The world's first personalized vaccine for melanoma, the deadliest form of skin cancer, is being tested on British patients for the first time.
Melanoma affects about 132,000 people a year worldwide and is known as the fifth most common type of cancer.
The drug has the potential to stop bladder, lung and kidney cancer and is custom designed for each person to identify cancer cells and stop the disease from coming back.
A phase 2 trial found that the vaccines drastically reduced the risk of the cancer returning in melanoma patients.
Now a definitive, phase 3 trial has been launched and is being led by University College London Hospitals NHS Foundation Trust.
The global phase 3 trial will now include a wider range of patients and aims to recruit around 1100 people.
One of the first patients in the trial is Steve Young, 52, who said: "I'm really, really excited and this is my best chance to stop the cancer."