RESUMO
BACKGROUND: Inhibition of PCSK9 (proprotein convertase subtilisin/kexin type 9)-low density lipoprotein receptor interaction with injectable monoclonal antibodies or small interfering RNA lowers plasma low density lipoprotein-cholesterol, but despite nearly 2 decades of effort, an oral inhibitor of PCSK9 is not available. Macrocyclic peptides represent a novel approach to target proteins traditionally considered intractable to small-molecule drug design. METHODS: Novel mRNA display screening technology was used to identify lead chemical matter, which was then optimized by applying structure-based drug design enabled by novel synthetic chemistry to identify macrocyclic peptide (MK-0616) with exquisite potency and selectivity for PCSK9. Following completion of nonclinical safety studies, MK-0616 was administered to healthy adult participants in a single rising-dose Phase 1 clinical trial designed to evaluate its safety, pharmacokinetics, and pharmacodynamics. In a multiple-dose trial in participants taking statins, MK-0616 was administered once daily for 14 days to characterize the safety, pharmacokinetics, and pharmacodynamics (change in low density lipoprotein cholesterol). RESULTS: MK-0616 displayed high affinity (Ki = 5pM) for PCSK9 in vitro and sufficient safety and oral bioavailability preclinically to enable advancement into the clinic. In Phase 1 clinical studies in healthy adults, single oral doses of MK-0616 were associated with >93% geometric mean reduction (95% CI, 84-103) of free, unbound plasma PCSK9; in participants on statin therapy, multiple-oral-dose regimens provided a maximum 61% geometric mean reduction (95% CI, 43-85) in low density lipoprotein cholesterol from baseline after 14 days of once-daily dosing of 20 mg MK-0616. CONCLUSIONS: This work validates the use of mRNA display technology for identification of novel oral therapeutic agents, exemplified by the identification of an oral PCSK9 inhibitor, which has the potential to be a highly effective cholesterol lowering therapy for patients in need.
Assuntos
Anticolesterolemiantes , Inibidores de Hidroximetilglutaril-CoA Redutases , Hipercolesterolemia , Adulto , Humanos , Anticolesterolemiantes/efeitos adversos , Colesterol , LDL-Colesterol , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Peptídeos/uso terapêutico , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismoRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) research and antiviral discovery are hampered by the lack of a cell-based virus replication system that can be readily adopted without biosafety level 3 (BSL-3) restrictions. Here, the construction of a noninfectious SARS-CoV-2 reporter replicon and its application in deciphering viral replication mechanisms and evaluating SARS-CoV-2 inhibitors are presented. The replicon genome is replication competent but does not produce progeny virions. Its replication can be inhibited by RdRp mutations or by known SARS-CoV-2 antiviral compounds. Using this system, a high-throughput antiviral assay has also been developed. Significant differences in potencies of several SARS-CoV-2 inhibitors in different cell lines were observed, which highlight the challenges of discovering antivirals capable of inhibiting viral replication in vivo and the importance of testing compounds in multiple cell culture models. The generation of a SARS-CoV-2 replicon provides a powerful platform to expand the global research effort to combat COVID-19.
Assuntos
Antivirais/farmacologia , COVID-19/virologia , Ensaios de Triagem em Larga Escala/métodos , Replicon/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Células A549 , Animais , Chlorocebus aethiops , RNA-Polimerase RNA-Dependente de Coronavírus/genética , Células HEK293 , Humanos , Replicon/genética , SARS-CoV-2/genética , Células Vero , Replicação Viral/efeitos dos fármacosRESUMO
PURPOSE: To develop a tool based on siRNA-mediated knockdown of hepatic P450 oxidoreductase (POR) to decrease the CYP-mediated metabolism of small molecule drugs that suffer from rapid metabolism in vivo, with the aim of improving plasma exposure of these drugs. METHODS: siRNA against the POR gene was delivered using lipid nanoparticles (LNPs) into rats. The time course of POR mRNA knockdown, POR protein knockdown, and loss of POR enzyme activity was monitored. The rat livers were harvested to produce microsomes to determine the impact of POR knockdown on the metabolism of several probe substrates. Midazolam (a CYP3A substrate with high intrinsic clearance) was administered into LNP-treated rats to determine the impact of POR knockdown on midazolam pharmacokinetics. RESULTS: Hepatic POR mRNA and protein levels were significantly reduced by administering siRNA and the maximum POR enzyme activity reduction (~85%) occurred 2 weeks post-dose. In vitro analysis showed significant reductions in metabolism of probe substrates due to POR knockdown in liver, and in vivo POR knockdown resulted in greater than 10-fold increases in midazolam plasma concentrations following oral dosing. CONCLUSIONS: Anti-POR siRNA can be used to significantly reduce hepatic metabolism by various CYPs as well as greatly increase the bioavailability of high clearance compounds following an oral dose, thus enabling it to be used as a tool to increase drug exposure in vivo.
