RESUMO
Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) continues to be a global threat due to its ability to evolve and generate new subvariants, leading to new waves of infection. Additionally, other coronaviruses like Middle East respiratory syndrome coronavirus (MERS-CoV, formerly known as hCoV-EMC), which first emerged in 2012, persist and continue to present a threat of severe illness to humans. The continued identification of novel coronaviruses, coupled with the potential for genetic recombination between different strains, raises the possibility of new coronavirus clades of global concern emerging. As a result, there is a pressing need for pan-CoV therapeutic drugs and vaccines. After the extensive optimization of an HCV protease inhibitor screening hit, a novel 3CLPro inhibitor (MK-7845) was discovered and subsequently profiled. MK-7845 exhibited nanomolar in vitro potency with broad spectrum activity against a panel of clinical SARS-CoV-2 subvariants and MERS-CoV. Furthermore, when administered orally, MK-7845 demonstrated a notable reduction in viral burdens by >6 log orders in the lungs of transgenic mice infected with SARS-CoV-2 (K18-hACE2 mice) and MERS-CoV (K18-hDDP4 mice).
Assuntos
Antivirais , SARS-CoV-2 , Animais , Camundongos , SARS-CoV-2/efeitos dos fármacos , Humanos , Antivirais/farmacologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Tratamento Farmacológico da COVID-19 , Inibidores de Proteases/farmacologia , COVID-19/virologia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologiaRESUMO
As SARS-CoV-2 continues to circulate, antiviral treatments are needed to complement vaccines. The virus's main protease, 3CLPro, is an attractive drug target in part because it recognizes a unique cleavage site, which features a glutamine residue at the P1 position and is not utilized by human proteases. Herein, we report the invention of MK-7845, a novel reversible covalent 3CLPro inhibitor. While most covalent inhibitors of SARS-CoV-2 3CLPro reported to date contain an amide as a Gln mimic at P1, MK-7845 bears a difluorobutyl substituent at this position. SAR analysis and X-ray crystallographic studies indicate that this group interacts with His163, the same residue that forms a hydrogen bond with the amide substituents typically found at P1. In addition to promising in vivo efficacy and an acceptable projected human dose with unboosted pharmacokinetics, MK-7845 exhibits favorable properties for both solubility and absorption that may be attributable to the unusual difluorobutyl substituent.
Assuntos
COVID-19 , Glutamina , Humanos , Glutamina/química , SARS-CoV-2 , Cisteína Endopeptidases/química , Invenções , Inibidores de Proteases/farmacologia , Amidas , Antivirais/farmacologia , Antivirais/químicaRESUMO
Amorphous solid dispersions feature prominently in the approach to mitigate low bioavailability of poorly water-soluble small molecules, particularly in the early development space focusing on toxicity evaluations and clinical studies in normal healthy volunteers, where high exposures are needed to establish safety margins. Spray drying has been the go-to processing route for a number of reasons, including ubiquitous availability of equipment, the ability to accommodate small scale deliveries, and established processes for delivering single phase amorphous material. Active pharmaceutical ingredients (APIs) with low glass transition temperatures (Tg) can pose challenges to this approach. This study addresses multiple routes towards overcoming issues encountered with a low Tg (â¼ 12 °C) API during manufacture of a spray dry intermediate (SDI). Even once formulated as an amorphous solid dispersion (ASD) with HPMCAS-LG, the Tg of the ASD was sufficiently low to require the use of non-ideal solvents, posing safety concerns and ultimately resulting in low yields with frequent process interruptions to resolve product build-up. To resolve challenges with spray drying the HPMCAS-L SDI, higher Tg polymers were assessed during spray drying, and an alternative antisolvent precipitation-based process was evaluated to generate co-precipitated amorphous dispersions (cPAD) with either HPMCAS-L or the additional higher Tg polymers. Both approaches were found to be viable alternatives to achieve single phase ASDs while demonstrating comparable in vitro and in vivo bioperformance compared to the SDI. The results of this effort offer valuable considerations for future early-stage activities for ASDs with low Tg APIs.
