New 'landmark' drug shown to prevent recurrence of deadly melanoma

Two US pharmaceutical giants, Merck and Moderna, say an experimental melanoma drug that delivers treatment tailored to a patient's specific tumour prevented the deadly form of skin cancer from returning in a large clinical trial.

Called "intismeran autogene," it is based on the same messenger ribonucleic acid technology behind Covid-19 vaccines.

Researchers have been working on developing mRNA treatments against cancer, but this is the first time one has shown positive results in a Phase 3 trial.

When delivered along with pembrolizumab, an immunotherapy drug and the current standard of care, intismeran autogene prevented melanoma recurrence and prevented the cancer from spreading to other organs, the companies said in a statement.

The news sent shares in Moderna soaring 128 per cent to $US143 ($200) while Merck's stock was up more than 10 per cent to $US149.50.

The trial lasted approximately a year and involved 1,137 patients who, following surgical removal of their cancers, were randomised into groups, with two-thirds receiving the new treatment plus pembrolizumab, while the rest received pembrolizumab alone.

The companies said they would present their data at an upcoming international conference and begin filings with regulators for approval.

Professor Georgina Long, the study's principal investigator and medical director of Melanoma Institute Australia said in a statement that the "results represent a landmark moment for adjuvant melanoma treatment".

"Intismeran in combination with pembrolizumab has the potential to establish a new treatment paradigm in the adjuvant melanoma setting, helping patients remain cancer-free for longer," she added. 

The treatment works by taking a sample of the patient's tumour and identifying its unique mutational signature, or "fingerprint," then using messenger RNA technology to fight it.

Messenger RNA technology uses synthetic molecular instructions wrapped in tiny fat bubbles to teach the body how to make specific proteins.

The technology came to the fore during the Covid-19 pandemic, when Moderna and Pfizer developed vaccines that were highly effective against serious forms of the illness.

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

"Together with Merck, we are now studying intismeran in combination with pembrolizumab and other anti-cancer therapies, and as a monotherapy, across multiple tumour types and stages of disease, including melanoma, lung, bladder and kidney cancers," Moderna chief executive Stephane Bancel said in a statement.