RESUMEN
Selective inhibition of the RGD (Arg-Gly-Asp) integrin αvß1 has been recently identified as an attractive therapeutic approach for the treatment of liver fibrosis given its function, target expression, and safety profile. Our identification of a non-RGD small molecule lead followed by focused, systematic changes to the core structure utilizing a crystal structure, in silico modeling, and a tractable synthetic approach resulted in the identification of a potent small molecule exhibiting a remarkable affinity for αvß1 relative to several other integrin isoforms measured. Azabenzimidazolone 25 demonstrated antifibrotic efficacy in an in vivo rat liver fibrosis model and represents a tool compound capable of further exploring the biological consequences of selective αvß1 inhibition.
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Diseño de Fármacos , Receptores de Vitronectina , Animales , Ratas , Humanos , Receptores de Vitronectina/antagonistas & inhibidores , Receptores de Vitronectina/metabolismo , Relación Estructura-Actividad , Cirrosis Hepática/tratamiento farmacológico , Modelos Moleculares , Descubrimiento de Drogas , Ratas Sprague-Dawley , Masculino , Cristalografía por Rayos X , Bencimidazoles/farmacología , Bencimidazoles/química , Bencimidazoles/síntesis químicaRESUMEN
Tau PET imaging using the tau specific PET tracer [18F]GTP1 has been and is part of therapeutic trials in Alzheimer's disease to monitor the accumulation of tau aggregates in the brain. Herein, we examined the metabolic processes of GTP1 and assessed the influence of smoking on its metabolism through in vitro assays. The tracer metabolic profile was assessed by incubating GTP1 with human liver microsomes (HLM) and human hepatocytes. Since smoking strongly stimulates the CYP1A2 enzyme activity, we incubated GTP1 with recombinant CYP1A2 to evaluate the role of the enzyme in tracer metabolism. It was found that GTP1 could form up to eleven oxidative metabolites with higher polarity than the parent. Only a small amount (2.6 % at 60 min) of a defluorinated metabolite was detected in HLM and human hepatocytes incubations highlighting the stability of GTP1 with respect to enzymatic defluorination. Moreover, the major GTP1 metabolites were not the product of CYP1A2 activity suggesting that smoking may not impact in vivo tracer metabolism and subsequently GTP1 brain kinetics.
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Enfermedad de Alzheimer , Proteínas tau , Humanos , Proteínas tau/metabolismo , Citocromo P-450 CYP1A2/metabolismo , Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Tomografía de Emisión de Positrones/métodosRESUMEN
Bromodomains are acetyllysine recognition domains present in a variety of human proteins. Bromodomains also bind small molecules that compete with acetyllysine, and therefore bromodomains have been targets for drug discovery efforts. Highly potent and selective ligands with good cellular permeability have been proposed as chemical probes for use in exploring the functions of many of the bromodomain proteins. We report here the discovery of a class of such inhibitors targeting the family VIII bromodomains of SMARCA2 (BRM) and SMARCA4 (BRG1), and PBRM1 (polybromo-1) bromodomain 5. We propose one example from this series, GNE-064, as a chemical probe for the bromodomains SMARCA2, SMARCA4, and PBRM1(5) with the potential for in vivo use.
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ADN Helicasas , Factores de Transcripción , Proteínas de Unión al ADN , Humanos , Proteínas Nucleares , Dominios ProteicosRESUMEN
Accurate prediction of human clearance (CL) and volume of distribution at steady state (Vd,ss) for small molecule drug candidates is an essential component of assessing likely efficacious dose and clinical safety margins. In 2021, the IQ Consortium Human PK Prediction Working Group undertook a survey of IQ member companies to understand the current PK prediction methods being used to estimate these parameters across the pharmaceutical industry. The survey revealed a heterogeneity in approaches being used across the industry (e.g., the use of allometric approaches, differing incorporation of binding terms, and inconsistent use of empirical correction factors for in vitro-in vivo extrapolation, IVIVE), which could lead to different PK predictions with the same input data. Member companies expressed an interest in improving human PK predictions by identifying the most appropriate compound-class specific methods, as determined by physiochemical properties and knowledge of CL pathways. Furthermore, there was consensus that increased understanding of the uncertainty inherent to the compound class-dependent prediction would be invaluable in aiding communication of human PK and dose uncertainty at the time of candidate nomination for development. The human PK Prediction Working Group is utilizing these survey findings to help interrogate clinical IV datasets from across the IQ consortium member companies to understand PK prediction accuracy and uncertainty from preclinical datasets.
