Intismeran met its main late-stage goal by reducing melanoma recurrence and also showed a benefit in limiting cancer spread when paired with Merck's Keytruda.
The 1,137-patient study marks the first positive Phase 3 result for an mRNA cancer vaccine and the first evidence that a personalized treatment can improve outcomes beyond Keytruda alone.
For Moderna, the result offers its clearest route yet beyond COVID products, with regulators potentially allowing a launch as early as next year if the treatment is approved.
Barclays estimates annual melanoma sales could reach about $3 billion by 2035, though Moderna's shares already surged as much as 160%, raising the bar for execution and uptake.
The melanoma win could also lift confidence in Moderna and Merck's similar personalized cancer programs in lung, breast and pancreatic tumors.