Skip to main content
CadNews - Comparative News Analysis
Topics
Sign in
Back to brief

Business & Finance · October 22, 2026

Moderna’s stock tumbles after reported leak of data for cancer vaccine

3 sources →

Moderna shares experienced a sharp decline on Thursday, dropping as much as 25% following a leak of clinical data regarding its experimental cancer vaccine. The vaccine, developed in partnership with Merck, is a personalized immunotherapy known as intismeran autogene. Despite the initial market reaction, full data released later in the day showed that the vaccine, when paired with Merck's Keytruda, reduced the risk of recurrence or death in certain melanoma patients by 42% compared to Keytruda alone.

Read the original coverage

Reported by multiple outlets

  • Moderna shares fell significantly on Thursday following a data leak.
  • The data concerns an experimental cancer vaccine developed by Moderna and Merck.
  • The vaccine is being tested in combination with Merck's immunotherapy drug, Keytruda.

Reported by only some outlets

  • Moderna's stock dropped as much as 25%.
  • The vaccine (intismeran autogene) reduced the risk of recurrence or death in melanoma patients by 42% compared to Keytruda alone.
  • Full data was released later on Thursday following the leak.
  • The data was originally expected to be shared at a medical conference over the weekend.
  • The stock drop reversed a significant 2026 rally driven by vaccine optimism.

About these outlets

CadNews does not determine absolute truth or endorse political viewpoints. It compares publicly available reporting, identifies shared facts, highlights framing differences, and flags uncertainty.