ABSTRACT
We report the analysis of an in-house fragment screening campaign for the oncology target MEK1. The application of virtual screening (VS) as a primary fragment screening approach, followed by biophysical validation using differential screening fluorimetry (DSF), with resultant binding mode determination by X-ray crystallography (X-ray), is presented as the most time and cost-effective combination of in silico and in vitro methods to identify fragments. We demonstrate the effectiveness of the VS-DSF workflow for the early identification of fragments to both 'jump-start' the drug discovery project and to complement biochemical screening data.
Subject(s)
Enzyme Inhibitors/pharmacology , Fluorometry/methods , MAP Kinase Kinase 1/antagonists & inhibitors , Crystallography, X-Ray , Drug Evaluation, Preclinical/methods , Enzyme Inhibitors/chemistry , Humans , MAP Kinase Kinase 1/chemistry , MAP Kinase Kinase 1/metabolism , Models, Molecular , Phosphorylation , Structure-Activity RelationshipABSTRACT
The HGF/MET pathway is frequently activated in a variety of cancer types. Several selective small molecule inhibitors of the MET kinase are currently in clinical evaluation, in particular for NSCLC, liver, and gastric cancer patients. We report herein the discovery of a series of triazolopyridazines that are selective inhibitors of wild-type (WT) MET kinase and several clinically relevant mutants. We provide insight into their mode of binding and report unprecedented crystal structures of the Y1230H variant. A multiparametric chemical optimization approach allowed the identification of compound 12 (SAR125844) as a development candidate. In this chemical series, absence of CYP3A4 inhibition was obtained at the expense of satisfactory oral absorption. Compound 12, a promising parenteral agent for the treatment of MET-dependent cancers, promoted sustained target engagement at tolerated doses in a human xenograft tumor model. Preclinical pharmacokinetics conducted in several species were predictive for the observed pharmacokinetic behavior of 12 in cancer patients.
Subject(s)
Benzothiazoles/pharmacology , Benzothiazoles/pharmacokinetics , Drug Discovery , Neoplasms, Experimental/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/pharmacokinetics , Proto-Oncogene Proteins c-met/antagonists & inhibitors , Urea/analogs & derivatives , Animals , Benzothiazoles/administration & dosage , Benzothiazoles/chemistry , Cell Proliferation/drug effects , Crystallography, X-Ray , Dose-Response Relationship, Drug , Humans , Mice , Models, Molecular , Molecular Structure , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/pathology , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-met/metabolism , Structure-Activity Relationship , Urea/administration & dosage , Urea/chemistry , Urea/pharmacokinetics , Urea/pharmacologyABSTRACT
We exploit the concept of using hydrogen bonds to link multiple ligands for maintaining simultaneous interactions with polyvalent binding sites. This approach is demonstrated by the syntheses and evaluation of pseudo-bivalent ligands as potent inhibitors of human beta-tryptase.