RESUMO
HCV NS5A inhibitors are the backbone of directly acting antiviral treatments against the hepatitis C virus (HCV). While these therapies are generally highly curative, they are less effective in some specific HCV patient populations. In the search for broader-acting HCV NS5A inhibitors that address these needs, we explored conformational restrictions imposed by the [7,5]-azabicyclic lactam moiety incorporated into daclatasvir (1) and related HCV NS5A inhibitors. Unexpectedly, compound 5 was identified as a potent HCV genotype 1a and 1b inhibitor. Molecular modeling of 5 bound to HCV genotype 1a suggested that the use of the conformationally restricted lactam moiety might have resulted in reorientation of its N-terminal carbamate to expose a new interaction with the NS5A pocket located between amino acids P97 and Y93, which was not easily accessible to 1. The results also suggest new chemistry directions that exploit the interactions with the P97-Y93 site toward new and potentially improved HCV NS5A inhibitors.
RESUMO
Indoleamine-2,3-dioxygenase 1 (IDO1) is a heme-containing enzyme that catalyzes the rate-limiting step in the kynurenine pathway of tryptophan (TRP) metabolism. As it is an inflammation-induced immunoregulatory enzyme, pharmacological inhibition of IDO1 activity is currently being pursued as a potential therapeutic tool for the treatment of cancer and other disease states. As such, a detailed understanding of the mechanism of action of IDO1 inhibitors with various mechanisms of inhibition is of great interest. Comparison of an apo-form-binding IDO1 inhibitor (GSK5628) to the heme-coordinating compound, epacadostat (Incyte), allows us to explore the details of the apo-binding inhibition of IDO1. Herein, we demonstrate that GSK5628 inhibits IDO1 by competing with heme for binding to a heme-free conformation of the enzyme (apo-IDO1), whereas epacadostat coordinates its binding with the iron atom of the IDO1 heme cofactor. Comparison of these two compounds in cellular systems reveals a long-lasting inhibitory effect of GSK5628, previously undescribed for other known IDO1 inhibitors. Detailed characterization of this apo-binding mechanism for IDO1 inhibition might help design superior inhibitors or could confer a unique competitive advantage over other IDO1 inhibitors vis-à-vis specificity and pharmacokinetic parameters.
Assuntos
Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Inibidores Enzimáticos/química , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Conformação MolecularRESUMO
Pan-genotype NS5A inhibitors underpin hugely successful hepatitis C virus (HCV) therapy. The discovery of GSK2818713 (13), a nonstructural protein 5A (NS5A) HCV inhibitor characterized by a significantly improved genotype coverage relative to first-generation NS5A inhibitor daclatasvir (DCV), is detailed herein. The SAR analysis revealed cooperative potency effects of the biphenylene, bicyclic pyrrolidine (Aoc), and methyl-threonine structural motifs. Relative to DCV, 13 improved activity against genotype 1a (gt1a) and gt1b NS5A variants as well as HCV chimeric replicons containing NS5A fragments from genotypes 2-6. Long-term treatment of subgenomic replicons with 13 potently and durably decreased HCV RNA levels for gt1a, gt2a, and gt3a. These properties, suitable pharmacokinetics, and the lack of cross-resistance resulted in the selection of 13 as a preclinical candidate.
Assuntos
Antivirais/química , Antivirais/farmacologia , Genótipo , Proteínas não Estruturais Virais/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos , Animais , Antivirais/metabolismo , Cães , Humanos , Camundongos , Ratos , Ratos Wistar , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/fisiologiaRESUMO
We report the discovery of a novel indoleamine 2,3-dioxygenase-1 (IDO1) inhibitor class through the affinity selection of a previously unreported indole-based DNA-encoded library (DEL). The DEL exemplar, spiro-chromane 1, had moderate IDO1 potency but high in vivo clearance. Series optimization quickly afforded a potent, low in vivo clearance lead 11. Although amorphous 11 was highly bio-available, crystalline 11 was poorly soluble and suffered disappointingly low bio-availability because of solubility-limited absorption. A prodrug approach was deployed and proved effective in discovering the highly bio-available phosphonooxymethyl 31, which rapidly converted to 11 in vivo. Obtaining crystalline 31 proved problematic, however; thus salt screening was performed in an attempt to circumvent this obstacle and successfully delivered greatly soluble and bio-available crystalline tris-salt 32. IDO1 inhibitor 32 is characterized by a low calculated human dose, best-in-class potential, and an unusual inhibition mode by binding the IDO1 heme-free (apo) form.