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Industria Farmacéutica , Modelos Biológicos , Humanos , Cinética , Preparaciones FarmacéuticasRESUMEN
An Erratum to this paper has been published: https://doi.org/10.1208/s12248-020-00535-z.
RESUMEN
The effect of food on pharmacokinetic properties of drugs is a commonly observed occurrence affecting about 40% of orally administered drugs. Within the pharmaceutical industry, significant resources are invested to predict and characterize a clinically relevant food effect. Here, the predictive performance of physiologically based pharmacokinetic (PBPK) food effect models was assessed via de novo mechanistic absorption models for 30 compounds using controlled, pre-defined in vitro, and modeling methodology. Compounds for which absorption was known to be limited by intestinal transporters were excluded in this analysis. A decision tree for model verification and optimization was followed, leading to high, moderate, or low food effect prediction confidence. High (within 0.8- to 1.25-fold) to moderate confidence (within 0.5- to 2-fold) was achieved for most of the compounds (15 and 8, respectively). While for 7 compounds, prediction confidence was found to be low (> 2-fold). There was no clear difference in prediction success for positive or negative food effects and no clear relationship to the BCS category of tested drug molecules. However, an association could be demonstrated when the food effect was mainly related to changes in the gastrointestinal luminal fluids or physiology, including fluid volume, motility, pH, micellar entrapment, and bile salts. Considering these findings, it is recommended that appropriately verified mechanistic PBPK modeling can be leveraged with high to moderate confidence as a key approach to predicting potential food effect, especially related to mechanisms highlighted here.
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Interacciones Alimento-Droga , Absorción Intestinal/fisiología , Modelos Biológicos , Administración Oral , Animales , Química Farmacéutica , Simulación por Computador , Perros , Liberación de Fármacos/fisiología , Humanos , Concentración de Iones de Hidrógeno , Mucosa Intestinal/metabolismo , Células de Riñón Canino Madin Darby , Permeabilidad , SolubilidadRESUMEN
A class of imidazoisoindole (III) heme-binding indoleamine-2,3-dioxygenase (IDO1) inhibitors were optimized via structure-based drug design into a series of tryptophan-2,3-dioxygenase (TDO)-selective inhibitors. Kynurenine pathway modulation was demonstrated in vivo, which enabled evaluation of TDO as a potential cancer immunotherapy target. As means of mitigating the risk of drug-drug interactions arising from cytochrome P450 inhibition, a novel property-based drug design parameter, herein referred to as the CYP Index, was implemented for the design of inhibitors with appreciable selectivity for TDO over CYP3A4. We anticipate the CYP Index will be a valuable design parameter for optimizing CYP inhibition of any small molecule inhibitor containing a Lewis basic motif capable of binding heme.
RESUMEN
IRAK4 kinase activity transduces signaling from multiple IL-1Rs and TLRs to regulate cytokines and chemokines implicated in inflammatory diseases. As such, there is high interest in identifying selective IRAK4 inhibitors for the treatment of these disorders. We previously reported the discovery of potent and selective dihydrobenzofuran inhibitors of IRAK4. Subsequent studies, however, showed inconsistent inhibition in disease-relevant pharmacodynamic models. Herein, we describe application of a human whole blood assay to the discovery of a series of benzolactam IRAK4 inhibitors. We identified potent molecule 19 that achieves robust in vivo inhibition of cytokines relevant to human disease.
RESUMEN
A series of pyrazolopyrimidine inhibitors of IRAK4 were developed from a high-throughput screen (HTS). Modification of an HTS hit led to a series of bicyclic heterocycles with improved potency and kinase selectivity but lacking sufficient solubility to progress in vivo. Structure-based drug design, informed by cocrystal structures with the protein and small-molecule crystal structures, yielded a series of dihydrobenzofurans. This semisaturated bicycle provided superior druglike properties while maintaining excellent potency and selectivity. Improved physicochemical properties allowed for progression into in vivo experiments, where lead molecules exhibited low clearance and showed target-based inhibition of IRAK4 signaling in an inflammation-mediated PK/PD mouse model.
