms: the vaccine teaches the immune system to find the cancer, while the inhibitor removes the brakes that prevent the immune system from attacking. This dual approach could provide a blueprint for treating other types of solid tumors beyond melanoma.
