RESUMEN
The development of new antibiotics to treat infections caused by drug-resistant Gram-negative pathogens is of paramount importance as antibiotic resistance continues to increase worldwide1. Here we describe a strategy for the rational design of diazabicyclooctane inhibitors of penicillin-binding proteins from Gram-negative bacteria to overcome multiple mechanisms of resistance, including ß-lactamase enzymes, stringent response and outer membrane permeation. Diazabicyclooctane inhibitors retain activity in the presence of ß-lactamases, the primary resistance mechanism associated with ß-lactam therapy in Gram-negative bacteria2,3. Although the target spectrum of an initial lead was successfully re-engineered to gain in vivo efficacy, its ability to permeate across bacterial outer membranes was insufficient for further development. Notably, the features that enhanced target potency were found to preclude compound uptake. An improved optimization strategy leveraged porin permeation properties concomitant with biochemical potency in the lead-optimization stage. This resulted in ETX0462, which has potent in vitro and in vivo activity against Pseudomonas aeruginosa plus all other Gram-negative ESKAPE pathogens, Stenotrophomonas maltophilia and biothreat pathogens. These attributes, along with a favourable preclinical safety profile, hold promise for the successful clinical development of the first novel Gram-negative chemotype to treat life-threatening antibiotic-resistant infections in more than 25 years.
Asunto(s)
Antibacterianos/farmacología , Diseño de Fármacos , Farmacorresistencia Bacteriana Múltiple , Bacterias Gramnegativas/efectos de los fármacos , Animales , Antibacterianos/química , Compuestos Aza/química , Compuestos Aza/farmacología , Ciclooctanos/química , Ciclooctanos/farmacología , Femenino , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Proteínas de Unión a las Penicilinas/antagonistas & inhibidores , Pseudomonas aeruginosa/efectos de los fármacos , beta-LactamasasRESUMEN
UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase (LpxC), the zinc metalloenzyme catalyzing the first committed step of lipid A biosynthesis in Gram-negative bacteria, has been a target for antibacterial drug discovery for many years. All inhibitor chemotypes reaching an advanced preclinical stage and clinical phase 1 have contained terminal hydroxamic acid, and none have been successfully advanced due, in part, to safety concerns, including hemodynamic effects. We hypothesized that the safety of LpxC inhibitors could be improved by replacing the terminal hydroxamic acid with a different zinc-binding group. After choosing an N-hydroxyformamide zinc-binding group, we investigated the structure-activity relationship of each part of the inhibitor scaffold with respect to Pseudomonas aeruginosa and Escherichia coli LpxC binding affinity, in vitro antibacterial potency and pharmacological properties. We identified a novel, potency-enhancing hydrophobic binding interaction for an LpxC inhibitor. We demonstrated in vivo efficacy of one compound in a neutropenic mouse E. coli infection model. Another compound was tested in a rat hemodynamic assay and was found to have a hypotensive effect. This result demonstrated that replacing the terminal hydroxamic acid with a different zinc-binding group was insufficient to avoid this previously recognized safety issue with LpxC inhibitors.
Asunto(s)
Amidohidrolasas/antagonistas & inhibidores , Antibacterianos/farmacología , Inhibidores Enzimáticos/química , Formamidas/química , Hemodinámica/efectos de los fármacos , Amidohidrolasas/metabolismo , Animales , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/uso terapéutico , Sitios de Unión , Cristalografía por Rayos X , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/patología , Femenino , Formamidas/metabolismo , Formamidas/farmacología , Formamidas/uso terapéutico , Semivida , Masculino , Ratones , Simulación de Dinámica Molecular , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
The matrix metalloproteinase enzyme MMP-13 plays a key role in the degradation of type II collagen in cartilage and bone in osteoarthritis (OA). An effective MMP-13 inhibitor would provide a disease modifying therapy for the treatment of arthritis, although this goal still continues to elude the pharmaceutical industry due to issues with safety. Our efforts have resulted in the discovery of a series of hydroxamic acid inhibitors of MMP-13 that do not significantly inhibit MMP-2 (gelatinase-1). MMP-2 has been implicated in the musculoskeletal side effects resulting from pan-MMP inhibition due to findings from spontaneously occurring human MMP-2 deletions. Analysis of the SAR of hundreds of previously prepared hydroxamate based MMP inhibitors lead us to 2-naphthylsulfonamide substituted hydroxamates which exhibited modest selectivity for MMP-13 versus MMP-2. This Letter describes the lead optimization of 1 and identification of inhibitors exhibiting >100-fold selectivity for MMP-13 over MMP-2.
