The launch of patient trials involving the world’s first personalised mRNA cancer vaccine for melanoma has been welcomed by experts for its “game-changing” potential to permanently cure cancer.
Surgery is generally the main treatment for melanoma, the biggest skin cancer killer, although radiotherapy, medicines and chemotherapy are also sometimes used.
Now, reports The Guardian, experts are testing new jabs that are custom-built for each patient and which tell their body to target cancer cells to prevent the disease ever coming back.
A phase 2 trial found the vaccines dramatically reduced the risk of the cancer returning in melanoma patients, and a final, phase 3, trial has just been launched, led by University College London Hospitals NHS Foundation Trust (UCLH).
Dr Heather Shaw, the trial’s national co-ordinating investigator, said the jabs had the potential to cure people with melanoma and are also being tested in other cancers, including lung, bladder and kidney.
“This is one of the most exciting things we’ve seen in a really long time,” she said. “It is a really finely honed tool… patients are excited.”
The vaccine is an individualised neo-antigen therapy, designed to trigger the immune system so it can fight back against a patient’s specific type of cancer and tumour.
Known as mRNA-4157 (V940), the vaccine targets tumour neo-antigens, which are expressed by tumours in a particular patient. These are markers on the tumour that can potentially be recognised by the immune system.
The jab carries coding for up to 34 neo-antigens and activates an anti-tumour immune response based on the unique mutations in a patient’s cancer.
To personalise it, a sample of tumour is removed during the patient’s surgery, followed by DNA sequencing and the use of artificial intelligence. The result is a custom-built anti-cancer jab that is specific to the patient’s tumour.
“This is very much an individualised therapy and it’s far cleverer in some senses than a vaccine,” said Shaw. “It is absolutely custom-built for the patient – you couldn’t give this to the next patient in the line because you wouldn’t expect it to work.
“They may have some shared new antigens, but they’re likely to have their own very individual new antigens that are important to their tumour and so, therefore, it is truly personalised.”
The ultimate aim is to permanently cure patients of their cancer, Shaw said. “I think there is a real hope that these will be the game-changers in immunotherapy.”
Phase 2 data found that people with serious high-risk melanomas who had the jab alongside the immunotherapy Keytruda were almost half (49%) as likely to die or have their cancer return after three years than those who were given only Keytruda.
Patients received 1mg of the mRNA vaccine every three weeks for a maximum of nine doses, and 200mg of Keytruda every three weeks (maximum 18 doses) for about a year.
The phase 3 global trial will now include a wider range of patients, and aims to recruit about 1 100 people. The UK arm aims to recruit at least 60 to 70 patients across eight centres.
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