Patients with deadly skin cancer could soon benefit from a personalised vaccine that has been shown to slash the risk of death or their cancer returning by nearly half.
Melanoma is one of the most aggressive and fatal types of skin cancer, affecting around 21,000 people every year in the UK.
Just 40 per cent of patients will survive their cancer for five years once it has spread to nearby lymph nodes and distant organs like the lungs, liver or brain.
Researchers behind the vaccine, intismeran, say the results could herald a new era in fighting disease.
The trial found that giving the vaccine alongside immunotherapy reduced the risk of melanoma spreading by 38 per cent over two years - compared to immunotherapy alone.
It is the first personalised cancer vaccine to show positive results in a phase three clinical trial.
Dr Catherine Elliott, Director of Research at Cancer Research UK, described the findings as 'promising', allowing more patients to remain cancer free after surgery.
'These results are really encouraging for people with melanoma, a cancer that can come back aggressively after surgery,' she said.
Intismeran uses the same mRNA technology as Covid Jabs
'Cancers differ from person to person, so research into tailored treatments is vital.'
The trial - due to be presented at the European Society of Medical Oncology (ESMO) cancer conference in Madrid - involved 1,137 patients whose cancer had been removed, but were at high risk of it returning.
All were treated with an immunotherapy drug called pembrolizumab for a year, which helps the body's immune system target and attack cancer cells.
Immunotherapies have become the mainstay for treating melanoma - but they don’t work for all patients as cancer cells can become resistant to therapy.
For this reason, researchers have started to look at adding vaccines.
Around two thirds of patients also received the vaccine with the rest given a placebo.
Intismeran is personalised to each patient, using information from their own tumours to help train their immune system to better recognise cancer cells, and target them if they return.
The trial - spearheaded by researchers at the Melanoma Institute Australia - found that at two years post treatment, patients who had received the jab were 42 per cent less likely to have seen their cancer come back, or spread to other organs.
For every 100 patients treated, adding the vaccine meant that an additional 12 people were alive and cancer-free two years after treatment.
However, approximately six more experienced treatment-related side effects including fever, fatigue and reactions around the injection site.
'Put another way, we would need to treat approximately nine patients to prevent one additional recurrence or death over that period,' Dr Lennard Lee, an expert in cancer vaccine research at the University of Oxford, said.
'That’s a remarkably encouraging result.'
Other experts who were not involved in the study welcomed the findings, saying the results could mark the turning point in cancer treatment.
'Melanoma is leading the way, but vaccines are being investigated in many other cancers, including cancers that are very difficult to treat and don’t respond well to current immune-based treatments,' Professor Alan Melcher, from the Institute of Cancer Research London said.
'The challenge now is working out which cancers and which patients are most likely to benefit, and which are the best vaccine targets to go for.
'We’re closer to cancer vaccines becoming part of routine treatment than we’ve ever been.'
The drug manufacturers MSD and Moderna say the same approach is already being tested against other tumours, including kidney, bladder and lung cancer.
And they hope to be able to file for approval from medicine regulators as early as next year.
However adoption by the NHS will depend on cost, given that each vaccine needs to be trained on the genetic fingerprint of an individual patient’s tumour.
The trial will continue so that the patients involved can be monitored – to see if their cancer returns and to assess whether the drug ultimately helps them live longer.
Dr Lee added that the findings are an important proof of principle for the field, but cautioned that the vaccine can only be considered a true breakthrough if all patients can benefit from it equally.
'The next challenge is to make it practically achievable and affordable for everyone affected by cancer,' he said.