This is a three-arm, open-label, randomised Phase II study to evaluate whether the different sequencing of dabrafenib and trametinib monotherapies and the upfront combination has an impact on translational or clinical activity in subjects with BRAF mutant metastatic unresectable stage IIIc or IV melanoma. Both dabrafenib and trametinib have demonstrated clinical activity as monotherapies and in combination in BRAF-mutant melanoma. However, duration of responses seem to be limited due to acquired drug resistance. The goal of this protocol is to study the sequential effects of BRAF and MEK inhibition on skin, blood and tumour biomarkers and to study the correlation between biomarkers and response to treatment and intrapatient toxicity. Approximately 54 eligible subjects will be randomised in the ratio of 1:1:1 to one of the three treatment arms.