Abstract
BACKGROUND: Pathogenic BRAF mutations drive constitutive MAPK pathway activation in melanoma, and targeted therapies with dabrafenib plus trametinib have improved outcomes in the adjuvant setting. However, the optimal duration of adjuvant therapy remains unclear. This retrospective study examined whether extending dabrafenib plus trametinib beyond 1 year offers additional clinical benefit in Chinese patients with resected Stage III melanoma. METHODS: Medical records from six centers were reviewed for adults with BRAF V600E/K-positive, completely resected Stage III melanoma who received at least 12 months of adjuvant dabrafenib plus trametinib. Patients were divided into a 1-year therapy group and a more-than-1-year therapy group. Relapse-free survival (RFS) was the primary end point; adverse events were also assessed. RESULTS: Of the 122 patients included, 77 received more than 1 year of adjuvant therapy. The more-than-1-year group experienced significantly better RFS (log-rank p = 0.04), and longer therapy independently reduced recurrence risk in multivariate analysis (HR, 2.42; p = 0.035). Adverse event profiles did not differ between groups, and toxicity-related treatment modifications occurred primarily within the first year. CONCLUSIONS: Extending dabrafenib plus trametinib beyond 1 year may provide improved RFS without increasing toxicity. Further prospective trials are warranted to confirm the impact on overall survival and identify optimal patient subsets for prolonged therapy.