A new cancer drug has proven capable of shrinking melanomas in clinical trials in Australia.

More than 10,000 Australians are treated for melanoma each year and 1,200 die from the cancer.

Scientists say the drug turns off the proteins that drive cancer cell growth, significantly reducing the size of the tumours. In one case the tumours were completely erased.

Associate Professor Grant MacArthur, who heads the cancer therapeutics program at the Peter MacCallum Cancer Centre, says early results published today in the journal Nature are promising.

"The key findings from this research are the ability of designing a drug to turn off proteins that drive growth of cancer cells, and this is done in a very rational, designed way," he said.

The New South Wales north coast is a region with one of Australia's highest rates of skin cancer. Associate Professor Austin Curtin, a general surgeon in the region, has had two patients take part in the trial.

"As a surgeon dealing with melanoma for over 20 years, we've been able to look after melanoma in its early stages by excising or by surgical excision, but the difficulty becomes the patients who get recurrent widespread disease," he said.

He says the trial shows genetic technology at its best.

"One young patient, only 23 with widespread metastatic disease, has had within weeks of starting the medication complete resolution of the secondaries in her bones, and the secondaries in the brain have also disappeared completely," he said.

"It's groundbreaking stuff. It's not yet the cure for melanoma, but it is showing us there is a light at the end of the tunnel. Previously we couldn't even see the end of the tunnel."

Scientists say they hope the drugs will eventually replace other cancer treatments, including chemotherapy.