Merck-Moderna vaccine cuts odds of skin cancer recurrence in half, study finds

A vaccine shows promising results in treating the most deadly form of skin cancer, Moderna and Merck announced on Thursday.

Those with severe melanomas who received the vaccine and Merck's cancer drug Keytruda were 49% less likely to die or have their cancer come back after three years than those who were given only Keytruda, the biotech companies said in a news release. 

The companies have begun Phase 3 trials of mRNA-4157 with Keytruda, given a breakthrough therapy designation by the Food and Drug Administration earlier this year. The designation is meant to expedite the development and review of drugs meant to treat life-threatening diseases.