Moderna and Merck announced positive results from a Phase 3 trial for their personalized mRNA cancer vaccine, intismeran, combined with Merck's immunotherapy Keytruda. The combination significantly reduced the risk of recurrence and spread of melanoma in patients who had their high-risk tumors surgically removed. This marks the first positive late-stage trial result for an mRNA cancer vaccine and has been hailed as a potential "game-changer" in cancer treatment.
The announcement led to a dramatic increase in both companies' stock prices. Moderna's shares surged by as much as 160% to 177%, adding approximately $45 billion to its market value in a single day. Merck's stock also climbed over 12%. Analysts have projected significant sales for intismeran, with Barclays estimating around $3 billion in melanoma sales by 2035, and William Blair analyst Myles Minter projecting peak annual sales of $5.4 billion in melanoma alone for Moderna's 50-50 revenue split with Merck.
While the detailed data has not yet been released, the interim analysis by independent data monitors allowed the companies to declare the trial a success, showing "statistically significant and clinically meaningful improvements" over Keytruda alone. This builds on positive Phase 2 data, where the combination reduced the relative risk of death or recurrence by 44% compared to Keytruda alone. The success of intismeran has boosted confidence in Moderna's broader pipeline of mRNA cancer vaccines, with ongoing trials for kidney, bladder, and non-small cell lung cancers expected to yield results later this year or next. However, some analysts, like Evercore ISI's Cory Kasimov and Leerink Partners' Daina Graybosch, caution that the market's euphoric response might have set expectations that are difficult to meet, especially given that melanoma is uniquely suited to a vaccine approach.