Assuntos
DNA/química , Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Pró-Fármacos/farmacologia , Compostos de Espiro/farmacologia , Animais , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Eutérios , Masculino , Estrutura Molecular , Pró-Fármacos/síntese química , Pró-Fármacos/farmacocinética , Compostos de Espiro/síntese química , Compostos de Espiro/farmacocinética , Relação Estrutura-AtividadeRESUMO
We recently reported the discovery of preclinical CCR5 inhibitor GSK214096, 1 (J. Med. Chem. 2011, 54, 756). Detailed characterization of 1 revealed that it exists as a mixture of four separable atropisomers A-D. The two slow-interconverting pairs of rotamers A + B and C + D were separated and further characterized. HIV and CCR5-mediated chemotaxis data strongly suggest that the antiviral potency of 1 is due to rotamers A + B and not C + D. Furthermore, integrated UV, vibrational circular dichroism VCD and computational approach allowed to determine the M chirality in C + D (and P chirality in A + B). These findings imply additional avenues to be pursued toward new CCR5 antagonists.
RESUMO
Rapid clinical progress of hepatitis C virus (HCV) replication inhibitors, including these selecting for resistance in the NS5A region (NS5A inhibitors), promises to revolutionize HCV treatment. Herein, we describe our explorations of diverse spiropyrrolidine motifs in novel NS5A inhibitors and a proposed interaction model. We discovered that the 1,4-dioxa-7-azaspiro[4.4]nonane motif in inhibitor 41H (GSK2236805) supported high potency against genotypes 1a and 1b as well as in genotype 1b L31V and Y93H mutants. Consistent with this, 41H potently suppressed HCV RNA in the 20-day RNA reduction assay. Pharmacokinetic and safety data supported further progression of 41H to the clinic.
Assuntos
Antivirais/farmacologia , Genótipo , Hepacivirus/efeitos dos fármacos , Pirrolidinas/farmacologia , Compostos de Espiro/farmacologia , Antivirais/química , Antivirais/farmacocinética , Desenho de Fármacos , Hepacivirus/genética , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Moleculares , Mutação , Pirrolidinas/química , Pirrolidinas/farmacocinética , RNA Viral/sangue , Compostos de Espiro/química , Compostos de Espiro/farmacocinéticaRESUMO
GSK2336805 is an inhibitor of hepatitis C virus (HCV) with picomolar activity on the standard genotype 1a, 1b, and 2a subgenomic replicons and exhibits a modest serum shift. GSK2336805 was not active on 22 RNA and DNA viruses that were profiled. We have identified changes in the N-terminal region of NS5A that cause a decrease in the activity of GSK2336805. These mutations in the genotype 1b replicon showed modest shifts in compound activity (<13-fold), while mutations identified in the genotype 1a replicon had a more dramatic impact on potency. GSK2336805 retained activity on chimeric replicons containing NS5A patient sequences from genotype 1 and patient and consensus sequences for genotypes 4 and 5 and part of genotype 6. Combination and cross-resistance studies demonstrated that GSK2336805 could be used as a component of a multidrug HCV regimen either with the current standard of care or in combination with compounds with different mechanisms of action that are still progressing through clinical development.
Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Genótipo , Hepacivirus/genética , Mutação/genética , Replicon/genética , Replicação Viral/efeitos dos fármacos , Replicação Viral/genéticaRESUMO
Non-structural 5A protein (NS5A) has emerged as an important pharmacological target for hepatitis C virus (HCV). However, little is known about the conformation of NS5A intracellularly or how NS5A inhibitors achieve the picomolar (pM) inhibition of virus replication. Here, we have presented two structurally related small molecules, one that potently inhibits HCV replication and selects for resistance in NS5A, and another that is inactive. Resistance to this antiviral was greater in genotype 1a than in genotype 1b replicons and mapped to domain 1 of NS5A. Using a novel cell-based assay that measures the intracellular proximity of fluorescent tags covalently attached to NS5A, we showed that only the active antiviral specifically disrupted the close proximity of inter- and intramolecular positions of NS5A. The active antiviral, termed compound 1, caused a repositioning of both the N and C termini of NS5A, including disruption of the close approximation of the N termini of two different NS5A molecules in a multimolecular complex. These data provide the first study of how antivirals that select resistance in domain 1 of NS5A alter the cellular conformation of NS5A. This class of antiviral disrupts the close proximity of the N termini of domain 1 in a NS5A complex but also alters the conformation of domain 3, and leads to large aggregates of NS5A. Current models predict that a multicomponent cocktail of antivirals is needed to treat HCV infection, so a mechanistic understanding of what each component does to the viral machinery will be important.
Assuntos
Antivirais/metabolismo , Hepacivirus/efeitos dos fármacos , Proteínas não Estruturais Virais/metabolismo , Linhagem Celular , Farmacorresistência Viral , Hepatócitos/virologia , Humanos , Conformação Proteica/efeitos dos fármacos , Seleção Genética , Replicação Viral/efeitos dos fármacosRESUMO
We have synthesized and evaluated a series of novel HCV NS3 protease inhibitors with various P4 capping groups, which include urea, carbamate, methoxy-carboxamide, cyclic carbamate and amide, pyruvic amide, oxamate, oxalamide and cyanoguanidine. Most of these compounds are remarkably potent, exhibiting single-digit to sub-nanomolar activity in the enzyme assay and cell-based replicon assay. Selected compounds were also evaluated in the protease-inhibitor-resistant mutant transient replicon assay, and they were found to show quite different potency profiles against a panel of HCV protease-inhibitor-resistant mutants.
Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Inibidores de Serina Proteinase/síntese química , Inibidores de Serina Proteinase/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Amidas/química , Animais , Antivirais/química , Carbamatos/química , Relação Dose-Resposta a Droga , Farmacorresistência Viral/genética , Guanidinas/química , Hepacivirus/enzimologia , Hepacivirus/genética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ácido Oxâmico/química , Ratos , Inibidores de Serina Proteinase/química , Relação Estrutura-Atividade , Ureia/química , Proteínas não Estruturais Virais/metabolismoRESUMO
The macrocyclic urea 2, a byproduct in the synthesis of benzoxaborole 1, was identified to be a novel and potent HCV protease inhibitor. We further explored this motif by synthesizing additional urea-based inhibitors and by characterizing them in replicase HCV protease-resistant mutants assay. Several compounds, exemplified by 12, were found to be more potent in HCV replicon assays than leading second generation inhibitors such as danoprevir and TMC-435350. Additionally, following oral administration, inhibitor 12 was found in rat liver in significantly higher concentrations than those reported for both danoprevir and TMC-435350, suggesting that inhibitor 12 has the combination of anti-HCV and pharmacokinetic properties that warrants further development of this series.
Assuntos
Antivirais/síntese química , Farmacorresistência Viral , Hepacivirus/efeitos dos fármacos , Inibidores de Serina Proteinase/síntese química , Ureia/análogos & derivados , Ureia/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Hepacivirus/enzimologia , Hepacivirus/genética , Interações Hidrofóbicas e Hidrofílicas , Fígado/metabolismo , Mutação , Ratos , Replicon/efeitos dos fármacos , Inibidores de Serina Proteinase/farmacocinética , Inibidores de Serina Proteinase/farmacologia , Relação Estrutura-Atividade , Ureia/farmacocinética , Ureia/farmacologia , Proteínas não Estruturais Virais/genéticaRESUMO
A novel series of P3 oxo-modified macrocyclic hepatitis C virus NS3/4A serine protease inhibitor was designed, synthesized and biologically evaluated. The hydroxy-substituted inhibitor 10 demonstrated high potency in genotype 1a and 1b replicon and in the panel of HCV protease mutants. Interestingly, the t-butyl carbonate analog 9c, while not the most potent one in this series, exhibited a virtually flat potency profile in the panel of HCV protease mutants, thus providing opportunity for further optimization.
