Moderna’s stock doubles on promising cancer-vaccine results

**Moderna's shares doubled in response to promising data on its experimental cancer vaccine, which combines the company's messenger-RNA platform with Merck's immunotherapy drug Keytruda. The results offer an early signal that mRNA technology — best known for its role in COVID-19 vaccines — may also be effective in oncology.**

**The candidate operates on two complementary fronts. The mRNA component is engineered to train the immune system to recognize tumor-specific antigens, while Keytruda works as a checkpoint inhibitor, blocking a protein that cancer cells use to evade immune attack. Together, the therapy aims to activate immune cells and keep them from being switched off.**

**For the market, the appeal lies in the size of the opportunity: successful cancer treatments would open a far larger commercial field than infectious disease. The key question now is whether these early results hold up in larger, late-stage trials, particularly against Keytruda as a standalone therapy. Regulatory approval is not assured, and the durability of the immune response remains unknown.**