RESUMO
New drugs with novel mechanisms of resistance are desperately needed to address both community and nosocomial infections due to Gram-negative bacteria. One such potential target is LpxC, an essential enzyme that catalyzes the first committed step of lipid A biosynthesis. Achaogen conducted an extensive research campaign to discover novel LpxC inhibitors with activity against Pseudomonas aeruginosa We report here the in vitro antibacterial activity and pharmacodynamics of ACHN-975, the only molecule from these efforts and the first ever LpxC inhibitor to be evaluated in phase 1 clinical trials. In addition, we describe the profiles of three additional LpxC inhibitors that were identified as potential lead molecules. These efforts did not produce an additional development candidate with a sufficiently large therapeutic window and the program was subsequently terminated.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Catálise/efeitos dos fármacos , Humanos , Pseudomonas aeruginosa/metabolismoRESUMO
A major challenge for new antibiotic discovery is predicting the physicochemical properties that enable small molecules to permeate Gram-negative bacterial membranes. We have applied physicochemical lessons from previous work to redesign and improve the antibacterial potency of pyridopyrimidine inhibitors of biotin carboxylase (BC) by up to 64-fold and 16-fold against Escherichia coli and Pseudomonas aeruginosa, respectively. Antibacterial and enzyme potency assessments in the presence of an outer membrane-permeabilizing agent or in efflux-compromised strains indicate that penetration and efflux properties of many redesigned BC inhibitors could be improved to various extents. Spontaneous resistance to the improved pyridopyrimidine inhibitors in P. aeruginosa occurs at very low frequencies between 10-8 and 10-9. However, resistant isolates had alarmingly high minimum inhibitory concentration shifts (16- to >128-fold) compared to the parent strain. Whole-genome sequencing of resistant isolates revealed that either BC target mutations or efflux pump overexpression can lead to the development of high-level resistance.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Carbono-Nitrogênio Ligases/antagonistas & inibidores , Escherichia coli/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Membrana Externa Bacteriana/efeitos dos fármacos , Membrana Externa Bacteriana/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carbono-Nitrogênio Ligases/genética , Carbono-Nitrogênio Ligases/metabolismo , Fenômenos Químicos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Testes de Sensibilidade Microbiana , Modelos Químicos , Estrutura Molecular , Mutação , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/genéticaRESUMO
UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) is a Zn2+ deacetylase that is essential for the survival of most pathogenic Gram-negative bacteria. ACHN-975 (N-((S)-3-amino-1-(hydroxyamino)-3-methyl-1-oxobutan-2-yl)-4-(((1R,2R)-2-(hydroxymethyl)cyclopropyl)buta-1,3-diyn-1-yl)benzamide) was the first LpxC inhibitor to reach human clinical testing and was discovered to have a dose-limiting cardiovascular toxicity of transient hypotension without compensatory tachycardia. Herein we report the effort beyond ACHN-975 to discover LpxC inhibitors optimized for enzyme potency, antibacterial activity, pharmacokinetics, and cardiovascular safety. Based on its overall profile, compound 26 (LPXC-516, (S)-N-(2-(hydroxyamino)-1-(3-methoxy-1,1-dioxidothietan-3-yl)-2-oxoethyl)-4-(6-hydroxyhexa-1,3-diyn-1-yl)benzamide) was chosen for further development. A phosphate prodrug of 26 was developed that provided a solubility of >30â mg mL-1 for parenteral administration and conversion into the active drug with a t1/2 of approximately two minutes. Unexpectedly, and despite our optimization efforts, the prodrug of 26 still possesses a therapeutic window insufficient to support further clinical development.
Assuntos
Amidoidrolases/antagonistas & inibidores , Antibacterianos/farmacologia , Di-Inos/farmacologia , Inibidores Enzimáticos/farmacologia , Coração/efeitos dos fármacos , Ácidos Hidroxâmicos/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/farmacocinética , Antibacterianos/toxicidade , Proteínas de Bactérias/antagonistas & inibidores , Cardiotoxicidade , Di-Inos/síntese química , Di-Inos/farmacocinética , Di-Inos/toxicidade , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/toxicidade , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/farmacocinética , Ácidos Hidroxâmicos/toxicidade , Masculino , Estrutura Molecular , Pró-Fármacos/síntese química , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Pró-Fármacos/toxicidade , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
Abrogation of errant signaling along the MAPK pathway through the inhibition of B-RAF kinase is a validated approach for the treatment of pathway-dependent cancers. We report the development of imidazo-benzimidazoles as potent B-RAF inhibitors. Robust in vivo efficacy coupled with correlating pharmacokinetic/pharmacodynamic (PKPD) and PD-efficacy relationships led to the identification of RAF265, 1, which has advanced into clinical trials.
