RESUMEN
Interleukin-1 receptor associated kinase 4 (IRAK4) is an essential mediator of the IL-1R and TLR signaling pathways, both of which have been implicated in multiple autoimmune conditions. Hence, blocking the activity of IRAK4 represents an attractive approach for the treatment of autoimmune diseases. The activity of this serine/threonine kinase is dependent on its kinase and scaffolding activities; thus, degradation represents a potentially superior approach to inhibition. Herein, we detail the exploration of structure-activity relationships that ultimately led to the identification of KT-474, a potent, selective, and orally bioavailable heterobifunctional IRAK4 degrader. This represents the first heterobifunctional degrader evaluated in a nononcology indication and dosed to healthy human volunteers. This molecule successfully completed phase I studies in healthy adult volunteers and patients with atopic dermatitis or hidradenitis suppurativa. Phase II clinical trials in both of these indications have been initiated.
RESUMEN
Developing therapies for the activated B-cell like (ABC) subtype of diffuse large B-cell lymphomas (DLBCL) remains an area of unmet medical need. A subset of ABC DLBCL tumors is driven by activating mutations in myeloid differentiation primary response protein 88 (MYD88), which lead to constitutive activation of interleukin-1 receptor associated kinase 4 (IRAK4) and cellular proliferation. IRAK4 signaling is driven by its catalytic and scaffolding functions, necessitating complete removal of this protein and its escape mechanisms for complete therapeutic suppression. Herein, we describe the identification and characterization of a dual-functioning molecule, KT-413 and show it efficiently degrades IRAK4 and the transcription factors Ikaros and Aiolos. KT-413 achieves concurrent degradation of these proteins by functioning as both a heterobifunctional degrader and a molecular glue. Based on the demonstrated activity and safety of KT-413 in preclinical studies, a phase 1 clinical trial in B-cell lymphomas, including MYD88 mutant ABC DLBCL, is currently underway.
Asunto(s)
Quinasas Asociadas a Receptores de Interleucina-1 , Linfoma de Células B Grandes Difuso , Mutación , Factor 88 de Diferenciación Mieloide , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Quinasas Asociadas a Receptores de Interleucina-1/antagonistas & inhibidores , Factor 88 de Diferenciación Mieloide/metabolismo , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Humanos , Animales , Línea Celular Tumoral , Descubrimiento de Drogas , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Ratones , Imidazoles/química , Imidazoles/farmacología , Imidazoles/metabolismo , Proteolisis/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
BACKGROUND: Tazemetostat (EPZ-6438) is a selective inhibitor of the histone methyltransferase EZH2 and currently in clinical development for non-Hodgkin lymphoma and genetically defined tumors. PROCEDURES: Tazemetostat was tested against the Pediatric Preclinical Testing Program (PPTP) solid tumor xenografts using a dose of 400 mg/kg administered twice daily by oral gavage for 28 days. H3K27me3:H3 ratios were determined in control and treated tumors. RESULTS: Tazemetostat induced significant differences in event-free survival (EFS) distribution compared with control in nine of 30 (30%) of the xenografts studied. Significant differences in EFS distribution were observed in five of seven (71%) rhabdoid tumor xenograft lines compared with four of 23 (17%) nonrhabdoid xenograft lines (chi-square [χ2 ] test P = 0.006). Tazemetostat induced tumor growth inhibition meeting criteria for intermediate and high EFS treated-to-control (T/C) activity in two of 25 (8%) and one of 25 (4%) xenografts, respectively. Intermediate and high activity for the EFS T/C metric was observed exclusively among rhabdoid tumor xenografts (three of five rhabdoid tumor vs 0 of 22 nonrhabdoid tumors (χ² test P < 0.001). One rhabdoid tumor xenograft (G401) showed stable disease. For one rhabdoid tumor (G401), delayed tumor regression to tazemetostat was noted following 1 week of tumor growth. Tazemetostat induced significant reduction of H3K27me3 levels in the majority of tumors compared with controls. CONCLUSIONS: Tazemetostat demonstrated significant antitumor activity in rhabdoid tumor models but showed no consistent activity against any other histology. Tazemetostat reduced H3K27me3 levels irrespective of tumor response. Further preclinical testing to evaluate tazemetostat in combination with other anticancer agents is warranted.
Asunto(s)
Antineoplásicos/farmacología , Benzamidas/farmacología , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Neoplasias Experimentales/tratamiento farmacológico , Piridonas/farmacología , Animales , Compuestos de Bifenilo , Proliferación Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Ratones , Ratones SCID , Morfolinas , Neoplasias Experimentales/patología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Inhibitors of the protein methyltransferase Enhancer of Zeste Homolog 2 (EZH2) may have significant therapeutic potential for the treatment of B cell lymphomas and other cancer indications. The ability of the scientific community to explore fully the spectrum of EZH2-associated pathobiology has been hampered by the lack of in vivo-active tool compounds for this enzyme. Here we report the discovery and characterization of EPZ011989, a potent, selective, orally bioavailable inhibitor of EZH2 with useful pharmacokinetic properties. EPZ011989 demonstrates significant tumor growth inhibition in a mouse xenograft model of human B cell lymphoma. Hence, this compound represents a powerful tool for the expanded exploration of EZH2 activity in biology.
