ABSTRACT
BACKGROUND: The development of beta-site amyloid-beta precursor protein cleaving enzyme (BACE) 1 inhibitors for the treatment of Alzheimer's disease requires optimization of inhibitor potency, selectivity, and brain penetration. Moreover, there is a need for low-dose compounds since liver toxicity was found with some BACE inhibitors. OBJECTIVE: To determine whether the high in vitro potency and robust pharmacodynamic effect of the BACE inhibitor LY3202626 observed in nonclinical species translated to humans. METHODS: The effect of LY3202626 versus vehicle on amyloid-ß (Aß) levels was evaluated in a series of in vitro assays, as well as in in vivo and multi-part clinical pharmacology studies. Aß levels were measured using analytical biochemistry assays in brain, plasma, and cerebrospinal fluid (CSF) of mice, dogs and humans. Nonclinical data were analyzed using an ANOVA followed by Tukey's post hoc test and clinical data used summary statistics. RESULTS: LY3202626 exhibited significant human BACE1 inhibition, with an IC50 of 0.615±0.101 nM in a fluorescence resonance energy transfer assay and an EC50 of 0.275±0.176ânM for lowering Aß1-40 and 0.228±0.244ânM for Aß1-42 in PDAPP neuronal cultures. In dogs, CSF Aß1hboxx concentrations were significantly reduced by â¼80% at 9 hours following a 1.5âmg/kg dose. In humans, CSF Aß1-42 was reduced by 73.1±7.96 % following administration of 6âmg QD. LY3202626 was found to freely cross the blood-brain barrier in dogs and humans. CONCLUSION: LY3202626 is a potent BACE1 inhibitor with high blood-brain barrier permeability. The favorable safety and pharmacokinetic/pharmacodynamic profile of LY3202626 supports further clinical development.
ABSTRACT
The beta-site APP cleaving enzyme 1, known as BACE1, has been a widely pursued Alzheimer's disease drug target owing to its critical role in the production of amyloid-beta. We have previously reported the clinical development of LY2811376 and LY2886721. LY2811376 advanced to Phase I before development was terminated due to nonclinical retinal toxicity. LY2886721 advanced to Phase II, but development was halted due to abnormally elevated liver enzymes. Herein, we report the discovery and clinical development of LY3202626, a highly potent, CNS-penetrant, and low-dose BACE inhibitor, which successfully addressed these key development challenges.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Heterocyclic Compounds, 2-Ring/pharmacology , Protease Inhibitors/pharmacology , Pyrazines/pharmacology , Pyrroles/pharmacology , Amyloid Precursor Protein Secretases/metabolism , Animals , Aspartic Acid Endopeptidases/metabolism , Blood-Brain Barrier/physiology , Brain/metabolism , Crystallography, X-Ray , Dogs , Drug Stability , Heterocyclic Compounds, 2-Ring/chemical synthesis , Heterocyclic Compounds, 2-Ring/pharmacokinetics , Humans , Madin Darby Canine Kidney Cells , Male , Mice , Microsomes, Liver/metabolism , Molecular Structure , Protease Inhibitors/chemical synthesis , Protease Inhibitors/metabolism , Protease Inhibitors/pharmacokinetics , Protein Binding , Pyrazines/chemical synthesis , Pyrazines/pharmacokinetics , Pyrroles/chemical synthesis , Pyrroles/pharmacokinetics , Rats , Structure-Activity RelationshipABSTRACT
We present the results of an investigation into the biographies, letters, and archives of approximately 50 well-known figures in Western intellectual and artistic history in the post-Enlightenment era. In this article, in the interest of space, we have limited our remarks to the biographies and partners of Virginia Woolf, Frida Kahlo, Max Weber, Edna St. Vincent Millay, William Moulton Marston, Erwin Schrodinger, and Victor Hugo. While some of these non-monogamous relationships are well known, some of the evidence of their existence has been ignored, misrecognized, or intentionally obscured. The results of this survey demonstrate that contemporary patterns of non-monogamies are deeply rooted in historical precedence. Our hope is that by outlining some of the themes in our historical findings we can help modern researchers better interpret their own quantitative and qualitative research. Additionally, we look particularly closely at relationships between metamours. A great deal of previous psychological and sexological research has focused on competitive behavior in sex and relationships, particularly competition between rivals. However, relatively little attention has been given to collaborative (or symbiotic) behavior. Our research has located a wealth of examples of metamours supporting one another in material, social, and psychological ways throughout their lives. Furthermore, we suggest that while our existing societal and social-scientific norms primarily focus on competitive sexual behaviors, much can be learnt from historically documented practices of consensual non-monogamy. These practices-however flawed-point to potentially emancipatory ways of living, loving and building relationships, families, and communities-as some contemporary research has demonstrated. Moreover, a future world might benefit from a turn to far more collaborative relationships-and such behavior is well within the realm of possibility.
