Publications by authors named "Lisa Shewchuk"

39 Publications

Half-Life Extension of BMP1/TLL Metalloproteinase Inhibitors Using Small-Molecule Human Serum Albumin Binders.

Bioconjug Chem 2021 Feb 1;32(2):279-289. Epub 2021 Feb 1.

GlaxoSmithKline U.K., Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.

Reducing the required frequence of drug dosing can improve the adherence of patients to chronic treatments. Hence, drugs with longer half-lives are highly desirable. One of the most promising approaches to extend the half-life of drugs is conjugation to human serum albumin (HSA). In this work, we describe the use of , a small-molecule noncovalent HSA binder, to extend the half-life and pharmacology of small-molecule BMP1/TLL inhibitors in humanized mice (HSA KI/KI). A series of conjugates of with BMP1/TLL inhibitors were prepared. In particular, showed good solubility and a half-life extension of >20-fold versus the parent molecule in the HSA KI/KI mice, reaching half-lives of >48 h with maintained maximal inhibition of plasma BMP1/TLL. The same conjugate showed a half-life of only 3 h in the wild-type mice, suggesting that the half-life extension was principally due to specific interactions with HSA. It is envisioned that conjugation to should be applicable to a wide range of small molecule or peptide drugs with short half-lives. In this context, AlbuBinders represent a viable alternative to existing half-life extension technologies.
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http://dx.doi.org/10.1021/acs.bioconjchem.0c00662DOI Listing
February 2021

The exploration of aza-quinolines as hematopoietic prostaglandin D synthase (H-PGDS) inhibitors with low brain exposure.

Bioorg Med Chem 2020 12 3;28(23):115791. Epub 2020 Oct 3.

GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, PA 19426, USA.

GlaxoSmithKline and Astex Pharmaceuticals recently disclosed the discovery of the potent H-PGDS inhibitor GSK2894631A 1a (IC = 9.9 nM) as part of a fragment-based drug discovery collaboration with Astex Pharmaceuticals. This molecule exhibited good murine pharmacokinetics, allowing it to be utilized to explore H-PGDS pharmacology in vivo. Yet, with prolonged dosing at higher concentrations, 1a induced CNS toxicity. Looking to attenuate brain penetration in this series, aza-quinolines, were prepared with the intent of increasing polar surface area. Nitrogen substitutions at the 6- and 8-positions of the quinoline were discovered to be tolerated by the enzyme. Subsequent structure activity studies in these aza-quinoline scaffolds led to the identification of 1,8-naphthyridine 1y (IC = 9.4 nM) as a potent peripherally restricted H-PGDS inhibitor. Compound 1y is efficacious in four in vivo inflammatory models and exhibits no CNS toxicity.
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http://dx.doi.org/10.1016/j.bmc.2020.115791DOI Listing
December 2020

Characterization of Apo-Form Selective Inhibition of Indoleamine 2,3-Dioxygenase*.

Chembiochem 2021 Feb 16;22(3):516-522. Epub 2020 Nov 16.

Drug Design and Selection, GlaxoSmithKline, 1250 S. Collegeville Road, Collegeville, PA, 19426, USA.

Indoleamine-2,3-dioxygenase 1 (IDO1) is a heme-containing enzyme that catalyzes the rate-limiting step in the kynurenine pathway of tryptophan (TRP) metabolism. As it is an inflammation-induced immunoregulatory enzyme, pharmacological inhibition of IDO1 activity is currently being pursued as a potential therapeutic tool for the treatment of cancer and other disease states. As such, a detailed understanding of the mechanism of action of IDO1 inhibitors with various mechanisms of inhibition is of great interest. Comparison of an apo-form-binding IDO1 inhibitor (GSK5628) to the heme-coordinating compound, epacadostat (Incyte), allows us to explore the details of the apo-binding inhibition of IDO1. Herein, we demonstrate that GSK5628 inhibits IDO1 by competing with heme for binding to a heme-free conformation of the enzyme (apo-IDO1), whereas epacadostat coordinates its binding with the iron atom of the IDO1 heme cofactor. Comparison of these two compounds in cellular systems reveals a long-lasting inhibitory effect of GSK5628, previously undescribed for other known IDO1 inhibitors. Detailed characterization of this apo-binding mechanism for IDO1 inhibition might help design superior inhibitors or could confer a unique competitive advantage over other IDO1 inhibitors vis-à-vis specificity and pharmacokinetic parameters.
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http://dx.doi.org/10.1002/cbic.202000298DOI Listing
February 2021

Discovery of Pyrazolocarboxamides as Potent and Selective Receptor Interacting Protein 2 (RIP2) Kinase Inhibitors.

