Moderna’s Personalized mRNA Cancer Vaccine Shows Promising Results
Sept 15, 2026
Seoyoung Kang
Moderna’s stock price recently rose after the company announced successful results from a Phase 3 clinical trial of a personalized mRNA cancer vaccine developed with Merck. This news has increased expectations that Moderna could enter the cancer treatment market. The outcome is especially important because it is the first positive Phase 3 result for a personalized mRNA-based cancer treatment. Moderna and Merck are now working toward getting the treatment approved and bringing it to patients.
mRNA vaccines are a newer type of vaccine technology. They use genetic information to tell our cells to make a specific antigen, which then causes the immune system to respond. Unlike traditional vaccines that may use weakened or inactive viruses, mRNA vaccines do not contain a live virus. Furthermore, because they do not need to grow a virus to make the vaccine, the mRNA can be designed and produced relatively quickly when a new disease appears.
However, mRNA cancer vaccines are a little different from vaccines used to prevent diseases such as COVID-19. Cancer vaccines are mainly used as a treatment after a patient has already been diagnosed with cancer. In this case, the goal is to lower the chance of the cancer coming back or spreading after surgery.
The treatment developed by Moderna and Merck is personalized for each patient. First, doctors analyze the genetic information from a patient's tumor. They look for mutations that are found in the cancer cells but not in normal cells. These mutations can produce proteins called neoantigens. The patient's mRNA vaccine is then designed based on these neoantigens. The vaccine helps the immune system recognize cancer cells and attack them.
The mRNA vaccine is used with Keytruda, an immunotherapy drug, to strengthen the immune system’s response against cancer cells.
The Phase 3 trial focused on patients with melanoma, a type of skin cancer. The combination of the personalized mRNA vaccine and Keytruda showed a significant improvement in preventing cancer from coming back and spreading compared with Keytruda alone. Researchers are also studying whether this technology can be used for other types of cancer, including lung and pancreatic cancer.
Although more research and the approval process are still needed, these results are an important step for personalized cancer treatment. In the future, treatments like this could make it possible to design cancer therapy based on the unique characteristics of each patient's tumor.
