Moderna, Merck personalised cancer vaccine succeeds in late-stage melanoma trial

An experimental personalised cancer vaccine from Merck & Co and Moderna helped prevent melanoma from returning or spreading in patients whose tumours had been removed through surgery, the companies said on Wednesday, in a potentially important breakthrough for Moderna's mRNA technology.

The treatment, intismeran autogene, was tested alongside Merck's blockbuster immunotherapy Keytruda in a Phase 3 trial involving more than 1,000 melanoma patients at high risk of recurrence.

The INTerpath-001 trial met its primary goal of improving recurrence-free survival and a key secondary goal of improving distant metastasis-free survival compared with Keytruda alone, the companies said.

The trial involved patients with completely resected stage IIB, IIC, III or IV cutaneous melanoma who had not previously received systemic therapy.

The companies did not disclose detailed efficacy figures from the Phase 3 trial.

The companies said the study would continue to assess overall survival and other secondary endpoints.

They plan to present detailed results at an upcoming international medical meeting and discuss filing applications with regulators.

The treatment is an individualised mRNA-based therapy designed using mutations specific to a patient's tumour. It aims to train the immune system to recognise and attack cancer cells carrying those mutations.

Unlike chemotherapy, which can also damage healthy cells, personalised cancer vaccines are designed to direct the immune response towards cancer-specific targets.

Tesla CEO Elon Musk said on Wednesday that mRNA technology could fundamentally change medicine, writing on X that mRNA has "tremendous promise for curing diseases" and that artificial RNA could make curing diseases "a software problem."

Moderna shares closed at $174.38, up 176.97%, their largest one-day percentage gain.

The results build on a Phase 2b study in melanoma, in which the combination of intismeran and Keytruda reduced the risk of recurrence or death by 49% and the risk of distant metastasis or death by 59% compared with Keytruda alone after five years of follow-up, the companies said.

The safety profile of the combination in the Phase 3 trial was consistent with previous studies, with no new safety signals reported.

Merck's Keytruda, which blocks the PD-1 pathway to help the immune system attack cancer, is one of the world's biggest-selling cancer drugs.

The companies' success comes as interest grows in using mRNA technology beyond infectious diseases.

Moderna's vaccine technology gained prominence through its COVID-19 vaccine, but the company has been expanding its pipeline into cancer and other diseases.