Personalized Melanoma Vaccine Could Be a ‘Game Changer’ by Teaching the Body to Fight Cancer Cells

The mRNA therapy, designed to prevent treated skin cancer from returning, is entering its third phase of trials

An over-the-shoulder shot of a woman, wearing blue gloves, preparing a syringe.
Researchers are recruiting some 1,100 people globally to participate in the trial's third phase. Ivan Radic via Flickr CC BY 2.0 DEED

A global trial has begun for the world’s first personalized vaccine for melanoma—the deadliest form of skin cancer, which affects about 132,000 people per year. If successful, the therapy will prevent melanoma from returning in patients who have already been treated.

Participants in the Phase III trial, led by the University College London Hospitals NHS Foundation Trust, begin by having a piece of their tumor surgically removed and its DNA sequenced. This genetic analysis informs the design of each person’s individualized vaccine, an mRNA therapy developed by drug giants Merck and Moderna.

Each vaccine prompts the patient’s body to create antibodies that attack specific markers found only on their cancerous cells. Using the collected DNA, the therapy can zero in on up to 34 of these unique markers in the patient’s tumors, known as neoantigens. This customized anti-tumor immune response, doctors and scientists hope, will prevent melanoma from recurring.

“This is one of the most exciting things we’ve seen in a really long time,” Heather Shaw, the national coordinating investigator for the trial, tells the Guardian’s Andrew Gregory. “This is very much an individualized therapy, and it’s far cleverer, in some senses, than a vaccine.”

Some 1,100 people are being recruited globally to participate in the therapy’s expanded trials, meant to gather more data on its effectiveness. Previous results from the Phase II study, published in February in The Lancet, showed the vaccine was effective alongside Keytruda immunotherapy. Patients in that trial experienced a “49 percent reduction in the risk of recurrence or death after three years compared with the standard treatment,” according to the United Kingdom’s National Institute for Health and Care Research.

One of the first people to enroll in the new trial is 52-year-old Steve Young, a musician from Hertfordshire in England. Young had a melanoma growth removed from his scalp last summer, and this treatment is intended to prevent his cancer from returning.

“[The trial] gave me a chance to feel like I was actually doing something to fight a potential unseen enemy,” he tells BBC Radio. “So rather than just sit there and wait and hope it was never going to come back, I actually had this chance to get involved in putting on some boxing gloves and squaring up to it.”

So far, the side effects of the shot have proven to be no worse than those of a Covid or flu vaccine, such as a sore arm and some fatigue.

The field of personalized cancer vaccines is still evolving. Earlier this month, a Gritstone Bio trial for a similar therapy meant to treat colorectal cancer failed, STAT News Jason Mast reports.

Still, researchers remain hopeful that, if this new trial is successful, similarly personalized mRNA therapies can be applied in the future to tumors in kidneys, lungs and bladders.

“I think there is a real hope that these will be the game changers in immunotherapy,” Shaw tells the Guardian.

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