Personalized mRNA vaccine for melanoma cut risk of cancer’s return in late-stage trial

Moderna and Merck’s personalized mRNA vaccine for melanoma reduced the risk of cancer recurrence and death by 42% compared with standard treatment in a trial.

A new personalized mRNA vaccine for melanoma is being hailed by some oncologists as a major breakthrough after it reduced the risk of cancer recurrence and death by 42% compared with standard treatment in a late-stage clinical trial. Dr. Robert Vonderheide, director of Penn Medicine’s Abramson Cancer Center and president-elect of the American Association for Cancer Research, said the results are a “game changer.” “It will be seen as the first step toward using cancer vaccines to their full potential,” said Vonderheide, who was not involved in the trial. The experimental vaccine, called intismeran, was developed by drugmakers Moderna and Merck. Intismeran is personalized to each patient, using genomic data from the patient’s tumor.

The new results will be presented Saturday at the annual meeting of the European Society for Medical Oncology in Madrid. The trial included 1,137 Stage 3 melanoma patients. All of the participants had undergone surgery to remove their tumors and were being treated with Merck’s immunotherapy drug Keytruda. In addition to Keytruda, 757 of the participants also got the personalized vaccine; the remaining 380 got a placebo. Two years later, 82% of the patients who received both the new vaccine and the immunotherapy hadn’t had a recurrence, compared with 70% in the immunotherapy plus placebo group. In Stage 3 melanoma, the cancer has spread to nearby