A personalised melanoma vaccine cut the risk of cancer returning in a large trial

A personalised mRNA vaccine, Intismeran, added to the immunotherapy Keytruda, cut the risk of dying or of melanoma returning by 42 percent at two years, compared with Keytruda alone. BBC News reported the trial on October 23, 2026. The risk of the cancer spreading was 38 percent lower.

The study followed 1,137 adults after surgery for melanoma. About two-thirds received the vaccine, which is built from the genetics of a person's tumour, and the rest received a placebo. Professor Pippa Corrie at Addenbrooke's Hospital in Cambridge ran part of the study. Tony Chapman, 75, of Corby, joined after a melanoma removed in 2019 returned in a lymph node and was operated on again. He does not know whether he received the vaccine or the placebo. Three years on, his six-month checks have found no cancer.

The results were due to be presented at the ESMO meeting in Madrid on October 24. They have not been peer-reviewed. Professor Alan Melcher of the Institute of Cancer Research, who was not part of the trial, called it an impressive proof of principle and said it cannot be assumed to work for every cancer. Longer follow-up is still needed for overall survival. The vaccine is not approved. MSD and Moderna are talking with regulators, and a filing next year is possible. Use on the NHS would also depend on cost. What this trial shows is a lower risk of return or death, at two years, in this group of adults with melanoma.