ACS Med Chem Lett 2019 Nov 11;10(11):1518-1523. Epub 2019 Oct 11.

GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States.

Herein we report the discovery of pyrazolocarboxamides as novel, potent, and kinase selective inhibitors of receptor interacting protein 2 kinase (RIP2). Fragment based screening and design principles led to the identification of the inhibitor series, and X-ray crystallography was used to inform key structural changes. Through key substitutions about the N1 and C5 N positions on the pyrazole ring significant kinase selectivity and potency were achieved. Bridged bicyclic pyrazolocarboxamide represents a selective and potent inhibitor of RIP2 and will allow for a more detailed investigation of RIP2 inhibition as a therapeutic target for autoinflammatory disorders.
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http://dx.doi.org/10.1021/acsmedchemlett.9b00141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862347PMC
November 2019

The discovery of quinoline-3-carboxamides as hematopoietic prostaglandin D synthase (H-PGDS) inhibitors.

Bioorg Med Chem 2019 04 11;27(8):1456-1478. Epub 2019 Feb 11.

Astex Pharmaceuticals, 436 Cambridge Science Park, Milton Road, Cambridge CB4 0QA, UK.

With the goal of discovering more selective anti-inflammatory drugs, than COX inhibitors, to attenuate prostaglandin signaling, a fragment-based screen of hematopoietic prostaglandin D synthase was performed. The 76 crystallographic hits were sorted into similar groups, with the 3-cyano-quinoline 1a (FP IC = 220,000 nM, LE = 0.43) being a potent member of the 6,6-fused heterocyclic cluster. Employing SAR insights gained from structural comparisons of other H-PGDS fragment binding mode clusters, the initial hit 1a was converted into the 70-fold more potent quinoline 1d (IC = 3,100 nM, LE = 0.49). A systematic substitution of the amine moiety of 1d, utilizing structural information and array chemistry, with modifications to improve inhibitor stability, resulted in the identification of the 300-fold more active H-PGDS inhibitor tool compound 1bv (IC = 9.9 nM, LE = 0.42). This selective inhibitor exhibited good murine pharmacokinetics, dose-dependently attenuated PGD production in a mast cell degranulation assay and should be suitable to further explore H-PGDS biology.
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http://dx.doi.org/10.1016/j.bmc.2019.02.017DOI Listing
April 2019

4,6-Diaminopyrimidines as Highly Preferred Troponin I-Interacting Kinase (TNNI3K) Inhibitors.

J Med Chem 2018 04 21;61(7):3076-3088. Epub 2018 Mar 21.

Structure-guided progression of a purine-derived series of TNNI3K inhibitors directed design efforts that produced a novel series of 4,6-diaminopyrimidine inhibitors, an emerging kinase binding motif. Herein, we report a detailed understanding of the intrinsic conformational preferences of the scaffold, which impart high specificity for TNNI3K. Further manipulation of the template based on the conformational analysis and additional structure-activity relationship studies provided enhancements in kinase selectivity and pharmacokinetics that furnished an advanced series of potent inhibitors. The optimized compounds (e.g., GSK854) are suitable leads for identifying new cardiac medicines and have been employed as in vivo tools in investigational studies aimed at defining the role of TNNI3K within heart failure.
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http://dx.doi.org/10.1021/acs.jmedchem.8b00125DOI Listing
April 2018

Discovery of a Highly Selective Tankyrase Inhibitor Displaying Growth Inhibition Effects against a Diverse Range of Tumor Derived Cell Lines.

J Med Chem 2017 07 27;60(13):5455-5471. Epub 2017 Jun 27.

Cellzome GmbH, A GlaxoSmithKline Company , Meyerhofstraße 1, 69117 Heidelberg, Germany.

The availability of high quality probes for specific protein targets is fundamental to the investigation of their function and their validation as therapeutic targets. We report the utilization of a dedicated chemoproteomic assay platform combining affinity enrichment technology with high-resolution protein mass spectrometry to the discovery of a novel nicotinamide isoster, the tetrazoloquinoxaline 41, a highly potent and selective tankyrase inhibitor. We also describe the use of 41 to investigate the biology of tankyrase, revealing the compound induced growth inhibition of a number of tumor derived cell lines, demonstrating the potential of tankyrase inhibitors in oncology.
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http://dx.doi.org/10.1021/acs.jmedchem.7b00137DOI Listing
July 2017

GSK114: A selective inhibitor for elucidating the biological role of TNNI3K.

