A patent update on PDK1 inhibitors (2015-present).

INTRODUCTION: 3-Phosphoinositide-dependent kinase 1 (PDK1), the "master kinase of the AGC protein kinase family", plays a key role in cancer development and progression. Although it has been rather overlooked, in the last decades a growing number of molecules have been developed to effectively modulate the PDK1 enzyme. Areas covered: This review collects different PDK1 inhibitors patented from October 2014 to December 2018. The molecules have been classified on the basis of the chemical structure/type of inhibition and for each general structure examples have been discussed in extenso. Expert opinion: The role of PDK1 in cancer development and progression as well as in metastasis formation and in chemoresistance has been confirmed by a large number of studies. Therefore, the pharmaceutical discovery in both public and private institutions is still ongoing despite the plentiful molecules already published. The majority of the new molecules synthetized interact with binding sites different from the ATP binding site (i.e. PIF pocket or DFG-out conformation). However, many researchers are still looking for innovative PDK1 modulation strategy such as combination of well-known inhibitory agents or multitarget ligands, aiming to block, together with PDK1, other different critical players in the wide panorama of proteins involved in tumor pathways.