A Study Comparing Trametinib and Dabrafenib Combination Therapy to Dabrafenib Monotherapy in Subjects With BRAF-mutant Melanoma

This was a two-arm, double-blinded, randomized, Phase III study comparing dabrafenib and trametinib combination therapy to dabrafenib administered with a placebo (dabrafenib monotherapy). Subjects with histologically confirmed cutaneous melanoma that is either Stage IIIC (unresectable) or Stage IV, and BRAF V600E/K mutation positive were screened for eligibility. Subjects who had prior systemic anti-cancer treatment in the advanced or metastatic setting were not eligible although prior systemic treatment in the adjuvant setting was allowed. Subjects were stratified according to the baseline lactate dehydrogenase level and BRAF genotype.

Dabrafenib and trametinib was administered orally at their recommended monotherapy doses of 150 mg b.i.d and 2 mg q.d., respectively. Subjects in the combination therapy arm received both agents; subjects in the dabrafenib monotherapy arm received dabrafenib and placebo. Treatment was continued in both arms until disease progression, death, unacceptable toxicity, or withdrawal of consent. After treatment discontinuation, subjects were followed for survival and disease progression as applicable to collect data for the secondary objective of overall survival (OS). Crossover to the combination therapy arm was allowed for subjects still receiving study treatment on the dabrafenib monotherapy arm after the positive result for the final OS analysis.