Bioorg Med Chem Lett 2016 Jul 14;26(14):3355-3358. Epub 2016 May 14.

Heart Failure DPU, GlaxoSmithKline, 709 Swedeland Road, King of Prussia, PA 19406, USA.

A series of selective TNNI3K inhibitors were developed by modifying the hinge-binding heterocycle of a previously reported dual TNNI3K/B-Raf inhibitor. The resulting quinazoline-containing compounds exhibit a large preference (up to 250-fold) for binding to TNNI3K versus B-Raf, are useful probes for elucidating the biological pathways associated with TNNI3K, and are leads for discovering novel cardiac medicines. GSK114 emerged as a leading inhibitor, displaying significant bias (40-fold) for TNNI3K over B-Raf, exceptional broad spectrum kinase selectivity, and adequate oral exposure to enable its use in cellular and in vivo studies.
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http://dx.doi.org/10.1016/j.bmcl.2016.05.033DOI Listing
July 2016

Identification of Purines and 7-Deazapurines as Potent and Selective Type I Inhibitors of Troponin I-Interacting Kinase (TNNI3K).

J Med Chem 2015 Sep 10;58(18):7431-48. Epub 2015 Sep 10.

Heart Failure Discovery Performance Unit and ‡Platform Technology and Sciences, GlaxoSmithKline , 709 Swedeland Road, King of Prussia, Pennsylvania 19406, United States.

A series of cardiac troponin I-interacting kinase (TNNI3K) inhibitors arising from 3-((9H-purin-6-yl)amino)-N-methyl-benzenesulfonamide (1) is disclosed along with fundamental structure-function relationships that delineate the role of each element of 1 for TNNI3K recognition. An X-ray structure of 1 bound to TNNI3K confirmed its Type I binding mode and is used to rationalize the structure-activity relationship and employed to design potent, selective, and orally bioavailable TNNI3K inhibitors. Identification of the 7-deazapurine heterocycle as a superior template (vs purine) and its elaboration by introduction of C4-benzenesulfonamide and C7- and C8-7-deazapurine substituents produced compounds with substantial improvements in potency (>1000-fold), general kinase selectivity (10-fold improvement), and pharmacokinetic properties (>10-fold increase in poDNAUC). Optimal members of the series have properties suitable for use in in vitro and in vivo experiments aimed at elucidating the role of TNNI3K in cardiac biology and serve as leads for developing novel heart failure medicines.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00931DOI Listing
September 2015

Discovery of 4-Amino-8-quinoline Carboxamides as Novel, Submicromolar Inhibitors of NAD-Hydrolyzing Enzyme CD38.

J Med Chem 2015 Sep 24;58(17):7021-56. Epub 2015 Aug 24.

GlaxoSmithKline Research and Development , 5 Moore Drive, P.O. Box 13398, Research Triangle Park, North Carolina 27709, United States.

Starting from the micromolar 8-quinoline carboxamide high-throughput screening hit 1a, a systematic exploration of the structure-activity relationships (SAR) of the 4-, 6-, and 8-substituents of the quinoline ring resulted in the identification of approximately 10-100-fold more potent human CD38 inhibitors. Several of these molecules also exhibited pharmacokinetic parameters suitable for in vivo animal studies, including low clearances and decent oral bioavailability. Two of these CD38 inhibitors, 1ah and 1ai, were shown to elevate NAD tissue levels in liver and muscle in a diet-induced obese (DIO) C57BL/6 mouse model. These inhibitor tool compounds will enable further biological studies of the CD38 enzyme as well as the investigation of the therapeutic implications of NAD enhancement in disease models of abnormally low NAD.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00992DOI Listing
September 2015

A pre-steady state and steady state kinetic analysis of the N-ribosyl hydrolase activity of hCD157.

Arch Biochem Biophys 2014 Dec 20;564:156-63. Epub 2014 Sep 20.