Subject(s)
Sexual Behavior , Sexual Partners , Humans , Qualitative Research , Social Norms , Surveys and QuestionnairesABSTRACT
Protein arginine methyltransferase 6 (PRMT6) catalyzes monomethylation and asymmetric dimethylation of arginine residues in various proteins, plays important roles in biological processes, and is associated with multiple cancers. To date, a highly selective PRMT6 inhibitor has not been reported. Here we report the discovery and characterization of a first-in-class, highly selective allosteric inhibitor of PRMT6, (R)-2 (SGC6870). (R)-2 is a potent PRMT6 inhibitor (IC50 = 77 ± 6 nM) with outstanding selectivity for PRMT6 over a broad panel of other methyltransferases and nonepigenetic targets. Notably, the crystal structure of the PRMT6-(R)-2 complex and kinetic studies revealed (R)-2 binds a unique, induced allosteric pocket. Additionally, (R)-2 engages PRMT6 and potently inhibits its methyltransferase activity in cells. Moreover, (R)-2's enantiomer, (S)-2 (SGC6870N), is inactive against PRMT6 and can be utilized as a negative control. Collectively, (R)-2 is a well-characterized PRMT6 chemical probe and a valuable tool for further investigating PRMT6 functions in health and disease.
Subject(s)
Benzodiazepinones/pharmacology , Enzyme Inhibitors/pharmacology , Nuclear Proteins/antagonists & inhibitors , Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Allosteric Regulation , Allosteric Site , Benzodiazepinones/chemical synthesis , Benzodiazepinones/metabolism , Crystallography, X-Ray , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/metabolism , HEK293 Cells , Humans , Nuclear Proteins/metabolism , Protein Binding , Protein-Arginine N-Methyltransferases/metabolism , StereoisomerismABSTRACT
Inhibition of BACE1 has become an important strategy in the quest for disease modifying agents to slow the progression of Alzheimer's disease. We previously reported the fragment-based discovery of LY2811376, the first BACE1 inhibitor reported to demonstrate robust reduction of human CSF Aß in a Phase I clinical trial. We also reported on the discovery of LY2886721, a potent BACE1 inhibitor that reached phase 2 clinical trials. Herein we describe the preparation and structure activity relationships (SAR) of a series of BACE1 inhibitors utilizing trans-cyclopropyl moieties as conformational constraints. The design, details of the stereochemically complex organic synthesis, and biological activity of these BACE1 inhibitors is described.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Cyclopropanes/pharmacology , Protease Inhibitors/pharmacology , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/metabolism , Crystallography, X-Ray , Cyclopropanes/chemical synthesis , Cyclopropanes/chemistry , Dose-Response Relationship, Drug , Humans , Ligands , Models, Molecular , Molecular Conformation , Protease Inhibitors/chemical synthesis , Protease Inhibitors/chemistry , Structure-Activity RelationshipABSTRACT
Clinical development of catechol-based orthosteric agonists of the dopamine D1 receptor has thus far been unsuccessful due to multiple challenges. To address these issues, we identified LY3154207 (3) as a novel, potent, and subtype selective human D1 positive allosteric modulator (PAM) with minimal allosteric agonist activity. Conformational studies showed LY3154207 adopts an unusual boat conformation, and a binding pose with the human D1 receptor was proposed based on this observation. In contrast to orthosteric agonists, LY3154207 showed a distinct pharmacological profile without a bell-shaped dose-response relationship or tachyphylaxis in preclinical models. Identification of a crystalline form of free LY3154207 from the discovery lots was not successful. Instead, a novel cocrystal form with superior solubility was discovered and determined to be suitable for development. This cocrystal form was advanced to clinical development as a potential first-in-class D1 PAM and is now in phase 2 studies for Lewy body dementia.
