Definition

An orally bioavailable inhibitor of mitogen-activated protein kinase kinase (MAP2K, MAPK/ERK kinase, or MEK) 1 and 2, with potential antineoplastic activity. Upon administration, MEK 1/2 Inhibitor FCN-159 selectively binds to and inhibits the activity of MEK1 and MEK2, preventing the activation of MEK1/2-dependent effector proteins and transcription factors, which may result in the inhibition of growth factor-mediated cell signaling and tumor cell proliferation. MEK1/2 are dual-specificity threonine/tyrosine kinases that play key roles in the activation of the RAS/RAF/MEK/ERK pathway that regulates cell growth. This pathway is often dysregulated in a variety of tumor cell types through BRAF, KRAS and NRAS mutations.