Platform Technology and Science, Molecular Discovery Research, Chemical Sciences, GlaxoSmithKline, 5 Moore Drive, 3.2094, Research Triangle Park, NC 27709, United States.

hCD157 catalyzes the hydrolysis of nicotinamide riboside (NR) and nicotinic acid riboside (NAR). The release of nicotinamide or nicotinic acid from NR or NAR was confirmed by spectrophotometric, HPLC and NMR analyses. hCD157 is inactivated by a mechanism-based inhibitor, 2'-deoxy-2'-fluoro-nicotinamide arabinoside (fNR). Modification of the enzyme during the catalytic cycle by NR, NAR, or fNR increased the intrinsic protein fluorescence by approximately 50%. Pre-steady state and steady state data were used to derive a minimal kinetic scheme for the hydrolysis of NR. After initial complex formation a reversible step (360 and 30s(-1)) is followed by a slow irreversible step (0.1s(-1)) that defined the rate limiting step, or kcat. The calculated KMapp value for NR in the hydrolytic reaction is 6nM. The values of the kinetic constants suggest that one biological function of cell-surface hCD157 is to bind and slowly hydrolyze NR, possibly converting it to a ligand-activated receptor. Differences in substrate preference between hCD157 and hCD38 were rationalized through a comparison of the crystal structures of the two proteins. This comparison identified several residues in hCD157 (F108 and F173) that can potentially hinder the binding of dinucleotide substrates (NAD+).
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http://dx.doi.org/10.1016/j.abb.2014.09.008DOI Listing
December 2014

Discovery of 1-(1,3,5-triazin-2-yl)piperidine-4-carboxamides as inhibitors of soluble epoxide hydrolase.

Bioorg Med Chem Lett 2013 Jun 16;23(12):3584-8. Epub 2013 Apr 16.

Department of Chemistry, Heart Failure Disease Performance Unit, Metabolic Pathways and Cardiovascular Therapeutic Area Unit, GlaxoSmithKline, 709 Swedeland Road, King of Prussia, PA 19406, USA.

1-(1,3,5-Triazin-yl)piperidine-4-carboxamide inhibitors of soluble epoxide hydrolase were identified from high through-put screening using encoded library technology. The triazine heterocycle proved to be a critical functional group, essential for high potency and P450 selectivity. Phenyl group substitution was important for reducing clearance, and establishing good oral exposure. Based on this lead optimization work, 1-[4-methyl-6-(methylamino)-1,3,5-triazin-2-yl]-N-{[[4-bromo-2-(trifluoromethoxy)]-phenyl]methyl}-4-piperidinecarboxamide (27) was identified as a useful tool compound for in vivo investigation. Robust effects on a serum biomarker, 9, 10-epoxyoctadec-12(Z)-enoic acid (the epoxide derived from linoleic acid) were observed, which provided evidence of robust in vivo target engagement and the suitability of 27 as a tool compound for study in various disease models.
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http://dx.doi.org/10.1016/j.bmcl.2013.04.019DOI Listing
June 2013

Structures of human DPP7 reveal the molecular basis of specific inhibition and the architectural diversity of proline-specific peptidases.

PLoS One 2012 29;7(8):e43019. Epub 2012 Aug 29.

Institute of Molecular Biosciences, University of Graz, Graz, Austria.

Proline-specific dipeptidyl peptidases (DPPs) are emerging targets for drug development. DPP4 inhibitors are approved in many countries, and other dipeptidyl peptidases are often referred to as DPP4 activity- and/or structure-homologues (DASH). Members of the DASH family have overlapping substrate specificities, and, even though they share low sequence identity, therapeutic or clinical cross-reactivity is a concern. Here, we report the structure of human DPP7 and its complex with a selective inhibitor Dab-Pip (L-2,4-diaminobutyryl-piperidinamide) and compare it with that of DPP4. Both enzymes share a common catalytic domain (α/β-hydrolase). The catalytic pocket is located in the interior of DPP7, deep inside the cleft between the two domains. Substrates might access the active site via a narrow tunnel. The DPP7 catalytic triad is completely conserved and comprises Ser162, Asp418 and His443 (corresponding to Ser630, Asp708 and His740 in DPP4), while other residues lining the catalytic pockets differ considerably. The "specificity domains" are structurally also completely different exhibiting a β-propeller fold in DPP4 compared to a rare, completely helical fold in DPP7. Comparing the structures of DPP7 and DPP4 allows the design of specific inhibitors and thus the development of less cross-reactive drugs. Furthermore, the reported DPP7 structures shed some light onto the evolutionary relationship of prolyl-specific peptidases through the analysis of the architectural organization of their domains.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0043019PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3430648PMC
February 2013

Discovery of 7-methyl-5-(1-{[3-(trifluoromethyl)phenyl]acetyl}-2,3-dihydro-1H-indol-5-yl)-7H-pyrrolo[2,3-d]pyrimidin-4-amine (GSK2606414), a potent and selective first-in-class inhibitor of protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK).

