ABSTRACT
The bromodomain and extra terminal (BET) family of proteins are an integral part of human epigenome regulation, the dysregulation of which is implicated in multiple oncology and inflammatory diseases. Disrupting the BET family bromodomain acetyl-lysine (KAc) histone protein-protein interaction with small-molecule KAc mimetics has proven to be a disease-relevant mechanism of action, and multiple molecules are currently undergoing oncology clinical trials. This work describes an efficiency analysis of published GSK pan-BET bromodomain inhibitors, which drove a strategic choice to focus on the identification of a ligand-efficient KAc mimetic with the hypothesis that lipophilic efficiency could be drastically improved during optimization. This focus drove the discovery of the highly ligand-efficient and structurally distinct benzoazepinone KAc mimetic. Following crystallography to identify suitable growth vectors, the benzoazepinone core was optimized through an explore-exploit structure-activity relationship (SAR) approach while carefully monitoring lipophilic efficiency to deliver I-BET432 (41) as an oral candidate quality molecule.
Subject(s)
Lysine , Transcription Factors , Humans , Lysine/metabolism , Ligands , Protein Domains , Histones/metabolismABSTRACT
FTY720 is the first oral small molecule approved for the treatment of people suffering from relapsing-remitting multiple sclerosis. It is a potent agonist of the S1P1 receptor, but its lack of selectivity against the S1P3 receptor has been linked to most of the cardiovascular side effects observed in the clinic. These findings have triggered intensive efforts toward the identification of a second generation of S1P3-sparing S1P1 agonists. We have recently disclosed a series of orally active tetrahydroisoquinoline (THIQ) compounds matching these criteria. In this paper we describe how we defined and implemented a strategy aiming at the discovery of selective structurally distinct follow-up agonists. This effort culminated with the identification of a series of orally active tetrahydropyrazolopyridines.
Subject(s)
Drug Discovery , Pyrazoles/administration & dosage , Pyrazoles/pharmacology , Pyridines/administration & dosage , Pyridines/pharmacology , Receptors, Lysosphingolipid/agonists , Administration, Oral , Animals , Cell Line , Dogs , Dose-Response Relationship, Drug , Humans , Male , Mice , Mice, Inbred Strains , Molecular Structure , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Pyridines/chemical synthesis , Pyridines/chemistry , Rats , Rats, Inbred Lew , Rats, Sprague-Dawley , Sphingosine-1-Phosphate Receptors , Structure-Activity RelationshipABSTRACT
Optimization of KDM6B (JMJD3) HTS hit 12 led to the identification of 3-((furan-2-ylmethyl)amino)pyridine-4-carboxylic acid 34 and 3-(((3-methylthiophen-2-yl)methyl)amino)pyridine-4-carboxylic acid 39 that are inhibitors of the KDM4 (JMJD2) family of histone lysine demethylases. Compounds 34 and 39 possess activity, IC50 ≤ 100 nM, in KDM4 family biochemical (RFMS) assays with ≥ 50-fold selectivity against KDM6B and activity in a mechanistic KDM4C cell imaging assay (IC50 = 6-8 µM). Compounds 34 and 39 are also potent inhibitors of KDM5C (JARID1C) (RFMS IC50 = 100-125 nM).
Subject(s)
Enzyme Inhibitors/chemistry , Histone Demethylases/antagonists & inhibitors , Jumonji Domain-Containing Histone Demethylases/antagonists & inhibitors , Pyridines/chemistry , Amination , Cell Line , Cell Membrane Permeability , Crystallography, X-Ray , Drug Design , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/pharmacology , Histone Demethylases/chemistry , Histone Demethylases/metabolism , Humans , Jumonji Domain-Containing Histone Demethylases/chemistry , Jumonji Domain-Containing Histone Demethylases/metabolism , Models, Molecular , Pyridines/pharmacokinetics , Pyridines/pharmacologyABSTRACT
Following the discovery of cell penetrant pyridine-4-carboxylate inhibitors of the KDM4 (JMJD2) and KDM5 (JARID1) families of histone lysine demethylases (e.g., 1), further optimization led to the identification of non-carboxylate inhibitors derived from pyrido[3,4-d]pyrimidin-4(3H)-one. A number of exemplars such as compound 41 possess interesting activity profiles in KDM4C and KDM5C biochemical and target-specific, cellular mechanistic assays.
