Drugmakers Moderna and Merck have announced final-stage trial results showing that the personalized mRNA vaccine Intismeran reduces the risk of recurrence and metastasis of melanoma. This marks the first time an mRNA cancer vaccine has achieved positive results in a large-scale trial, sending Moderna's stock soaring by 160%.
Interim results from the study, released Wednesday, showed the treatment met two key goals: reducing cancer recurrence and preventing tumor spread. Full study details have not yet been published but are expected to be presented at an upcoming medical conference, according to the drugmakers.
Stephen Hoge, President of Moderna, said thousands of patients who have had high-risk melanoma tumors surgically removed could benefit from the vaccine next year if regulatory approval is granted. According to the U.S. National Cancer Institute, more than 1.5 million people in the U.S. were living with melanoma in 2023.
The vaccine was developed in collaboration with pharmaceutical giant Merck and is being tested in combination with the immunotherapy drug Keytruda. The experimental vaccine works by training patients' immune systems to fight tumors, targeting mutations in cancer cells. Similar approaches are being tested against other cancers, including lung, breast, and pancreatic cancer.
Previous studies have suggested that mRNA vaccines can help the immune system recognize and attack cancer cells in mice, as well as in analyses of cancer patient records. The results come as the administration of U.S. President Donald Trump has cut mRNA research funding.
Merck said the two companies have begun discussions with regulators about the treatment. Karen Knudsen, CEO of the Parker Institute for Cancer Immunotherapy, said Moderna's results could signal a new era in solid tumor cancer treatment.
"This positive result brings us into the next phase of immunotherapy—a promising start and where everything begins," Knudsen said.