J Med Chem 2012 Aug 8;55(16):7193-207. Epub 2012 Aug 8.

Oncology Research, Protein Dynamics DPU, GlaxoSmithKline Research and Development, Collegeville, Pennsylvania 19426, United States.

Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is activated in response to a variety of endoplasmic reticulum stresses implicated in numerous disease states. Evidence that PERK is implicated in tumorigenesis and cancer cell survival stimulated our search for small molecule inhibitors. Through screening and lead optimization using the human PERK crystal structure, we discovered compound 38 (GSK2606414), an orally available, potent, and selective PERK inhibitor. Compound 38 inhibits PERK activation in cells and inhibits the growth of a human tumor xenograft in mice.
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http://dx.doi.org/10.1021/jm300713sDOI Listing
August 2012

Discovery of an inhibitor of insulin-like growth factor 1 receptor activation: implications for cellular potency and selectivity over insulin receptor.

Biochem Pharmacol 2009 Dec 7;78(12):1438-47. Epub 2009 Aug 7.

Department of Biological Reagents and Assay Development, Research Triangle Park, GlaxoSmithKline, Inc., NC 27709, United States.

Insulin-like growth factor 1 receptor (IGF-1R) is an attractive target for anti-cancer therapy due to its anti-apoptotic effect on tumor cells, but inhibition of insulin receptor (IR) may have undesired metabolic consequences. The primary sequences of the ATP substrate-binding sites of these receptors are identical and the crystal structures of the activated kinase domains are correspondingly similar. Thus, most small-molecule inhibitors described to date are equally potent against the activated kinase domains of IGF-1R and IR. In contrast, the non-phosphorylated kinase domains of these receptors have several structural features that may accommodate differences in binding affinity for kinase inhibitors. We used a cell-based assay measuring IGF-1R autophosphorylation as an inhibitor screen, and identified a potent purine derivative that is selective compared to IR. Surprisingly, the compound is a weak inhibitor of the activated IGF-1R tyrosine kinase domain. Biochemical and structural studies are presented that indicate the compound preferentially binds to the ATP site of non-phosphorylated IGF-1R compared to phosphorylated IGF-1R. The potential selectivity and potency advantages of this binding mode are discussed.
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http://dx.doi.org/10.1016/j.bcp.2009.07.022DOI Listing
December 2009

Thienopyrimidine-based dual EGFR/ErbB-2 inhibitors.

Bioorg Med Chem Lett 2009 Feb 7;19(3):817-20. Epub 2008 Dec 7.

Department of Oncology Medicinal Chemistry, GlaxoSmithKline, Five Moore Drive, Research Triangle Park, NC 27709-3398, USA.

Two new series of potent and selective dual EGFR/ErbB-2 kinase inhibitors derived from novel thienopyrimidine cores have been identified. Isomeric thienopyrimidine cores were evaluated as isosteres for a 4-anilinoquinazoline core and several analogs containing the thieno[3,2-d]pyrimidine core showed anti-proliferative activity with IC(50) values less than 1 microM against human tumor cells in vitro.
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http://dx.doi.org/10.1016/j.bmcl.2008.12.011DOI Listing
February 2009

Discovery and optimization of imidazo[1,2-a]pyridine inhibitors of insulin-like growth factor-1 receptor (IGF-1R).

Bioorg Med Chem Lett 2009 Feb 20;19(3):1004-8. Epub 2008 Nov 20.

GlaxoSmithKline, Five Moore Drive, Research Triangle Park, NC 27709, USA.

The optimization of imidazo[1,2-a]pyridine inhibitors as potent and selective inhibitors of IGF-1R is presented. Further optimization of oral exposure in mice is also discussed. Detailed selectivity, in vitro activity, and in vivo PK profiles of an optimized compound is also highlighted.
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http://dx.doi.org/10.1016/j.bmcl.2008.11.058DOI Listing
February 2009

Optimization of 4,6-bis-anilino-1H-pyrrolo[2,3-d]pyrimidine IGF-1R tyrosine kinase inhibitors towards JNK selectivity.

Bioorg Med Chem Lett 2009 Jan 24;19(2):360-4. Epub 2008 Nov 24.

GlaxoSmithKline, Oncology R&D, 5 Moore Drive, Research Triangle Park, NC 27709, USA.