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Quinasas Asociadas a Receptores de Interleucina-1/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Aminoquinolinas/síntesis química , Aminoquinolinas/metabolismo , Aminoquinolinas/farmacología , Animales , Benzofuranos/síntesis química , Benzofuranos/metabolismo , Benzofuranos/farmacología , Dominio Catalítico , Femenino , Humanos , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Ratones Endogámicos C57BL , Estructura Molecular , Unión Proteica , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/metabolismo , Pirazoles/síntesis química , Pirazoles/metabolismo , Pirimidinas/síntesis química , Pirimidinas/metabolismo , Ratas , Transducción de Señal/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
A novel and rapid method to determine the potency of inhibitors for tryptophan 2, 3-dioxygenase (TDO2) activities in human and preclinical species was successfully developed and validated utilizing LC-MS/MS. Previously reported TDO2 activity assays are resource intensive, requiring cloning and overexpression of TDO2. Here, we demonstrated that liver cytosol contained sufficient active TDO2 for evaluating the potency of TDO2 inhibitors across multiple species. TDO2 expression in human cytosol was estimated by LC-MS/MS to be 41â¯pmoL/mg cytosolic protein, with similar levels in dogs and monkeys, whereas mice and rats had 9.6 and 5.0-fold greater expression, respectively. Reaction conditions for TDO2-mediated conversion of l-tryptophan to kynurenine were optimized. Marked differences in kinetic parameters and inhibition potency were observed in TDO2 across species, with different Km values in dog (0.055â¯mM), monkey (0.070â¯mM), human (0.19â¯mM), mouse (0.32â¯mM) and rat (0.36â¯mM). Subsequently, IC50 values were determined for a series of TDO2 inhibitors in liver cytosol of five species, and good agreement with the literature values was observed for human enzyme. Taken together, these data indicate that TDO2 inhibition can be rapidly determined in readily available hepatic cytosol to assess potential species differences in potency.
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Bioensayo , Citosol/enzimología , Hígado/enzimología , Espectrometría de Masas , Triptófano Oxigenasa/análisis , Animales , Perros , Haplorrinos , Humanos , Ratones , RatasRESUMEN
Tryptophan 2,3-dioxygenase 2 (TDO2) catalyzes the conversion of tryptophan to the immunosuppressive metabolite kynurenine. TDO2 overexpression has been observed in a number of cancers; therefore, TDO inhibition may be a useful therapeutic intervention for cancers. We identified an aminoisoxazole series as potent TDO2 inhibitors from a high-throughput screen (HTS). An extensive medicinal chemistry effort revealed that both the amino group and the isoxazole moiety are important for TDO2 inhibitory activity. Computational modeling yielded a binding hypothesis and provided insight into the observed structure-activity relationships. The optimized compound 21 is a potent TDO2 inhibitor with modest selectivity over indolamine 2,3-dioxygenase 1 (IDO1) and with improved human whole blood stability.
RESUMEN
The pH labile metabolite, hydrophobicity, high oral dose and systematic exposure of GDC-0810 posed tremendous challenges to develop a LC-MS method for a stable isotope labeled aBA study. In this study, we explored practical solutions to balance stability and sensitivity and to cope with the impact of high Cp.o. to Ci.v. ratio on the labeling selection and assay dynamic range. A [13C9] GDC-0810 was synthesized to minimize the isotopic interference between PO dose, internal standard and I.V. microtracer. A highly sensitive LC-MS assay was validated for quantitation of [13C9] GDC-0810 from 5 to 1250â¯pg/mL. The optimized method was applied to a proof of concept cynomolgus monkey aBA study and the bioavailability calculated using microtracer dosing and regular dosing were similar to each other.
