Vemurafenib treatment for patients with locally advanced, unresectable stage IIIC or metastatic melanoma and activating exon 15 BRAF mutations other than V600E.

Abstract

BRAF mutations are found in ~50% of metastatic melanomas, most commonly in codon V600. Vemurafenib improves progression-free survival and overall survival in patients with advanced BRAF-mutated melanoma. The results of a descriptive study evaluating vemurafenib in patients with advanced melanoma harbouring BRAF mutations other than V600E are reported. Eligible patients with stage IIIC or IV melanoma and non-V600E BRAF mutations received vemurafenib (960 mg, twice daily). End points included investigator-assessed best overall response rate (primary), time to response, duration of response, progression-free survival, overall survival and safety. Planned (V600K vs. non-V600K mutations) subgroup analyses were carried out. Thirty-one patients were enrolled; 13 (42%) had V600K mutations and 18 (58%) had other mutations. Investigator-assessed confirmed that the best overall response rate was 23% (95% confidence interval=10-41%) in the overall population, and was similar between patients with V600K mutations (23%; 95% confidence interval=5-54%) versus other mutations (22%; 95% confidence interval=6-48%). Responses were observed in patients with V600K (n=3), V600E2 (n=1), V600R (n=1), L597S (n=1) and D594G (n=1) mutations. No new safety signals were reported. Vemurafenib showed activity in patients with advanced melanoma with rarer BRAF mutations.