ABSTRACT
Herein we disclose SAR studies that led to a series of isoindoline ureas which we recently reported were first-in-class, non-substrate nicotinamide phosphoribosyltransferase (NAMPT) inhibitors. Modification of the isoindoline and/or the terminal functionality of screening hit 5 provided inhibitors such as 52 and 58 with nanomolar antiproliferative activity and preclinical pharmacokinetics properties which enabled potent antitumor activity when dosed orally in mouse xenograft models. X-ray crystal structures of two inhibitors bound in the NAMPT active-site are discussed.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cytokines/antagonists & inhibitors , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Nicotinamide Phosphoribosyltransferase/antagonists & inhibitors , Urea/analogs & derivatives , Urea/pharmacology , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Cytokines/chemistry , Cytokines/metabolism , Drug Discovery , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/therapeutic use , Humans , Isoindoles/chemistry , Isoindoles/pharmacokinetics , Isoindoles/pharmacology , Isoindoles/therapeutic use , Mice , Models, Molecular , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/pathology , Nicotinamide Phosphoribosyltransferase/chemistry , Nicotinamide Phosphoribosyltransferase/metabolism , Structure-Activity Relationship , Urea/pharmacokinetics , Urea/therapeutic useABSTRACT
An NMR fragment screen for binders to the bromodomains of BRD4 identified 2-methyl-3-ketopyrroles 1 and 2. Elaboration of these fragments guided by structure-based design provided lead molecules with significant activity in a mouse tumor model. Further modifications to the methylpyrrole core provided compounds with improved properties and enhanced activity in a mouse model of multiple myeloma.