Moderna shares surged 60% in premarket trading on Wednesday after the company and Merck announced interim success in a late-stage trial of their experimental melanoma vaccine. The personalized mRNA-based therapy, developed under the name Intismeran, demonstrated a statistically significant reduction in cancer recurrence when combined with Merck’s immunotherapy Keytruda.
The trial enrolled 1,137 high-risk patients with stage IIB-IV melanoma whose tumors had been surgically removed. Participants were randomized to receive up to nine doses of Keytruda plus the personalized vaccine or Keytruda alone over approximately one year. The combination therapy met both primary and secondary endpoints, including reducing recurrence and preventing spread to other parts of the body. No new safety concerns were identified during the study.
Moderna’s shares rose to $103.60 in premarket trading, while Merck’s climbed 7.5% before the bell. The companies previously reported mid-stage trial results in January, showing a 49% reduction in the risk of recurrence or death after five years. Analysts at Barclays estimate the therapy could generate about $3 billion in melanoma treatment revenue by 2035.
Melanoma, the deadliest form of skin cancer, affects more than 1.5 million people in the U.S., according to National Cancer Institute data from 2023. The trial’s findings underscore the potential of mRNA technology in oncology beyond its initial application in COVID-19 vaccines. Moderna also highlighted its broader pipeline, which includes FDA-approved flu and COVID-19 vaccines, as well as experimental shots for norovirus and Lyme disease.
