ABSTRACT
Polycomb repressive complex 2 (PRC2) has been shown to play a major role in transcriptional silencing in part by installing methylation marks on lysine 27 of histone 3. Dysregulation of PRC2 function correlates with certain malignancies and poor prognosis. EZH2 is the catalytic engine of the PRC2 complex and thus represents a key candidate oncology target for pharmacological intervention. Here we report the optimization of our indole-based EZH2 inhibitor series that led to the identification of CPI-1205, a highly potent (biochemical IC50 = 0.002 µM, cellular EC50 = 0.032 µM) and selective inhibitor of EZH2. This compound demonstrates robust antitumor effects in a Karpas-422 xenograft model when dosed at 160 mg/kg BID and is currently in Phase I clinical trials. Additionally, we disclose the co-crystal structure of our inhibitor series bound to the human PRC2 complex.
Subject(s)
Antineoplastic Agents/pharmacology , Clinical Trials, Phase I as Topic , Enzyme Inhibitors/pharmacology , Histone-Lysine N-Methyltransferase/antagonists & inhibitors , Indoles/pharmacology , Lymphoma, B-Cell/drug therapy , Piperidines/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Dogs , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Histone Methyltransferases , Histone-Lysine N-Methyltransferase/metabolism , Humans , Indoles/chemical synthesis , Indoles/chemistry , Models, Molecular , Molecular Structure , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/pathology , Piperidines/chemical synthesis , Piperidines/chemistry , Rats , Structure-Activity RelationshipABSTRACT
The discovery and optimization of a series of small molecule EZH2 inhibitors is described. Starting from dimethylpyridone HTS hit (2), a series of indole-based EZH2 inhibitors were identified. Biochemical potency and microsomal stability were optimized during these studies and afforded compound 22. This compound demonstrates nanomolar levels of biochemical potency (IC50=0.002 µM), cellular potency (EC50=0.080 µM), and afforded tumor regression when dosed (200 mpk SC BID) in an EZH2 dependent tumor xenograft model.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Indoles/chemistry , Polycomb Repressive Complex 2/antagonists & inhibitors , Animals , Antineoplastic Agents/chemical synthesis , Cell Line, Tumor , Chemistry Techniques, Synthetic , Drug Design , Drug Discovery , Drug Screening Assays, Antitumor , Drug Stability , Enhancer of Zeste Homolog 2 Protein , HeLa Cells/drug effects , Humans , Inhibitory Concentration 50 , Mice , Molecular Targeted Therapy/methods , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
The histone lysine methyltransferase (MT) Enhancer of Zeste Homolog 2 (EZH2) is considered an oncogenic driver in a subset of germinal center B-cell-like diffuse large B cell lymphoma (GCB-DLBCL) and follicular lymphoma due to the presence of recurrent, monoallelic mutations in the EZH2 catalytic domain. These genomic data suggest that targeting the EZH2 MT activity is a valid therapeutic strategy for the treatment of lymphoma patients with EZH2 mutations. Here we report the identification of highly potent and selective EZH2 small molecule inhibitors, their validation by a cellular thermal shift assay, application across a large cell panel representing various non-Hodgkin's lymphoma (NHL) subtypes, and their efficacy in EZH2mutant-containing GCB-DLBCL xenograft models. Surprisingly, our EZH2 inhibitors selectively affect the turnover of trimethylated, but not monomethylated histone H3 lysine 27 at pharmacologically relevant doses. Importantly, we find that these inhibitors are broadly efficacious also in NHL models with wild-type EZH2.
