A pair of drugs that make the immune system attack skin cancer has been approved for use in the NHS in England, and Dr Alan Worsley from Cancer Research UK says "we're experiencing progress we've never seen before".
At trial, the combination of drugs shrank the most aggressive form of skin cancer in 69 per cent of patients, and the decision to approve the drugs is one of the fastest in NHS history.
Dr Worsley, the senior science research officer at Cancer Research UK, is very encouraged.
"These two drugs work very similarly but in a slightly different way," he told Julia Hartley-Brewer. "Each one is cutting the brakes on the immune cells in the body, trying to help them find and seek out cancer cells.
"Two of these drugs together versus either one alone really seemed to show increased survival. This has really been quite a quick, speedy approval process.
"We're definitely experiencing progress that we haven't seen before. What's happened here is as a result of a real step change in an understanding of how cancer works."
However, he said that drugs do come with a risk.
"We really hope to see benefits in the future. When you do combine these treatments you do also get a much higher risk of side effects, so where we really need to go now is to find out how best we can use these treatments.
"Typically it's fever, those kind of immune reactions that are going on. There's might be something going on that you didn't even realise, because your immune system was handling it.
"What we need to do now is see how we can get this to work for other cancer types and how best we can mix and match what we've got."
Skin cancer cases are on the increase, he warns.
"It is something that is on the rise, with the growth of holidays and people taking trips. This new announcement about new treatments is fantastic, but one of the best ways is to avoid it by keeping safe in the sun."