Dabrafenib and Trametinib Versus Dabrafenib and Placebo for Val600 BRAF-mutant Melanoma: A Multicentre, Double-Blind, Phase 3 Randomised Controlled Trial

Lancet. 2015 Aug 1;386(9992):444-51. doi: 10.1016/S0140-6736(15)60898-4. Epub 2015 May 31.

Abstract

Background: Previously, a study of ours showed that the combination of dabrafenib and trametinib improves progression-free survival compared with dabrafenib and placebo in patients with BRAF Val600Lys/Glu mutation-positive metastatic melanoma. The study was continued to assess the secondary endpoint of overall survival, which we report in this Article.

Methods: We did this double-blind phase 3 study at 113 sites in 14 countries. We enrolled previously untreated patients with BRAF Val600Glu or Val600Lys mutation-positive unresectable stage IIIC or stage IV melanoma. Participants were computer-randomised (1:1) to receive a combination of dabrafenib (150 mg orally twice daily) and trametinib (2 mg orally once daily), or dabrafenib and placebo. The primary endpoint was progression-free survival and overall survival was a secondary endpoint. This study is registered with ClinicalTrials.gov, number NCT01584648.

Findings: Between May 4, 2012, and Nov 30, 2012, we screened 947 patients for eligibility, of whom 423 were randomly assigned to receive dabrafenib and trametinib (n=211) or dabrafenib only (n=212). The final data cutoff was Jan 12, 2015, at which time 222 patients had died. Median overall survival was 25·1 months (95% CI 19·2-not reached) in the dabrafenib and trametinib group versus 18·7 months (15·2-23·7) in the dabrafenib only group (hazard ratio [HR] 0·71, 95% CI 0·55-0·92; p=0·0107). Overall survival was 74% at 1 year and 51% at 2 years in the dabrafenib and trametinib group versus 68% and 42%, respectively, in the dabrafenib only group. Based on 301 events, median progression-free survival was 11·0 months (95% CI 8·0-13·9) in the dabrafenib and trametinib group and 8·8 months (5·9-9·3) in the dabrafenib only group (HR 0·67, 95% CI 0·53-0·84; p=0·0004; unadjusted for multiple testing). Treatment-related adverse events occurred in 181 (87%) of 209 patients in the dabrafenib and trametinib group and 189 (90%) of 211 patients in the dabrafenib only group; the most common was pyrexia (108 patients, 52%) in the dabrafenib and trametinib group, and hyperkeratosis (70 patients, 33%) in the dabrafenib only group. Grade 3 or 4 adverse events occurred in 67 (32%) patients in the dabrafenib and trametinib group and 66 (31%) patients in the dabrafenib only group.

Interpretation: The improvement in overall survival establishes the combination of dabrafenib and trametinib as the standard targeted treatment for BRAF Val600 mutation-positive melanoma. Studies assessing dabrafenib and trametinib in combination with immunotherapies are ongoing.

Funding: GlaxoSmithKline.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Disease-Free Survival
  • Double-Blind Method
  • Drug Therapy, Combination
  • Female
  • Humans
  • Imidazoles / administration & dosage*
  • Male
  • Melanoma / drug therapy*
  • Middle Aged
  • Oximes / administration & dosage*
  • Proto-Oncogene Proteins B-raf / genetics
  • Pyridones / administration & dosage*
  • Pyrimidinones / administration & dosage*
  • Treatment Outcome
  • Young Adult

Substances

  • Imidazoles
  • Oximes
  • Pyridones
  • Pyrimidinones
  • trametinib
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • dabrafenib

Associated data

  • ClinicalTrials.gov/NCT01584648