RESUMEN
Stereochemically and structurally complex cyclic dinucleotide-based stimulator of interferon genes (STING) agonists were designed and synthesized to access a previously unexplored chemical space. The assessment of biochemical affinity and cellular potency, along with computational, structural, and biophysical characterization, was applied to influence the design and optimization of novel STING agonists, resulting in the discovery of MK-1454 as a molecule with appropriate properties for clinical development. When administered intratumorally to immune-competent mice-bearing syngeneic tumors, MK-1454 exhibited robust tumor cytokine upregulation and effective antitumor activity. Tumor shrinkage in mouse models that are intrinsically resistant to single-agent therapy was further enhanced when treating the animals with MK-1454 in combination with a fully murinized antimouse PD-1 antibody, mDX400. These data support the development of STING agonists in combination with pembrolizumab (humanized anti-PD-1 antibody) for patients with tumors that are partially responsive or nonresponsive to single-agent anti-PD-1 therapy.
Asunto(s)
Proteínas de la Membrana , Neoplasias , Animales , Citocinas , Humanos , Inmunoterapia/métodos , Interferones , Ratones , Neoplasias/tratamiento farmacológicoRESUMEN
The purpose of this research was to assess variability in pharmacokinetic profiles (PK variability) in preclinical species and identify the risk factors associated with the properties of a drug molecule that contribute to the variability. Exposure data in mouse, rat, dog, and monkey for a total of 16,592 research compounds studied between 1999 and 2013 were included in the analysis. Both in vivo study parameters and in silico/experimental physicochemical properties of the molecules were analyzed. Areas under the plasma concentration vs time curves (AUC) were used to assess PK variability. PK variability was calculated as the ratio of the highest AUC within a defined set of AUC values (AUCmax) over the lowest AUC within that set (AUCmin). Both intra- and inter-animal variability were analyzed, with intra-animal exposures found to be more variable than inter-animal exposures. While several routes of administration were initially studied, the analysis was focused on the oral route, which corresponds to the large majority of data points and displays higher variability than the subcutaneous, intraperitoneal, or intravenous routes. The association between inter-animal PK variability and physical properties was studied, and low solubility, high administered dose, high preclinical dose number (PDo), and pH-dependent solubility were found to be associated with high variability in exposures. Permeability-as assessed by the measured permeability coefficient in the LLC-PK1 cell line-was also considered but appeared to only have a weak association with variability. Consistent with these findings, BCS class I and III compounds were found to be less prone to PK variability than BCS class II and IV compounds. A modest association of PK variability with clearance was observed while the association with bioavailability, a higher PK variability for compounds with lower bioavailability, appeared to be more pronounced. Finally, two case studies that highlight PK variability issues are described, and successful mitigation strategies are presented.
Asunto(s)
Evaluación Preclínica de Medicamentos/métodos , Animales , Área Bajo la Curva , Líquidos Corporales/metabolismo , Perros , Humanos , Concentración de Iones de Hidrógeno , Absorción Intestinal/fisiología , Células LLC-PK1 , Ratones , Permeabilidad , Preparaciones Farmacéuticas/metabolismo , Farmacocinética , Ratas , PorcinosRESUMEN
Optimization of a series of highly potent and kinome selective carbon-linked carboxamide spleen tyrosine kinase (Syk) inhibitors with favorable drug-like properties is described. A pervasive Ames liability in an analogous nitrogen-linked carboxamide series was obviated by replacement with a carbon-linked moiety. Initial efforts lacked on-target potency, likely due to strain induced between the hinge binding amide and solvent front heterocycle. Consideration of ground state and bound state energetics allowed rapid realization of improved solvent front substituents affording subnanomolar Syk potency and high kinome selectivity. These molecules were also devoid of mutagenicity risk as assessed via the Ames test using the TA97a Salmonella strain.
