Aug 20, 2026 01:52 AM
(This post was last modified: Aug 20, 2026 01:53 AM by Magical Realist.)
Aug 19 (Reuters) - Moderna (MRNA.O), and Merck (MRK.N) said, on Wednesday that a personalized mRNA cancer vaccine reduced the risk of recurrence and spread of melanoma in a late-stage trial, a major success in a new field of cancer treatment that sent Moderna's shares surging as much as 160%.
The companies tested the vaccine together with Merck's immunotherapy drug Keytruda, a widely used melanoma treatment. Thousands of patients who have undergone surgery to remove high-risk melanoma tumors could benefit as soon as next year if regulators approve the vaccine, Moderna President Stephen Hoge said in an interview.
This is the first positive late-stage trial result for an mRNA cancer vaccine, which trains a patient's immune system to fight tumors by targeting specific mutations in those cells, and the first such study to show that adding a treatment to Keytruda worked better than that therapy alone. Merck, Moderna and other companies are testing similar approaches against lung, breast and pancreatic cancers.
Karen Knudsen, CEO of the Parker Institute for Cancer Immunotherapy, said the Moderna results could signal a new era for treating solid-tumor cancers.
"The positive hit here leads us into truly this next phase in immunotherapy," Knudsen said. "This is an auspicious start — this is where things begin.
The results signaled a reversal of fortune for Moderna, which has struggled to generate new products beyond its COVID-19 vaccine and faced pushback over its mRNA technology from President Donald Trump's administration. U.S. Health and Human Services Secretary Robert F. Kennedy Jr. has criticized the safety and efficacy of mRNA vaccines and cut $500 million in mRNA vaccine projects.
Still, the National Cancer Institute has continued to fund trials of cancer vaccines, including those based on mRNA.
Moderna shares surged to multiyear highs, adding nearly $40 billion to the company's market capitalization. Merck climbed 12% on hopes the vaccine will expand its prospects in cancer as Keytruda, once the world's best-selling drug, faces patent expiration later this decade.
The trial results attracted new investor interest in the biotech sector broadly. The Nasdaq Biotechnology Index (.NBI), opens new tab climbed 5.2% to a record high."
The companies tested the vaccine together with Merck's immunotherapy drug Keytruda, a widely used melanoma treatment. Thousands of patients who have undergone surgery to remove high-risk melanoma tumors could benefit as soon as next year if regulators approve the vaccine, Moderna President Stephen Hoge said in an interview.
This is the first positive late-stage trial result for an mRNA cancer vaccine, which trains a patient's immune system to fight tumors by targeting specific mutations in those cells, and the first such study to show that adding a treatment to Keytruda worked better than that therapy alone. Merck, Moderna and other companies are testing similar approaches against lung, breast and pancreatic cancers.
Karen Knudsen, CEO of the Parker Institute for Cancer Immunotherapy, said the Moderna results could signal a new era for treating solid-tumor cancers.
"The positive hit here leads us into truly this next phase in immunotherapy," Knudsen said. "This is an auspicious start — this is where things begin.
The results signaled a reversal of fortune for Moderna, which has struggled to generate new products beyond its COVID-19 vaccine and faced pushback over its mRNA technology from President Donald Trump's administration. U.S. Health and Human Services Secretary Robert F. Kennedy Jr. has criticized the safety and efficacy of mRNA vaccines and cut $500 million in mRNA vaccine projects.
Still, the National Cancer Institute has continued to fund trials of cancer vaccines, including those based on mRNA.
Moderna shares surged to multiyear highs, adding nearly $40 billion to the company's market capitalization. Merck climbed 12% on hopes the vaccine will expand its prospects in cancer as Keytruda, once the world's best-selling drug, faces patent expiration later this decade.
The trial results attracted new investor interest in the biotech sector broadly. The Nasdaq Biotechnology Index (.NBI), opens new tab climbed 5.2% to a record high."