RESUMO
A diaryl ketone series was identified as vanin-1 inhibitors from a high-throughput screening campaign. While this novel scaffold provided valuable probe 2 that was used to build target confidence, concerns over the ketone moiety led to the replacement of this group. The successful replacement of this moiety was achieved with pyrimidine carboxamides derived from cyclic secondary amines that were extensively characterized using biophysical and crystallographic methods as competitive inhibitors of vanin-1. Through optimization of potency and physicochemical and ADME properties, and guided by co-crystal structures with vanin-1, 3 was identified with a suitable profile for advancement into preclinical development.
Assuntos
Amidoidrolases/antagonistas & inibidores , Piridinas/síntese química , Piridinas/farmacologia , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Cristalografia por Raios X , Sulfato de Dextrana , Cães , Descoberta de Drogas , Feminino , Proteínas Ligadas por GPI/antagonistas & inibidores , Ensaios de Triagem em Larga Escala , Cetonas/química , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Piridinas/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
Through fragment-based drug design focused on engaging the active site of IRAK4 and leveraging three-dimensional topology in a ligand-efficient manner, a micromolar hit identified from a screen of a Pfizer fragment library was optimized to afford IRAK4 inhibitors with nanomolar potency in cellular assays. The medicinal chemistry effort featured the judicious placement of lipophilicity, informed by co-crystal structures with IRAK4 and optimization of ADME properties to deliver clinical candidate PF-06650833 (compound 40). This compound displays a 5-unit increase in lipophilic efficiency from the fragment hit, excellent kinase selectivity, and pharmacokinetic properties suitable for oral administration.
Assuntos
Descoberta de Drogas , Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , Isoquinolinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Administração Oral , Relação Dose-Resposta a Droga , Humanos , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Isoquinolinas/administração & dosagem , Isoquinolinas/química , Lactamas , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Relação Estrutura-AtividadeRESUMO
ITK (interleukin-2-inducible T-cell kinase) is a critical component of signal transduction in T-cells and has a well-validated role in their proliferation, cytokine release and chemotaxis. ITK is an attractive target for the treatment of T-cell-mediated inflammatory diseases. In the present study we describe the discovery of kinase inhibitors that preferentially bind to an allosteric pocket of ITK. The novel ITK allosteric site was characterized by NMR, surface plasmon resonance, isothermal titration calorimetry, enzymology and X-ray crystallography. Initial screening hits bound to both the allosteric pocket and the ATP site. Successful lead optimization was achieved by improving the contribution of the allosteric component to the overall inhibition. NMR competition experiments demonstrated that the dual-site binders showed higher affinity for the allosteric site compared with the ATP site. Moreover, an optimized inhibitor displayed non-competitive inhibition with respect to ATP as shown by steady-state enzyme kinetics. The activity of the isolated kinase domain and auto-activation of the full-length enzyme were inhibited with similar potency. However, inhibition of the activated full-length enzyme was weaker, presumably because the allosteric site is altered when ITK becomes activated. An optimized lead showed exquisite kinome selectivity and is efficacious in human whole blood and proximal cell-based assays.
Assuntos
Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Trifosfato de Adenosina/farmacologia , Regulação Alostérica , Sítio Alostérico , Cristalização , Cristalografia por Raios X , Humanos , Modelos Moleculares , Conformação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Ressonância de Plasmônio de SuperfícieRESUMO
This paper describes the identification and optimization of a novel series of DFG-out binding p38 inhibitors as inhaled agents for the treatment of chronic obstructive pulmonary disease. Structure based drug design and "inhalation by design" principles have been applied to the optimization of the lead series exemplied by compound 1a. Analogues have been designed to be potent and selective for p38, with an emphasis on slow enzyme dissociation kinetics to deliver prolonged lung p38 inhibition. Pharmacokinetic properties were tuned with high intrinsic clearance and low oral bioavailability in mind, to minimize systemic exposure and reduce systemically driven adverse events. High CYP mediated clearance and glucuronidation were targeted to achieve high intrinsic clearance coupled with multiple routes of clearance to minimize drug-drug interactions. Furthermore, pharmaceutical properties such as stability, crystallinity, and solubility were considered to ensure compatibility with a dry powder inhaler. 1ab (PF-03715455) was subsequently identified as a clinical candidate from this series with efficacy and safety profiles confirming its potential as an inhaled agent for the treatment of COPD.
Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Compostos Azabicíclicos/síntese química , Compostos de Metilureia/síntese química , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Pirazóis/síntese química , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Administração por Inalação , Animais , Anti-Inflamatórios não Esteroides/farmacocinética , Anti-Inflamatórios não Esteroides/farmacologia , Compostos Azabicíclicos/farmacocinética , Compostos Azabicíclicos/farmacologia , Sítios de Ligação , Permeabilidade da Membrana Celular , Cristalografia por Raios X , Cães , Estabilidade de Medicamentos , Humanos , Técnicas In Vitro , Cinética , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Compostos de Metilureia/farmacocinética , Compostos de Metilureia/farmacologia , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Pirazóis/farmacocinética , Pirazóis/farmacologia , Ratos , Solubilidade , Ressonância de Plasmônio de Superfície , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Quinases p38 Ativadas por Mitógeno/químicaRESUMO
We report the use of fragment screening and fragment based drug design to develop a PI3γ kinase fragment hit into a lead. Initial fragment hits were discovered by high concentration biochemical screening, followed by a round of virtual screening to identify additional ligand efficient fragments. These were developed into potent and ligand efficient lead compounds using structure guided fragment growing and merging strategies. This led to a potent, selective, and cell permeable PI3γ kinase inhibitor with good metabolic stability that was useful as a preclinical tool compound.
Assuntos
Descoberta de Drogas , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Estabilidade de Medicamentos , Modelos Moleculares , Relação Estrutura-AtividadeRESUMO
A series of potent chiral PDE5 inhibitors are described that are based on the sildenafil architecture but exhibit much greater selectivity over PDE6. Eudismic analysis of the SAR in this series provided a clear illustration of Pfeiffer's rule and indicated that the chiral motif was involved in a highly-stereoselective interaction with PDE5. This PDE5 specificity translated to levels of selectivity over PDE6 that were hitherto unprecedented in the sildenafil scaffold. UK-371,800 (compound 8) was identified as a development candidate from this series that married sildenafil-like molecular properties with high selectivity over PDE6. Clinical data confirm that UK-371,800 has markedly superior human pharmacokinetics to a previously-described higher molecular weight achiral analogue in this template (compound 1).
Assuntos
Disfunção Erétil/tratamento farmacológico , Inibidores da Fosfodiesterase 5 , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/farmacocinética , Piperazinas/síntese química , Piperazinas/farmacocinética , Sulfonas/síntese química , Sulfonas/farmacocinética , 3',5'-GMP Cíclico Fosfodiesterases/antagonistas & inibidores , Técnicas de Química Combinatória , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Masculino , Estrutura Molecular , Inibidores de Fosfodiesterase/química , Inibidores de Fosfodiesterase/farmacologia , Piperazinas/química , Piperazinas/farmacologia , Purinas/síntese química , Purinas/química , Purinas/farmacocinética , Purinas/farmacologia , Citrato de Sildenafila , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacologiaRESUMO
The reaction of 1,3-diphenyl-2-propenyl acetate (9) with dimethylmalonate to give the substitution product 10 is effectively catalyzed by Pd complexes containing chiral imine-sulfide chelate ligands derived from amino acids. The ligand of choice, (S)-N-2'-chlorobenzylidene-2-amino-3-methyl-1-thiophenylbutane (6e), prepared in only two steps from (S)-valinol, gave an ee of 94%. Because the explanation of selectivity with the majority of other nitrogen-sulfur chelate ligands in this reaction assumes the selectivity to be controlled by an electronic bias, which contradicts our results, we characterized the Pd-allyl intermediate 14 by X-ray diffraction and solution NMR. The possible mechanism of chirality transfer is discussed. The site of nucleophilic attack on the allyl ligand is not trans to the perceived better pi-acceptor ligand (sulfur), which would be analogous to chiral nitrogen-phosphorus systems. This reaction occurs trans to the imine donor, and the enantioselectivity is ultimately controlled by the subtle steric environment of the chiral imine-sulfur chelate ligand, which predisposes the allyl unit of the reaction intermediate to a preferred reaction trajectory. In light of results that emphasize the power of electronic desymmetrization for chiral recognition, these results suggest that electronically dissimilar ligands may not give rise to chiral recognition through electronic dissimilarity.