Vemurafenib in Chinese patients with BRAFV600 mutation–positive unresectable or metastatic melanoma: an open-label, multicenter phase I study

Lu Si, Xiaoshi Zhang, Zhen Xu, Qiudi Jiang, Lilian Bu, Xuan Wang, Lili Mao, Weijiang Zhang, Nicole Richie, Jun Guo

Melanoma is a rare, deadly disease without effective treatment options in China. Vemurafenib is a selective inhibitor of oncogenic BRAFV600 kinase approved in more than 90 countries, based on results obtained primarily in Caucasian patients. Limited data are available regarding the efficacy and safety of vemurafenib in Asian patients. This phase I study investigated the pharmacokinetics, efficacy, and tolerability of vemurafenib (960 mg twice daily) in Chinese patients with BRAFV600 mutation-positive unresectable or metastatic melanoma. The study included two cohorts: a pharmacokinetic cohort (n = 20) and an expansion cohort (n = 26). After 21 days of dosing, vemurafenib demonstrated marked accumulation and relatively constant steady-state exposure over the dosing period. Confirmed best overall response rate was 52.2% (95% CI 37.0-67.1%). Median progression-free survival was 8.3 months (95% CI 5.7-10.9%); median overall survival was 13.5 months (95% CI 12.2%-not estimable). The most common adverse events were dermatitis acneiform, arthralgia, diarrhea, blood cholesterol level increase, blood bilirubin level increase, melanocytic nevus, and alopecia. A total of nine grade 3 or 4 adverse events were reported in seven patients (15.2%). Overall, vemurafenib showed a favorable benefit-risk profile among Chinese patients. Pharmacokinetics, safety, and efficacy were generally consistent with those reported in Caucasian patients. ClinicalTrials.gov identification: NCT01910181 . Registered 29 July 2013, prospectively registered.