RESUMEN
BACKGROUND AND PURPOSE: Asthma presents as a heterogeneous syndrome characterized by airway obstruction, inflammation and hyper-reactivity (AHR). Spleen tyrosine kinase (Syk) mediates allergen-induced mast cell degranulation, a central component of allergen-induced inflammation and AHR. However, the role of Syk in IgE-mediated constriction of human small airways remains unknown. In this study, we addressed whether selective inhibition of Syk attenuates IgE-mediated constriction and mast cell mediator release in human small airways. EXPERIMENTAL APPROACH: Human precision cut lung slices (hPCLS) ex vivo derived from non-asthmatic donors were incubated overnight with human IgE, dexamethasone, montelukast, antihistamines or a selective Syk inhibitor (SYKi). High-affinity IgE receptor (FcεRI) activation by anti-IgE cross-linking was performed, and constriction and mediator release measured. Airway constriction was normalized to that induced by maximal carbachol stimulation. Syk expression (determined by qPCR and immunoblot) was also evaluated in human primary airway smooth muscle (HASM) cells to determine whether Syk directly modulates HASM function. KEY RESULTS: While dexamethasone had little effect on FcεR-mediated contraction, montelukast or antihistamines partially attenuated the response. SYKi abolished anti-IgE-mediated contraction and suppressed the release of mast cell or basophil mediators from the IgE-treated hPCLS. In contrast, SYKi had little effect on the non-allergic contraction induced by carbachol. Syk mRNA and protein were undetectable in HASM cells. CONCLUSIONS AND IMPLICATIONS: A selective Syk inhibitor, but not corticosteroids, abolished FcεR-mediated contraction in human small airways ex vivo. The mechanism involved FcεRI receptor activation on mast cells or basophils that degranulate causing airway constriction, rather than direct actions on HASM.
Asunto(s)
Inmunoglobulina E/inmunología , Pulmón/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Bazo/enzimología , Células Cultivadas , Humanos , Técnicas In Vitro , Pulmón/citología , Pulmón/enzimología , Pulmón/inmunología , Contracción Muscular/efectos de los fármacos , Contracción Muscular/inmunología , Músculo Liso/enzimología , Músculo Liso/inmunología , Inhibidores de Proteínas Quinasas/química , Proteínas Tirosina Quinasas/metabolismoRESUMEN
Development of a series of highly kinome-selective spleen tyrosine kinase (Syk) inhibitors with favorable druglike properties is described. Early leads were discovered through X-ray crystallographic analysis, and a systematic survey of cores within a selected chemical space focused on ligand binding efficiency. Attenuation of hERG ion channel activity inherent within the initial chemotype was guided through modulation of physicochemical properties including log D, PSA, and pKa. PSA proved most effective for prospective compound design. Further profiling of an advanced compound revealed bacterial mutagenicity in the Ames test using TA97a Salmonella strain, and subsequent study demonstrated that this mutagenicity was pervasive throughout the series. Identification of intercalation as a likely mechanism for the mutagenicity-enabled modification of the core scaffold. Implementation of a DNA binding assay as a prescreen and models in DNA allowed resolution of the mutagenicity risk, affording molecules with favorable potency, selectivity, pharmacokinetic, and off-target profiles.
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Amidas/farmacología , Canales de Potasio Éter-A-Go-Go/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Bazo/enzimología , Amidas/síntesis química , Amidas/química , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Canales de Potasio Éter-A-Go-Go/genética , Canales de Potasio Éter-A-Go-Go/metabolismo , Humanos , Modelos Moleculares , Estructura Molecular , Pruebas de Mutagenicidad , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Proteínas Tirosina Quinasas/metabolismo , Bazo/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
This report documents the first example of a specific inhibitor of protein kinases with preferential binding to the activated kinase conformation: 5H-benzo[4,5]cyclohepta[1,2-b]pyridin-5-one 11r (MK-8033), a dual c-Met/Ron inhibitor under investigation as a treatment for cancer. The design of 11r was based on the desire to reduce time-dependent inhibition of CYP3A4 (TDI) by members of this structural class. A novel two-step protocol for the synthesis of benzylic sulfonamides was developed to access 11r and analogues. We provide a rationale for the observed selectivity based on X-ray crystallographic evidence and discuss selectivity trends with additional examples. Importantly, 11r provides full inhibition of tumor growth in a c-Met amplified (GTL-16) subcutaneous tumor xenograft model and may have an advantage over inactive form kinase inhibitors due to equal potency against a panel of oncogenic activating mutations of c-Met in contrast to c-Met inhibitors without preferential binding to the active kinase conformation.