Subject(s)
Isoquinolines/pharmacology , Receptors, Dopamine D1/agonists , Acetylcholine/metabolism , Administration, Oral , Allosteric Regulation/drug effects , Animals , Binding Sites , Crystallography, X-Ray , Cyclic AMP/metabolism , HEK293 Cells , Half-Life , Humans , Isoquinolines/chemistry , Isoquinolines/pharmacokinetics , Kidney/drug effects , Kidney/metabolism , Locomotion/drug effects , Mice , Molecular Conformation , Protein Isoforms/agonists , Protein Isoforms/metabolism , Rats , Receptors, Dopamine D1/metabolism , Small Molecule Libraries/chemistry , Small Molecule Libraries/metabolism , Small Molecule Libraries/pharmacology , Structure-Activity RelationshipABSTRACT
The BACE1 enzyme is a key target for Alzheimer's disease. During our BACE1 research efforts, fragment screening revealed that bicyclic thiazine 3 had low millimolar activity against BACE1. Analysis of the co-crystal structure of 3 suggested that potency could be increased through extension toward the S3 pocket and through conformational constraint of the thiazine core. Pursuit of S3-binding groups produced low micromolar inhibitor 6, which informed the S3-design for constrained analogs 7 and 8, themselves prepared via independent, multi-step synthetic routes. Biological characterization of BACE inhibitors 6-8 is described.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Bridged Bicyclo Compounds/chemical synthesis , Protease Inhibitors/chemical synthesis , Thiazines/chemical synthesis , Amyloid Precursor Protein Secretases/chemistry , Amyloid Precursor Protein Secretases/isolation & purification , Animals , Aspartic Acid Endopeptidases/chemistry , Aspartic Acid Endopeptidases/isolation & purification , Brain Chemistry , Bridged Bicyclo Compounds/chemistry , Crystallography, X-Ray , Drug Design , Humans , Mice , Molecular Conformation , Molecular Docking Simulation , Protease Inhibitors/chemistry , Stereoisomerism , Thiazines/chemistryABSTRACT
BACE1 is a key protease controlling the formation of amyloid ß, a peptide hypothesized to play a significant role in the pathogenesis of Alzheimer's disease (AD). Therefore, the development of potent and selective inhibitors of BACE1 has been a focus of many drug discovery efforts in academia and industry. Herein, we report the nonclinical and early clinical development of LY2886721, a BACE1 active site inhibitor that reached phase 2 clinical trials in AD. LY2886721 has high selectivity against key off-target proteases, which efficiently translates in vitro activity into robust in vivo amyloid ß lowering in nonclinical animal models. Similar potent and persistent amyloid ß lowering was observed in plasma and lumbar CSF when single and multiple doses of LY2886721 were administered to healthy human subjects. Collectively, these data add support for BACE1 inhibition as an effective means of amyloid lowering and as an attractive target for potential disease modification therapy in AD.
Subject(s)
Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid beta-Peptides/metabolism , Aspartic Acid Endopeptidases/antagonists & inhibitors , Heterocyclic Compounds, 2-Ring/pharmacology , Picolinic Acids/pharmacology , Protease Inhibitors/pharmacology , Amyloid beta-Peptides/blood , Amyloid beta-Peptides/cerebrospinal fluid , Animals , Disease Models, Animal , Dogs , Heterocyclic Compounds, 2-Ring/pharmacokinetics , Heterocyclic Compounds, 2-Ring/therapeutic use , Humans , Mice , Picolinic Acids/pharmacokinetics , Picolinic Acids/therapeutic use , Protease Inhibitors/pharmacokinetics , Protease Inhibitors/therapeutic useABSTRACT
According to the amyloid cascade hypothesis, cerebral deposition of amyloid-ß peptide (Aß) is critical for Alzheimer's disease (AD) pathogenesis. Aß generation is initiated when ß-secretase (BACE1) cleaves the amyloid precursor protein. For more than a decade, BACE1 has been a prime target for designing drugs to prevent or treat AD. However, development of such agents has turned out to be extremely challenging, with major hurdles in cell penetration, oral bioavailability/metabolic clearance, and brain access. Using a fragment-based chemistry strategy, we have generated LY2811376 [(S)-4-(2,4-difluoro-5-pyrimidin-5-yl-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]thiazin-2-ylamine], the first orally available non-peptidic BACE1 inhibitor that produces profound Aß-lowering effects in animals. The biomarker changes obtained in preclinical animal models translate into man at doses of LY2811376 that were safe and well tolerated in healthy volunteers. Prominent and long-lasting Aß reductions in lumbar CSF were measured after oral dosing of 30 or 90 mg of LY2811376. This represents the first translation of BACE1-driven biomarker changes in CNS from preclinical animal models to man. Because of toxicology findings identified in longer-term preclinical studies, this compound is no longer progressing in clinical development. However, BACE1 remains a viable target because the adverse effects reported here were recapitulated in LY2811376-treated BACE1 KO mice and thus are unrelated to BACE1 inhibition. The magnitude and duration of central Aß reduction obtainable with BACE1 inhibition positions this protease as a tractable small-molecule target through which to test the amyloid hypothesis in man.
