Hauschild A, et al. - Researchers conducted this phase 3 trial of patients with resected BRAF V600–mutant stage III melanoma who were randomly assigned to 12 months of adjuvant dabrafenib plus trametinib vs placebo to present an updated relapse-free survival (RFS) analysis via extended study follow-up and a cure-rate model analysis to approximate the proportion of patients presumed to stay relapse free long term. This longer follow-up confirms that dabrafenib plus trametinib has RFS benefit. As per subgroup analysis, dabrafenib plus trametinib benefited patients irrespective of baseline factors.

Methods

• Researchers reported updated RFS (primary end point) and distant metastasis–free survival.
• They also analyzed RFS by subgroups defined by baseline disease stage (American Joint Committee on Cancer 7th and 8th editions), nodal metastatic burden, and ulceration status.
• They used a Weibull mixture cure-rate model to determine the proportion of patients who stayed relapse free long term.

Results

• Three- and four-year RFS rates were 59% (95% CI, 55% to 64%) and 54% (95% CI, 49% to 59%) in the dabrafenib plus trametinib arm and 40% (95% CI, 35% to 45%) and 38% (95% CI, 34% to 44%) in the placebo arm at median follow-up of 44 months (dabrafenib plus trametinib) and 42 months (placebo), respectively (HR, 0.49; 95% CI, 0.40 to 0.59).
• Dabrafenib plus trametinib arm also displayed favorable distant metastasis–free survival (HR, 0.53; 95% CI, 0.42 to 0.67).
• The dabrafenib plus trametinib arm and the placebo arm had estimated cure rate of 54% (95% CI, 49% to 59%) and 37% (95% CI, 32% to 42%), respectively.
• Similar treatment benefit was evident with subgroup analysis of RFS regardless of baseline factors, including disease stage, nodal metastatic burden, and ulceration.