N. Engl. J. Med. 363, 809–819 (2010)

A small clinical trial has shown promising results for a targeted therapy against one of the most aggressive and intractable forms of cancer: metastatic melanoma.

The drug, named PLX4032, inhibits a mutated form of a protein called B-RAF. Mutated B-RAF is found in up to 60% of all melanomas and drives cell proliferation.

Keith Flaherty of Massachusetts General Hospital in Boston and his colleagues tested the drug in 16 patients with a particular B-RAF mutation and found that tumours shrank by at least 30% in 11 of the patients. In a follow-up study of 32 participants, tumours shrank in 24 and disappeared entirely in 2 patients. During the trial, five patients who did not have the mutation did not respond to the drug.