RESUMEN
Danvatirsen is a Generation 2.5 antisense oligonucleotide under clinical development. Population PK modelling was conducted using data from 3 available danvatirsen Phase I/II studies in oncology patients to investigate the impact of flat dosing on exposure compared to ideal body weight-based dosing. A total of 126 patients who received danvatirsen doses ranging from 1 to 4 mg/kg as monotherapy or in combination with durvalumab, most at 3 mg/kg (n = 70), was used in the danvatirsen population PK analysis. A 2-compartment model with linear elimination described the data well. Covariate analysis revealed ideal body weight was not a significant covariate on the PK of danvatirsen; nor was age, sex or race. The model-based simulation suggested that steady state weekly AUC and Cmax were very similar between 3 mg/kg and 200 mg flat dosing (geometric mean of AUC: 62.5 vs. 63.4 mg h/L and Cmax: 26.2 vs. 26.5 mg/L for two dose groups) with slightly less overall between-subject variability in the flat dosing regimen. The switch to flat dosing was approved by multiple regulatory agencies, including FDA, EMA, PMDA and ANSM. Several ongoing studies have been evaluating flat dosing. Interim analysis from an ongoing study (D5660C00016, NCT03421353) has shown the observed steady state concentration from 200 mg flat dose is in agreement with the model predictions. The population PK model could be further utilized in subsequent exposure-response efficacy and safety modelling.
Asunto(s)
Neoplasias/tratamiento farmacológico , Oligonucleótidos/administración & dosificación , Oligonucleótidos/farmacocinética , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/farmacocinética , Peso Corporal/fisiología , Simulación por Computador , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Tasa de Depuración Metabólica/fisiología , Persona de Mediana Edad , Modelos Biológicos , Neoplasias/metabolismo , Oligonucleótidos Antisentido/farmacocinéticaRESUMEN
The design and synthesis of a novel series of 2,6-disubstituted pyrazine derivatives as CK2 kinase inhibitors is described. Structure-guided optimization of a 5-substituted-3-thiophene carboxylic acid screening hit (3a) led to the development of a lead compound (12b), which shows inhibition in both enzymatic and cellular assays. Subsequent design and hybridization efforts also led to the unexpected identification of analogs with potent PIM kinase activity (14f).
Asunto(s)
Quinasa de la Caseína II/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Pirazinas/farmacología , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacocinética , Pirazinas/síntesis química , Pirazinas/química , Pirazinas/farmacocinética , Relación Estructura-ActividadRESUMEN
Upregulation of Pim kinases is observed in several types of leukemias and lymphomas. Pim-1, -2, and -3 promote cell proliferation and survival downstream of cytokine and growth factor signaling pathways. AZD1208 is a potent, highly selective, and orally available Pim kinase inhibitor that effectively inhibits all three isoforms at <5 nM or <150 nM in enzyme and cell assays, respectively. AZD1208 inhibited the growth of 5 of 14 acute myeloid leukemia (AML) cell lines tested, and sensitivity correlates with Pim-1 expression and STAT5 activation. AZD1208 causes cell cycle arrest and apoptosis in MOLM-16 cells, accompanied by a dose-dependent reduction in phosphorylation of Bcl-2 antagonist of cell death, 4EBP1, p70S6K, and S6, as well as increases in cleaved caspase 3 and p27. Inhibition of p4EBP1 and p-p70S6K and suppression of translation are the most representative effects of Pim inhibition in sensitive AML cell lines. AZD1208 inhibits the growth of MOLM-16 and KG-1a xenograft tumors in vivo with a clear pharmacodynamic-pharmacokinetic relationship. AZD1208 also potently inhibits colony growth and Pim signaling substrates in primary AML cells from bone marrow that are Flt3 wild-type or Flt3 internal tandem duplication mutant. These results underscore the therapeutic potential of Pim kinase inhibition for the treatment of AML.
