Merck-Moderna Cancer Vaccine Shows Promising Results in Landmark Trial

Pharmaceutical giants Merck and Moderna announced landmark results from their trial of a personalized mRNA cancer vaccine. The study found that when combined with Keytruda, the vaccine delayed melanoma recurrence in patients who had undergone surgery to remove the tumor. This is the first phase 3 randomized trial to show that a neoantigen vaccine can reduce cancer recurrence.

The trial involved 1,137 high-risk patients and used an mRNA-based experimental vaccine called intismeran. The vaccine uses the mutations in a person's melanoma tumor and is given alongside Keytruda, an existing treatment. Participants received up to nine doses of Keytruda and the mRNA vaccine, or Keytruda alone for a year.

The study found that the combination of vaccine and drug delayed recurrence, but the companies did not release specific efficacy numbers. These will be shared at an upcoming medical meeting and with regulators. The results have significant implications for cancer treatment, as melanoma is the most deadly common form of skin cancer in the US.