Assuntos
Descoberta de Drogas , Hepacivirus/efeitos dos fármacos , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Ciclopropanos , Hepacivirus/genética , Humanos , Hidroxilação , Concentração Inibidora 50 , Isoindóis , Lactamas/química , Lactamas/farmacologia , Lactamas Macrocíclicas , Estrutura Molecular , Mutação , Prolina/análogos & derivados , Inibidores de Proteases/química , Sulfonamidas/química , Sulfonamidas/farmacologiaRESUMO
A novel series of cyclic urea-based CCR5 antagonists was designed aiming to resolve instability issue in the fasted simulated intestinal fluid (FSIF) associated with the acyclic urea moiety in 1. This class of CCR5 compounds demonstrated high antiviral activities against HIV-1 infection in both HOS and PBL assays. Further evaluation of these compounds indicated that 16-R not only substantially enhanced its stability, but also exhibited excellent pharmacokinetics properties.
Assuntos
Fármacos Anti-HIV/farmacologia , Antagonistas dos Receptores CCR5 , Descoberta de Drogas , Ureia/química , Ureia/farmacologia , Fármacos Anti-HIV/química , HIV-1/efeitos dos fármacosRESUMO
A novel series of pyridyl carboxamide-based CCR5 inhibitors was designed, synthesized, and demonstrated to be highly potent against HIV-1 infection in both HOS and PBL assays. Attempts to evaluate this series of compounds in a rat PK model revealed its instability in rat plasma. A hypothesis for this liability was proposed, and strategies to overcome this issue were pursued, leading to discovery of highly potent 40 and 41, which featured dramatically improved rat PK profiles.
Assuntos
Fármacos Anti-HIV/farmacocinética , Antagonistas dos Receptores CCR5 , Ácidos Carboxílicos/farmacocinética , Amidas/química , Animais , Fármacos Anti-HIV/sangue , Fármacos Anti-HIV/química , Ácidos Carboxílicos/sangue , Ácidos Carboxílicos/química , Descoberta de Drogas , RatosRESUMO
We recently described ( J. Med. Chem. 2008 , 51 , 6538 - 6546 ) a novel class of CCR5 antagonists with strong anti-HIV potency. Herein, we detail SAR converting leads 1 and 2 to druglike molecules. The pivotal structural motif enabling this transition was the secondary sulfonamide substituent. Further fine-tuning of the substituent pattern in the sulfonamide paved the way to enhancing potency and bioavailability and minimizing hERG inhibition, resulting in discovery of clinical compound 122 (GSK163929).
Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Compostos Azabicíclicos/química , Compostos Azabicíclicos/farmacologia , Antagonistas dos Receptores CCR5 , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Piperidinas/química , Piperidinas/farmacologia , Animais , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/metabolismo , Área Sob a Curva , Compostos Azabicíclicos/síntese química , Compostos Azabicíclicos/metabolismo , Benzimidazóis , Cães , Desenho de Fármacos , Canais de Potássio Éter-A-Go-Go/genética , Canais de Potássio Éter-A-Go-Go/metabolismo , Haplorrinos , Humanos , Piperidinas/síntese química , Piperidinas/metabolismo , Ratos , Relação Estrutura-Atividade , Sulfonamidas , TropanosRESUMO
We have synthesized and evaluated a new series of acyclic P4-benzoxaborole-based HCV NS3 protease inhibitors. Structure-activity relationships were investigated, leading to the identification of compounds 5g and 17 with low nanomolar potency in the enzymatic and cell-based replicon assay. The linker-truncated compound 5j was found to exhibit improved absorption and oral bioavailability in rats, suggesting that further reduction of molecular weight and polar surface area could result in improved drug-like properties of this novel series.
