The US Food and Drug Administration on Wednesday approved a new drug, Zelboraf, to treat late-stage melanoma, the most dangerous type of skin cancer, after it was shown to extend patients' survival.

Made by Genentech, a US subsidiary of the Swiss pharmaceutical giant Roche, Zelboraf (vemurafenib) is the second melanoma drug this year, following Yervoy (ipilimumab) in March, and was given a rush approval by US regulators.

The treatment only works in about half of patients with advanced melanoma, those whose tumors express a gene mutation called BRAF V600E, meaning it could help about 10,000 patients in the United States, according to experts.

Only a few treatments for melanoma currently exist, and most have little success in extending the life of patients. Most people diagnosed with advanced melanoma die within 11 months, said Tim Turnham of the Melanoma Research Foundation.

"This is a really big deal," Turnham told AFP. "This is two drugs after 13 years of nothing."

Zelboraf works by blocking a protein that is involved with cell growth.

"This is a whole new approach to tackling melanoma," explained Turnham. "This actually goes into the malignant tumor cells and shuts them down."

The FDA said the approval of Zelboraf comes with a "first-of-a-kind test" called the cobas 4800 BRAF V600 mutation test to determine if patients have the type of cancer that the drug can treat.

"Today's approval of Zelboraf and the cobas test is a great example of how companion diagnostics can be developed and used to ensure patients are exposed to highly effective, more personalized therapies in a safe manner," said Alberto Gutierrez, director of the Office of In Vitro Diagnostic Device Evaluation and Safety in the FDA's Center for Devices and Radiological Health.

The regulatory agency had set a goal date of deciding on the drug by late October, but issued the decision early after an international trial of 675 patients with late-stage melanoma with the BRAF V600E mutation.

According to the National Cancer Institute, 68,130 new cases of melanoma were diagnosed in the United States last year and about 8,700 people died from the disease.

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