Moderna, Merck mRNA cancer vaccine prevents melanoma from returning

Byline: Nathaniel Weixel; dated 08/19/26 10:54 AM ET.

VERBATIM:
- Lead: "An experimental personalized mRNA-based cancer vaccine from Merck and Moderna was successful at preventing melanoma from returning or spreading in a late-stage trial of high risk patients, the companies announced Wednesday."
- The study "met its main goal of extending 'recurrence-free survival' (RFS)" and "also met a secondary goal of preventing cancer from spreading to different parts of the body."
- Results were "clinically meaningful," but the companies "didn't specify how long patients lived after treatment without their cancer returning."
- "The trial will continue, and more details will be presented at a medical conference later this year."
- Moderna CEO Stephane Bancel: "We have started to demonstrate the potential of an entirely new class of medicine."
- "Top health officials have been openly hostile to mRNA technology" (though "Moderna did recently win approval for its mRNA-based flu vaccine").
- Merck Research Laboratories President Dean Li, on CNBC's "Squawk Box": "an earlier study showed most people who were disease free after one year remained disease free after five years"; Li said the companies "will likely begin talking to federal regulators 'in the next few months.'"
- "The trial enrolled 1,137 patients" randomized to "receive the vaccine and Keytruda or Keytruda alone for approximately one year."
- A Phase 2 study showed the vaccine-plus-Keytruda combo "reduced the risk of melanoma recurrence or death by 49 percent compared with Keytruda alone."
- "Melanoma accounts for only about 1 percent of skin cancers but causes the highest percentage of deaths."

AUDIT NOTE: The Hill's piece does NOT mention any stock-price movement (a silence vs. Reuters' 160%/$40 billion figures). Lead asserts the trial "was successful." Flags the Trump-administration mRNA hostility as "Top health officials have been openly hostile to mRNA technology."