The SAR of C5' functional groups with terminal basic amines at the C6 aniline of 4,6-bis-anilino-1H-pyrrolo[2,3-d]pyrimidines is reported. Examples demonstrate potent inhibition of IGF-1R with 1000-fold selectivity over JNK1 and 3 in enzymatic assays.
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http://dx.doi.org/10.1016/j.bmcl.2008.11.077DOI Listing
January 2009

Discovery of 4,6-bis-anilino-1H-pyrrolo[2,3-d]pyrimidines: potent inhibitors of the IGF-1R receptor tyrosine kinase.

Bioorg Med Chem Lett 2009 Jan 18;19(2):469-73. Epub 2008 Nov 18.

GlaxoSmithKline, Oncology R&D, 5 Moore Drive, 3.4184.4B, PO Box 13398, Research Triangle Park, NC 27709-3398, USA.

The evaluation of a series of 4,6-bis-anilino-1H-pyrrolo[2,3-d]pyrimidines as inhibitors of the IGF-1R (IGF-IR) receptor tyrosine kinase is reported. Examples demonstrate nanomolar potencies in in vitro enzyme and mechanistic cellular assays as well as promising in vivo pharmacokinetics in rat.
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http://dx.doi.org/10.1016/j.bmcl.2008.11.046DOI Listing
January 2009

Synthesis and evaluation of pyrazolo[1,5-b]pyridazines as selective cyclin dependent kinase inhibitors.

Bioorg Med Chem Lett 2008 Nov 24;18(21):5758-62. Epub 2008 Sep 24.

Department of Oncology, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.

A novel series of pyrazolo[1,5-b]pyridazines have been synthesized and identified as cyclin dependant kinase inhibitors potentially useful for the treatment of solid tumors. Modification of the hinge-binding amine or the C(2)- and C(6)-substitutions on the pyrazolopyridazine core provided potent inhibitors of CDK4 and demonstrated enzyme selectivity against VEGFR-2 and GSK3beta.
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http://dx.doi.org/10.1016/j.bmcl.2008.09.069DOI Listing
November 2008

X-ray crystal structure of the novel enhanced-affinity glucocorticoid agonist fluticasone furoate in the glucocorticoid receptor-ligand binding domain.

J Med Chem 2008 Jun 4;51(12):3349-52. Epub 2008 Jun 4.

An X-ray crystal structure is reported for the novel enhanced-affinity glucocorticoid agonist fluticasone furoate (FF) in the ligand binding domain of the glucocorticoid receptor. Comparison of this structure with those of dexamethasone and fluticasone propionate shows the 17 alpha furoate ester to occupy more fully the lipophilic 17 alpha pocket on the receptor, which may account for the enhanced glucocorticoid receptor binding of FF.
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http://dx.doi.org/10.1021/jm800279tDOI Listing
June 2008

6-Ethynylthieno[3,2-d]- and 6-ethynylthieno[2,3-d]pyrimidin-4-anilines as tunable covalent modifiers of ErbB kinases.

Proc Natl Acad Sci U S A 2008 Feb 19;105(8):2773-8. Epub 2008 Feb 19.

Department of Assay Development, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.

Analysis of the x-ray crystal structure of mono-substituted acetylenic thienopyrimidine 6 complexed with the ErbB family enzyme ErbB-4 revealed a covalent bond between the terminal carbon of the acetylene moiety and the sulfhydryl group of Cys-803 at the solvent interface. The identification of this covalent adduct suggested that acetylenic thienopyrimidine 6 and related analogs might also be capable of forming an analogous covalent adduct with EGFR, which has a conserved cysteine (797) near the ATP binding pocket. To test this hypothesis, we treated a truncated, catalytically competent form of EGFR (678-1020) with a structurally related propargylic amine (8). An investigation of the resulting complex by mass spectrometry revealed the formation of a covalent complex of thienopyrimidine 8 with Cys-797 of EGFR. This finding enabled us to readily assess the irreversibility of various inhibitors and also facilitated a structure-activity relationship understanding of the covalent modifying potential and biological activity of a series of acetylenic thienopyrimidine compounds with potent antitumor activity. Several ErbB family enzyme and cell potent 6-ethynyl thienopyrimidine kinase inhibitors were found to form covalent adducts with EGFR.
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http://dx.doi.org/10.1073/pnas.0708281105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2268535PMC
February 2008

Impact of common epidermal growth factor receptor and HER2 variants on receptor activity and inhibition by lapatinib.

Cancer Res 2008 Jan;68(2):571-9

Department of Translational Medicine, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, USA.

