Moderna’s personalized mRNA cancer vaccine with Keytruda slashes melanoma death or recurrence risk by 42%

Trial results show reduced risk

The Phase 3 study compared Moderna’s vaccine plus Merck’s Keytruda with Keytruda alone. It tracked more than 1,100 people with melanoma. The combination reduced the risk of death or recurrence by 42%, the companies said. It also cut the risk of cancer spreading by 38%.

At the two-year mark, 82.2% of people treated with both medicines remained cancer-free. The figure was 70% among those who received Keytruda alone.

A vaccine tailored to tumors

The vaccine is designed around mutations specific to each patient’s tumor and was tested with Keytruda, an immunotherapy that boosts the immune system. The findings provide the first data showing that this pairing can halt the disease. Moderna CEO Stephane Bancel said the results open a new chapter in cancer treatment. In an interview, he described the clinical impact of creating T cells specific to a patient’s tumor as “very profound.”

Approval plans and investor focus

Moderna and Merck are preparing to file for US regulatory approval. Bancel said they expect to launch the personalized cancer vaccine in 2027. Before the trial results were discussed, several Wall Street analysts said investors were looking for a reduction in recurrence risk of at least 40%. Minter called the results “great data, in our view,” while noting that investors would continue to debate the fundamental valuation.