Cancer vaccine wards off recurrence for up to three years

The world’s first cancer vaccine prevents cancer returning in melanoma patients for as long as three years, new results from a major clinical trial shows.

Georgina Long from the Melanoma Institute of Australia.

The world’s first cancer vaccine has been found to prevent cancer returning in melanoma patients for as long as three years, new ­results from a major clinical trial show.

The cancer vaccine that has been developed by Moderna is now moving to phase 3 studies after the second tranche of data from the phase 2 study showed the stunning results.

The vaccine, which is dubbed mRNA-4157/V940, is a personalised mRNA vaccine that is given in conjunction with the immunotherapy drug Keytruda. It had already been found to reduce the recurrence of melanoma by 50 per cent in initial human trials when administered alongside the immunotherapy drug.

Now new data shows that among patients with resected high-risk stage III or IV melanoma, adjuvant treatment with the vaccine in combination with Keytruda continued to demonstrate a clinically meaningful improvement in recurrence-free survival for as long as three years. The prevention of cancer recurrence was found in the latter ­stages of the phase 2 trial to be as high as 49 per cent.

“The really important point is that we saw the maintenance of that benefit now out to three years, which gives us confidence that this substantial reduction in the risk of relapse is likely to be durable for a long time,” said Moderna president Stephen Hoge. “Therefore the potential for this therapy is as good as we hoped a year ago.

“I think it’s confirmatory that this really does have the potential to be a new approach to treating cancer patients, and across a wide range of cancers.”

Cancer vaccines are in their infancy and Moderna’s vaccine for melanoma patients is the first that has been developed. The technology was accelerated by Covid-19, when mRNA vaccines were widely trialled and proved effective. The technology is now being invested in heavily around the world, including in Australia which has established a number of research facilities and manufacturing plants.

Cancer vaccines are formulated to be specific to each patient’s cancer and are ­developed based on the individual’s tumour biopsies, which are then genetically sequenced. Scientists identify that person’s cancer cells’ specific mutations and create an mRNA vaccine that primes the immune system’s t-cells to target the ­mutated cells.

“This is an era of individualised medicine,” said Dr Hoge. “This is a medication that’s very different than anything else that’s been used, because you make it for one patient based on what their individual cancer looks like. We’ve always wanted to move down a path of individualised medicine, but this is a sign that we may be going down that path.”

Other cancer vaccines are now in development, including by brain cancer suffering and eminent pathologist Richard Scolyer and his colleague Georgina Long, who are using the melanoma technology and applying it to Professor Scolyer’s brain cancer.

Professor Scolyer announced earlier this year that he was “patient zero in what may become the new frontier of brain cancer treatment”.

Professor Long was a principle investigator in Moderna’s melanoma cancer vaccine. She emphasised the phase 2 study was a small study involving 157 patients and would now need to be replicated in a larger phase 3 trial, which has begun recruiting.

“It’s a platform for identifying something novel and new in each individual patient’s tumour … and making an mRNA vaccine to stimulate their tumour against their unique melanoma,” Professor Long said.

“The implications are that this could work in other cancers. But it’s still early days.”

Moderna said it may consider applying to regulators for conditional approval of the vaccine before the phase 3 study is complete based on the good phase 2 results.