Personalized vaccine reduces the risk of melanoma returning, but benefits for other cancers remain unproven

A new personalized cancer vaccine called Intismeran has shown promising results in a major clinical trial. The study included 1,137 adults with melanoma, a type of skin cancer, whose tumors had previously been removed by surgery. The vaccine was given alongside Keytruda, an established drug that helps the immune system recognize and attack cancer cells.

According to the reported results, the combination reduced the risk of melanoma returning or death by 42% compared with Keytruda alone. After two years, 82.2% of patients who received the combination were alive without their disease returning, compared with 70% of those who received Keytruda alone. The risk of melanoma spreading to other parts of the body was also reduced by 38%.

These figures need to be interpreted carefully. A 42% reduction in risk does not mean that 42% of patients were cured or that the vaccine prevented every recurrence. The results apply to a specific group of patients and compare the combination treatment with an existing therapy.

The vaccine is made individually for each patient using genetic information from their tumor. A similar approach is already being studied for kidney, bladder and lung cancer. However, promising results in melanoma do not prove that the same method will work against other types of cancer.

Important questions remain. The trial results have not yet been published in a peer-reviewed medical journal, and researchers will continue monitoring participants to find out how long the benefits last and whether the treatment helps patients live longer overall. The manufacturers are engaging with regulators about possible approval, but the treatment is not yet widely available.

The findings represent an important and encouraging development in melanoma treatment, not a universal vaccine against cancer. Further research is needed before the long-term benefits and potential use against other cancers can be established.