Merck unveiled pivotal results from its investigational mRNA-based cancer immunotherapy on Thursday at the European Society for Medical Oncology congress in Berlin, reporting improved recurrence-free survival in high-risk melanoma patients across three late-stage trials.

The lead programme, developed with Moderna, pairs the individualised neoantigen therapy V940 with Merck's checkpoint inhibitor Keytruda. The combination reduced the risk of recurrence or death compared with Keytruda alone in patients who had undergone surgery for advanced melanoma.

The therapy uses a patient's tumour genetics to build a tailored vaccine manufactured individually for each recipient. Dr Eliav Barr, Merck's chief medical officer, said the results confirmed earlier Phase 2b findings and supported expansion into additional tumour types, including lung cancer.

Merck confirmed the full datasets would be submitted to health authorities in the United States and Europe in the coming months. Analysts said positive readouts could accelerate regulatory filings and strengthen Merck's oncology pipeline as Keytruda approaches patent expiry later this decade. Moderna shares, which have struggled since the decline in Covid vaccine demand, were expected to react to the data.