Subject(s)
Alzheimer Disease/cerebrospinal fluid , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid beta-Peptides/metabolism , Aspartic Acid Endopeptidases/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Neurons/drug effects , Adult , Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/analysis , Amyloid beta-Peptides/cerebrospinal fluid , Amyloid beta-Protein Precursor/cerebrospinal fluid , Amyloid beta-Protein Precursor/genetics , Analysis of Variance , Animals , Aspartic Acid Endopeptidases/analysis , Cells, Cultured , Cerebral Cortex/cytology , Crystallography/methods , Disease Models, Animal , Dogs , Dose-Response Relationship, Drug , Embryo, Mammalian , Enzyme Inhibitors/blood , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Male , Mice , Mice, Transgenic , Middle Aged , Models, Chemical , Mutation/genetics , Peptide Fragments/cerebrospinal fluid , Pyrimidines/pharmacology , Pyrimidines/therapeutic use , Rats , Rats, Sprague-Dawley , Thiazines/pharmacology , Thiazines/therapeutic use , Time Factors , Young AdultABSTRACT
A novel series of bacterial topoisomerase (3-aminoquinazolinediones) inhibitors are described. The side-chain SAR against Gram-positive and Gram-negative organisms as well as DNA gyrase activity is reported.
Subject(s)
Anti-Bacterial Agents , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/enzymology , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/enzymology , Quinazolinones , Topoisomerase II Inhibitors , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Combinatorial Chemistry Techniques , Fluoroquinolones/chemical synthesis , Fluoroquinolones/chemistry , Fluoroquinolones/pharmacology , Microbial Sensitivity Tests , Molecular Structure , Quinazolinones/chemical synthesis , Quinazolinones/chemistry , Quinazolinones/pharmacology , Structure-Activity RelationshipABSTRACT
Analogs to a series of D-phenylglycinamide-derived factor Xa inhibitors were discovered. It was found that the S4 amide linkage can be replaced with an ether linkage to reduce the peptide character of the molecules and that this substitution leads to an increase in binding affinity that is not predicted based on modeling. Inhibitors which incorporate ether, amino, or alkyl S4 linkage motifs exhibit similar levels of binding affinity and also demonstrate potent in vitro functional activity, however, binding affinity in this series is strongly dependent on the nature of the S1 binding element.
Subject(s)
Anticoagulants/pharmacology , Factor Xa Inhibitors , Glycine/analogs & derivatives , Serine Proteinase Inhibitors/pharmacology , Anticoagulants/chemistry , Crystallography, X-Ray , Ethanolamines , Glycine/chemistry , Models, Molecular , Peptides/chemistry , Serine Proteinase Inhibitors/chemistryABSTRACT
A series of non-covalent inhibitors of the serine protease dipeptidyl peptidase IV (DPP-IV) were found to adopt a U-shaped binding conformation in X-ray co-crystallization studies. Remarkably, Tyr547 undergoes a 70 degrees side-chain rotation to accommodate the inhibitor and allows access to a previously unexposed area of the protein backbone for hydrogen bonding.
Subject(s)
Dipeptidyl-Peptidase IV Inhibitors , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacology , Animals , Binding Sites , Computer Simulation , Crystallography, X-Ray , Dipeptidyl Peptidase 4/blood , Drug Evaluation, Preclinical , Hydrogen Bonding , Male , Models, Molecular , Molecular Conformation , Protease Inhibitors/chemistry , Rats , Rats, Wistar , Spectrometry, FluorescenceABSTRACT
A series of 3-aminoquinazolinediones was synthesized and evaluated for its antibacterial and DNA gyrase activity. The SAR around the quinazolinedione core was explored and the optimal substitutions were combined to give two compounds, 2r and 2s, with exceptional enzyme potency (IC50 = 0.2 microM) and activity against gram-positive organisms (MIC's = 0.015-0.06 microg/mL).
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Quinazolinones/chemical synthesis , Quinazolinones/pharmacology , Topoisomerase II Inhibitors , Amines/chemistry , Amines/pharmacology , Anti-Bacterial Agents/chemistry , DNA Gyrase , Gram-Positive Bacteria/drug effects , Inhibitory Concentration 50 , Quinazolinones/chemistry , Structure-Activity RelationshipABSTRACT
The 3-aminoquinzolinediones represent a new series of antibacterial agents structurally related to the fluoroquinolones. They are inhibitors of bacterial gyrase and topoisomerase IV and demonstrate clinically useful antibacterial activity against fastidious Gram-negative and Gram-positive organisms, including multidrug- and fluoroquinolone-resistant organisms. These agents also demonstrate in vivo efficacy in murine systemic infection models.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Quinazolinones/chemical synthesis , DNA Topoisomerase IV/antagonists & inhibitors , Drug Resistance, Multiple, Bacterial/drug effects , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Methicillin Resistance , Microbial Sensitivity Tests , Structure-Activity Relationship , Topoisomerase II InhibitorsABSTRACT
The synthesis and biological evaluation of novel tetrahydroisoquinoline, tetrahydroquinoline, and tetrahydroazepine antagonists of the human and rat H(3) receptors are described. The substitution around these rings as well as the nature of the substituent on nitrogen is explored. Several compounds with high affinity and selectivity for the human and rat H(3) receptors are reported.