The goal of this study was to characterize the effects of non-small cell lung carcinoma (NSCLC)-associated mutations in epidermal growth factor receptor (EGFR/ErbB1) and HER2 (ErbB2) on interactions with the dual tyrosine kinase inhibitor lapatinib. Biochemical studies show that commonly observed variants of EGFR [G719C, G719S, L858R, L861Q, and Delta746-750 (del15)] are enzyme activating, increasing the tyrosine kinase V(max) and increasing the K(m)((app)) for ATP. The point mutations G719C and L861Q had minor effects on lapatinib K(i)s, whereas EGFR mutations L858R and del15 had a higher K(i) for lapatinib than wild-type EGFR. Structural analysis of wild-type EGFR-lapatinib complexes and modeling of the EGFR mutants were consistent with these data, suggesting that loss of structural flexibility and possible stabilization of the active-like conformation could interfere with lapatinib binding, particularly to the EGFR deletion mutants. Furthermore, EGFR deletion mutants were relatively resistant to lapatinib-mediated inhibition of receptor autophosphorylation in recombinant cells expressing the variants, whereas EGFR point mutations had a modest or no effect. Of note, EGFR T790M, a receptor variant found in patients with gefitinib-resistant NSCLC, was also resistant to lapatinib-mediated inhibition of receptor autophosphorylation. Two HER2 insertional variants found in NSCLC were less sensitive to lapatinib inhibition than two HER2 point mutants. The effects of lapatinib on the proliferation of human NSCLC tumor cell lines expressing wild-type or variant EGFR and HER2 cannot be explained solely on the basis of the biochemical activity or receptor autophosphorylation in recombinant cells. These data suggest that cell line genetic heterogeneity and/or multiple determinants modulate the role played by EGFR/HER2 in regulating cell proliferation.
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http://dx.doi.org/10.1158/0008-5472.CAN-07-2404DOI Listing
January 2008

The discovery of substituted 4-(3-hydroxyanilino)-quinolines as potent RET kinase inhibitors.

Bioorg Med Chem Lett 2007 Nov 25;17(21):5886-93. Epub 2007 Aug 25.

GlaxoSmithKline, Molecular Discovery Research Chemistry, 5 Moore Drive, Research Triangle Park, NC 27709, USA.

Substituted 4-(3-hydroxyanilino)-quinoline compounds, initially identified as small-molecule inhibitors of src family kinases, have been evaluated as potential inhibitors of RET kinase. Three compounds, 38, 31, and 40, had K(i)'s of 3, 25, and 50 nM in an in vitro kinase assay; while a cell based kinase assay showed K(i)'s of 300, 100, and 45 nM, respectively. These compounds represent potential new leads for the treatment of medullary and papillary thyroid cancer.
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http://dx.doi.org/10.1016/j.bmcl.2007.07.104DOI Listing
November 2007

Crystallization of protein-ligand complexes.

Acta Crystallogr D Biol Crystallogr 2007 Jan 13;63(Pt 1):72-9. Epub 2006 Dec 13.

Department of Computational, Analytical and Structural Sciences, Glaxo SmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, USA.

Obtaining diffraction-quality crystals has long been a bottleneck in solving the three-dimensional structures of proteins. Often proteins may be stabilized when they are complexed with a substrate, nucleic acid, cofactor or small molecule. These ligands, on the other hand, have the potential to induce significant conformational changes to the protein and ab initio screening may be required to find a new crystal form. This paper presents an overview of strategies in the following areas for obtaining crystals of protein-ligand complexes: (i) co-expression of the protein with the ligands of interest, (ii) use of the ligands during protein purification, (iii) cocrystallization and (iv) soaks.
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http://dx.doi.org/10.1107/S0907444906047020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2483499PMC
January 2007

Prediction of multiple binding modes of the CDK2 inhibitors, anilinopyrazoles, using the automated docking programs GOLD, FlexX, and LigandFit: an evaluation of performance.

J Chem Inf Model 2006 Nov-Dec;46(6):2552-62

Chemistry Department, Tsukuba Research Laboratories, GlaxoSmithKline K.K., 43 Wadai, Tsukuba, Ibaraki 300-4247, Japan.

