RESUMO
The bromodomain and extra-terminal (BET) family of proteins, consisting of the bromodomains containing protein 2 (BRD2), BRD3, BRD4, and the testis-specific BRDT, are key epigenetic regulators of gene transcription and has emerged as an attractive target for anticancer therapy. Herein, we describe the discovery of a novel potent BET bromodomain inhibitor, using a systematic structure-based approach focused on improving potency, metabolic stability, and permeability. The optimized dimethylisoxazole aryl-benzimidazole inhibitor exhibited high potency towards BRD4 and related BET proteins in biochemical and cell-based assays and inhibited tumor growth in two proof-of-concept preclinical animal models.
Assuntos
Benzimidazóis/farmacologia , Descoberta de Drogas , Isoxazóis/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Fatores de Transcrição/antagonistas & inibidores , Administração Oral , Animais , Benzimidazóis/química , Benzimidazóis/metabolismo , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Isoxazóis/administração & dosagem , Isoxazóis/química , Isoxazóis/metabolismo , Camundongos , Estrutura Molecular , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Domínios Proteicos/efeitos dos fármacos , Relação Estrutura-Atividade , Fatores de Transcrição/metabolismoRESUMO
A series of 2'-fluorinated C-nucleosides were prepared and tested for anti-HCV activity. Among them, the triphosphate of 2'-fluoro-2'-C-methyl adenosine C-nucleoside (15) was a potent and selective inhibitor of the NS5B polymerase and maintained activity against the S282T resistance mutant. A number of phosphoramidate prodrugs were then prepared and evaluated leading to the identification of the 1-aminocyclobutane-1-carboxylic acid isopropyl ester variant (53) with favorable pharmacokinetic properties including efficient liver delivery in animals.
Assuntos
Antivirais/química , Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Nucleosídeos/química , Nucleosídeos/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Amidas/química , Amidas/farmacocinética , Amidas/farmacologia , Animais , Antivirais/farmacocinética , Células CACO-2 , Linhagem Celular , Cricetinae , Descoberta de Drogas , Farmacorresistência Viral , Halogenação , Hepacivirus/genética , Hepacivirus/fisiologia , Hepatite C/tratamento farmacológico , Humanos , Metilação , Simulação de Acoplamento Molecular , Nucleosídeos/farmacocinética , Ácidos Fosfóricos/química , Ácidos Fosfóricos/farmacocinética , Ácidos Fosfóricos/farmacologia , Mutação Puntual , Pró-Fármacos/química , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Chronic hepatitis B (CHB) virus infection afflicts hundreds of millions of people and causes nearly one million deaths annually. The high levels of circulating viral surface antigen (HBsAg) that characterize CHB may lead to T-cell exhaustion, resulting in an impaired antiviral immune response in the host. Agents that suppress HBsAg could help invigorate immunity toward infected hepatocytes and facilitate a functional cure. A series of dihydropyridoisoquinolizinone (DHQ) inhibitors of human poly(A) polymerases PAPD5/7 were reported to suppress HBsAg in vitro. An example from this class, RG7834, briefly entered the clinic. We set out to identify a potent, orally bioavailable, and safe PAPD5/7 inhibitor as a potential component of a functional cure regimen. Our efforts led to the identification of a dihydropyridophthalazinone (DPP) core with improved pharmacokinetic properties. A conformational restriction strategy and optimization of core substitution led to GS-8873, which was projected to provide deep HBsAg suppression with once-daily dosing.
RESUMO
Cancer cell proliferation requires precise control of E2F1 activity; excess activity promotes apoptosis. Here, we developed cell-permeable and bioavailable macrocycles that selectively kill small cell lung cancer (SCLC) cells with inherent high E2F1 activity by blocking RxL-mediated interactions of cyclin A and cyclin B with select substrates. Genome-wide CRISPR/Cas9 knockout and random mutagenesis screens found that cyclin A/B RxL macrocyclic inhibitors (cyclin A/Bi) induced apoptosis paradoxically by cyclin B- and Cdk2-dependent spindle assembly checkpoint activation (SAC). Mechanistically, cyclin A/Bi hyperactivate E2F1 and cyclin B by blocking their RxL-interactions with cyclin A and Myt1, respectively, ultimately leading to SAC activation and mitotic cell death. Base editor screens identified cyclin B variants that confer cyclin A/Bi resistance including several variants that disrupted cyclin B:Cdk interactions. Unexpectedly but consistent with our base editor and knockout screens, cyclin A/Bi induced the formation of neo-morphic Cdk2-cyclin B complexes that promote SAC activation and apoptosis. Finally, orally-bioavailable cyclin A/Bi robustly inhibited tumor growth in chemotherapy-resistant patient-derived xenograft models of SCLC. This work uncovers gain-of-function mechanisms by which cyclin A/Bi induce apoptosis in cancers with high E2F activity, and suggests cyclin A/Bi as a therapeutic strategy for SCLC and other cancers driven by high E2F activity.
