RÉSUMÉ
Through regulation of the epigenome, the bromodomain and extra terminal (BET) family of proteins represent important therapeutic targets for the treatment of human disease. Through mimicking the endogenous N-acetyl-lysine group and disrupting the protein-protein interaction between histone tails and the bromodomain, several small molecule pan-BET inhibitors have progressed to oncology clinical trials. This work describes the medicinal chemistry strategy and execution to deliver an orally bioavailable tetrahydroquinoline (THQ) pan-BET candidate. Critical to the success of this endeavor was a potency agnostic analysis of a data set of 1999 THQ BET inhibitors within the GSK collection which enabled identification of appropriate lipophilicity space to deliver compounds with a higher probability of desired oral candidate quality properties. SAR knowledge was leveraged via Free-Wilson analysis within this design space to identify a small group of targets which ultimately delivered I-BET567 (27), a pan-BET candidate inhibitor that demonstrated efficacy in mouse models of oncology and inflammation.
Sujet(s)
Aminoquinoléines/composition chimique , Conception de médicament , Protéines/métabolisme , Administration par voie orale , Aminoquinoléines/métabolisme , Aminoquinoléines/pharmacocinétique , Aminoquinoléines/usage thérapeutique , Animaux , Benzoates/composition chimique , Benzoates/métabolisme , Sites de fixation , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cristallographie aux rayons X , Chiens , Période , Humains , Mâle , Souris , Conformation moléculaire , Simulation de dynamique moléculaire , Tumeurs/traitement médicamenteux , Protéines/antagonistes et inhibiteurs , Rats , Relation structure-activitéRÉSUMÉ
The profound efficacy of pan-BET inhibitors is well documented, but these epigenetic agents have shown pharmacology-driven toxicity in oncology clinical trials. The opportunity to identify inhibitors with an improved safety profile by selective targeting of a subset of the eight bromodomains of the BET family has triggered extensive medicinal chemistry efforts. In this article, we disclose the identification of potent and selective drug-like pan-BD2 inhibitors such as pyrazole 23 (GSK809) and furan 24 (GSK743) that were derived from the pyrrole fragment 6. We transpose the key learnings from a previous pyridone series (GSK620 2 as a representative example) to this novel class of inhibitors, which are characterized by significantly improved solubility relative to our previous research.
Sujet(s)
Furanes/pharmacologie , Protéines/antagonistes et inhibiteurs , Pyrazoles/pharmacologie , Relation dose-effet des médicaments , Furanes/composition chimique , Humains , Structure moléculaire , Protéines/métabolisme , Pyrazoles/composition chimique , Relation structure-activitéRÉSUMÉ
Domain-specific BET bromodomain ligands represent an attractive target for drug discovery with the potential to unlock the therapeutic benefits of antagonizing these proteins without eliciting the toxicological aspects seen with pan-BET inhibitors. While we have reported several distinct classes of BD2 selective compounds, namely, GSK620, GSK549, and GSK046, only GSK046 shows high aqueous solubility. Herein, we describe the lead optimization of a further class of highly soluble compounds based upon a picolinamide chemotype. Focusing on achieving >1000-fold selectivity for BD2 over BD1 ,while retaining favorable physical chemical properties, compound 36 was identified as being 2000-fold selective for BD2 over BD1 (Brd4 data) with >1 mg/mL solubility in FaSSIF media. 36 represents a valuable new in vivo ready molecule for the exploration of the BD2 phenotype.
Sujet(s)
Protéines du cycle cellulaire/antagonistes et inhibiteurs , Pyridines/pharmacologie , Facteurs de transcription/antagonistes et inhibiteurs , Protéines du cycle cellulaire/métabolisme , Relation dose-effet des médicaments , Humains , Modèles moléculaires , Structure moléculaire , Pyridines/composition chimique , Relation structure-activité , Facteurs de transcription/métabolismeRÉSUMÉ
A number of reports have recently been published describing the discovery and optimization of bromo and extraterminal inhibitors which are selective for the second bromodomain (BD2); these include our own work toward GSK046 (3) and GSK620 (5). This paper describes our approach to mitigating the genotoxicity risk of GSK046 by replacement of the acetamide functionality with a heterocyclic ring. This was followed by a template-hopping and hybridization approach, guided by structure-based drug design, to incorporate learnings from other BD2-selective series, optimize the vector for the amide region, and explore the ZA cleft, leading to the identification of potent, selective, and bioavailable compounds 28 (GSK452), 39 (GSK737), and 36 (GSK217).