Assuntos
Sistema Enzimático do Citocromo P-450/genética , Técnicas de Silenciamento de Genes/métodos , RNA Interferente Pequeno/farmacologia , Animais , Química Farmacêutica , Diclofenaco/metabolismo , Técnicas In Vitro , Masculino , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Midazolam/metabolismo , Nanopartículas , Ligação Proteica , RatosRESUMO
A series of methoxynaphthalene amides were prepared and evaluated as alternatives to quinolizidinone amide M1 positive allosteric modulators. A methoxy group was optimal for M1 activity and addressed key P-gp issues present in the aforementioned quinolizidinone amide series.
Assuntos
Amidas/química , Naftalenos/química , Quinolizidinas/química , Receptor Muscarínico M1/metabolismo , Regulação Alostérica , Amidas/síntese química , Amidas/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Camundongos , Ligação Proteica , Receptor Muscarínico M1/química , Relação Estrutura-AtividadeRESUMO
SAR study of the piperidine moiety in a series of quinolizidinone carboxylic acid M(1) positive allosteric modulators was examined. While the SAR was generally flat, compounds were identified with high CNS exposure to warrant additional in vivo evaluation.
Assuntos
Piperidinas/farmacologia , Regulação Alostérica , Animais , Células CHO , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Piperidinas/metabolismo , Relação Estrutura-AtividadeRESUMO
Fused aromatics such as naphthalene were identified as highly potent and CNS penetrant M(1) positive allosteric modulators during an SAR study to replace the phenyl B-ring linkage.
Assuntos
Naftóis/química , Receptor Muscarínico M1/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/sangue , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/líquido cefalorraquidiano , Regulação Alostérica/efeitos dos fármacos , Animais , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Humanos , Estrutura Molecular , Naftóis/farmacologia , Quinolonas/química , Quinolonas/farmacologia , Ratos , Relação Estrutura-AtividadeRESUMO
Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a key regulator of plasma LDL-cholesterol (LDL-C) and a clinically validated target for the treatment of hypercholesterolemia and coronary artery disease. Starting from second-generation lead structures such as 2, we were able to refine these structures to obtain extremely potent bi- and tricyclic PCSK9 inhibitor peptides. Optimized molecules such as 44 demonstrated sufficient oral bioavailability to maintain therapeutic levels in rats and cynomolgus monkeys after dosing with an enabled formulation. We demonstrated target engagement and LDL lowering in cynomolgus monkeys essentially identical to those observed with the clinically approved, parenterally dosed antibodies. These molecules represent the first report of highly potent and orally bioavailable macrocyclic peptide PCSK9 inhibitors with overall profiles favorable for potential development as once-daily oral lipid-lowering agents. In this manuscript, we detail the design criteria and multiparameter optimization of this novel series of PCSK9 inhibitors.
Assuntos
Inibidores de PCSK9/farmacologia , Peptídeos Cíclicos/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Cristalografia por Raios X , Macaca fascicularis , Estrutura Molecular , Inibidores de PCSK9/química , Inibidores de PCSK9/farmacocinética , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
The phenyl ring in a series of quinolone carboxylic acid M(1) positive allosteric modulators was replaced with a variety of heterocycles in order to reduce protein plasma binding and enhance CNS exposure.
Assuntos
Ácidos Carboxílicos/farmacologia , Compostos Heterocíclicos/farmacologia , Piridonas/química , Regulação Alostérica , Animais , Proteínas Sanguíneas/química , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacocinética , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacocinética , Humanos , RatosRESUMO
Incorporation of hydroxycycloalkyl fused pyridone carboxylic acids in lieu of quinolone carboxylic acids enhance free fraction without increased susceptibility to P-glycoprotein transport.
Assuntos
Ácidos Carboxílicos/farmacologia , Piridonas/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Regulação Alostérica , Animais , Ácidos Carboxílicos/química , Camundongos , Transporte Proteico , RatosRESUMO
An iterative analog library synthesis approach was employed in the exploration of a quinolone carboxylic acid series of selective M(1) positive allosteric modulators, and strategies for improving potency and plasma free fraction were identified.