Asunto(s)
Apoptosis/efectos de los fármacos , Compuestos de Bifenilo/farmacología , Proliferación Celular/efectos de los fármacos , Leucemia Mieloide Aguda/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Tiazolidinas/farmacología , Animales , Compuestos de Bifenilo/farmacocinética , Western Blotting , Ciclo Celular , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Leucemia Mieloide Aguda/enzimología , Leucemia Mieloide Aguda/patología , Ratones , Ratones SCID , Inhibidores de Proteínas Quinasas/farmacocinética , Proteínas Proto-Oncogénicas c-pim-1/metabolismo , Tiazolidinas/farmacocinética , Distribución Tisular , Células Tumorales CultivadasRESUMEN
During the lead generation and optimization of PARP inhibitors blocking centrosome clustering, it was discovered that increasing hydrogen bond acceptor (HBA) strength improved cellular potency but led to elevated Caco2 and MDR1 efflux and thus poor oral bioavailability. Conversely, compounds with lower efflux had reduced potency. The project team was able to improve the bioavailability by reducing efflux through systematic modifications to the strength of the HBA by changing the electronic properties of neighboring groups, whilst maintaining sufficient acceptor strength for potency. Additionally, it was observed that enantiomers with different potency showed similar efflux, which is consistent with the promiscuity of efflux transporters. Eventually, a balance between potency and low efflux was achieved for a set of lead compounds with good bioavailability which allowed the project to progress towards establishing in vivo pharmacokinetic/pharmacodynamic relationships.
Asunto(s)
Centrosoma/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacocinética , Administración Oral , Animales , Disponibilidad Biológica , Células CACO-2 , Perros , Humanos , Enlace de Hidrógeno , Células de Riñón Canino Madin Darby , Ratones , Inhibidores de Poli(ADP-Ribosa) Polimerasas/administración & dosificación , RatasRESUMEN
We have discovered a novel class of heterocyclic sulfonamides that act as antagonists of the S1P1 receptor. While members of this series identified from a high-throughput screen showed promising levels of potency in a cell-based assay measuring the inhibition of receptor internalization, most compounds were excessively lipophilic and contained an oxidation-prone thioether moiety. As a result, such compounds suffered from poor physical properties and metabolic stability, limiting their utility as in vivo probes. By removing the thioether group and systematically developing an understanding of structure-activity relationships and the effects of lipophilicity on potency within this series, we have been able to identify potent compounds with vastly improved physical properties. A representative enantiopure triazole sulfonamide (33) has measurable bioavailability following a low (3mg/kg) oral dose in rat, highlighting an achievement of the early hit-to-lead efforts for this series.
Asunto(s)
Descubrimiento de Drogas , Compuestos Heterocíclicos/síntesis química , Compuestos Heterocíclicos/farmacología , Receptores de Lisoesfingolípidos/antagonistas & inhibidores , Sulfonamidas/síntesis química , Sulfonamidas/farmacología , Animales , Compuestos Heterocíclicos/química , Unión Proteica/efectos de los fármacos , Ratas , Relación Estructura-Actividad , Sulfonamidas/químicaRESUMEN
The propensity for cancer cells to accumulate additional centrosomes relative to normal cells could be exploited for therapeutic benefit in oncology. Following literature reports that suggested TNKS1 (tankyrase 1) and PARP16 may be involved with spindle structure and function and may play a role in suppressing multi-polar spindle formation in cells with supernumerary centrosomes, we initiated a phenotypic screen to look for small molecule poly (ADP-ribose) polymerase (PARP) enzyme family inhibitors that could produce a multi-polar spindle phenotype via declustering of centrosomes. Screening of AstraZeneca's collection of phthalazinone PARP inhibitors in HeLa cells using high-content screening techniques identified several compounds that produced a multi-polar spindle phenotype at low nanomolar concentrations. Characterization of these compounds across a broad panel of PARP family enzyme assays indicated that they had activity against several PARP family enzymes, including PARP1, 2, 3, 5a, 5b, and 6. Further optimization of these initial hits for improved declustering potency, solubility, permeability, and oral bioavailability resulted in AZ0108, a PARP1, 2, 6 inhibitor that potently inhibits centrosome clustering and is suitable for in vivo efficacy and tolerability studies.
