A new drug is effective against advanced forms of the most common type of skin cancer, according to US research.

Three new research papers published in the New England Journal of Medicine show that the drug vismodegib (also called Erivedge) can treat and prevent basal-cell carcinomas (BCCs), even those that have spread to other parts of the body.

The drug was approved by the US authorities in January 2012. It is awaiting approval by European regulators.

In the journal's editorial, Dr John Lear from Manchester Royal Infirmary said: "It is a landmark day for patients with basal cell carcinoma and all those involved in their care - the greatest advance in therapy yet seen for this disease."

But he also cautioned that side effects could be unpleasant, including taste loss, hair loss, and muscle cramps.

One paper outlines the results of a clinical trial in which vismodegib was given to patients with Gorlin syndrome, a rare genetic disease in which individuals have tens to hundreds of BCCs.

There is currently no cure for Gorlin syndrome - patients usually undergo regular surgery to remove the tumours. But vismodegib greatly slowed the progress of the disease. On average, people who took the drug developed only two tumours a year, compared with 29 in people who took a placebo.

A second clinical trial published today was the basis for the approval of vismodegib in the US five months ago. The trial shows that the drug is effective for some people with previously 'untreatable' BCCs - advanced tumours that are extremely large ('locally advanced') or have spread (metastasised) to other parts of the body.

The drug caused tumours to shrink in 43 per cent of patients with locally advanced disease, and 30 per cent of patients with metastatic disease.

Vismodegib works by targeting a molecular process inside cells known as the 'hedgehog' signalling pathway, whose precise functioning was unravelled by Cancer Research UK scientists in the 1990s.

This pathway, which involves a gene known as 'hedgehog', is activated in people with BCC in a way that does not normally occur in healthy cells. Vismodegib limits this effect.

A third research paper outlines the use of vismodegib to treat a man who had BCCs all over his body, but who did not have Gorlin syndrome.

Researchers analysed his genetic material and found faults that suggested he should respond to vismodegib - and he did.

Dr Safia Danovi, senior science information officer at Cancer Research UK, said: "Cancer Research UK played a key role in the early development of this drug and we're delighted that it has reached this important milestone. If vismodegib is approved in the UK, it will provide advanced BCC patients an alternative to potentially disfiguring surgery, which until now has been the only way of controlling this disease.

"This is great news for patients and it's thanks to the generosity of our supporters that we're able to invest in the kinds of early stage research that can so often spark advances like this."

She added that the charity hopes that this vismodegib will receive its European licence quickly, so that UK patients can benefit as soon as possible from the drug.

Basal cell carcinoma affects about 100,000 people in the UK, and is often caused by excessive exposure to UV radiation such as sunlight.

The vast majority of people are diagnosed at an early stage, before it has spread and when surgical treatment is an effective, although potentially disfiguring, cure.

Source: CRUK