Moderna and Merck's personalized skin cancer treatment shows sustained effect in five-year follow-up

Moderna and Merck’s personalized skin cancer treatment shows a sustained effect and reduces the risk of recurrence or death in a five-year follow-up, Reuters reports. The data raises expectations for both companies ahead of the announcement of key Phase 3 results.

The encouraging data comes from a study investigating the vaccine Intismeran autogene (a personalized anti-cancer vaccine based on mRNA technology being developed by Moderna) in combination with Merck’s Keytruda. The follow-up was conducted on patients with high-risk melanoma following complete surgical removal of the tumor. Compared to treatment with Keytruda alone, the combination therapy reduced the risk of recurrence or death by 44% after two years. After three years, the risk was reduced by 49%, with results remaining at the same levels after 5 years. Full data has not yet been disclosed; however, the published interim information supports the hypothesis that the vaccine’s mechanism leads to a long-lasting therapeutic effect.

Moderna CEO Stéphane Bancel stated during the J.P. Morgan Healthcare Conference 2026 that expectations for the durability of the effect are based on long-standing evidence. He explained that the vaccine reprograms the immune system’s T-cells.

Intismeran, also known as mRNA-4157 or V940, is a synthetic mRNA vaccine encoding up to 34 neoantigens. These are selected individually for each patient based on the mutational profile of the tumor’s DNA. The goal is to induce a specific T-cell immune response against cancer cells.

The publication of two-year Phase 2b results in 2023 encouraged the two companies to launch a large-scale program of pivotal clinical trials. The most advanced part, a Phase 3 study, has already recruited participants and could present interim results later this year. However, the exact timing remains unclear. The reason is that the study is tied to the occurrence of a certain number of events, but according to Bancel, final data is expected in 2026.

Moderna identifies Intismeran as one of its key future growth drivers. The vaccine’s potential will depend on results in melanoma and other oncological indications. Currently, Merck and Moderna are conducting Phase 3 trials in two forms of lung cancer, in addition to seven Phase 1 and 2 trials in various other tumor types.