A personalized mRNA vaccine, intismeran, slashes melanoma recurrence risk by 42% when paired with immunotherapy, marking a major breakthrough in cancer treatment.
New cancer vaccine shows promise
A new personalized cancer treatment combining a messenger RNA vaccine with immunotherapy has been shown to reduce the risk of melanoma recurrence or death by 42 percent, according to a phase 3 trial. The findings were shared at the end of October 2026 during the European Society for Medical Oncology (ESMO) congress and are expected to appear in the New England Journal of Medicine.
Vaccine is tailored to each patient
The vaccine, called intismeran, was developed jointly by MSD (Merck & Co) and Moderna. It is the first messenger RNA therapy to demonstrate such a significant benefit and the first of its kind to be manufactured from each patient's tumor tissue. This personalization allows the treatment to target specific proteins found in the patient's cancer cells.
Process involves identifying cancer-specific proteins
The treatment begins with a biopsy, where tumor cells are compared to the patient's healthy cells to identify neoantigens—abnormal proteins unique to the cancer. These neoantigens are then encoded into messenger RNA and injected into the patient. The patient's cells use this information to show the immune system what the cancer looks like.
Immunotherapy boosts the body's defenses
Pembrolizumab, a standard immunotherapy drug, is used alongside the vaccine. It helps the immune system by removing the "brakes" that tumors use to avoid detection and attack. This combination aims to enhance the body's natural ability to fight cancer more effectively.
Expert highlights historic achievement
Georgina Long, who led the global trial, is the medical director of the Melanoma Institute Australia and a professor at the University of Sydney. She stated that this achievement marks a first in the history of cancer drug development, as no previous treatment has shown such a significant benefit in this way.