Assuntos
Química Farmacêutica , Secagem por Atomização , Humanos , Composição de Medicamentos/métodos , Química Farmacêutica/métodos , Solubilidade , PolímerosRESUMO
Drug resistance to first-line antimalarials-including artemisinin-is increasing, resulting in a critical need for the discovery of new agents with novel mechanisms of action. In collaboration with the Walter and Eliza Hall Institute and with funding from the Wellcome Trust, a phenotypic screen of Merck's aspartyl protease inhibitor library identified a series of plasmepsin X (PMX) hits that were more potent than chloroquine. Inspired by a PMX homology model, efforts to optimize the potency resulted in the discovery of leads that, in addition to potently inhibiting PMX, also inhibit another essential aspartic protease, plasmepsin IX (PMIX). Further potency and pharmacokinetic profile optimization efforts culminated in the discovery of WM382, a very potent dual PMIX/X inhibitor with robust in vivo efficacy at multiple stages of the malaria parasite life cycle and an excellent resistance profile.
RESUMO
Tricyclic pyrrolopyrimidines (TPPs) are a new class of antibacterials inhibiting the ATPase of DNA gyrase. TPP8, a representative of this class, is active against Mycobacterium abscessus in vitro. Spontaneous TPP8 resistance mutations mapped to the ATPase domain of M. abscessus DNA gyrase, and the compound inhibited DNA supercoiling activity of recombinant M. abscessus enzyme. Further profiling of TPP8 in macrophage and mouse infection studies demonstrated proof-of-concept activity against M. abscessus ex vivo and in vivo.
Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Adenosina Trifosfatases , Animais , Antibacterianos/farmacologia , DNA Girase/genética , Camundongos , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Micobactérias não Tuberculosas , Pirimidinas , PirróisRESUMO
Nasal congestion is one of the most troublesome symptoms of many upper airways diseases. We characterized the effect of selective α2c-adrenergic agonists in animal models of nasal congestion. In porcine mucosa tissue, compound A and compound B contracted nasal veins with only modest effects on arteries. In in vivo experiments, we examined the nasal decongestant dose-response characteristics, pharmacokinetic/pharmacodynamic relationship, duration of action, potential development of tolerance, and topical efficacy of α2c-adrenergic agonists. Acoustic rhinometry was used to determine nasal cavity dimensions following intranasal compound 48/80 (1%, 75 µl). In feline experiments, compound 48/80 decreased nasal cavity volume and minimum cross-sectional areas by 77% and 40%, respectively. Oral administration of compound A (0.1-3.0 mg/kg), compound B (0.3-5.0 mg/kg), and d-pseudoephedrine (0.3 and 1.0 mg/kg) produced dose-dependent decongestion. Unlike d-pseudoephedrine, compounds A and B did not alter systolic blood pressure. The plasma exposure of compound A to produce a robust decongestion (EC(80)) was 500 nM, which related well to the duration of action of approximately 4.0 hours. No tolerance to the decongestant effect of compound A (1.0 mg/kg p.o.) was observed. To study the topical efficacies of compounds A and B, the drugs were given topically 30 minutes after compound 48/80 (a therapeutic paradigm) where both agents reversed nasal congestion. Finally, nasal-decongestive activity was confirmed in the dog. We demonstrate that α2c-adrenergic agonists behave as nasal decongestants without cardiovascular actions in animal models of upper airway congestion.
Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Descongestionantes Nasais/farmacologia , Receptores Adrenérgicos alfa 2/metabolismo , Rinite Vasomotora/tratamento farmacológico , Administração Intranasal , Administração Oral , Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Agonistas de Receptores Adrenérgicos alfa 2/farmacocinética , Agonistas de Receptores Adrenérgicos alfa 2/uso terapêutico , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Animais , Gatos , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Técnicas In Vitro , Masculino , Descongestionantes Nasais/administração & dosagem , Descongestionantes Nasais/farmacocinética , Descongestionantes Nasais/uso terapêutico , Mucosa Nasal/irrigação sanguínea , Mucosa Nasal/efeitos dos fármacos , Mucosa Nasal/metabolismo , Rinite Vasomotora/metabolismo , Suínos , Vasoconstrição/efeitos dos fármacosRESUMO
A novel series of benzimidazolone-containing histamine H3-receptor antagonists were prepared and their structure-activity relationship was explored. These benzimidazolone analogs demonstrate potent H3-receptor binding affinities, no P450 enzyme inhibition, and strong H3 functional activity. Compound 1o exhibits the best overall profile with H3Ki=0.95nM and rat AUC=12.9µMh.
Assuntos
Benzimidazóis/química , Benzimidazóis/farmacologia , Antagonistas dos Receptores Histamínicos H3/química , Antagonistas dos Receptores Histamínicos H3/farmacologia , Animais , Benzimidazóis/síntese química , Benzimidazóis/farmacocinética , Sistema Enzimático do Citocromo P-450/metabolismo , Cobaias , Antagonistas dos Receptores Histamínicos H3/síntese química , Antagonistas dos Receptores Histamínicos H3/farmacocinética , Humanos , Ratos , Receptores Histamínicos H3/metabolismo , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Blood vessels of the nasal mucosa are richly innervated by sympathetic nerves and neural mechanism is of great interest in upper respiratory tract disorders. This study was designed to determine the role of α2-adrenoceptors and, more specifically, α2C-adrenoceptors, on neurogenic sympathetic vasoconstrictor responses in pig nasal mucosa, and to define the pharmacologic profile of a novel selective α2C-adrenoreceptor agonist. METHODS: Electrical field stimulation (EFS) was applied to nasal mucosa strips placed in an organ bath and attached to force displacement transducers for continuous recording of isometric tension. The affinity and functional activity of compound B for α2C-adrenoceptors were determined by binding analysis and the ability of compound B to stimulate [(35)S]GTPγS binding to the receptors. Compound B was also tested in a postjunctional α2C-adrenoreceptor bioassay. RESULTS: EFS-induced contractions were partly blocked by the α2-adrenoreceptor antagonist yohimbine (41.1%) and the α2C-adrenoreceptor antagonist JP-1302 had no effect. The α2-adrenoreceptor agonist clonidine, but not compound B, exerted a significant blockade (70.6%). Compound B had high affinity (K(i) = 18 nM), produced potent agonist (EC50 = 279 nM) and good efficacy (E(max) = 73%) responses at the α2C-adrenoceptors, and displayed good functional agonist potency in the human saphenous vein α2C-adrenoreceptor bioassay (pD2 = 6.2). CONCLUSION: (1) Neurogenic vasomotor contractility is largely regulated through an α-adrenergic mechanism; (2) pig nasal mucosa possesses post- and prejunctional α2-adrenoceptors; (3) the α2C-adrenoreceptor subtype does not seem to be involved; and (4) compound B is a novel, highly selective, and potent α2C-adrenoreceptor agonist.