Asunto(s)
Centrosoma/metabolismo , Ftalazinas/química , Inhibidores de Poli(ADP-Ribosa) Polimerasas/química , Administración Oral , Animales , Sitios de Unión , Células CACO-2 , Centrosoma/efectos de los fármacos , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos , Células HeLa , Humanos , Microsomas/metabolismo , Conformación Molecular , Simulación de Dinámica Molecular , Ftalazinas/administración & dosificación , Ftalazinas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/administración & dosificación , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Estructura Terciaria de Proteína , Ratas , Tanquirasas/antagonistas & inhibidores , Tanquirasas/metabolismoRESUMEN
Checkpoint kinase 1 (Chk1, CHEK1) is a Ser/Thr protein kinase that plays a key role in mediating the cellular response to DNA-damage. Synthesis and evaluation of a previously described class of Chk1 inhibitors, triazoloquinolones/triazolones (TZs) is further described herein. Our investigation of structure-activity relationships led to the identification of potent inhibitors 14c, 14h and 16e. Key challenges included modulation of physicochemical properties and pharmacokinetic (PK) parameters to enable compound testing in a Chk1 specific hollow fiber pharmacodynamic model. In this model, 16e was shown to abrogate topotecan-induced cell cycle arrest in a dose dependent manner. The demonstrated activity of TZs in this model in combination with a chemotherapeutic agent as well as radiotherapy validates this series of Chk1 inhibitors. X-ray crystal structures (PDB code: 2YEX and 2YER) for an initial lead and an optimized analog are also presented.
Asunto(s)
Antineoplásicos/síntesis química , Neoplasias del Colon/terapia , Inhibidores de Proteínas Quinasas/síntesis química , Proteínas Quinasas/metabolismo , Triazoles/síntesis química , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Neoplasias del Colon/enzimología , Terapia Combinada , Cristalografía por Rayos X , Daño del ADN , Relación Dosis-Respuesta a Droga , Humanos , Ratones , Ratones Desnudos , Modelos Moleculares , Conformación Proteica , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/uso terapéutico , Relación Estructura-Actividad , Topotecan/farmacología , Triazoles/farmacocinética , Triazoles/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Novel substituted benzylidene-1,3-thiazolidine-2,4-diones (TZDs) have been identified as potent and highly selective inhibitors of the PIM kinases. The synthesis and SAR of these compounds are described, along with X-ray crystallographic, anti-proliferative, and selectivity data.
Asunto(s)
Compuestos de Bencilideno/química , Inhibidores de Proteínas Quinasas/química , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Tiazolidinedionas/química , Animales , Compuestos de Bencilideno/farmacología , Línea Celular , Proliferación Celular/efectos de los fármacos , Descubrimiento de Drogas , Humanos , Modelos Moleculares , Inhibidores de Proteínas Quinasas/farmacología , Ratas , Relación Estructura-Actividad , Tiazolidinedionas/farmacologíaRESUMEN
BACKGROUND: The Regulatory T cell (Treg) lineage is defined by the transcription factor FOXP3, which controls immune-suppressive gene expression profiles. Tregs are often recruited in high frequencies to the tumor microenvironment where they can suppress antitumor immunity. We hypothesized that pharmacological inhibition of FOXP3 by systemically delivered, unformulated constrained ethyl-modified antisense oligonucleotides could modulate the activity of Tregs and augment antitumor immunity providing therapeutic benefit in cancer models and potentially in man. METHODS: We have identified murine Foxp3 antisense oligonucleotides (ASOs) and clinical candidate human FOXP3 ASO AZD8701. Pharmacology and biological effects of FOXP3 inhibitors on Treg function and antitumor immunity were tested in cultured Tregs and mouse syngeneic tumor models. Experiments were controlled by vehicle and non-targeting control ASO groups as well as by use of multiple independent FOXP3 ASOs. Statistical significance of biological effects was evaluated by one or two-way analysis of variance with multiple comparisons. RESULTS: AZD8701 demonstrated a dose-dependent knockdown of FOXP3 in primary Tregs, reduction of suppressive function and efficient target downregulation in humanized mice at clinically relevant doses. Surrogate murine FOXP3 ASO, which efficiently downregulated Foxp3 messenger RNA and protein levels in primary Tregs, reduced Treg suppressive function in immune suppression assays in vitro. FOXP3 ASO promoted more than 70% reduction in FOXP3 levels in Tregs in vitro and in vivo, strongly modulated Treg effector molecules (eg, ICOS, CTLA-4, CD25 and 4-1BB), and augmented CD8+ T cell activation and produced antitumor activity in syngeneic tumor models. The combination of FOXP3 ASOs with immune checkpoint blockade further enhanced antitumor efficacy. CONCLUSIONS: Antisense inhibitors of FOXP3 offer a promising novel cancer immunotherapy approach. AZD8701 is being developed clinically as a first-in-class FOXP3 inhibitor for the treatment of cancer currently in Ph1a/b clinical trial (NCT04504669).