Sujet(s)
Protéines du cycle cellulaire/antagonistes et inhibiteurs , Domaines protéiques/effets des médicaments et des substances chimiques , Bibliothèques de petites molécules/composition chimique , Bibliothèques de petites molécules/pharmacologie , Facteurs de transcription/antagonistes et inhibiteurs , Protéines du cycle cellulaire/composition chimique , Protéines du cycle cellulaire/métabolisme , Conception de médicament , Découverte de médicament , Humains , Facteurs de transcription/composition chimique , Facteurs de transcription/métabolismeRÉSUMÉ
Pan-bromodomain and extra terminal domain (BET) inhibitors interact equipotently with the eight bromodomains of the BET family of proteins and have shown profound efficacy in a number of in vitro phenotypic assays and in vivo pre-clinical models in inflammation or oncology. A number of these inhibitors have progressed to the clinic where pharmacology-driven adverse events have been reported. To better understand the contribution of each domain to their efficacy and improve their safety profile, selective inhibitors are required. This article discloses the profile of GSK046, also known as iBET-BD2, a highly selective inhibitor of the second bromodomains of the BET proteins that has undergone extensive pre-clinical in vitro and in vivo characterization.
Sujet(s)
Amides/synthèse chimique , Conception de médicament , Facteurs de transcription/antagonistes et inhibiteurs , Amides/composition chimique , Amides/métabolisme , Animaux , Dérivés du benzène/composition chimique , Sites de fixation , Protéines du cycle cellulaire/antagonistes et inhibiteurs , Protéines du cycle cellulaire/métabolisme , Cristallographie aux rayons X , Humains , Microsomes du foie/métabolisme , Simulation de dynamique moléculaire , Domaines protéiques , Théorie quantique , Rats , Relation structure-activité , Facteurs de transcription/métabolismeRÉSUMÉ
The profound efficacy, yet associated toxicity of pan-BET inhibitors is well documented. The possibility of an ameliorated safety profile driven by significantly selective (>100-fold) inhibition of a subset of the eight bromodomains is enticing, but challenging given the close homology. Herein, we describe the X-ray crystal structure-directed optimization of a novel weak fragment ligand with a pan-second bromodomain (BD2) bias, to potent and highly BD2 selective inhibitors. A template hopping approach, enabled by our parallel research into an orthogonal template (15, GSK046), was the basis for the high selectivity observed. This culminated in two tool molecules, 20 (GSK620) and 56 (GSK549), which showed an anti-inflammatory phenotype in human whole blood, confirming their cellular target engagement. Excellent broad selectivity, developability, and in vivo oral pharmacokinetics characterize these tools, which we hope will be of broad utility to the field of epigenetics research.
Sujet(s)
Anti-inflammatoires/composition chimique , Ligands , Facteurs de transcription/antagonistes et inhibiteurs , Administration par voie orale , Amides/composition chimique , Amides/métabolisme , Amides/pharmacocinétique , Animaux , Anti-inflammatoires/métabolisme , Anti-inflammatoires/pharmacocinétique , Sites de fixation , Protéines du cycle cellulaire/antagonistes et inhibiteurs , Protéines du cycle cellulaire/métabolisme , Cristallographie aux rayons X , Chiens , Période , Humains , Liaison hydrogène , Mâle , Simulation de dynamique moléculaire , Domaines protéiques , Rats , Rat Wistar , Relation structure-activité , Facteurs de transcription/métabolismeRÉSUMÉ
The DNA papillomaviruses infect squamous epithelium and can cause persistent, benign and sometimes malignant hyperproliferative lesions. Effective antiviral drugs to treat human papillomavirus (HPV) infection are lacking and here we investigate the anti-papillomavirus activity of novel epigenetic targeting drugs, BET bromodomain inhibitors. Bromodomain and Extra-Terminal domain (BET) proteins are host proteins which regulate gene transcription, they bind acetylated lysine residues in histones and non-histone proteins via bromodomains, functioning as scaffold proteins in the formation of transcriptional complexes at gene regulatory regions. The BET protein BRD4 has been shown to be involved in the papillomavirus life cycle, as a co-factor for viral E2 and also mediating viral partitioning in some virus types. We set out to study the activity of small molecule BET bromodomain inhibitors in models of papillomavirus infection. Several BET inhibitors reduced HPV11 E1ËE4 mRNA expression in vitro and topical therapeutic administration of an exemplar compound I-BET762, abrogated CRPV cutaneous wart growth in rabbits, demonstrating translation of anti-viral effects to efficacy in vivo. Additionally I-BET762 markedly reduced viability of HPV16 infected W12â¯cells compared to non-infected C33A cells. The molecular mechanism for the cytotoxicity to W12â¯cells is unknown but may be through blocking viral-dependent cell-survival factors. We conclude that these effects, across multiple papillomavirus types and in vivo, highlight the potential to target BET bromodomains to treat HPV infection.