Assuntos
Mucosa Nasal/efeitos dos fármacos , Receptores Adrenérgicos alfa 2/fisiologia , Acridinas/farmacologia , Agonistas Adrenérgicos/farmacologia , Antagonistas Adrenérgicos/farmacologia , Animais , Clonidina/farmacologia , Estimulação Elétrica , Acoplamento Excitação-Contração , Mucosa Nasal/inervação , Técnicas de Cultura de Órgãos , Piperazinas/farmacologia , Veia Safena/efeitos dos fármacos , Suínos , Sistema Nervoso Simpático , Vasoconstrição/efeitos dos fármacos , Ioimbina/farmacologiaRESUMO
We define the pharmacological and pharmacokinetic profiles of a novel α(2C)-adrenoceptor agonist, compound A [N-[3,4-dihydro-4-(1H-imidazol-4-ylmethyl)-2H-1,4-benzoxazin-6-yl]-N-ethyl-N'-methylurea]. This compound has high affinity (K(i)) for the human α(2C)-adrenoceptor (K(i) = 12 nM), and 190- to 260-fold selectivity over the α(2A)- and α(2B)-adrenoceptor subtypes. In cell-based functional assays, compound A produced good agonist (EC(50) = 166 nM) and efficacy (E(max) = 64%) responses at the α(2C)-adrenoceptor, much lower potency and efficacy at the α(2A)-adrenoceptor (EC(50) = 1525 nM; E(max) = 8%) and α(2B)-adrenoceptor (EC(50) = 5814 nM; E(max) = 21%) subtypes, and low or no affinity and functional activity at the α(1A)-, α(1B)-, and α(1D)-adrenoceptor subtypes. In the human saphenous vein postjunctional α(2C)-adrenoceptor bioassay, compound A functions as a potent agonist (pD(2) = 6.3). In a real-time contraction bioassay of pig nasal mucosa, compound A preferentially constricted the veins (EC(50) = 108 nM), and the magnitude of arteriolar contraction reached only 50% of the maximum venular responses. Compound A exhibited no effect on locomotor activity, sedation, and body temperature in mice (up to 100 mg/kg) and did not cause hypertension and mydriasis (30 mg/kg) in conscious rats. Compound A is orally bioavailable (24%) with good plasma exposure. This compound is a substrate for the efflux P-glycoprotein transporter, resulting in very low central nervous system (CNS) penetration. In summary, compound A is a highly selective, orally active, and non-CNS-penetrating α(2C)-adrenoceptor agonist with desirable in vitro and in vivo pharmacological properties suitable for the treatment of nasal congestion.
Assuntos
Agonistas Adrenérgicos/química , Agonistas Adrenérgicos/farmacologia , Compostos de Metilureia/química , Compostos de Metilureia/farmacologia , Morfolinas/química , Morfolinas/farmacologia , Atividade Motora/efeitos dos fármacos , Mucosa Nasal/efeitos dos fármacos , Receptores Adrenérgicos alfa 2/metabolismo , Veia Safena/efeitos dos fármacos , Agonistas Adrenérgicos/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Masculino , Compostos de Metilureia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas/metabolismo , Atividade Motora/fisiologia , Mucosa Nasal/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/agonistas , Proteínas Recombinantes/metabolismo , Veia Safena/metabolismo , SuínosAssuntos
Descoberta de Drogas , Agonistas dos Receptores Histamínicos/uso terapêutico , Antagonistas dos Receptores Histamínicos/uso terapêutico , Receptores Histamínicos H3/fisiologia , Animais , Indústria Farmacêutica , Agonismo Inverso de Drogas , Agonistas dos Receptores Histamínicos/química , Agonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores Histamínicos/química , Antagonistas dos Receptores Histamínicos/farmacologia , Humanos , Ligantes , Setor PrivadoRESUMO
BACKGROUND: Nasal congestion is the most troublesome symptom associated with a variety of upper airway diseases, including allergic rhinitis and the common cold. A better understanding of the mechanisms that regulate nasal cavity caliber may engender the development of novel treatment strategies. It is well accepted that alpha-adrenergic (both alpha(1) and alpha(2)) mechanisms play a fundamental role in the control and maintenance of basal nasal patency. JP-1302 is a selective alpha(2c)-subtype antagonist that has been recently described in the scientific literature. Thus, we sought to examine the potential effects of this new pharmacological