Asunto(s)
Neoplasias , Oligonucleótidos Antisentido , Animales , Modelos Animales de Enfermedad , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Humanos , Terapia de Inmunosupresión , Inmunoterapia , Ratones , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Linfocitos T Reguladores , Microambiente TumoralRESUMEN
Checkpoint Kinase-1 (Chk1, CHK1, CHEK1) is a Ser/Thr protein kinase that mediates cellular responses to DNA-damage. A novel class of Chk1 inhibitors, triazoloquinolones/triazolones (TZ's) was identified by high throughput screening. The optimization of these hits to provide a lead series is described.
Asunto(s)
Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Quinasas/efectos de los fármacos , Triazoles/química , Triazoles/farmacología , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Cristalografía por Rayos X , Descubrimiento de Drogas , Modelos Moleculares , Relación Estructura-ActividadRESUMEN
JAK1, JAK2, JAK3, and TYK2 belong to the JAK (Janus kinase) family. They play critical roles in cytokine signaling. Constitutive activation of JAK/STAT pathways is associated with a wide variety of diseases. Particularly, pSTAT3 is observed in response to the treatment with inhibitors of oncogenic signaling pathways such as EGFR, MAPK, and AKT and is associated with resistance or poorer response to agents targeting these pathways. Among the JAK family kinases, JAK1 has been shown to be the primary driver of STAT3 phosphorylation and signaling; therefore, selective JAK1 inhibition can be a viable means to overcome such treatment resistances. Herein, an account of the medicinal chemistry optimization from the promiscuous kinase screening hit 3 to the candidate drug 21 (AZD4205), a highly selective JAK1 kinase inhibitor, is reported. Compound 21 has good preclinical pharmacokinetics. Compound 21 displayed an enhanced antitumor activity in combination with an approved EGFR inhibitor, osimertinib, in a preclinical non-small-cell lung cancer (NSCLC) xenograft NCI-H1975 model.
Asunto(s)
Indoles/uso terapéutico , Janus Quinasa 1/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/uso terapéutico , Acrilamidas/farmacología , Compuestos de Anilina/farmacología , Animales , Línea Celular Tumoral , Diseño de Fármacos , Descubrimiento de Drogas , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inhibidores , Femenino , Humanos , Indoles/síntesis química , Indoles/farmacocinética , Ratones Desnudos , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacocinética , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A series of amidoheteroaryl compounds were designed and synthesized as inhibitors of B-Raf kinase. Several compounds from the series show excellent potency in biochemical, phenotypic and mode of action cellular assays. Potent examples from the series have also demonstrated good plasma exposure following an oral dose in rodents and activity against the Ras-Raf pathway in tumor bearing mice.
