Merck and Moderna’s success with a personalized cancer vaccine designed to keep melanoma at bay opens a ​new avenue of treatment that doctors hope will work against many types of tumors.

Pharma companies Merck and Moderna have announced that their personalised mRNA cancer vaccine, combined with the immunotherapy drug Keytruda, has cleared phase three human trials for melanoma.

The companies said their Phase 3 trial of intismeran autogene, when used with Merck's cancer immunotherapy Keytruda, met its key goals in patients with melanoma that had been surgically removed but wa...