Vemurafenib in metastatic melanoma patients with brain metastases: an open-label, single-arm, phase 2, multicentre study.

Abstract

METHODS

Patients with BRAFV600 mutated melanoma with BM were enrolled into cohort 1 (previously untreated BM) and cohort 2 (previously treated BM) and received vemurafenib (960 mg BID) until disease progression (PD) or intolerance. Primary endpoint was best overall response rate (BORR) in the brain in cohort 1 that was evaluated using modified RECIST 1.1 criteria using lesions ≥0.5 cm to assess response.

CONCLUSIONS

The study demonstrates clinically meaningful response rates of melanoma BM to vemurafenib, which was well tolerated and without significant CNS toxicity.

BACKGROUND

Vemurafenib has shown activity in patients with BRAFV600 mutated melanoma with brain metastases (BM). This phase 2 study evaluated vemurafenib in patients with/without prior treatment for BM.

RESULTS

146 patients were treated (cohort 1 n = 90; cohort 2 n = 56), 62% of whom were male. Median (range) time since diagnosis of BM: 1.0 (0-9) month in cohort 1 and 4.2 (1-68) months in cohort 2. Median duration of treatment was 4.1 months (range 0.3-34.5) in cohort 1 and 4.1 months (range 0.2-27.6) in cohort 2. Intracranial BORR in cohort 1 by an independent review committee (IRC) was 18% (2 CRs, 14 PRs). Extracranial BORR by IRC was 33% in cohort 1 and 23% in cohort 2. Median PFS (brain only, investigator-assessed) was 3.7 months (range 0.03-33.4; IQR 1.9-5.6) in cohort 1 and 4.0 months (range 0.3-27.4; IQR 2.2-7.4) in cohort 2. Median OS was 8.9 months (range 0.6-34.5; IQR 4.9-17.0) in cohort 1 and 9.6 months (range 0.7-34.3; IQR 4.5-18.4) in cohort 2. Adverse events (AEs) were similar in type, grade and frequency to other studies of single-agent vemurafenib. Grade 3/4 AEs occurred in 59 (66%) patients in cohort 1 and 36 (64%) in cohort 2. Overall, 84% of patients died during the study (86% in cohort 1 and 80% in cohort 2), mainly due to disease progression.