A vaccine has been shown to help keep melanoma, the deadliest form of skin cancer, from coming back in patients at higher risk of recurrence, the drug makers said.

About 112,000 new melanoma cases will be diagnosed this year in the US. More than 8,500 are expected to die from this cancer in 2026.

Intismeran autogene, made by Moderna, could eventually save lives by helping keep cancer under control in more patients.

The new drug was tested with Keytruda (aka pembrolizumab, an immunotherapy made by Merck) in phase 3 trials, the final major stage of testing before a drug can be submitted to the FDA for approval.

Melanoma is the deadliest form of skin cancer. Africa Studio – stock.adobe.com

The companies said this is the first positive phase 3 result for a personalized cancer vaccine and shows “meaningful improvement” over treatment with Keytruda alone, which has been used for more than a decade in cancer care.

The results mark a step forward in the effort to treat not just melanoma but other forms of cancer with vaccines designed to help keep patients disease-free.

Controlling melanoma

With intismeran and Keytruda together, researchers found that patients with later-stage melanoma (stage 2B up to stage 4) went longer without their cancer returning and without it spreading to distant parts of the body.

The new drug is an mRNA vaccine, like the vaccines used for COVID-19. These work by giving the body instructions on how to identify and fight a disease.

Unlike the COVID vaccine, intismeran is personalized.

This means each vaccine has information that’s unique to a patient’s specific cancer. It works by teaching the immune system what to look for so it can better find and destroy the cancer on its own.

This has benefits over treatments such as chemotherapy, which can launch a broad attack on both healthy and cancerous cells. Cancer vaccines like intismeran are designed to be more targeted, giving immune system specific information about the cancer so it can continue to recognize and attack it.

This is especially important for later-stage melanoma patients, who have a much higher risk of recurrence. For example, someone with stage 2C cancer had a 45% chance of recurrence, while someone with stage 3C cancer had an 85% chance.

Patients with a later stage of melanoma have a higher risk of the cancer coming back after treatment. Maris – stock.adobe.com

A revolutionary treatment, a step closer to a cure

There are a number of other cancer vaccines using intismeran being studied in phase 2 and 3 trials, with the goal of treating cancers like lung cancer, bladder cancer and kidney cancer.

The vaccines don’t work on their own, which is why they’re being tested with an immunotherapy like Keytruda.

That’s because even when the body is given specific information about the tumor so it knows what to hunt, tumors can sometimes evade detection by tricking the immune system.

Keytruda works with the cancer vaccine by helping prevent cancer cells from hiding from the immune system, allowing T-cells to come in and kill them.

Cancer vaccines are an enormously promising field because of their precise targeted, approach and potential to provide long-term protection against recurrence.

Experts believe that in the future, cancer vaccines could help “to eradicate advanced cancer, cure patients in the adjuvant setting, and prevent the development of malignancy in high-risk patients.”