RESUMEN
Oral selective estrogen receptor degraders (SERD) could become the backbone of endocrine therapy (ET) for estrogen receptor-positive (ER+) breast cancer, as they achieve greater inhibition of ER-driven cancers than current ETs and overcome key resistance mechanisms. In this study, we evaluated the preclinical pharmacology and efficacy of the next-generation oral SERD camizestrant (AZD9833) and assessed ER-co-targeting strategies by combining camizestrant with CDK4/6 inhibitors (CDK4/6i) and PI3K/AKT/mTOR-targeted therapy in models of progression on CDK4/6i and/or ET. Camizestrant demonstrated robust and selective ER degradation, modulated ER-regulated gene expression, and induced complete ER antagonism and significant antiproliferation activity in ESR1 wild-type (ESR1wt) and mutant (ESR1m) breast cancer cell lines and patient-derived xenograft (PDX) models. Camizestrant also delivered strong antitumor activity in fulvestrant-resistant ESR1wt and ESR1m PDX models. Evaluation of camizestrant in combination with CDK4/6i (palbociclib or abemaciclib) in CDK4/6-naive and -resistant models, as well as in combination with PI3Kαi (alpelisib), mTORi (everolimus), or AKTi (capivasertib), indicated that camizestrant was active with CDK4/6i or PI3K/AKT/mTORi and that antitumor activity was further increased by the triple combination. The response was observed independently of PI3K pathway mutation status. Overall, camizestrant shows strong and broad antitumor activity in ER+ breast cancer as a monotherapy and when combined with CDK4/6i and PI3K/AKT/mTORi. SIGNIFICANCE: Camizestrant, a next-generation oral SERD, shows promise in preclinical models of ER+ breast cancer alone and in combination with CDK4/6 and PI3K/AKT/mTOR inhibitors to address endocrine resistance, a current barrier to treatment.
Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Receptores de Estrógenos/metabolismo , Proteínas Proto-Oncogénicas c-akt , Fosfatidilinositol 3-Quinasas/metabolismo , Antagonistas de Estrógenos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Quinasa 4 Dependiente de la Ciclina , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéuticoRESUMEN
The value of an integrated mathematical modelling approach for protein degraders which combines the benefits of traditional turnover models and fully mechanistic models is presented. Firstly, we show how exact solutions of the mechanistic models of monovalent and bivalent degraders can provide insight on the role of each system parameter in driving the pharmacological response. We show how on/off binding rates and degradation rates are related to potency and maximal effect of monovalent degraders, and how such relationship can be used to suggest a compound optimization strategy. Even convoluted exact steady state solutions for bivalent degraders provide insight on the type of observations required to ensure the predictive capacity of a mechanistic approach. Specifically for PROTACs, the structure of the exact steady state solution suggests that the total remaining target at steady state, which is easily accessible experimentally, is insufficient to reconstruct the state of the whole system at equilibrium and observations on different species (such as binary/ternary complexes) are necessary. Secondly, global sensitivity analysis of fully mechanistic models for PROTACs suggests that both target and ligase baselines (actually, their ratio) are the major sources of variability in the response of non-cooperative systems, which speaks to the importance of characterizing their distribution in the target patient population. Finally, we propose a pragmatic modelling approach which incorporates the insights generated with fully mechanistic models into simpler turnover models to improve their predictive ability, hence enabling acceleration of drug discovery programs and increased probability of success in the clinic.
Asunto(s)
Modelos Biológicos , Modelos Teóricos , Humanos , Proteínas , Descubrimiento de DrogasRESUMEN
Due to increased reliance on glycolysis, which produces lactate, monocarboxylate transporters (MCTs) are often upregulated in cancer. MCT4 is associated with the export of lactic acid from cancer cells under hypoxia, so inhibition of MCT4 may lead to cytotoxic levels of intracellular lactate. In addition, tumor-derived lactate is known to be immunosuppressive, so MCT4 inhibition may be of interest for immuno-oncology. At the outset, no potent and selective MCT4 inhibitors had been reported, but a screen identified a triazolopyrimidine hit, with no close structural analogues. Minor modifications to the triazolopyrimidine were made, alongside design of a constrained linker and broad SAR exploration of the biaryl tail to improve potency, physical properties, PK, and hERG. The resulting clinical candidate 15 (AZD0095) has excellent potency (1.3 nM), MCT1 selectivity (>1000×), secondary pharmacology, clean mechanism of action, suitable properties for oral administration in the clinic, and good preclinical efficacy in combination with cediranib.
