Melanoma personalised mRNA vaccine trial begins in UK

A new 'personalised' treatment for melanoma, based on the same technology behind the COVID-19 vaccines (see BioNews 1109), is now in Phase 3 trials in the UK.

The vaccine, known as mRNA-4157 (V940), is designed to activate the patient's immune system to specifically target their tumour. By enabling a more personalised approach to treatment, researchers hope that outcomes for patients with melanoma, as well as other cancers, can be improved.

'This is one of the most exciting things we've seen in a really long time' Dr Heather Shaw, the national co-ordinating investigator for the trial based at University College London Hospitals (UCLH), said. 'This is a really finely honed tool. To be able to sit there and say to your patients that you're offering them something that's effectively like the Fat Duck at Bray versus McDonald's – it's that level of cordon bleu that's coming to them'.

Melanoma is the deadliest form of skin cancer, which affects around 132,000 people per year globally. While surgery is the main treatment method, melanoma is also considered to be uniquely suited to immune-based treatments, as it often triggers a strong immune response.

The vaccine activates this immune response by targeting specific neoantigens, which are proteins expressed on the surfaces of tumour cells that the immune system uses for identifying the tumour cells.

By analysing a sample from a patient's tumour, researchers can find the set of neoantigens expressed by that tumour. This allows for a personalised mRNA vaccine to be developed, which specifically targets that patient's tumour.

'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', said Dr Shaw. 'They may have some shared new antigens, but they're likely to have their own individual new antigens that are important to their tumour and so, therefore, it is truly personalised.'

The vaccine, developed by Moderna and Merck Sharp and Dohme, has already undergone Phase 2 trials which found that patients treated with the vaccine, alongside the immunotherapy Keytruda, were 49 percent less likely to experience death or recurrence after three years, compared with those who received only Keytruda.

This new trial will aim to recruit between 60 to 70 patients across multiple UK centres, as part of a global trial of around 1100 people.

'I'm really, really excited' said Steve Young, a musician from Hertfordshire who was one of the first patients at UCLH to receive the treatment. He told the Radio 4 Today programme, '[the trial] gave me a chance to feel like I was actually doing something to fight a potential unseen enemy'.