Merck, Moderna claim 'promising' skin cancer vaccine results in key trial

The vaccine, called intismeran autogene, showed "statistically significant and clinically meaningful improvements" for skin cancer patients when used with Merck's Keytruda treatment, the companies said in a statement.

Unlike conventional vaccines, so-called therapeutic vaccines like intismeran treat rather than prevent a disease, by training the body's own immune system against a tumour or other invaders.

The news sent shares in biotech specialist Moderna soaring in early New York trading, up more than 90 percent to around $120 a share, while Merck's stock was up 10 percent.

"This represents the first positive Phase 3 readout for an individualised neoantigen therapy (INT) and for an mRNA-based cancer therapy," the companies said.

They were referring to messenger RNA technology, which proved highly effective against serious forms of Covid-19.

They did not provide specific details of the study results, nor say when the US Food and Drug Administration might accept the vaccine's admission for approval.

Both the FDA and the European Medicines Agency have placed the therapy on an expedited review pathway.

Melanoma is one of the deadliest forms of skin cancer, with over 330,000 new cases diagnosed worldwide in 2022, the companies said.

"For many years, the idea of creating an mRNA treatment designed specifically for an individual patient's cancer was aspirational. We are now helping turn that vision into a reality," Moderna's CEO Stephane Bancel said in the statement.