Benefit of the combination of encorafenib + binimetinib in the treatment of BRAF V600 mutant melanoma – updated results of the COLUMBUS study

06/2020

MUDr. Eugen Kubala

Onkologická klinika 1. LF UK a Thomayerovy nemocnice, Praha

SUMMARY

Treatment of advanced and metastatic melanoma with the BRAF V600 mutation by combination therapy with BRAF and MEK inhibitors encorafenib and binimetinib was demonstrated in the COLUMBUS study, the results of which were updated in June 2020. Encorafenib is an ATP-competitive BRAF inhibitor capable of blocking several mutated forms of BRAF kinase for 30 hours (e.g. V600E, V600D and V600K) in tumor melanoma cells against other BRAF inhibitors dabrafenib (2 hours) or vemurafenib (0.5 hours). It allows almost permanent inhibition of the mutated form of BRAF protein kinase. According to the updated results of the COLUMBUS study, the median PFS results for the combination of encorafenib + binimetinib at 14.9 months versus vemurafenib were confirmed at 7.3 months. Significant is the comparison of the two BRAF inhibitors encorafenib and vemurafenib, which indicated a higher efficacy of encorafenib versus vemurafenib median PFS 9.6 vs 7.3 months HR 0.68 (95% CI 0.52-0.88; p = 0.0038) Combination of the BRAF inhibitor encorafenib and the MEK inhibitor binimetinib significantly shifted the median PFS of 16.4 months and the median overall survival (OS) of 33.6 months without increasing toxicity over the established and used combinations of BRAF and MEK inhibitors used in the treatment of BRAF V600 mutant melanoma. In long-term follow-up of COMBO 450 (the combination encorafenib 450 mg and binimetinib 45 mg) vs vemurafenib (vemurafenib 960 mg) patients, 26% vs 12% of patients achieved 48-month PFS. Another primary endpoint of the COLUMBUS study was an updated outcome of OS.4-year survival was achieved in 39% of patients treated with COMBO450 combination therapy, 37% of patients treated with encorafenib 300 mg (ENCO300) monotherapy, and 26% of patients treated with vemurafenib (VEM). The updated results of the COLUMBUS study presented at ASCO (American Society of Clinical Oncology Congress) 2020 confirmed that the combination of encorafenib and binimetinib is a highly effective treatment for BRAF V600 mutant melanoma.

Key words

melanoma, encorafenib, binimetinib, COLUMBUS study