Vemurafenib (PLX4032, RG7204) (Synonyms: RG-7204, Ro 51-85426, Vemurafenib)

Vemurafenib (PLX4032; RG7204) is a first-in-class, selective, potent inhibitor of B-RAF kinase, with IC50s of 31 and 48 nM for RAFV600E and c-RAF-1, respectively.

Vemurafenib (PLX4032) selectively blocks the RAF/MEK/ERK pathway in BRAF mutant cells[1]. RG7204 is a potent inhibitor of proliferation in those expressing RAFV600E but not BRAFWT in 17 melanoma cell lines. Vemurafenib (RG7204) induces MEK and ERK phosphorylation at high concentrations in CHL-1 cells[2]. Ectopic expression of EGFR in melanoma cells is sufficient to cause resistance to PLX4032[3].

Vemurafenib (PLX4032, 20, 25, 75 mg/kg, p.o.) causes dose-dependent inhibition of tumor growth, with higher exposures resulting in tumor regression of BRAF mutant xenografts[1]. RG7204 (12.5, 25, and 75 mg/kg, p.o.) significantly inhibits tumor growth and induced tumor regression in mice bearing LOX tumor xenografts[2].

References:
[1]. Bollag G, et al. Clinical efficacy of a RAF inhibitor needs broad target blockade in BRAF-mutant melanoma. Nature, 2010, 467(7315), 596-599.
[2]. Yang H, et al. RG7204 (PLX4032), a selective BRAFV600E inhibitor, displays potent antitumor activity in preclinical melanoma models. Cancer Res, 2010, 70(13), 5518-5527.
[3]. Prahallad A, et al. Unresponsiveness of colon cancer to BRAF(V600E) inhibition through feedback activation of EGFR. Nature, 2012, 483(7387), 100-103.
[4]. Shelledy L, et al. Vemurafenib: First-in-Class BRAF-Mutated Inhibitor for the Treatment of Unresectable or MetastaticMelanoma. J Adv Pract Oncol. 2015 Jul-Aug;6(4):361-5.