Subject(s)
Apoptosis/drug effects , Enzyme Inhibitors/toxicity , Histones/metabolism , Polycomb Repressive Complex 2/antagonists & inhibitors , Small Molecule Libraries/toxicity , Amino Acid Sequence , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Disease Models, Animal , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/therapeutic use , Histones/chemistry , Humans , Kinetics , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/pathology , Lymphoma, Non-Hodgkin/metabolism , Lymphoma, Non-Hodgkin/pathology , Methylation , Mice , Mice, Nude , Mutation , Peptides/analysis , Polycomb Repressive Complex 2/genetics , Polycomb Repressive Complex 2/metabolism , Small Molecule Libraries/chemistry , Small Molecule Libraries/therapeutic use , Transplantation, HeterologousABSTRACT
Crizotinib (1), an anaplastic lymphoma kinase (ALK) receptor tyrosine kinase inhibitor approved by the U.S. Food and Drug Administration in 2011, is efficacious in ALK and ROS positive patients. Under pressure of crizotinib treatment, point mutations arise in the kinase domain of ALK, resulting in resistance and progressive disease. The successful application of both structure-based and lipophilic-efficiency-focused drug design resulted in aminopyridine 8e, which was potent across a broad panel of engineered ALK mutant cell lines and showed suitable preclinical pharmacokinetics and robust tumor growth inhibition in a crizotinib-resistant cell line (H3122-L1196M).
Subject(s)
Drug Resistance, Neoplasm/genetics , Point Mutation , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Pyridines/pharmacology , Receptor Protein-Tyrosine Kinases/genetics , Anaplastic Lymphoma Kinase , Crizotinib , HumansABSTRACT
The posttranslational modification of chromatin through acetylation at selected histone lysine residues is governed by histone acetyltransferases (HATs) and histone deacetylases (HDACs). The significance of this subset of the epigenetic code is interrogated and interpreted by an acetyllysine-specific protein-protein interaction with bromodomain reader modules. Selective inhibition of the bromo and extra C-terminal domain (BET) family of bromodomains with a small molecule is feasible, and this may represent an opportunity for disease intervention through the recently disclosed antiproliferative and anti-inflammatory properties of such inhibitors. Herein, we describe the discovery and structure-activity relationship (SAR) of a novel, small-molecule chemical probe for BET family inhibition that was identified through the application of structure-based fragment assessment and optimization techniques. This has yielded a potent, selective compound with cell-based activity (PFI-1) that may further add to the understanding of BET family function within the bromodomains.
Subject(s)
Molecular Probes/pharmacology , Nuclear Proteins/metabolism , Quinazolinones/pharmacology , Sulfonamides/pharmacology , Transcription Factors/antagonists & inhibitors , Cell Cycle Proteins , Crystallography, X-Ray , Humans , Models, Molecular , Molecular Probes/chemical synthesis , Molecular Structure , Nuclear Proteins/antagonists & inhibitors , Protein Binding , Quinazolinones/chemical synthesis , Structure-Activity Relationship , Sulfonamides/chemical synthesis , Sulfonamides/chemistryABSTRACT
This paper reports the synthesis and biological activity of a novel series of aryl-morpholine dopamine receptor agonists. Several compounds show high levels of functional selectivity for the D3 over the D2 dopamine receptor. Compound 26 has >1000-fold functional selectivity and has been successfully progressed in vivo using an intranasal delivery route.
Subject(s)
Dopamine Agonists/administration & dosage , Dopamine Agonists/chemical synthesis , Drug Design , Receptors, Dopamine D3/agonists , Administration, Intranasal , Animals , Crystallography, X-Ray , Dogs , Dopamine Agonists/chemistry , Dopamine Agonists/pharmacokinetics , Humans , Models, Molecular , Molecular Structure , Rats , Receptors, Dopamine D3/metabolism , Stereoisomerism , Structure-Activity RelationshipABSTRACT
A series of substituted glutaramides were synthesised using Candoxatrilat 1 as a lead and evaluated for potency against neutral endopeptidase (NEP) as a potential treatment for female sexual arousal disorder (FSAD). In this paper, we describe studies in which we were able to increase NEP activity substantially over the levels reported for previous compounds from this programme by appropriate substitution in both the P(1)(') and P(2)(') regions. Optimisation led to the 4-chlorophenpropylamide S-30 which was selected as a candidate for further study.
