Discovery of BAY-985, a Highly Selective TBK1/IKKε Inhibitor

The serine/threonine kinase TBK1 (TANK-binding kinase 1) and its homologue IKK epsilon are noncanonical members of the inhibitor of the nuclear factor kappa B (I kappa B) kinase family. These kinases play important roles in multiple cellular pathways and, in particular, in inflammation. Herein, we describe our investigations on a family of benzimidazoles and the identification of the potent and highly selective TBK1/IKK epsilon inhibitor BAY-985. BAY-985 inhibits the cellular phosphorylation of interferon regulatory factor 3 and displays antiproliferative efficacy in the melanoma cell line SK-MEL-2 but showed only weak antitumor activity in the SK-MEL-2 human melanoma xenograft model.