Moderna Shares Fall More Than 25% on Apparent Early Release of Cancer Vaccine Data

Moderna shares fell more than 25% and Merck shares fell more than 3% on October 22, 2026, after an apparent early release of data on intismeran autogene, the personalized mRNA cancer vaccine they develop together, Investing.com reported. The release was not a scheduled company announcement. Moderna's August Phase 3 melanoma result rested on an interim analysis.