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Isótopos de Carbono/química , Cinamatos/farmacocinética , Indazoles/farmacocinética , Administración Intravenosa , Administración Oral , Animales , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión/métodos , Humanos , Macaca fascicularis , Modelos Animales , Espectrometría de Masas en Tándem/métodosRESUMEN
Indoleamine and tryptophan 2,3-dioxygenases (IDO1 and TDO2) are pyrrolases catalyzing the oxidative cleavage of the 2,3-double bond of L-tryptophan in kynurenine pathway. In the tumor microenvironment, their increased activity prevents normal immune function, i.e. tumor cell recognition and elimination by cytotoxic T-cells. Consequently, inhibition of the kynurenine pathway may enhance the activity of cancer immunotherapeutics by reversing immune dysfunction. We sought to investigate the properties of radiolabeled 5-[18F]fluorotryptophan with respect to its ability for measuring IDO1 and TDO2 activity by positron emission tomography (PET). RESULTS: L-5-[18F]fluorotryptophan and D-5-[18F]fluorotryptophan were synthesized by Cu(I) catalyzed [18F]fluorodeboronylation of Boc/tBu protected precursors in moderate yields (1.5±0.6%) sufficient for pre-clinical studies. The specific activity of the product was 407-740GBq/µmol, radiochemical purity >99% and enantiomeric excess 90-99%. Enzymatic assay confirmed that L-5-fluorotryptophan is an IDO1 and TDO2 substrate whereas the D-isomer is not. In-vitro cell uptake experiments using CT26 cells with doxycycline-induced overexpression of human-IDO1 and human-TDO2 revealed an elevated cell uptake of L-5-[18F]fluorotryptophan upon induction of IDO1 or TDO2 enzymes compared to baseline; however, the uptake was observed only in the presence of low L-tryptophan levels in media. PET imaging experiments performed using tumor bearing mouse models expressing IDO1 at various levels (CT26, CT26-hIDO1, 17082A, 17095A) showed tumor uptake of the tracer elevated up to 8%ID/g; however, the observed tumor uptake could not be attributed to IDO1 activity in the tumor tissue. The metabolism of L- and D- isomers was markedly different in vivo, the D-isomer was excreted by a combination of hepatobiliary and renal routes, the L-isomer underwent extensive metabolism to [18F]fluoride. CONCLUSION: The observed in vivo tumor uptake of the tracer could not be attributed to IDO1 or TDO2 enzyme activity in the tumor, presumably due to competition with endogenous tryptophan as well as rapid tracer metabolism.
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Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Tomografía de Emisión de Positrones/métodos , Triptófano Oxigenasa/metabolismo , Triptófano/análogos & derivados , Animales , Línea Celular Tumoral , Ratones , Radioquímica , Estereoisomerismo , Triptófano/químicaRESUMEN
Bromo and extra terminal (BET) proteins (BRD2, BRD3, BRD4 and BRDT) are epigenetic transcriptional regulators required for efficient expression of growth promoting, cell cycle progression and antiapoptotic genes. Through their bromodomain, these proteins bind to acetylated lysine residues of histones and are recruited to transcriptionally active chromatin. Inhibition of the BET-histone interaction provides a tractable therapeutic strategy to treat diseases that may have epigenetic dysregulation. JQ1 is a small molecule that blocks BET interaction with histones. It has been shown to decrease proliferation of patient-derived multiple myeloma in vitro and to decrease tumor burden in vivo in xenograft mouse models. While targeting BET appears to be a viable and efficacious approach, the nonclinical safety profile of BET inhibition remains to be well-defined. We report that mice dosed with JQ1 at efficacious exposures demonstrate dose-dependent decreases in their lymphoid and immune cell compartments. At higher doses, JQ1 was not tolerated and due to induction of significant body weight loss led to early euthanasia. Flow cytometry analysis of lymphoid tissues showed a decrease in both B- and T-lymphocytes with a concomitant decrease in peripheral white blood cells that was confirmed by hematology. Further investigation with the inactive enantiomer of JQ1 showed that these in vivo effects were on-target mediated and not elicited through secondary pharmacology due to chemical structure.