Asunto(s)
Antineoplásicos , Neoplasias , Simportadores , Humanos , Ácido Láctico , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Hipoxia , Transportadores de Ácidos MonocarboxílicosRESUMEN
We have developed a novel mechanistic pharmacokinetic-pharmacodynamic (PK/PD) model to describe the time course of plasma triglyceride (TAG) after Oral Lipid Tolerance Test (OLTT) and the effects of AZD7687, an inhibitor of diacylglycerol acyltransferase 1 (DGAT1), in humans, rats, and mice. Pharmacokinetic and plasma TAG data were obtained both in animals and in two phase I OLTT studies. In the PK/PD model, the introduction of exogenous TAG is represented by a first order process. The endogenous production and removal of TAG from plasma are described with a turnover model. AZD7687 inhibits the contribution of exogenous TAG into circulation. One or two compartment models with first order absorption was used to describe the PK of AZD7687 for the different species. Nonlinear mixed effect modeling was used to fit the model to the data. The effects of AZD7687 on the plasma TAG time course during an OLTT as well as interindividual variability were well described by the model in all three species. Meal fat content or data from single vs repeated dosing did not affect model parameter estimates. Body mass index was found to be a significant covariate on the plasma TAG baseline. The system parameters of the model will facilitate analysis for other compounds and provide tools to bring the standard of OLTT data analysis closer to the analyses of Oral Glucose Tolerance Test data maximizing knowledge gain.
Asunto(s)
Acetatos/farmacología , Análisis de Datos , Diacilglicerol O-Acetiltransferasa/antagonistas & inhibidores , Modelos Biológicos , Pirazinas/farmacología , Triglicéridos/sangre , Animales , Biomarcadores/sangre , Índice de Masa Corporal , Estudios de Cohortes , Diacilglicerol O-Acetiltransferasa/metabolismo , Grasas de la Dieta/metabolismo , Prueba de Tolerancia a la Glucosa/métodos , Voluntarios Sanos , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Comidas , Ratones , Ratones Endogámicos ICR , Ratas , Ratas Wistar , Especificidad de la Especie , Factores de TiempoRESUMEN
Described is a quantitative-mass-spectrometry-imaging (qMSI) methodology for the analysis of lactate and glutamate distributions in order to delineate heterogeneity among mouse tumor models used to support drug-discovery efficacy testing. We evaluate and report on preanalysis-stabilization methods aimed at improving the reproducibility and efficiency of quantitative assessments of endogenous molecules in tissues. Stability experiments demonstrate that optimum stabilization protocols consist of frozen-tissue embedding, post-tissue-sectioning desiccation, and storage at -80 °C of tissue sections sealed in vacuum-tight containers. Optimized stabilization protocols are used in combination with qMSI methodology for the absolute quantitation of lactate and glutamate in tumors, incorporating the use of two different stable-isotope-labeled versions of each analyte and spectral-clustering performed on each tissue section using k-means clustering to allow region-specific, pixel-by-pixel quantitation. Region-specific qMSI was used to screen different tumor models and identify a phenotype that has low lactate heterogeneity, which will enable accurate measurements of lactate modulation in future drug-discovery studies. We conclude that using optimized qMSI protocols, it is possible to quantify endogenous metabolites within tumors, and region-specific quantitation can provide valuable insight into tissue heterogeneity and the tumor microenvironment.
Asunto(s)
Ácido Glutámico/análisis , Ácido Láctico/análisis , Espectrometría de Masas , Animales , Femenino , Ácido Glutámico/metabolismo , Ácido Láctico/metabolismo , Ratones , Ratones Desnudos , Neoplasias Experimentales/química , Neoplasias Experimentales/diagnóstico por imagen , Neoplasias Experimentales/metabolismoRESUMEN
GPR120 agonists have therapeutic potential for the treatment of diabetes, but few selective agonists have been reported. We identified an indazole-6-phenylcyclopropylcarboxylic acid series of GPR120 agonists and conducted SAR studies to optimize GPR120 potency. Furthermore, we identified a (S,S)-cyclopropylcarboxylic acid structural motif which gave selectivity against GPR40. Good oral exposure was obtained with some compounds displaying unexpected high CNS penetration. Increased MDCK efflux was utilized to identify compounds such as 33 with lower CNS penetration, and activity in oral glucose tolerance studies was demonstrated. Differential activity was observed in GPR120 null and wild-type mice indicating that this effect operates through a mechanism involving GPR120 agonism.
Asunto(s)
Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacología , Indazoles/química , Indazoles/farmacología , Receptores Acoplados a Proteínas G/agonistas , Animales , Glucemia/análisis , Ácidos Carboxílicos/farmacocinética , Humanos , Indazoles/farmacocinética , Ratones , Ratones Endogámicos C57BL , Modelos MolecularesRESUMEN
The PIK3CA gene, encoding the p110α catalytic unit of PI3Kα, is one of the most frequently mutated oncogenes in human cancer. Hence, PI3Kα is a target subject to intensive efforts in identifying inhibitors and evaluating their therapeutic potential. Here, we report studies with a novel PI3K inhibitor, AZD8835, currently in phase I clinical evaluation. AZD8835 is a potent inhibitor of PI3Kα and PI3Kδ with selectivity versus PI3Kß, PI3Kγ, and other kinases that preferentially inhibited growth in cells with mutant PIK3CA status, such as in estrogen receptor-positive (ER(+)) breast cancer cell lines BT474, MCF7, and T47D (sub-µmol/L GI50s). Consistent with this, AZD8835 demonstrated antitumor efficacy in corresponding breast cancer xenograft models when dosed continuously. In addition, an alternative approach of intermittent high-dose scheduling (IHDS) was explored given our observations that higher exposures achieved greater pathway inhibition and induced apoptosis. Indeed, using IHDS, monotherapy AZD8835 was able to induce tumor xenograft regression. Furthermore, AZD8835 IHDS in combination with other targeted therapeutic agents further enhanced antitumor activity (up to 92% regression). Combination partners were prioritized on the basis of our mechanistic insights demonstrating signaling pathway cross-talk, with a focus on targeting interdependent ER and/or CDK4/6 pathways or alternatively a node (mTOR) in the PI3K-pathway, approaches with demonstrated clinical benefit in ER(+) breast cancer patients. In summary, AZD8835 IHDS delivers strong antitumor efficacy in a range of combination settings and provides a promising alternative to continuous dosing to optimize the therapeutic index in patients. Such schedules merit clinical evaluation. Mol Cancer Ther; 15(5); 877-89. ©2016 AACR.
Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/metabolismo , Oxadiazoles/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Piperidinas/farmacología , Animales , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Análisis por Conglomerados , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Perfilación de la Expresión Génica , Humanos , Isoenzimas , Ratones , Oxadiazoles/química , Piperidinas/química , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A new series of pyrazinecarboxamide DGAT1 inhibitors was designed to address the need for a candidate drug with good potency, selectivity, and physical and DMPK properties combined with a low predicted dose in man. Rational design and optimization of this series led to the discovery of compound 30 (AZD7687), which met the project objectives for potency, selectivity, in particular over ACAT1, solubility, and preclinical PK profiles. This compound showed the anticipated excellent pharmacokinetic properties in human volunteers.
Asunto(s)
Acetatos/química , Diacilglicerol O-Acetiltransferasa/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Pirazinas/química , Acetatos/farmacocinética , Acetatos/farmacología , Animales , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/farmacocinética , Inhibidores Enzimáticos/farmacología , Humanos , Espectroscopía de Resonancia Magnética , Pirazinas/farmacocinética , Pirazinas/farmacología , Ratas , SolubilidadRESUMEN
Plaques in the parenchyma of the brain containing Abeta peptides are one of the hallmarks of Alzheimer's disease. These Abeta peptides are produced by the final proteolytic cleavage of the amyloid precursor protein by the intramembraneous aspartyl protease gamma-secretase. Thus, one approach to lowering levels of Abeta has been via the inhibition of the gamma-secretase enzyme. Here, we report a novel, bioavailable gamma-secretase inhibitor, N-[cis-4-[(4-chlorophenyl)sulfonyl]-4-(2,5-difluorophenyl)cyclohexyl]-1,1,1-trifluoromethanesulfonamide (MRK-560) that displayed oral pharmacokinetics suitable for once-a-day dosing. It was able to markedly reduce Abeta in the brain and cerebrospinal fluid (CSF) in the rat, with ED(50) values of 6 and 10 mg/kg, respectively. Time-course experiments using MRK-560 demonstrated these reductions in Abeta could be maintained for 24 h, and comparable temporal reductions in rat brain and CSF Abeta(40) further suggested that these two pools of Abeta are related. This relationship between the brain and CSF Abeta was maintained when MRK-560 was dosed once a day for 2 weeks, and accordingly, when all the data for the dose-response curve and time courses were correlated, a strong association was observed between the brain and CSF Abeta levels. These results demonstrate that MRK-560 is an orally bioavailable gamma-secretase inhibitor with the ability to markedly reduce Abeta peptide in the brain and CSF of the rat and confirm the utility of the rat for assessing the effects of gamma-secretase inhibitors on central nervous system Abeta(40) levels in vivo.
Asunto(s)
Péptidos beta-Amiloides/líquido cefalorraquídeo , Péptidos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Endopeptidasas/metabolismo , Fragmentos de Péptidos/líquido cefalorraquídeo , Fragmentos de Péptidos/metabolismo , Inhibidores de Proteasas/farmacología , Sulfonamidas/farmacología , Sulfonas/farmacología , Administración Oral , Secretasas de la Proteína Precursora del Amiloide , Animales , Encéfalo/enzimología , Relación Dosis-Respuesta a Droga , Masculino , Inhibidores de Proteasas/sangre , Inhibidores de Proteasas/líquido cefalorraquídeo , Ratas , Ratas Sprague-Dawley , Sulfonamidas/sangre , Sulfonamidas/líquido cefalorraquídeo , Sulfonas/sangre , Sulfonas/líquido cefalorraquídeoRESUMEN
The protease gamma-secretase plays a pivotal role in the synthesis of pathogenic amyloid-beta in Alzheimer's disease (AD). Here, we report a further extension to a series of cyclohexyl sulfone-based gamma-secretase inhibitors which has allowed the preparation of highly potent compounds which also demonstrate robust Abeta(40) lowering in vivo (e.g., compound 32, MED 1mg/kg p.o. in APP-YAC mice).