Vemurafenib is an orally available inhibitor of mutated BRAF-serine-threonine kinase. It is especially potent against the BRAF V600E mutation. This mutation involves the substitution of glutamic acid for valine at codon 600. The BRAF oncogene, most of which have the V600E mutation, activates mitogen-activated kinase (MAPK) pathway which results in cell growth, proliferation, and metastasis. Vemurafenib blocks these downstream processes to inhibit tumour growth and eventually trigger apoptosis. Vemurafenib does not have antitumour effects against melanoma cell lines with the wild-type BRAF mutation.
Vemurafenib is metabolized by CYP3A4 and the metabolites make up 5% of the components in plasma. The parent compound makes up for the remaining 95%.