REVOLUTIONARY personalised cancer vaccines tailored to individual patients have produced highly promising results in an early clinical trial.

The vaccines against deadly melanoma skin cancer triggered a "very strong" immune response in three patients with no adverse side effects.

Crucially, the customised vaccines appeared to boost the number and diversity of immune system "killer T-cells" that target tumours.

Scientists believe they could pave the way to personalised immunotherapy not only for melanoma but also other cancers.

Dr Alan Worsley, senior science communications officer at Cancer Research UK, said: "This exciting but very early stage trial shows that it may be possible to create vaccines that are tailored to the specific genetic mistakes in a patient's cancer.

"At the moment it's not clear how effective this immunotherapy would be at killing cancer cells in the body and improving survival, but this promising study sets the stage for creating vaccines that are designed to target each patient's individual tumour in the future."

Previous cancer vaccines have focused on normal proteins commonly present at high levels in particular kinds of tumour. But those same proteins are also found in healthy cells, making it difficult to trigger a potent immune response.

The new approach involved first mapping the DNA of individual patients' tumours and samples of healthy tissue to identify proteins unique to cancer cells.

Computer analysis and laboratory tests revealed which of these "neoantigens" would be most likely to stimulate a strong immune response and work in a vaccine.

Trial leader Dr Gerald Linette, from Washington University School of Medicine in St Louis, US, said: "Our team has developed a new strategy for personalised cancer immunotherapy.

"Many researchers have hypothesised that it would be possible to use neoantigens to broadly activate the human immune system, but we didn't know that for sure until now. We still have much more work to do, but this is an important first step and opens the door to personalised immune-based cancer treatments."