Prognostic significance of distant metastasis-free interval in patients with relapsed melanoma treated with BRAF with or without MEK inhibitors.

This retrospective cohort study assessed the prognostic significance of distant metastasis-free interval (DMFI) in patients with relapsed BRAF-mutant melanoma treated with BRAF with or without MEK inhibitors (BRAFi±MEKi). Patients with a DMFI of up to 24 months were compared with those with DMFI of more than 24 months, with regard to their postrelapse progression-free survival (PR-PFS) and overall survival (PR-OS). In total, 109 patients were included in the study. Median DMFI was 25.3 (range: 3.4-188.2) months. Median PR-PFS in patients with DMFI of more than 24 months was 7.9 months [95% confidence interval (CI): 6.2-9.7] compared with 5.4 (95% CI: 4.2-6.7) months of those with shorter DMFI (P=0.016). Median PR-OS was 15.6 months (95% CI: 13.6-17.6) in patients with DMFI of more than 24 months and 12.0 months (95% CI: 9.0-15.0) with DMFI of up to 24 months (P=0.289). Multivariate Cox regression analysis showed that DMFI was independently and strongly associated with improved PR-PFS (adjusted hazard ratio=3.21, 95% CI: 1.78-5.77, ≤24 vs. >24 months) and longer PR-OS (adjusted hazard ratio: 2.09, 95% CI: 1.15-3.80, ≤24 vs. >24 months). The present cohort study is one of the first to confirm the association of DMFI of more than 24 months with an indolent disease course, as shown by longer PR-PFS and PR-OS, in patients with relapsed stage IV melanoma treated by BRAF inhibitor/MEK inhibitor.