RESUMO
Utilizing structure-based drug design, a novel dihydropyridopyrimidinone series which exhibited potent Hsp90 inhibition, good pharmacokinetics upon oral administration, and an excellent pharmacokinetic/pharmacodynamic relationship in vivo was developed from a commercial hit. The exploration of this series led to the selection of NVP-HSP990 as a development candidate.
Assuntos
Antineoplásicos/síntese química , Piridonas/síntese química , Pirimidinas/síntese química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Camundongos , Piridonas/farmacocinética , Piridonas/farmacologia , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Relação Estrutura-AtividadeRESUMO
A novel oral Hsp90 inhibitor, NVP-HSP990, has been developed and characterized in vitro and in vivo. In vitro, NVP-HSP990 exhibits single digit nanomolar IC(50) values on three of the Hsp90 isoforms (Hsp90α, Hsp90ß, and GRP94) and 320 nanomolar IC(50) value on the fourth (TRAP-1), with selectivity against unrelated enzymes, receptors, and kinases. In c-Met amplified GTL-16 gastric tumor cells, NVP-HSP990 dissociated the Hsp90-p23 complex, depleted client protein c-Met, and induced Hsp70. NVP-HSP990 potently inhibited the growth of human cell lines and primary patient samples from a variety of tumor types. In vivo, NVP-HSP990 exhibits drug-like pharmaceutical and pharmacologic properties with high oral bioavailability. In the GTL-16 xenograft model, a single oral administration of 15 mg/kg of NVP-HSP990 induced sustained downregulation of c-Met and upregulation of Hsp70. In repeat dosing studies, NVP-HSP990 treatment resulted in tumor growth inhibition of GTL-16 and other human tumor xenograft models driven by well-defined oncogenic Hsp90 client proteins. On the basis of its pharmacologic profile and broad-spectrum antitumor activities, clinical trials have been initiated to evaluate NVP-HSP990 in advanced solid tumors.
Assuntos
Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Piridonas/farmacologia , Pirimidinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Administração Oral , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Área Sob a Curva , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Concentração Inibidora 50 , Taxa de Depuração Metabólica , Camundongos , Camundongos Nus , Camundongos SCID , Estrutura Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Piridonas/administração & dosagem , Piridonas/farmacocinética , Pirimidinas/administração & dosagem , Pirimidinas/farmacocinética , Carga Tumoral/efeitos dos fármacosRESUMO
The inhibition of key receptor tyrosine kinases (RTKs) that are implicated in tumor vasculature formation and maintenance, as well as tumor progression and metastasis, has been a major focus in oncology research over the last several years. Many potent small molecule inhibitors of vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) kinases have been evaluated. More recently, compounds that act through the complex inhibition of multiple kinase targets have been reported and may exhibit improved clinical efficacy. We report herein a series of potent, orally efficacious 4-amino-3-benzimidazol-2-ylhydroquinolin-2-one analogues as inhibitors of VEGF, PDGF, and fibroblast growth factor (FGF) receptor tyrosine kinases. Compounds in this class, such as 5 (TKI258), are reversible ATP-competitive inhibitors of VEGFR-2, FGFR-1, and PDGFRbeta with IC(50) values <0.1 microM. On the basis of its favorable in vitro and in vivo properties, compound 5 was selected for clinical evaluation and is currently in phase I clinical trials.
Assuntos
Desenho de Fármacos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Quinolonas/química , Quinolonas/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Animais , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Modelos Moleculares , Inibidores de Proteínas Quinases/farmacocinética , Quinolonas/farmacocinética , Relação Estrutura-AtividadeRESUMO
Two methods have been developed for the highly efficient enzymatic synthesis of L-fructose: one is based on rhamnulose-1-phosphate aldolase and acid phosphatase using racemic glyceraldehyde and dihydroxyacetone phosphate as substrates; the other is to generate enantiomerically pure L-glyceraldehyde in situ from glycerol for the aldol reaction, using galactose oxidase catalyzed oxidation of glycerol in the presence of catalase. Using this four-enzyme system, enantiomerically pure L-fructose was obtained. Using the more expensive dihydroxyacetone phosphate, the yield was 55% after purification.