An Australian-led cancer vaccine trial has significantly cut the risk of melanoma recurrence and death, in a world-first breakthrough described by researchers as a “moon landing” moment.

The remarkable results of the phase three trial, which combined a personalised mRNA vaccine with a standard post-surgery immunotherapy drug, signify a new frontier in cancer treatment.

Principal investigator professor Georgina Long, who was named Australian of the Year alongside the late Richard Scolyer in 2024, said the trial was a “very, very big leap forward.”

“It’s all the cliches: a landmark moment, moon landing, first flight — it really is a foundational shift,” she said.

It is hoped the development will lead to future breakthroughs in other forms of cancers, by using personalised vaccines which sequence a patient’s own tumour to train the immune system to destroy cancer cells after surgery.

Moderna and Merck announced on Friday the individualised vaccine, intismeran, reduced the risk of melanoma recurrence or death by 42 per cent when combined with immunotherapy drug Keytruda, compared to patients who only underwent immunotherapy.

The trial involved 1137 high risk melanoma patients who had undergone surgery to remove their melanoma and is world’s most advanced study using tailor-made medicine to fight cancer.

The results showed that 82 per cent of participants who received a combination of both treatments were melanoma free after two years, compared to 70 per cent of those given only Keytruda.

Australian mRNA Cancer Vaccine Hub Director associate professor Seth Cheetham described the finding as an “incredible breakthrough” in cancer research.

“This is the first really large trial that’s shown definitively that this technology works, it reduces the risk of recurrence or spread and results in better outcomes compared to standards of care,” he said.

“This is really the gold standard, and it’s what the entire field has been waiting on. It really is the antithesis of a one-size-fits-all approach, which has dominated cancer care for a long time. It’s pioneering a new kind of medicine, in which we are looking at each tumour individually and crafting a unique treatment for it.”

Professor Cheetham said the greatest challenge now was to deliver the medicine at scale.

“Responsive manufacture will be essential in a country where someone is diagnosed with melanoma every 30 minutes,” he said.

“Each patient’s tumour must be sequenced, its neoantigens (abnormal proteins found on cancer cells) selected by an algorithm, and a bespoke mRNA manufactured and quality tested within weeks.

“So, a commercial program will need tens of thousands of individual batches a year rather than a few large ones.”

Moderna chief executive Stephane Bancel said the impact of the trial was “very profound”.

“With this ability to create new T cells that are specific to your tumour … the clinical impact is very profound, and as we saw in the Phase 2 (trial), very lasting,” he said.

Professor Long, a University of Sydney researcher and co-medical director at the Melanoma Institute Australia, explained the treatment was different to traditional vaccines which prevent disease in healthy people.

“This is a therapeutic vaccine, meaning it is designed for people who already have cancer, to help stop the cancer coming back,” she said.

“Even after surgery to remove a melanoma when it has spread to lymph nodes and distant parts of the body, there is always a risk that the cancer can return.”

Intismeran is made with the same Nobel Prize-winning mRNA technology used in the development of the COVID-19 vaccines.

Professor Long’s enduring partnership with fellow Australian Melanoma Institute co-director and close friend Professor Scolyer, who died from brain cancer in June, has led to numerous advances in melanoma treatment in recent years.

Known as “Australia’s cancer”, melanoma was fatal in its advanced stages less than a decade ago but has become a curable disease thanks to advances in immunotherapy.

But one person still dies in Australia from the disease every six hours.

Last year a life-saving therapy which delivered pre-surgery combination immunotherapy for high-risk stage three melanoma patients was listed on the Pharmaceutical Benefits Scheme after a successful trial led by Professor Long.

The trial of frontline treatment NADINA proved “without a doubt” that giving combination immunotherapy before, rather than after, surgery led to higher survival rates in patients.

“This is great for melanoma and sets a benchmark for all cancers. Australia is leading the way in revolutionising cancer treatment across the globe,” Professor Long said last year.

The latest trial will be presented at the European Society of Medical Oncology on Sunday, and the results have also been accepted for publication in the New England Journal of Medicine.