Merck and Moderna Say Personalized mRNA Melanoma Vaccine Cut Recurrence Risk in Phase 3 Trial

Merck and Moderna reported that an experimental personalized mRNA vaccine, called intismeran, given with the immunotherapy drug Keytruda, reduced the risk of melanoma recurrence or death by 42% compared with Keytruda alone. The Phase 3 trial enrolled 1,137 patients with Stage IIB-IV melanoma whose tumors had been surgically removed. The companies released detailed results Thursday: at two years, 82.2% of patients given the vaccine plus Keytruda were alive without recurrence, versus 70% on Keytruda alone. The combination also cut the risk of distant spread or death by 38%. Dr. Marjorie Green, Merck's head of oncology clinical development, told The New York Times the vaccine effectively trains the body to recognize and kill the cancer, and said Merck plans to seek regulatory approval as soon as possible. Scientists sequence each patient's tumor to find mutated proteins found only on cancer cells, then use mRNA to train the immune system to attack them. The technology is the same Nobel Prize-winning mRNA approach behind COVID-19 vaccines. Researchers are also testing therapeutic vaccines for kidney, bladder, non-small-cell lung and pancreatic cancer and glioblastoma.

Right-leaning Daily Wire leads with the trial's numbers, including the 42% and 38% risk reductions, the two-year survival rates and the 1,137-patient size, and quotes Merck's Green and a researcher, Dr. Robert Vonderheide. Its headline calls the vaccine a promising advance. Left-leaning outlets tracked by Crosswire had not reported this story at the time of writing, while alternative and right-leaning outlets had. The Times of Israel, the alternative source, offers a distinct angle: its headline stresses that the vaccine sharply lowers the chance of tumors returning, and it names intismeran and ties it to the COVID-19 mRNA technology. The available text shows no real factual conflict between the two, only different emphases.