Vemurafenib is an oral serine-threonine kinase inhibitor of mutated BRAF.1 It has marked antitunour effects against melanoma cell lines with the BRAF V600E mutation but not wild-type BRAF.2
The BRIM-3 study recruited 675 patients with previously untreated metastatic melanoma expressing the BRAF V600E mutation. Patients were randomised to receive either oral vemurafenib (960mg twice daily) or intravenous dacarbazine (1g/m2 every 3 weeks). The co-primary endpoints were overall and progression-free survival (PFS); interim analysis was planned following 98 deaths and final analysis following 196 deaths.2
Overall survival in the interim analysis and PFS in the interim analysis associated vemurafenib with a relative risk reduction of 63% in the risk of death and of 74% in the risk of either death or disease progression compared with dacarbazine (p<0.001 for both comparisons). Following recommendations from the independent review of the interim analyses, patients were switched from dacarbazine to vemurafenib to complete treatment. Overall response rates were 48% for vemurafenib and 5% for dacarbazine.2
Adverse events seen most commonly amongst patients who received vemurafenib included cutaneous events, arthralgia and fatigue. Investigators noted squamous cell carcinoma and keratoacanthoma (or both) in 18% of patients who received vemurafenib; all lesions were treated with simple excision.2
1. Zelboraf Summary of Product Characteristics, February 2012.
2. Chapman PB et al. N Engl J Med 2011; 364(26): 2507-16.
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Further information: Roche