Moderna Investors Should Brace for More Whiplash

A facts-only brief, written by a local AI model from this article in The Wall Street Journal, October 24, 2026. It may contain mistakes, and it is not the article: the full story is at wsj.com.

Moderna shares dropped approximately 20% following the release of trial data showing its personalized cancer vaccine reduced the risk of melanoma recurrence or death by 42% when combined with Merck’s Keytruda. The stock had nearly quadrupled since August after initial announcements of the partnership, leading to a valuation that analysts argue exceeds the potential market value of the melanoma treatment alone. The vaccine sequences patient tumors to target up to 34 specific mutations, aiming to enhance the immune response beyond what Keytruda achieves independently. While the results met the roughly 40% efficacy threshold required for approval, the market reaction reflects skepticism about the therapy’s applicability to other cancer types where immune environments are less favorable.

Background

• Moderna’s stock value peaked near $200 billion in 2021 before falling to approximately $10 billion last year due to declining vaccine sales.
• The personalized vaccine costs an estimated $300,000 per patient, raising questions about its value compared to extending the use of Keytruda, which faces generic competition after its 2028 patent expiration.
• Future data for kidney cancer is expected within months, while bladder cancer trial results are anticipated in 2027, with lung cancer testing also underway.

Read the full article at wsj.com

More from Saturday, October 24: