Hauschild A, et al. - Given that dabrafenib plus trametinib improved relapse-free survival (RFS) vs placebo (hazard ratio [HR], 0.47; P < .001) in patients with resected BRAF V600–mutant stage III melanoma, researchers performed extended study follow-up and a cure-rate model analysis to estimate the fraction of patients expected to remain relapse free long term. They present an updated RFS analysis. An RFS benefit associated with dabrafenib plus trametinib was confirmed in longer follow-up. Irrespective of baseline factors, dabrafenib plus trametinib was found to be beneficial for patients; this was seen in subgroup analysis.

Methods

• Researchers performed this phase III trial, wherein, they randomly assigned patients with resected BRAF V600–mutant stage III melanoma to 12 months of adjuvant dabrafenib plus trametinib vs placebo.
• Updated RFS (primary end point) and distant metastasis–free survival were reported.
• They 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 estimate the fraction of patients who remained relapse free long term.

Results

• A median follow-up of 44 months (dabrafenib plus trametinib) and 42 months (placebo) was performed.
• During this period, the estimated 3- and 4-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, respectively (HR, 0.49; 95% CI, 0.40 to 0.59).
• Dabrafenib plus trametinib was also favored by distant metastasis–free survival (HR, 0.53; 95% CI, 0.42 to 0.67).
• In the dabrafenib plus trametinib arm vs in the placebo arm, the estimated cure rate was 54% (95% CI, 49% to 59%) vs 37% (95% CI, 32% to 42%), respectively.
• Irrespective of baseline factors, including disease stage, nodal metastatic burden, and ulceration, similar treatment benefit was seen in subgroup analysis of RFS.