An international team, led by University of California, says that the KG5 drug works by making cancer cells "commit suicide"; it stops tumorous cells multiplying and they then shut themselves down, the ''Nature Medicine'' journal reported.
The radical drug will bring fresh hope to patients with aggressive and deadly tumours and could be available in as little as five years, say the scientists, who hope to deliver it in pill form, which has very few side-effects.
Lead scientist Prof David Cheresh said the drug "blocks the function of proliferation" and the malignant cells commit suicide when they can''t multiply. Proved effective in tests against pancreatic, breast and kidney cancers, it could well have a positive effect on a broad range of other tumours.
KG5 works in a totally different way to traditional therapies by altering the structure of a cancer growth protein, an enzyme known as RAF.
The protein has been long-studied, but its role in cell division -- critical to cell proliferation and tumour growth -- is a surprise. Existing treatments block RAF's activity.
However, KG5 changes the entire shape of the protein, which neutralises it without leading to unwanted side-effects.