Asunto(s)
Química Farmacéutica/métodos , Inhibidores Enzimáticos/síntesis química , Mutación , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Administración Oral , Animales , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Humanos , Concentración 50 Inhibidora , Ratones , Modelos Químicos , Ratas , Relación Estructura-Actividad , Quinasas raf/metabolismo , Proteínas ras/metabolismoRESUMEN
An acyl-CoA dehydrogenase has been identified as part of the mitochondrial beta-oxidation pathway in the ascomycete fungus Aspergillus nidulans. Disruption of the scdA gene prevented use of butyric acid (C(4)) and hexanoic acid (C(6)) as carbon sources and reduced cellular butyryl-CoA dehydrogenase activity by 7.5-fold. While the mutant strain exhibited wild-type levels of growth on erucic acid (C(22:1)) and oleic acid (C(18:1)), some reduction in growth was observed with myristic acid (C(14)). The DeltascdA mutation was found to be epistatic to a mutation downstream in the beta-oxidation pathway (disruption of enoyl-CoA hydratase). The DeltascdA mutant was also unable to use isoleucine or valine as a carbon source. Transcription of scdA was observed in the presence of either fatty acids or amino acids. When the mutant was grown in medium containing either isoleucine or valine, organic acid analysis of culture supernatants showed accumulation of 2-oxo acid intermediates of branched chain amino acid catabolism, suggesting feedback inhibition of the upstream branched-chain alpha-keto acid dehydrogenase.
Asunto(s)
Acil-CoA Deshidrogenasas/metabolismo , Aspergillus nidulans/metabolismo , Ácidos Grasos/metabolismo , Isoleucina/metabolismo , Valina/metabolismo , Acilcoenzima A/química , Acilcoenzima A/metabolismo , Acil-CoA Deshidrogenasas/genética , Aspergillus nidulans/genética , Ácidos Erucicos/química , Ácidos Erucicos/metabolismo , Ácidos Grasos/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Prueba de Complementación Genética , Isoleucina/química , Estructura Molecular , Mutación , Ácido Mirístico/química , Ácido Mirístico/metabolismo , Ácido Oléico/química , Ácido Oléico/metabolismo , Oxidación-Reducción , Transcripción GenéticaRESUMEN
The bisamide class of kinase inhibitors was identified as being active against CSF-1R. The synthesis and SAR of pyridyl and thiazolyl bisamides are reported, along with the pharmacokinetic properties and in vivo activity of selected examples.
Asunto(s)
Amidas/farmacología , Antineoplásicos/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Receptor de Factor Estimulante de Colonias de Macrófagos/antagonistas & inhibidores , Tiazoles/farmacología , Células 3T3 , Amidas/química , Amidas/farmacocinética , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Femenino , Humanos , Ratones , Ratones Desnudos , Ratas , Receptor de Factor Estimulante de Colonias de Macrófagos/genética , Tiazoles/química , Tiazoles/farmacocinéticaRESUMEN
Checkpoint kinase-1 (Chk1, CHEK1) is a Ser/Thr protein kinase that mediates the cellular response to DNA-damage. A novel class of 2-ureido thiophene carboxamide urea (TCU) Chk1 inhibitors is described. Inhibitors in this chemotype were optimized for cellular potency and selectivity over Cdk1.
Asunto(s)
Química Farmacéutica/métodos , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Quinasas/química , Amidas/química , Apoptosis , Carbono/química , Ciclo Celular , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Daño del ADN , Diseño de Fármacos , Humanos , Concentración 50 Inhibidora , Modelos Químicos , Éteres Fenílicos/química , Tiofenos/química , Urea/químicaRESUMEN
BRD4 is a transcriptional co-activator functioning to recruit regulatory complexes to acetylated chromatin. A subset of High-grade Serous Ovarian Cancer (HGSOC) patients are typified by focal, recurrent BRD4 gene amplifications. Despite previously described cancer dependencies, it is unclear whether BRD4 amplification events are oncogenic in HGSOC. We find that physiologically relevant levels of expression of BRD4 isoforms in non-transformed ovarian cells result in cellular transformation. Transcriptional profiling of BRD4-transformed ovarian cells, and BRD4-amplified HGSOC patient samples revealed shared expression patterns, including enriched MYC, and E2F1 gene signatures. Furthermore, we demonstrate that a novel BET inhibitor, AZD5153, is highly active in BRD4-amplified patient derived xenografts and uncover Neuregulin-1 as a novel BRD4 effector. Experiments involving Neuregulin-1 inhibition and exogenous addition, demonstrate Neuregulin-1 as necessary and sufficient for BRD4-mediated transformation. This study demonstrates the oncogenic potential of BRD4 amplification in cancer and establishes BRD4-amplified HGSOC as a potential patient population that could benefit from BET inhibitors.