tool on basal nasal patency. METHODS: Using acoustic rhinometry, we studied the activity of the selective alpha(2c)-antagonist JP-1302 on nasal cavity volumes in an anesthetized cat. Cumulative concentrations of JP-1302 were applied directly into the right nasal cavity. Changes in the nasal cavity geometry of the drug-treated naris relative to the untreated left nasal cavity were determined. In separate studies, the nonselective alpha(2)-antagonist yohimbine and the nonselective alpha(1)-antagonist prazosin were run as comparators. Systolic blood pressure was measured at the hind leg, using an ultrasonic Doppler flow detector. RESULTS: JP-1302 (0.03, 0.1, 0.3 and 1.0%) administered by the intranasal route decreased nasal cavity volumes from baseline values by 17, 25, 40 and 40%, respectively. Yohimbine (0.03, 0.1, 0.3 and 1.0%) decreased volumes by 19, 36, 46 and 53%, and topical administration of the nonselective alpha(1)-antagonist prazosin (0.001, 0.003, 0.01, 0.03 and 0.1%) decreased volumes by 6, 47, 56, 64 and 71%, respectively. JP-1302, yohimbine and prazosin, at the dose level tested, did not alter the blood pressure. CONCLUSIONS: The present set of experiments indicates that both alpha(1)- and alpha(2)-adrenergic receptors are involved in the maintenance of basal nasal patency in the cat. Moreover, alpha(2c)-receptors may play a significant role in the sympathetic control of upper airway function.
Assuntos
Cavidade Nasal/fisiologia , Neurônios/fisiologia , Receptores Adrenérgicos alfa 2/fisiologia , Sistema Nervoso Simpático/fisiologia , Acridinas/administração & dosagem , Acridinas/efeitos adversos , Acridinas/farmacologia , Administração Intranasal , Antagonistas de Receptores Adrenérgicos alfa 1 , Antagonistas de Receptores Adrenérgicos alfa 2 , Antagonistas Adrenérgicos alfa/administração & dosagem , Antagonistas Adrenérgicos alfa/efeitos adversos , Antagonistas Adrenérgicos alfa/farmacologia , Anestesia , Animais , Pressão Sanguínea/efeitos dos fármacos , Gatos , Relação Dose-Resposta a Droga , Masculino , Cavidade Nasal/anatomia & histologia , Cavidade Nasal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/farmacologia , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/fisiologia , Rinite/tratamento farmacológico , Rinometria Acústica , Sistema Nervoso Simpático/efeitos dos fármacosRESUMO
Structural features of the substituted 4-piperidinyl urea analogs 1, responsible for the H3 antagonist activity, have been identified. Structure-activity relationship of the H3 receptor affinity, hERG ion channel inhibitory activity and their separation is described. Preliminary pharmacokinetic evaluation of the compounds of the series is addressed.
Assuntos
Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Antagonistas dos Receptores Histamínicos/farmacologia , Piperidinas/farmacologia , Receptores Histamínicos H3/metabolismo , Ureia/farmacologia , Animais , Canais de Potássio Éter-A-Go-Go/metabolismo , Antagonistas dos Receptores Histamínicos/química , Antagonistas dos Receptores Histamínicos/farmacocinética , Humanos , Piperidinas/química , Piperidinas/farmacocinética , Ratos , Relação Estrutura-Atividade , Ureia/química , Ureia/farmacocinéticaRESUMO
The histamine H(3) receptor is involved in the central and peripheral regulation of levels of histamine and other neurotransmitters (e.g., acetylcholine, noradrenaline, dopamine, serotonin and GABA), which sets it up as a target in the treatment of various CNS (e.g., depression, schizophrenia, ADHD, dementia, neuropathic pain and sleep disorders), metabolic syndrome (e.g., obesity) and allergic disorders. Novel chemical series from the most recent 2 years of patent literature have been reviewed. While overall structural diversity is moderate, these represent or relate to some of the compounds progressing through clinical trials (e.g., GSK-189254). However, an H(3) receptor drug still has yet to reach the market. Patenting activity is likely to remain high in the near future, bolstered by the commercial promise of potential H(3) receptor drugs.