Asunto(s)
Benzocicloheptenos/metabolismo , Benzocicloheptenos/farmacología , Descubrimiento de Drogas , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-met/metabolismo , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Sulfonamidas/metabolismo , Sulfonamidas/farmacología , Animales , Benzocicloheptenos/química , Línea Celular Tumoral , Perros , Activación Enzimática/efectos de los fármacos , Femenino , Humanos , Ratones , Modelos Moleculares , Conformación Proteica , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-met/química , Ratas , Especificidad por Sustrato , Sulfonamidas/química , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
An efficient two-step strategy has been developed to access diversely functionalized benzylic sulfonamides. Execution of this strategy required the development of two reaction methods: the palladium-catalyzed cross-coupling of aryl halides with CH-acidic methanesulfonamides and a metathesis reaction between the resulting alpha-arylated sulfonamides and diverse amines. The broad scope of the cross-coupling process combined with a versatile sulfonamide metathesis constitutes an efficient strategy for the synthesis of various benzylic sulfonamides.
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Compuestos de Bencilo/síntesis química , Paladio/química , Sulfonamidas/síntesis química , Compuestos de Bencilo/química , Catálisis , Estructura Molecular , Sulfonamidas/químicaRESUMEN
Studies of carbohydrates have been hampered by the lack of chemical strategies for the expeditious construction and coupling of differentially protected monosaccharides. Here, a synthetic route based on aldol coupling of three aldehydes is presented for the de novo production of polyol differentiated hexoses in only two chemical steps. The dimerization of alpha-oxyaldehydes, catalyzed by l-proline, is then followed by a tandem Mukaiyama aldol addition-cyclization step catalyzed by a Lewis acid. Differentially protected glucose, allose, and mannose stereoisomers can each be selected, in high yield and stereochemical purity, simply by changing the solvent and Lewis acid used. The reaction sequence also efficiently produces (13)C-labeled analogs, as well as structural variants such as 2-amino- and 2-thio-substituted derivatives.
Asunto(s)
Hexosas/síntesis química , Prolina/química , Ácidos , Aldehídos/química , Isótopos de Carbono , Catálisis , Ciclización , Dimerización , Hexosas/química , Hexosas/aislamiento & purificación , Conformación Molecular , Estructura Molecular , Solventes , EstereoisomerismoRESUMEN
The first enantioselective catalytic direct cross-aldol reaction that employs nonequivalent aldehydes has been accomplished using proline as the reaction catalyst. Structural variation in both the aldol donor (R1 = Me, n-Bu, Bn, 91 to >99%) and aldol acceptor (R2 = I-Pr, I-Bu, c-C6H11, Et, Ph, 97-99% ee) are possible while maintaining high reaction efficiency (75-88% yield). Significantly, this new aldol variant allows facile enantioselective access to a broad range of beta-hydroxy aldehydes which are valuable intermediates in polyketide syntheses.
RESUMEN
The first general approach to enantioselective catalysis of the Diels-Alder reaction with simple ketone dienophiles has been accomplished. The use of iminium catalysis has enabled enantioselective access to a fundamental Diels-Alder reaction variant that has previously been unavailable using chiral Lewis acid catalysis. A new chiral amine catalyst has been developed that allows a variety of monodentate cyclic and acyclic ketones to successfully participate in enantioselective [4 + 2] cycloadditions. A wide spectrum of cyclic and acyclic diene substrates can also be accommodated in this new organocatalytic transformation. A computational model is provided that is in accord with the sense of enantioinduction observed for all reactions conducted during the course of this study.