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Azepinas/farmacología , Sistema Inmunológico/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Triazoles/farmacología , Animales , Azepinas/administración & dosificación , Relación Dosis-Respuesta a Droga , Epigenómica , Sistema Inmunológico/patología , Linfocitos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Reticulocitos/efectos de los fármacos , Triazoles/administración & dosificaciónRESUMEN
Data from the clinical absolute bioavailability (F) study with cobimetinib suggested that F was lower than predicted based on its low hepatic extraction and good absorption. The CYP3A4 transgenic (Tg) mouse model with differential expression of CYP3A4 in the liver (Cyp3a(-/-)Tg-3A4Hep) or intestine (Cyp3a(-/-)Tg-3A4Int) and both liver and intestine (Cyp3a(-/-)Tg-3A4Hep/Int) were used to study the contribution of intestinal metabolism to the F of cobimetinib. In addition, the effect of CYP3A4 inhibition and induction on cobimetinib exposures was tested in the Cyp3a(-/-)Tg-3A4Hep/Int and PXR-CAR-CYP3A4/CYP3A7 mouse models, respectively. After i.v. administration of 1 mg/kg cobimetinib to wild-type [(WT) FVB], Cyp3a(-/-)Tg-3A4Hep, Cyp3a(-/-)Tg-3A4Int, or Cyp3a(-/-)Tg-3A4Hep/Int mice, clearance (CL) (26-35 ml/min/kg) was similar in the CYP3A4 transgenic and WT mice. After oral administration of 5 mg/kg cobimetinib, the area under the curve (AUC) values of cobimetinib in WT, Cyp3a(-/-)Tg-3A4Hep, Cyp3a(-/-)Tg-3A4Int, or Cyp3a(-/-)Tg-3A4Hep/Int mice were 1.35, 3.39, 1.04, and 0.701 µMâ h, respectively. The approximately 80% lower AUC of cobimetinib in transgenic mice when intestinal CYP3A4 was present suggested that the intestinal first pass contributed to the oral CL of cobimetinib. Oxidative metabolites observed in human circulation were also observed in the transgenic mice. In drug-drug interaction (DDI) studies using Cyp3a(-/-)Tg-3A4Hep/Int mice, 8- and 4-fold increases in oral and i.v. cobimetinib exposure, respectively, were observed with itraconazole co-administration. In PXR-CAR-CYP3A4/CYP3A7 mice, rifampin induction decreased cobimetinib oral exposure by approximately 80%. Collectively, these data support the conclusion that CYP3A4 intestinal metabolism contributes to the oral disposition of cobimetinib and suggest that under certain circumstances the transgenic model may be useful in predicting clinical DDIs.
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Antineoplásicos/farmacocinética , Azetidinas/farmacocinética , Citocromo P-450 CYP3A/metabolismo , Mucosa Intestinal/enzimología , MAP Quinasa Quinasa 1/antagonistas & inhibidores , Microsomas Hepáticos/enzimología , Piperidinas/farmacocinética , Inhibidores de Proteínas Quinasas/farmacocinética , Administración Oral , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/sangre , Hidrocarburo de Aril Hidroxilasas/genética , Hidrocarburo de Aril Hidroxilasas/metabolismo , Azetidinas/administración & dosificación , Azetidinas/sangre , Disponibilidad Biológica , Citocromo P-450 CYP3A/química , Citocromo P-450 CYP3A/genética , Inductores del Citocromo P-450 CYP3A/efectos adversos , Inhibidores del Citocromo P-450 CYP3A/efectos adversos , Evaluación Preclínica de Medicamentos , Interacciones Farmacológicas , Femenino , Semivida , Humanos , Inyecciones Intravenosas , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , MAP Quinasa Quinasa 1/metabolismo , Tasa de Depuración Metabólica , Ratones Noqueados , Ratones Transgénicos , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Piperidinas/administración & dosificación , Piperidinas/sangre , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/sangre , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismoRESUMEN
Aliphatic nitrogen heterocycles such as piperazine, piperidine, pyrrolidine, morpholine, aziridine, azetidine, and azepane are well known building blocks in drug design and important core structures in approved drug therapies. These core units have been targets for metabolic attack by P450s and other drug metabolizing enzymes such as aldehyde oxidase and monoamine oxidase (MAOs). The electron rich nitrogen and/or α-carbons are often major sites of metabolism of alicyclic amines. The most common biotransformations include N-oxidation, N-conjugation, oxidative N-dealkylation, ring oxidation, and ring opening. In some instances, the metabolic pathways generate electrophilic reactive intermediates and cause bioactivation. However, potential bioactivation related adverse events can be attenuated by structural modifications. Hence it is important to understand the biotransformation pathways to design stable drug candidates that are devoid of metabolic liabilities early in the discovery stage. The current review provides a comprehensive summary of biotransformation and bioactivation pathways of aliphatic nitrogen containing heterocycles and strategies to mitigate metabolic liabilities.