Asunto(s)
Antineoplásicos/farmacología , Regulación Neoplásica de la Expresión Génica , Compuestos Heterocíclicos con 2 Anillos/farmacología , Proteínas Nucleares/genética , Neoplasias Ováricas/genética , Piperazinas/farmacología , Factores de Transcripción/genética , Algoritmos , Animales , Carcinogénesis/genética , Proteínas de Ciclo Celular , Línea Celular Tumoral , Proliferación Celular , Cistadenocarcinoma Seroso/genética , Femenino , Expresión Génica , Perfilación de la Expresión Génica , Humanos , Ratones , Trasplante de Neoplasias , Neurregulina-1/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Proteínas/genética , Proteínas/metabolismo , Pirazoles , Piridazinas , Transducción de Señal , Factores de Transcripción/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Checkpoint kinase 1 (CHK1) inhibitors are potential cancer therapeutics that can be utilized for enhancing the efficacy of DNA damaging agents. Multiple small molecule CHK1 inhibitors from different chemical scaffolds have been developed and evaluated in clinical trials in combination with chemotherapeutics and radiation treatment. Scaffold morphing of thiophene carboxamide ureas (TCUs), such as AZD7762 (1) and a related series of triazoloquinolines (TZQs), led to the identification of fused-ring bicyclic CHK1 inhibitors, 7-carboxamide thienopyridines (7-CTPs), and 7-carboxamide indoles. X-ray crystal structures reveal a key intramolecular noncovalent sulfur-oxygen interaction in aligning the hinge-binding carboxamide group to the thienopyridine core in a coplanar fashion. An intramolecular hydrogen bond to an indole NH was also effective in locking the carboxamide in the preferred bound conformation to CHK1. Optimization on the 7-CTP series resulted in the identification of lead compound 44, which displayed respectable drug-like properties and good in vitro and in vivo potency.
Asunto(s)
Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/antagonistas & inhibidores , Descubrimiento de Drogas , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/química , Daño del ADN , Humanos , Indoles/química , Modelos Moleculares , Dominios Proteicos , Piridinas/químicaRESUMEN
: PARP proteins represent a class of post-translational modification enzymes with diverse cellular functions. Targeting PARPs has proven to be efficacious clinically, but exploration of the therapeutic potential of PARP inhibition has been limited to targeting poly(ADP-ribose) generating PARP, including PARP1/2/3 and tankyrases. The cancer-related functions of mono(ADP-ribose) generating PARP, including PARP6, remain largely uncharacterized. Here, we report a novel therapeutic strategy targeting PARP6 using the first reported PARP6 inhibitors. By screening a collection of PARP compounds for their ability to induce mitotic defects, we uncovered a robust correlation between PARP6 inhibition and induction of multipolar spindle (MPS) formation, which was phenocopied by PARP6 knockdown. Treatment with AZ0108, a PARP6 inhibitor with a favorable pharmacokinetic profile, potently induced the MPS phenotype, leading to apoptosis in a subset of breast cancer cells in vitro and antitumor effects in vivo. In addition, Chk1 was identified as a specific substrate of PARP6 and was further confirmed by enzymatic assays and by mass spectrometry. Furthermore, when modification of Chk1 was inhibited with AZ0108 in breast cancer cells, we observed marked upregulation of p-S345 Chk1 accompanied by defects in mitotic signaling. Together, these results establish proof-of-concept antitumor efficacy through PARP6 inhibition and highlight a novel function of PARP6 in maintaining centrosome integrity via direct ADP-ribosylation of Chk1 and modulation of its activity. SIGNIFICANCE: These findings describe a new inhibitor of PARP6 and identify a novel function of PARP6 in regulating activation of Chk1 in breast cancer cells.
