Melanoma mRNA Vaccine Cuts Risk of Death or Recurrence by 42% in Phase 3 Trial

A personalised mRNA vaccine for melanoma has cut the risk of the cancer coming back or causing death by 42% in a large late-stage trial, drug makers Moderna and Merck have reported. The vaccine, called intismeran autogene, was given together with the immunotherapy drug Keytruda.

The Phase 3 trial, named INTerpath-001, included 1,137 patients with high-risk melanoma that had been surgically removed. After a median follow-up of 24.6 months, patients who received the vaccine plus Keytruda had a 42% lower risk of recurrence or death than those who received Keytruda alone.

The risk of the cancer spreading to distant parts of the body or causing death was 38% lower in the vaccine group. After two years, 82.2% of patients in the vaccine group were free of recurrence, compared with 70.0% in the Keytruda-only group.

The vaccine is personalised, meaning it is made for each patient using the genetic code of their own tumour. It is designed to teach the immune system to recognise and attack cancer cells that carry those tumour markers.

Melanoma is the most serious form of skin cancer. When it is caught early and removed by surgery, many patients recover, but high-risk cases often return, which is why new treatments after surgery matter so much.

There are important limits to the news. The vaccine is not yet approved for use, and the companies have not yet shown that it improves overall survival. Regulators will review the full data before deciding whether patients can receive it.

Still, experts say a 42% reduction in recurrence or death in a trial of this size is a strong result, and it adds to growing evidence that personalised mRNA vaccines could become a new tool against cancer.

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