A personalised mRNA cancer vaccine, used alongside an existing immunotherapy drug, has been linked to a 42 percent reduction in the risk of melanoma returning or patients dying after surgery, according to clinical trial results.
Patients who received the experimental vaccine, called intismeran autogene, together with the approved immunotherapy drug Keytruda, had a 42 percent lower risk of cancer recurrence or death compared with those who received Keytruda alone, CNN reports.
The vaccine uses the same mRNA technology that underpins Moderna's COVID-19 shot, but instead of targeting a virus, it is designed to help the immune system recognise and attack cancer cells.
It is custom-built for each patient: after surgery removes the tumour, a sample is sequenced and the vaccine is tailored to genetic markers most likely to trigger an immune response.
"This personalised cancer vaccine boosts the body's immune response only against the cancer cells that are there," Dr Michael Postow, chief of the melanoma service at Memorial Sloan Kettering Cancer Center, told CNN. "It is a much more targeted immune boost directly against that patient's individual tumour."
Developers Merck and Moderna said they are engaging with regulatory authorities following the results. Analysts at RBC Capital Markets expect the US Food and Drug Administration to approve the therapy next year, although no approval has yet been granted.
The companies are also testing the technology against lung and pancreatic cancers.
The results were presented at a meeting of the European Society for Medical Oncology in Madrid and are based on a median follow-up of around two years.
The trial is continuing to assess overall survival, with the companies noting a "favourable trend" but saying it is too early to draw conclusions, CNN reported.
Despite the findings, Moderna's shares fell 18 percent on Thursday, with analysts pointing out that the results were slightly less striking than those of an earlier, smaller trial. Even so, the stock remains up more than 500 percent year-to-date.