Asunto(s)
Ácidos Hidroxámicos/farmacología , Inhibidores de la Metaloproteinasa de la Matriz , Inhibidores de Proteasas/farmacología , Sulfonamidas/química , Cristalografía por Rayos X , Ácidos Hidroxámicos/química , Modelos Moleculares , Inhibidores de Proteasas/química , Relación Estructura-ActividadRESUMEN
Herein we report the discovery of a family of novel yet simple, amino-acid derived class I HDAC inhibitors that demonstrate isoform selectivity via access to the internal acetate release channel. Isoform selectivity criteria is discussed on the basis of X-ray crystallography and molecular modeling of these novel inhibitors bound to HDAC8, potentially revealing insights into the mechanism of enzymatic function through novel structural features revealed at the atomic level.
Asunto(s)
Ácido Acético/metabolismo , Aminoácidos/química , Aminoácidos/farmacología , Inhibidores de Histona Desacetilasas/química , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Cristalografía por Rayos X , Diseño de Fármacos , Histona Desacetilasas/química , Humanos , Modelos Moleculares , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismoRESUMEN
Multidrug resistant Gram-negative bacterial infections are an increasing public health threat due to rapidly rising resistance toward ß-lactam antibiotics. The hydrolytic enzymes called ß-lactamases are responsible for a large proportion of the resistance phenotype. ß-Lactamase inhibitors (BLIs) can be administered in combination with ß-lactam antibiotics to negate the action of the ß-lactamases, thereby restoring activity of the ß-lactam. Newly developed BLIs offer some advantage over older BLIs in terms of enzymatic spectrum but are limited to the intravenous route of administration. Reported here is a novel, orally bioavailable diazabicyclooctane (DBO) ß-lactamase inhibitor. This new DBO, ETX1317, contains an endocyclic carbon-carbon double bond and a fluoroacetate activating group and exhibits broad spectrum activity against class A, C, and D serine ß-lactamases. The ester prodrug of ETX1317, ETX0282, is orally bioavailable and, in combination with cefpodoxime proxetil, is currently in development as an oral therapy for multidrug resistant and carbapenem-resistant Enterobacterales infections.
Asunto(s)
Antibacterianos/química , Compuestos de Azabiciclo/química , Inhibidores de beta-Lactamasas/química , beta-Lactamasas/química , Administración Oral , Animales , Antibacterianos/farmacocinética , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Compuestos de Azabiciclo/metabolismo , Compuestos de Azabiciclo/farmacología , Compuestos de Azabiciclo/uso terapéutico , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Semivida , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Proteínas de Unión a las Penicilinas/química , Proteínas de Unión a las Penicilinas/metabolismo , Profármacos/química , Profármacos/metabolismo , Unión Proteica , Ratas , Enfermedades de la Piel/tratamiento farmacológico , Enfermedades de la Piel/patología , Enfermedades de la Piel/veterinaria , Relación Estructura-Actividad , Inhibidores de beta-Lactamasas/metabolismo , Inhibidores de beta-Lactamasas/farmacología , Inhibidores de beta-Lactamasas/uso terapéutico , beta-Lactamasas/metabolismoRESUMEN
Multidrug-resistant (MDR) bacterial infections are a serious threat to public health. Among the most alarming resistance trends is the rapid rise in the number and diversity of ß-lactamases, enzymes that inactivate ß-lactams, a class of antibiotics that has been a therapeutic mainstay for decades. Although several new ß-lactamase inhibitors have been approved or are in clinical trials, their spectra of activity do not address MDR pathogens such as Acinetobacter baumannii. This report describes the rational design and characterization of expanded-spectrum serine ß-lactamase inhibitors that potently inhibit clinically relevant class A, C and D ß-lactamases and penicillin-binding proteins, resulting in intrinsic antibacterial activity against Enterobacteriaceae and restoration of ß-lactam activity in a broad range of MDR Gram-negative pathogens. One of the most promising combinations is sulbactam-ETX2514, whose potent antibacterial activity, in vivo efficacy against MDR A. baumannii infections and promising preclinical safety demonstrate its potential to address this significant unmet medical need.
Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Compuestos de Azabiciclo/química , Compuestos de Azabiciclo/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Inhibidores de beta-Lactamasas/química , Inhibidores de beta-Lactamasas/farmacología , Infecciones por Acinetobacter/tratamiento farmacológico , Infecciones por Acinetobacter/microbiología , Animales , Compuestos de Azabiciclo/uso terapéutico , Compuestos de Azabiciclo/toxicidad , Carbapenémicos/farmacología , Perros , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Farmacorresistencia Bacteriana Múltiple , Enterobacteriaceae/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Humanos , Ratones , Modelos Moleculares , Proteínas de Unión a las Penicilinas/antagonistas & inhibidores , Ratas , Sulbactam/química , Sulbactam/farmacología , Inhibidores de beta-Lactamasas/uso terapéutico , Inhibidores de beta-Lactamasas/toxicidad , beta-Lactamasas/metabolismo , beta-Lactamas/farmacologíaRESUMEN
The matrix metalloproteinase enzyme MMP-13 plays a key role in the degradation of type II collagen in cartilage and bone in osteoarthritis (OA). An effective MMP-13 inhibitor would therefore be a novel disease modifying therapy for the treatment of arthritis. Our efforts have resulted in the discovery of a series of carboxylic acid inhibitors of MMP-13 that do not significantly inhibit the related MMP-1 (collagenase-1) or tumor necrosis factor-alpha (TNF-alpha) converting enzyme (TACE). It has previously been suggested (but not proven) that inhibition of the latter two enzymes could lead to side effects. A promising carboxylic acid lead 9 was identified and a convergent synthesis developed. This paper describes the optimization of 9 and the identification of a compound 24f for further development. Compound 24f is a subnanomolar inhibitor of MMP-13 (IC(50) value 0.5 nM and K(i) of 0.19 nM) having no activity against MMP-1 or TACE (IC(50) of >10000 nM). Furthermore, in a rat model of MMP-13-induced cartilage degradation, 24f significantly reduced proteoglycan release following oral dosing at 30 mg/kg (75% inhibition, p < 0.05) and at 10 mg/kg (40% inhibition, p < 0.05).
Asunto(s)
Cartílago/efectos de los fármacos , Inhibidores de la Metaloproteinasa de la Matriz , Piperidinas/farmacología , Inhibidores de Proteasas/síntesis química , Sulfonamidas/farmacología , Animales , Cartílago/metabolismo , Bovinos , Colágeno Tipo II/metabolismo , Cristalografía por Rayos X , Concentración 50 Inhibidora , Piperidinas/administración & dosificación , Piperidinas/síntesis química , Piperidinas/farmacocinética , Inhibidores de Proteasas/administración & dosificación , Inhibidores de Proteasas/farmacocinética , Inhibidores de Proteasas/farmacología , Proteoglicanos/metabolismo , Ratas , Relación Estructura-Actividad , Sulfonamidas/administración & dosificación , Sulfonamidas/síntesis química , Sulfonamidas/farmacocinéticaRESUMEN
To improve the pharmacokinetics of a previously reported series of dipeptidyl nitrile cathepsin B inhibitors, the P(2)-P(3) amide group was replaced with an arylamine. Further optimization of this template resulted in highly potent and selective inhibitors with excellent oral availability.