Cancer mRNA Vaccine Reduces Risk of Melanoma Returning

Study results presented at the American Association for Cancer Research meeting found that people with advanced melanoma treated with Moderna’s experimental vaccine, mRNA-4157/V940, and Merck’s immunotherapy drug Keytruda were less likely to have their cancer return than people who took the immunotherapy drug alone.

Melanoma is a type of skin cancer that, if caught early enough, has a high survival rate. However, treating melanoma becomes more challenging once it has spread to other areas of the body.

One of the first treatments doctors use after surgically removing melanoma is an immunotherapy drug called pembrolizumab (Keytruda). Made by Merck, the medication works by blocking the cancer cell’s ability to evade the immune system.

However, the chances of melanoma coming back are high if the cancer has spread to lymph nodes or other organs.

Now, researchers have discovered that adding an experimental mRNA vaccine made by Moderna called mRNA-4157/V940 to Keytruda treatment lowered the risk of melanoma recurrence by 44% compared to the immunotherapy drug alone.

The research was presented on April 16 at the American Association for Cancer Research meeting in Orlando, FL, and will appear in a peer-reviewed journal at a later date.

To conduct the clinical trial — funded by Merck and Moderna — the scientists recruited people with a high risk of melanoma returning. They gave 50 participants Keytruda and 107 a combination of Keytruda and mRNA-4157/V940.

Among 107 participants who received both the experimental vaccine and Keytruda, 22.4% had their cancer return within a two-year follow-up. In contrast, 40% of the people given Keytruda alone had their cancer return.

In a statement, Dr. Ryan Sullivan, researcher and melanoma expert at Mass General Cancer says, "from a general cancer therapeutic standpoint, this is a potential major breakthrough."

Moderna’s mRNA-4157/V940 takes about eight weeks to develop. Scientists create it using genetic material from the person’s cancer cells removed during surgery. After it’s injected into the body, the vaccine teaches the immune system to recognize unique neoantigens in their specific melanoma.

The scientists say that once Keytruda removes the cancer cell’s ability to hide, they become vulnerable to the vaccine-educated immune system.

Because of the study's promising findings, the team plans to conduct a randomized phase 3 clinical trial with 1,000 people this summer. However, it could take three to four years to learn the study results. Still, the team says that if the mRNA cancer vaccine proves to be safe and effective, they expect FDA approval within that time frame.