Assuntos
Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Inibidores de Proteases/química , Inibidores de Proteases/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
We describe the synthesis and potency of a novel series of N-substituted 2-phenyl- and 2-methyl-2-phenyl-1,4-diaminobutane- based CCR5 antagonists. Compounds 7a and 12f were found to be potent in anti-HIV assays and bioavailable in the low-dose rat PK model.
Assuntos
Fármacos Anti-HIV/síntese química , Antagonistas dos Receptores CCR5 , Putrescina/química , Animais , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacocinética , Fármacos Anti-HIV/farmacologia , Linhagem Celular , Modelos Animais de Doenças , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Concentração Inibidora 50 , Ratos , Ratos Sprague-DawleyRESUMO
Following the discovery that hydroxylated derivative 3 (Fig. 1) was one of the oxidative metabolites of the original lead 1, it was found that hydroxylated compound 4 possesses higher in vitro anti-HIV potency than the corresponding non-hydroxylated compound 2. Structural hybridation of 4 with the orally available analog 5 resulted in another orally-available spirodiketopiperazine CCR5 antagonist 6a that possesses more favorable pharmaceutical profile for use as a drug candidate.
Assuntos
Fármacos Anti-HIV/química , Antagonistas dos Receptores CCR5 , Dicetopiperazinas/química , Compostos de Espiro/química , Administração Oral , Animais , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacocinética , Linhagem Celular Tumoral , Dicetopiperazinas/síntese química , Dicetopiperazinas/farmacocinética , Dicetopiperazinas/farmacologia , Avaliação Pré-Clínica de Medicamentos , Proteína do Núcleo p24 do HIV/metabolismo , HIV-1/metabolismo , Humanos , Microssomos Hepáticos/metabolismo , Ratos , Receptores CCR5/metabolismo , Compostos de Espiro/síntese química , Compostos de Espiro/farmacologia , EstereoisomerismoRESUMO
We disclose here a series of P4-benzoxaborole-substituted macrocyclic HCV protease inhibitors. These inhibitors are potent against HCV NS3 protease, their anti-HCV replicon potencies are largely impacted by substitutions on benzoxaborole ring system and P2∗ groups. P2∗ 2-thiazole-isoquinoline provides best replicon potency. The in vitro SAR studies and in vivo PK evaluations of selected compounds are described herein.
Assuntos
Antivirais/síntese química , Hepacivirus/enzimologia , Compostos Macrocíclicos/química , Inibidores de Proteases/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Antivirais/química , Antivirais/farmacocinética , Isoquinolinas/química , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/farmacocinética , Inibidores de Proteases/química , Inibidores de Proteases/farmacocinética , Ratos , Relação Estrutura-Atividade , Tiazóis/química , Proteínas não Estruturais Virais/metabolismoRESUMO
Modification of the acyl moiety in the CCR5 lead molecule 2 led to identification of several new classes of CCR5 antagonists. Antiviral activity and pharmacokinetic properties of the synthesized compounds were evaluated. Structure-activity relationship (SAR) derived from these studies further guided the optimization efforts, ultimately leading to the discovery of 36 with an acceptable drug-like profile.
Assuntos
Fármacos Anti-HIV/química , Antagonistas dos Receptores CCR5 , HIV-1/efeitos dos fármacos , Ureia/análogos & derivados , Animais , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacocinética , Linhagem Celular Tumoral , Cães , Avaliação Pré-Clínica de Medicamentos , Haplorrinos , Humanos , Piridinas/química , Ratos , Receptores CCR5/metabolismo , Relação Estrutura-Atividade , Ureia/síntese química , Ureia/farmacocinética , Replicação Viral/efeitos dos fármacosRESUMO
Several series of carbamate, urea and carboxamide-based CCR5 antagonists have been discovered via optimizations at the amine portion of lead compound 2. All compounds were evaluated for their antiviral activities. Lead urea 29 showed good pharmacokinetic properties, justifying further development of this series.