Definition

An orally bioavailable small molecule and deep cyclic inhibitor (DCI) of mitogen-activated protein kinase kinase (MAP2K; MAPKK; MEK), with potential antineoplastic activity. Upon oral administration, IMM-6-415 targets, binds to and inhibits the activity of MEK, thereby inhibiting the activation of MEK-dependent effector proteins and inhibits the proliferation of tumor cells in which RAS and/or RAF are mutated. The threonine/tyrosine protein kinase MEK plays a key role in the RAS/RAF/MEK/ERK signaling pathway, which is frequently upregulated in a variety of tumor cell types and regulates key cellular activities including cell growth, proliferation, survival, differentiation and apoptosis. Mutations in Ras and Raf may induce constitutive signal transduction and uncontrolled MAPK signaling. As a DCI, this agent, having a short half-life, allows for pulsatile targeted inhibition that deprives tumor cells of sustained oncogenic pathway signaling. It may also improve tolerability.