TAK-632 is a selective inhibitor of BRAF, CRAF and BRAF-V600E kinase with IC50 value of 8.3 nM, 1.4 nM and 2.4 nM [1].
RAF kinases are a family of three serine/threonine-specific protein kinases and play an important role in the RAS-RAF-MEK-ERK signal transduction cascade, as well as the mitogen-activated protein kinase (MAPK) cascade [2].
TAK-632 is a potent pan-RAF kinase inhibitor and has a higher selectivity compared with the reported pan-RAF kinase inhibitor vemurafenib. When tested with SK-MEL-2 cells, TAK-632 showed induction on the BRAF-CRAF dimmers formation in a dose-dependent manner. In melanoma cell lines A375 and SK-MEL-2, TAK-632 exhibited significant antiproliferative effects with GI50 value of 6 nom/L and 11 nom/L, respectively [1].
In mouse model with SK-MEL-2 subcutaneous xenograft, oral administration of TAK-632 caused significant reduction of phosphorylated ERK and tumor growth at the dose of 60 or 120 mg/kg/d once daily for 21 days without severe toxicity [1].
It is also reported that TAK-632 is a potent inhibitor of pERK with IC50 value of 25 nM [1].
References:
[1]. Nakamura, A., et al., Antitumor activity of the selective pan-RAF inhibitor TAK-632 in BRAF inhibitor-resistant melanoma. Cancer Res, 2013. 73(23): p. 7043-55.
[2]. Korkut, A., et al., Perturbation biology nominates upstream-downstream drug combinations in RAF inhibitor resistant melanoma cells. Elife, 2015. 4.