RESUMO
A preclinical drug candidate, MRK-1 (Merck candidate drug parent compound), was found to elicit tumor regression in a mouse xenograft model. Analysis of samples from these studies revealed significant levels of two circulating metabolites, whose identities were confirmed by comparison with authentic standards using liquid chromatography-tandem mass spectrometry. These metabolites were found to have an in vitro potency similar to that of MRK-1 against the pharmacological target and were therefore thought to contribute to the observed efficacy. To predict this contribution in humans, a pharmacokinetic (PK) modeling approach was developed. At the mouse efficacious dose, the areas under the plasma concentration time curves (AUCs) of the active metabolites were normalized by their in vitro potency compared with MRK-1. These normalized metabolite AUCs were added to that of MRK-1 to yield a composite efficacious unbound AUC, expressed as "parent drug equivalents," which was used as the target AUC for predictions of the human efficacious dose. In vitro and preclinical PK studies afforded predictions of the PK of MRK-1 and the two active metabolites in human as well as the relative pathway flux to each metabolite. These were used to construct a PK model (Berkeley Madonna, version 8.3.18; Berkeley Madonna Inc., University of California, Berkeley, CA) and to predict the human dose required to achieve the target parent equivalent exposure. These predictions were used to inform on the feasibility of the human dose in terms of size, frequency, formulation, and likely safety margins, as well as to aid in the design of preclinical safety studies.
Assuntos
Antineoplásicos/farmacocinética , Descoberta de Drogas/métodos , Cálculos da Dosagem de Medicamento , Modelos Biológicos , Ativação Metabólica , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/sangue , Área Sob a Curva , Cromatografia Líquida , Humanos , Camundongos , Espectrometria de Massas em Tandem , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin subfamily A member 2 (SMARCA2), also known as Brahma homologue (BRM), is a Snf2-family DNA-dependent ATPase. BRM and its close homologue Brahma-related gene 1 (BRG1), also known as SMARCA4, are mutually exclusive ATPases of the large ATP-dependent SWI/SNF chromatin-remodeling complexes involved in transcriptional regulation of gene expression. No small molecules have been reported that modulate SWI/SNF chromatin-remodeling activity via inhibition of its ATPase activity, an important goal given the well-established dependence of BRG1-deficient cancers on BRM. Here, we describe allosteric dual BRM and BRG1 inhibitors that downregulate BRM-dependent gene expression and show antiproliferative activity in a BRG1-mutant-lung-tumor xenograft model upon oral administration. These compounds represent useful tools for understanding the functions of BRM in BRG1-loss-of-function settings and should enable probing the role of SWI/SNF functions more broadly in different cancer contexts and those of other diseases.
Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , DNA Helicases/genética , Desenho de Fármacos , Mutação , Proteínas Nucleares/genética , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Administração Oral , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Camundongos , Modelos Moleculares , Conformação Proteica , Relação Estrutura-Atividade , Fatores de Transcrição/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The ERK/MAPK pathway plays a central role in the regulation of critical cellular processes and is activated in more than 30% of human cancers. Specific BRAF and MEK inhibitors have shown clinical efficacy in patients for the treatment of BRAF-mutant melanoma. However, the majority of responses are transient, and resistance is often associated with pathway reactivation of the ERK signal pathway. Acquired resistance to these agents has led to greater interest in ERK, a downstream target of the MAPK pathway. De novo design efforts of a novel scaffold derived from SCH772984 by employing hydrogen bond interactions specific for ERK in the binding pocket identified 1-(1H-pyrazolo[4,3-c]pyridin-6-yl)ureas as a viable lead series. Sequential SAR studies led to the identification of highly potent and selective ERK inhibitors with low molecular weight and high LE. Compound 21 exhibited potent target engagement and strong tumor regression in the BRAF(V600E) xenograft model.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Ureia/análogos & derivados , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Camundongos , Modelos Moleculares , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , Ureia/síntese química , Ureia/química , Ureia/farmacologiaRESUMO
BACKGROUND: Understanding the relationship between dose, lung exposure, and drug efficacy continues to be a challenging aspect of inhaled drug development. An experimental inhalation platform was developed using mometasone furoate to link rodent lung exposure to its in vivo pharmacodynamic (PD) effects. METHODS: We assessed the effect of mometasone delivered directly to the lung in two different rodent PD models of lung inflammation. The data obtained were used to develop and evaluate a mathematical model to estimate drug dissolution, transport, distribution, and efficacy, following inhaled delivery in rodents and humans. RESULTS: Mometasone directly delivered to the lung, in both LPS and Alternaria alternata rat models, resulted in dose dependent inhibition of BALf cellular inflammation. The parameters for our mathematical model were calibrated to describe the observed lung and systemic exposure profiles of mometasone in humans and in animal models. We found that physicochemical properties, such as lung fluid solubility and lipophilicity, strongly influenced compound distribution and lung retention. CONCLUSIONS: Presently, we report on a novel and sophisticated mathematical model leading to improvements in a current inhaled drug development practices by providing a quantitative understanding of the relationship between PD effects and drug concentration in lungs.
Assuntos
Alternariose/tratamento farmacológico , Anti-Inflamatórios/administração & dosagem , Cálculos da Dosagem de Medicamento , Pneumopatias Fúngicas/tratamento farmacológico , Pulmão/efeitos dos fármacos , Modelos Biológicos , Furoato de Mometasona/administração & dosagem , Pneumonia/tratamento farmacológico , Administração por Inalação , Aerossóis , Alternaria , Alternariose/metabolismo , Alternariose/microbiologia , Alternariose/fisiopatologia , Animais , Anti-Inflamatórios/farmacocinética , Modelos Animais de Doenças , Humanos , Lipopolissacarídeos , Pulmão/metabolismo , Pulmão/fisiopatologia , Pneumopatias Fúngicas/metabolismo , Pneumopatias Fúngicas/microbiologia , Pneumopatias Fúngicas/fisiopatologia , Masculino , Furoato de Mometasona/farmacocinética , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Ratos Endogâmicos BN , Ratos Sprague-Dawley , Especificidade da Espécie , Distribuição TecidualRESUMO
A potent and selective Factor IXa (FIXa) inhibitor was subjected to a series of liver microsomal incubations, which generated a number of metabolites. Using automated ligand identification system-affinity selection (ALIS-AS) methodology, metabolites in the incubation mixture were prioritized by their binding affinities to the FIXa protein. Microgram quantities of the metabolites of interest were then isolated through microisolation analytical capabilities, and structurally characterized using MicroCryoProbe heteronuclear 2D NMR techniques. The isolated metabolites recovered from the NMR experiments were then submitted directly to an in vitro FIXa enzymatic assay. The order of the metabolites' binding affinity to the Factor IXa protein from the ALIS assay was completely consistent with the enzymatic assay results. This work showcases an innovative and efficient approach to uncover structure-activity relationships (SARs) and guide drug design via microisolation-structural characterization and ALIS capabilities.