Moderna's Shares Double on Cancer Vaccine News

Moderna's shares more than doubled Wednesday morning on the news that an experimental mRNA-based vaccine aimed at keeping melanoma from spreading or coming back showed "statistically significant and clinically meaningful improvements" among high-risk cancer patients. Moderna and Merck on Wednesday said a test of the personalized cancer vaccine intismeran, paired with Merck's immunotherapy drug Keytruda, helped delay the return of the deadliest form of skin cancer in high-risk patients who had previously had surgery to remove a melanoma. The Wall Street Journal reports they said a secondary goal of curtailing the spread of cancer to other organs was also met.

The companies have not yet released full data or published their results in a medical journal, and they did not specify how long patients lived without their cancer advancing. The companies plan to share more at an upcoming medical conference, reports NBC News. Moderna's stock was up 130% as of 11am ET, while Merck's had risen about 10%. The Journal sums up the potential significance: "The results mark the first successful late-stage trial for a personalized mRNA cancer therapy, validating decades of research into custom treatments engineered specifically for an individual's tumor mutations." How it works:

• While traditional vaccines prevent infections, intismeran is a personalized therapeutic vaccine that is built using a blood sample and biopsy of the patient's particular melanoma. The Journal explains genetic analysis surfaces those cancer cell mutations "that are likely to alert the immune system. Those mutation targets are encoded into mRNA and manufactured" into a personalized shot. It takes about six weeks for that to happen, and patients take Keytruda during that time.
• CNN reports the Phase 3 trial involved 1,137 high-risk patients with stage IIB-IV melanoma. Patients received as many as nine doses of Keytruda plus the personalized vaccine, or Keytruda alone.
• CNN adds that the companies in January shared results from a mid-stage trial that showed the treatment cut the risk of recurrence or death by 49% after five years.