RESUMO
Toll-like receptor 8 (TLR8) recognizes pathogen-derived single-stranded RNA fragments to trigger innate and adaptive immune responses. Chronic hepatitis B (CHB) is associated with a dysfunctional immune response, and therefore a selective TLR8 agonist may be an effective treatment option. Structure-based optimization of a dual TLR7/8 agonist led to the identification of the selective TLR8 clinical candidate (R)-2-((2-amino-7-fluoropyrido[3,2-d]pyrimidin-4-yl)amino)-2-methylhexan-1-ol (GS-9688, (R)-7). Potent TLR8 agonism (IL-12p40 EC50 = 220 nM) and >100-fold TLR7 selectivity (IFN-α EC50 > 50 µM) was observed in human peripheral blood mononuclear cells (PBMCs). The TLR8-ectodomain:(R)-7 complex confirmed TLR8 binding and a direct ligand interaction with TLR8 residue Asp545. Oral (R)-7 had good absorption and high first pass clearance in preclinical species. A reduction in viral markers was observed in HBV-infected primary human hepatocytes treated with media from PBMCs stimulated with (R)-7, supporting the clinical development of (R)-7 for the treatment of CHB.
Assuntos
Antivirais/farmacologia , Hepatite B Crônica/tratamento farmacológico , Hexanóis/farmacologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Receptor 8 Toll-Like/agonistas , Administração Oral , Animais , Antivirais/administração & dosagem , Antivirais/síntese química , Antivirais/metabolismo , Cristalografia por Raios X , Cães , Descoberta de Drogas , Vírus da Hepatite B/efeitos dos fármacos , Hexanóis/administração & dosagem , Hexanóis/síntese química , Hexanóis/metabolismo , Humanos , Macaca fascicularis , Estrutura Molecular , Domínios Proteicos , Piridinas/administração & dosagem , Piridinas/síntese química , Piridinas/metabolismo , Pirimidinas/administração & dosagem , Pirimidinas/síntese química , Pirimidinas/metabolismo , Ratos , Relação Estrutura-Atividade , Receptor 8 Toll-Like/metabolismoRESUMO
A series of C3 halobenzyl-substituted tricyclic HIV integrase inhibitors was prepared. Improvement in cell-based inhibitor potency was observed in comparison to previously disclosed tricyclic pyrroloquinolines carrying the 'halobenzyl tail' at the lactam nitrogen. Animal PK for several of the C3-substituted inhibitors was examined, with a dihaloaryl analog achieving good balance in protein-shifted EC(50) and t(1/2) in animal PK studies.
Assuntos
Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacologia , Inibidores de Integrase de HIV/síntese química , Inibidores de Integrase de HIV/farmacologia , Pirróis/síntese química , Pirróis/farmacologia , Quinolinas/síntese química , Quinolinas/farmacologia , Administração Oral , Animais , Fármacos Anti-HIV/química , Cães , Desenho de Fármacos , Inibidores de Integrase de HIV/química , Humanos , Estrutura Molecular , Pirróis/química , Quinolinas/química , Ratos , Relação Estrutura-AtividadeRESUMO
SAR studies on the para-fluorobenzyl moiety of tricyclic HIV integrase inhibitors are discussed and lead compounds with potency and PK properties comparable to raltegravir were identified.
