We have treated 45 patients with V600 mutated melanoma including patients with V600R mutation between July 2011 and October 2012 with the selective BRAF inhibitor dabrafenib (n=43) or vemurafenib (n=2) via a compassionate access programme. The overall response rate was 50% for the whole population with a progression-free survival of 5.5 months. Five objective responses were seen in six assessable patients with V600R BRAF mutation (n=9).

In 17 melanoma cell lines, RG7204 was a potent inhibitor of proliferation in those expressing BRAFV600E but not BRAFWT (Fig. 1). RG7204 also potently inhibited proliferation of melanoma cell lines expressing other codon 600 BRAF mutations (V600D, V600K, and V600R).