A new vaccine has been developed that – when used in conjunction with existing therapies – has been found to not only successfully treat aggressive melanoma, but also can prevent its recurrence.

Researchers at the Scripps Research Institute in San Diego, California, worked with experts at other medical institutions to develop the vaccine that has proven 100% successful when tested in mice. They first screened around 100,000 compounds to look for one that could help them boost the effectiveness of a commonly-used cancer immunotherapy drug.

The co-lead of the study, Professor Dale Boger, commented: “Just as a vaccine can train the body to fight off external pathogens, this vaccine trains the immune system to go after the tumour. This co-therapy produced a complete response — a curative response — in the treatment of melanoma.”

Skin cancer study

Three groups were tested – the first were given the cancer vaccine and the second the vaccine plus a molecule called Diprovocim that boosts the immune response. The third group were given the cancer vaccine and a chemical known as alum which also activates the immune system but in a different way. All three groups were also given the anti-PD-L1 immunotherapy used in cancer treatment. The group that received the vaccine plus Diprovocim in addition to the anti-PD-L1 therapy had a 100% survival rate over 54 days.

The researchers established that Diprovocim boosts the immune response by ‘prompting’ the immune system to produce tumour-infiltrating leukocytes, a type of cell that attacks and kills cancer tumours.

Once an individual has been diagnosed and treated for skin cancer, their risk of developing skin cancer again increases greatly so what was also exciting was that the vaccine also protected the body from tumour recurrence.

So far results have only been demonstrated in mice with a genetically-engineered tumour so further testing is required into how this Diprovocium-boosted vaccine will work in humans and also how it might work in combination with other cancer therapies.