Sujet(s)
Benzodiazépines/usage thérapeutique , Composés hétérocycliques avec 4 noyaux ou plus/usage thérapeutique , Protéines nucléaires/antagonistes et inhibiteurs , Papillomaviridae/effets des médicaments et des substances chimiques , Facteurs de transcription/antagonistes et inhibiteurs , Verrues/traitement médicamenteux , Acétylation , Animaux , Lignée cellulaire tumorale , Survie cellulaire , Épigenèse génétique , Lysine , Mâle , Papillomaviridae/génétique , Domaines protéiques , Lapins , Verrues/virologieRÉSUMÉ
A novel series of quinoline isoxazole BET family bromodomain inhibitors are discussed. Crystallography is used to illustrate binding modes and rationalize their SAR. One member, I-BET151 (GSK1210151A), shows good oral bioavailability in both the rat and minipig as well as demonstrating efficient suppression of bacterial induced inflammation and sepsis in a murine in vivo endotoxaemia model.
Sujet(s)
Composés hétérocycliques avec 4 noyaux ou plus/composition chimique , Isoxazoles/synthèse chimique , Protéines de tissu nerveux/antagonistes et inhibiteurs , Quinoléines/synthèse chimique , Animaux , Sites de fixation , Cristallographie aux rayons X , Cochons d'Inde , Composés hétérocycliques avec 4 noyaux ou plus/métabolisme , Inflammation/traitement médicamenteux , Isoxazoles/composition chimique , Isoxazoles/pharmacologie , Souris , Modèles moléculaires , Liaison aux protéines/effets des médicaments et des substances chimiques , Quinoléines/composition chimique , Quinoléines/pharmacologie , RatsRÉSUMÉ
The discovery, synthesis and biological evaluation of a novel series of 7-isoxazoloquinolines is described. Several analogs are shown to increase ApoA1 expression within the nanomolar range in the human hepatic cell line HepG2.
Sujet(s)
Apolipoprotéine A-I/métabolisme , Découverte de médicament , Composés hétérocycliques avec 4 noyaux ou plus/composition chimique , Composés hétérocycliques avec 4 noyaux ou plus/pharmacologie , Protéines nucléaires/antagonistes et inhibiteurs , Quinoléines/composition chimique , Régulation positive/effets des médicaments et des substances chimiques , Animaux , Anti-inflammatoires/composition chimique , Anti-inflammatoires/pharmacologie , Cellules HepG2 , Histone acetyltransferases , Chaperons d'histones , Humains , Concentration inhibitrice 50 , Souris , Souris de lignée BALB C , Protéines de tissu nerveux , Protéines nucléaires/métabolisme , Quinoléines/pharmacologie , Rats , Relation structure-activitéRÉSUMÉ
Bromodomains are epigenetic reader modules that regulate gene transcription through their recognition of acetyl-lysine modified histone tails. Inhibitors of this protein-protein interaction have the potential to modulate multiple diseases as demonstrated by the profound anti-inflammatory and antiproliferative effects of a recently disclosed class of BET compounds. While these compounds were discovered using phenotypic assays, here we present a highly efficient alternative approach to find new chemical templates, exploiting the abundant structural knowledge that exists for this target class. A phenyl dimethyl isoxazole chemotype resulting from a focused fragment screen has been rapidly optimized through structure-based design, leading to a sulfonamide series showing anti-inflammatory activity in cellular assays. This proof-of-principle experiment demonstrates the tractability of the BET family and bromodomain target class to fragment-based hit discovery and structure-based lead optimization.