Asunto(s)
ADP Ribosa Transferasas/antagonistas & inhibidores , Neoplasias de la Mama/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Huso Acromático/efectos de los fármacos , Huso Acromático/metabolismo , Animales , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Inhibidores de Poli(ADP-Ribosa) Polimerasas/química , Transducción de Señal/efectos de los fármacos , Especificidad por Sustrato , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Janus kinases (JAKs) have been demonstrated to be critical in cytokine signaling and have thus been implicated in both cancer and inflammatory diseases. The JAK family consists of four highly homologous members: JAK1-3 and TYK2. The development of small-molecule inhibitors that are selective for a specific family member would represent highly desirable tools for deconvoluting the intricacies of JAK family biology. Herein, we report the discovery of a potent JAK1 inhibitor, 24, which displays â¼1000-fold selectivity over the other highly homologous JAK family members (determined by biochemical assays), while also possessing good selectivity over other kinases (determined by panel screening). Moreover, this compound was demonstrated to be orally bioavailable and possesses acceptable pharmacokinetic parameters. In an in vivo study, the compound was observed to dose dependently modulate the phosphorylation of STAT3 (a downstream marker of JAK1 inhibition).
Asunto(s)
Janus Quinasa 1/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Administración Oral , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Disponibilidad Biológica , Línea Celular , Cristalografía por Rayos X , Humanos , Janus Quinasa 1/química , Janus Quinasa 1/metabolismo , Janus Quinasa 2/antagonistas & inhibidores , Janus Quinasa 2/metabolismo , Janus Quinasa 3/metabolismo , Ratones , Fosforilación/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: The Janus kinase (JAK) and signal transduction and activation of transcription (STAT) signaling pathway is an attractive target in multiple cancers. Activation of the JAK-STAT pathway is important in both tumorigenesis and activation of immune responses. In diffuse large B-cell lymphoma (DLBCL), the transcription factor STAT3 has been associated with aggressive disease phenotype and worse overall survival. While multiple therapies inhibit upstream signaling, there has been limited success in selectively targeting STAT3 in patients. Antisense oligonucleotides (ASOs) represent a compelling therapeutic approach to target difficult to drug proteins such as STAT3 through of mRNA targeting. We report the evaluation of a next generation STAT3 ASO (AZD9150) in a non-Hodgkin's lymphoma population, primarily consisting of patients with DLBCL. METHODS: Patients with relapsed or treatment refractory lymphoma were enrolled in this expansion cohort. AZD9150 was administered at 2 mg/kg and the 3 mg/kg (MTD determined by escalation cohort) dose levels with initial loading doses in the first week on days 1, 3, and 5 followed by weekly dosing. Patients were eligible to remain on therapy until unacceptable toxicity or progression. Blood was collected pre- and post-treatment for analysis of peripheral immune cells. RESULTS: Thirty patients were enrolled, 10 at 2 mg/kg and 20 at 3 mg/kg dose levels. Twenty-seven patients had DLBCL. AZD9150 was safe and well tolerated at both doses. Common drug-related adverse events included transaminitis, fatigue, and thrombocytopenia. The 3 mg/kg dose level is the recommended phase 2 dose. All responses were seen among DLBCL patients, including 2 complete responses with median duration of response 10.7 months and 2 partial responses. Peripheral blood cell analysis of three patients without a clinical response to therapy revealed a relative increase in proportion of macrophages, CD4+, and CD8+ T cells; this trend did not reach statistical significance. CONCLUSIONS: AZD9150 was well tolerated and demonstrated efficacy in a subset of heavily pretreated patients with DLBCL. Studies in combination with checkpoint immunotherapies are ongoing. TRIAL REGISTRATION: Registered at ClinicalTrials.gov: NCT01563302 . First submitted 2/13/2012.