Patients with advanced melanoma, which kills an Australian every six hours, have lived longer when given a new drug than those on the current treatment.
Clinical trials recorded a one-year survival rate for 74 per cent of patients taking Keytruda, compared to 58 per cent of those on Yervoy.
Associate Professor Georgina Long from the Melanoma Institute Australia said she hoped the ground-breaking results would lead to Keytruda being listed on the Pharmaceutical Benefits Scheme.
The study, published in the New England Journal of Medicine, looked at 834 patients from around the world who had advanced melanoma, meaning it has spread to organs such as the liver or lung.
It found that anti-PD-1 antibody pembrolizumbab (Keytruda) prolonged survival and had less high-grade toxicity and side-effects compared with ipilimumbab (Yervoy).
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The new drug also reduced the size of the tumours in about 70 per cent of the patients.
"These results are world-first, where two effective immunotherapies are directly compared, and we significantly improve outcomes for patients even further," Prof Long said.
As the latest trials have only run for a year, Prof Long said it was too early to know how long a person could survive "If you are a shrinker".
But she said 30 per cent of patients had no tumour shrinkage on the new drug and other trials were being carried out on them.
"This breakthrough is probably the most important development in the treatment of this disease ever, and a landmark in terms of cancer treatment in general," said Macquarie University's Professor Rick Kefford.
