Moderna Inc.’s experimental personalized cancer vaccine reduced the risk of relapse or death from melanoma when combined with Merck & Co.’s Keytruda in a mid-stage trial, a key step in expanding the use of messenger RNA technology beyond COVID-19 prevention. 

The two therapies cut the risk of death or recurrence of the lethal skin cancer by 44 per cent, the companies said Tuesday in a statement. The drugmakers plan to move the combination into final-stage studies next year. Moderna shares rose 13 per cent at market open in New York.

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Merck’s Keytruda, which prevents cancer cells from evading immune system defenses against tumors, has become a mainstay of melanoma treatment, both in advanced inoperable cases and prevention of recurrences after surgery. The Moderna vaccine trial, is aimed at using an mRNA vaccine to stimulate additional immune response beyond those achieved with Keytruda alone.

The results provide the first real evidence of benefit for an mRNA cancer therapy, but the results of the study also suggest “a limited number of events or lack of effect in a subgroup of patients,” Bloomberg Intelligence analyst Sam Fazeli wrote. 

Skin cancers are by far the most common human tumors, and melanoma — an aggressive, hard-to-treat form — accounts for about one per cent of the total. About 100,000 people are diagnosed annually with melanoma, and more than 7,000 of them die each year, according to the American Cancer Society. 

To make the vaccine, Moderna takes a biopsy of a tumor, isolates some of the proteins and integrates them into a vaccine that teaches the immune system to recognize those markers. That helps the body fight the cancer if or when it returns.

NEW APPLICATIONS

Researchers have been working on personalized cancer vaccines for decades with only limited success, not least because they’re hard to manufacture on a large scale. Moderna’s messenger RNA technology is more flexible than many older technologies, making one-of-a-kind bespoke shots more practical to produce.

The company has been searching for successful new applications for mRNA, which facilitated fast development and production of COVID-19 vaccines. Companies including BioNTech SE, Pfizer Inc.’s partner in making COVID vaccines, had been experimenting with mRNA vaccines against cancer before the pandemic. 

Moderna believes it now has enough data to test its vaccine in other types of cancers, Chief Executive Officer Stéphane Bancel said in an interview with Bloomberg Television. 

“Is it going to work everywhere? I don’t know. But we’re going to try aggressively,” he said, adding Moderna has a formidable balance sheet thanks to its COVID vaccine sales and Merck will be splitting the development costs. 

Shares of Moderna rose 19 per cent, to $196.45, at 9:49 a.m. in New York, and Merck shares were up less than 1 per cent. Moderna’s fallen 35 per cent this year through Monday. Merck is up 42 per cent.