Assuntos
Fluorbenzenos/química , Inibidores de Integrase de HIV/síntese química , Animais , Fármacos Anti-HIV/química , Fármacos Anti-HIV/metabolismo , Fármacos Anti-HIV/farmacologia , Ligação Competitiva/fisiologia , Disponibilidade Biológica , Linhagem Celular , Cães , Fluorbenzenos/metabolismo , Fluorbenzenos/farmacologia , Inibidores de Integrase de HIV/administração & dosagem , Inibidores de Integrase de HIV/farmacologia , HIV-1/efeitos dos fármacos , HIV-1/metabolismo , Humanos , Ratos , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
A series of C5-aza tricyclic HIV integrase inhibitors was prepared. A highly potent and orally bioavailable compound (compound 9) was identified and selected for development.
Assuntos
Azacitidina/análogos & derivados , Inibidores de Integrase de HIV/farmacologia , Administração Oral , Animais , Azacitidina/química , Azacitidina/farmacologia , Disponibilidade Biológica , Cristalografia por Raios X , Cães , Inibidores de Integrase de HIV/síntese química , Inibidores de Integrase de HIV/química , Inibidores de Integrase de HIV/farmacocinética , Humanos , Compostos Orgânicos/química , Compostos Orgânicos/farmacocinética , Compostos Orgânicos/farmacologia , Pirrolidinonas , Raltegravir Potássico , RatosRESUMO
Ribose modified 1'-C-cyano pyrimidine nucleosides were synthesized. A silver triflate mediated Vorbrüggen reaction was used to generate the nucleoside scaffold and follow-up chemistry provided specific ribose modified analogs. Nucleosides and phosphoramidate prodrugs were tested for their anti-HCV activity.
Assuntos
RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Hepacivirus/enzimologia , Nucleosídeos de Pirimidina/síntese química , Nucleosídeos de Pirimidina/farmacologia , Técnicas de Química Sintética , Inibidores Enzimáticos/química , Nucleosídeos de Pirimidina/químicaRESUMO
[reaction: see text] The asymmetric synthesis of a highly functionalized pentacyclic tetrahydroisoquinoline relevant to the ecteinascidin, saframycin, safracin, and renieramycin family of antitumor alkaloids is described.
Assuntos
Dioxóis/síntese química , Isoquinolinas/síntese química , Animais , Antineoplásicos Alquilantes/síntese química , Antineoplásicos Alquilantes/química , Dioxóis/química , Isoquinolinas/química , Modelos Moleculares , Estereoisomerismo , Tetra-Hidroisoquinolinas , Trabectedina , Urocordados/químicaRESUMO
Hepatitis C virus (HCV) infection presents an unmet medical need requiring more effective treatment options. Nucleoside inhibitors (NI) of HCV polymerase (NS5B) have demonstrated pan-genotypic activity and durable antiviral response in the clinic, and they are likely to become a key component of future treatment regimens. NI candidates that have entered clinical development thus far have all been N-nucleoside derivatives. Herein, we report the discovery of a C-nucleoside class of NS5B inhibitors. Exploration of adenosine analogs in this class identified 1'-cyano-2'-C-methyl 4-aza-7,9-dideaza adenosine as a potent and selective inhibitor of NS5B. A monophosphate prodrug approach afforded a series of compounds showing submicromolar activity in HCV replicon assays. Further pharmacokinetic optimization for sufficient oral absorption and liver triphosphate loading led to identification of a clinical development candidate GS-6620. In a phase I clinical study, the potential for potent activity was demonstrated but with high intra- and interpatient pharmacokinetic and pharmacodynamic variability.
Assuntos
Antivirais/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Hepacivirus/enzimologia , Hepatite C/tratamento farmacológico , Nucleosídeos/farmacologia , Compostos Organofosforados/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Cães , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Hepatite C/enzimologia , Hepatite C/virologia , Humanos , Nucleosídeos/química , Compostos Organofosforados/química , Ratos , Carga ViralRESUMO
This communication details both the syntheses and biological evaluation of a novel class of HIV-1 integrase inhibitors. When the quinoline moiety is replaced with the quinoxoline moiety, the antiviral activity is significantly compromised. Similarly, introduction of imidazole to replace the pyridine ring is deleterious to the potency of the compound against the enzyme. Substitution at the 3-position of the pyridine has been investigated. The presence of the pyridine ring in the tricyclic core is preferred for antiviral activity against HIV integrase.