Anilinopyrazoles as CDK2 inhibitors can adopt multiple binding modes depending on the substituents at the 5-position of the pyrazole ring, based on CDK2/cyclin A crystallographic studies. Three commercially available docking programs, FlexX, GOLD, and LigandFit, were tested with 63 anilinopyrazole analogues in an attempt to reproduce the binding modes observed in the crystal structures. Each docking program gave different ligand conformations depending on the scoring or energy functions used. FlexX/drugscore, GOLD/chemscore, and LigandFit/plp were the best combinations of each docking program in reproducing the ligand conformations observed in the crystal structures. The 63 analogues were divided into two groups, type-A and type-B, depending on the substituent at the 5-position of the pyrazole ring. Although an alternate binding mode, observed in a crystal structure of one type-B compound, could not be reproduced with any of the above docking/scoring combinations, GOLD, with a template constraint based on the crystal structure coordinates, was able to reproduce the pose. As for type-A compounds, all docking conditions yielded similar poses to those observed in crystal structures. When predicting activities by scoring programs, the combination of docking with LigandFit/plp and scoring with LIGSCORE1_CFF gave the best correlation coefficient (r=0.60) between experimental pIC50 values and top-ranked rescores of 30 poses of each compound. With regard to type-A compounds, the correlation was 0.69. However, when 11 compounds, whose top-ranked rescored poses did not demonstrate the correct binding modes in reference to the crystal structure, were removed, the correlation rose to 0.75. Consequently, predicting activity on the basis of correct binding modes was found to be reliable.
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http://dx.doi.org/10.1021/ci600186bDOI Listing
February 2007

5-(1H-Benzimidazol-1-yl)-3-alkoxy-2-thiophenecarbonitriles as potent, selective, inhibitors of IKK-epsilon kinase.

Bioorg Med Chem Lett 2006 Dec 25;16(24):6236-40. Epub 2006 Sep 25.

GlaxoSmithKline R&D, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK.

The identification and hit-to-lead exploration of a novel, potent and selective series of substituted benzimidazole-thiophene carbonitrile inhibitors of IKK-epsilon kinase is described. Compound 12e was identified with an IKK-epsilon enzyme potency of pIC(50) 7.4, and has a highly encouraging wider selectivity profile, including selectivity within the IKK kinase family.
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http://dx.doi.org/10.1016/j.bmcl.2006.09.018DOI Listing
December 2006

Novel, potent P2-P3 pyrrolidine derivatives of ketoamide-based cathepsin K inhibitors.

Bioorg Med Chem Lett 2006 Mar 11;16(6):1735-9. Epub 2006 Jan 11.

Department of Medicinal Chemistry, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.

Starting from a potent pantolactone ketoamide cathepsin K inhibitor discovered from structural screening, conversion of the lactone scaffold to a pyrrolidine scaffold allowed exploration of the S(3) subsite of cathepsin K. Manipulation of P3 and P1' groups afforded potent inhibitors with drug-like properties.
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http://dx.doi.org/10.1016/j.bmcl.2005.11.101DOI Listing
March 2006

Semicarbazone-based inhibitors of cathepsin K, are they prodrugs for aldehyde inhibitors?

Bioorg Med Chem Lett 2006 Feb 15;16(4):978-83. Epub 2005 Nov 15.

Department of Research Bioanalysis and Drug Metabolism, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.

Starting from potent aldehyde inhibitors with poor drug properties, derivatization to semicarbazones led to the identification of a series of semicarbazone-based cathepsin K inhibitors with greater solubility and better pharmacokinetic profiles than their parent aldehydes. Furthermore, a representative semicarbazone inhibitor attenuated bone resorption in an ex vivo rat calvarial bone resorption model. However, based on enzyme inhibition comparisons at neutral pH, semicarbazone hydrolysis rates, and 13C NMR experiments, these semicarbazones probably function as prodrugs of aldehydes.
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http://dx.doi.org/10.1016/j.bmcl.2005.10.108DOI Listing
February 2006

P2-P3 conformationally constrained ketoamide-based inhibitors of cathepsin K.

Bioorg Med Chem Lett 2005 Aug;15(15):3540-6

Department of Medicinal Chemistry, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.

An orally bioavailable series of ketoamide-based cathepsin K inhibitors with good pharmacokinetic properties has been identified. Starting from a potent inhibitor endowed with poor drug properties, conformational constraint of the P(2)-P(3) linker and modifications to P(1') elements led to an enhancement in potency, solubility, clearance, and bioavailability. These optimized inhibitors attenuated bone resorption in a rat TPTX hypocalcemic bone resorption model.
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http://dx.doi.org/10.1016/j.bmcl.2005.05.062DOI Listing
August 2005