COLUMBUS 7-year update: a randomized, open-label, phase III trial of encorafenib plus binimetinib versus vemurafenib or encorafenib in patients with BRAF V600E/K-mutant melanoma

Background Treatment with encorafenib plus binimetinib and encorafenib monotherapy is associated with improved progression-free survival (PFS) and overall survival (OS) compared with vemurafenib in patients with BRAF V600E/K-mutant metastatic melanoma. We report results from the 7-year analysis of COLUMBUS part 1 (NCT01909453) at 99.7 months (median duration between randomization and data cutoff). Methods 577 patients with locally advanced unresectable or metastatic BRAF V600E/K-mutant melanoma who were treatment-naive or progressed after first-line immunotherapy were randomized 1:1:1 to encorafenib 450 mg once daily (QD) plus binimetinib 45 mg twice daily (BID) (n = 192), vemurafenib 960 mg BID (n = 191), or encorafenib monotherapy 300 mg QD (n = 194). No prior BRAF/MEK inhibitor was allowed. Results Seven-year PFS and OS rates (95% CI) were 21.2% (14.7%–28.4%) and 27.4% (21.2%–33.9%) in the encorafenib plus binimetinib arm and 6.4% (2.1%–14.0%) and 18.2% (12.8%–24.3%) in the vemurafenib arm, respectively. Median melanoma-specific survival (95% CI) was 36.8 months (27.7–51.5 months) in the encorafenib plus binimetinib arm and 19.3 months (14.8–25.9 months) in the vemurafenib arm. Thirty-four long-term responders (complete/partial response ongoing at 7 years) were identified across arms. Conclusions This is the longest follow-up from a phase III trial of BRAF/MEK inhibitor combination in BRAF V600E/K-mutant metastatic melanoma. Safety results were consistent with the known tolerability profile of encorafenib plus binimetinib. Results support the long-term efficacy and known safety of encorafenib plus binimetinib in this population and provide new insights on long-term responders. Interactive data visualization is available at the COLUMBUS dashboard (https://clinical-trials.dimensions.ai/columbus7/).