RESUMEN
Patients with non-Hodgkin lymphoma (NHL) are treated today with a cocktail of drugs referred to as CHOP (Cyclophosphamide, Hydroxyldaunorubicin, Oncovin, and Prednisone). Subsets of patients with NHL of germinal center origin bear oncogenic mutations in the EZH2 histone methyltransferase. Clinical testing of the EZH2 inhibitor EPZ-6438 has recently begun in patients. We report here that combining EPZ-6438 with CHOP in preclinical cell culture and mouse models results in dramatic synergy for cell killing in EZH2 mutant germinal center NHL cells. Surprisingly, we observe that much of this synergy is due to Prednisolone - a glucocorticoid receptor agonist (GRag) component of CHOP. Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag. Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL. These preclinical data reveal an unanticipated biological intersection between GR-mediated gene regulation and EZH2-mediated chromatin remodeling. The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.
Asunto(s)
Antineoplásicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Benzamidas/farmacología , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Linfoma no Hodgkin/tratamiento farmacológico , Piridonas/farmacología , Animales , Compuestos de Bifenilo , Línea Celular Tumoral , Ciclofosfamida/farmacología , Dexametasona/farmacología , Doxorrubicina/farmacología , Evaluación Preclínica de Medicamentos , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Glucocorticoides/farmacología , Humanos , Linfoma no Hodgkin/metabolismo , Ratones SCID , Morfolinas , Trasplante de Neoplasias , Prednisolona/farmacología , Prednisona/farmacología , Distribución Aleatoria , Receptores de Glucocorticoides/agonistas , Receptores de Glucocorticoides/metabolismo , Vincristina/farmacologíaRESUMEN
EPZ-5676 [(2R,3R,4S,5R)-2-(6-amino-9H-purin-9-yl)-5-((((1r,3S)-3-(2-(5-(tert-butyl)-1H-benzo[d]imidazol-2-yl)ethyl)cyclobutyl)(isopropyl)amino)methyl)tetrahydrofuran-3,4-diol], a small-molecule inhibitor of the protein methyltransferase DOT1L, is currently under clinical investigation for acute leukemias bearing MLL-rearrangements (MLL-r). In this study, we evaluated EPZ-5676 in combination with standard of care (SOC) agents for acute leukemias as well as other chromatin-modifying drugs in cellular assays with three human acute leukemia cell lines: MOLM-13 (MLL-AF9), MV4-11 (MLL-AF4), and SKM-1 (non-MLL-r). Studies were performed to evaluate the antiproliferative effects of EPZ-5676 combinations in a cotreatment model in which the second agent was added simultaneously with EPZ-5676 at the beginning of the assay, or in a pretreatment model in which cells were incubated for several days in the presence of EPZ-5676 prior to the addition of the second agent. EPZ-5676 was found to act synergistically with the acute myeloid leukemia (AML) SOC agents cytarabine or daunorubicin in MOLM-13 and MV4-11 MLL-r cell lines. EPZ-5676 is selective for MLL-r cell lines as demonstrated by its lack of effect either alone or in combination in the nonrearranged SKM-1 cell line. In MLL-r cells, the combination benefit was observed even when EPZ-5676 was washed out prior to the addition of the chemotherapeutic agents, suggesting that EPZ-5676 sets up a durable, altered chromatin state that enhances the chemotherapeutic effects. Our evaluation of EPZ-5676 in conjunction with other chromatin-modifying drugs also revealed a consistent combination benefit, including synergy with DNA hypomethylating agents. These results indicate that EPZ-5676 is highly efficacious as a single agent and synergistically acts with other chemotherapeutics, including AML SOC drugs and DNA hypomethylating agents in MLL-r cells.
Asunto(s)
Antineoplásicos/administración & dosificación , Bencimidazoles/administración & dosificación , Proliferación Celular/efectos de los fármacos , Inhibidores de Crecimiento/administración & dosificación , Leucemia Mieloide Aguda/tratamiento farmacológico , Metiltransferasas/antagonistas & inhibidores , Línea Celular Tumoral , Sinergismo Farmacológico , N-Metiltransferasa de Histona-Lisina , Humanos , Leucemia Mieloide Aguda/patología , Metilación/efectos de los fármacos , Metiltransferasas/metabolismoRESUMEN
Mutations within the catalytic domain of the histone methyltransferase EZH2 have been identified in subsets of patients with non-Hodgkin lymphoma (NHL). These genetic alterations are hypothesized to confer an oncogenic dependency on EZH2 enzymatic activity in these cancers. We have previously reported the discovery of EPZ005678 and EPZ-6438, potent and selective S-adenosyl-methionine-competitive small molecule inhibitors of EZH2. Although both compounds are similar with respect to their mechanism of action and selectivity, EPZ-6438 possesses superior potency and drug-like properties, including good oral bioavailability in animals. Here, we characterize the activity of EPZ-6438 in preclinical models of NHL. EPZ-6438 selectively inhibits intracellular lysine 27 of histone H3 (H3K27) methylation in a concentration- and time-dependent manner in both EZH2 wild-type and mutant lymphoma cells. Inhibition of H3K27 trimethylation (H3K27Me3) leads to selective cell killing of human lymphoma cell lines bearing EZH2 catalytic domain point mutations. Treatment of EZH2-mutant NHL xenograft-bearing mice with EPZ-6438 causes dose-dependent tumor growth inhibition, including complete and sustained tumor regressions with correlative diminution of H3K27Me3 levels in tumors and selected normal tissues. Mice dosed orally with EPZ-6438 for 28 days remained tumor free for up to 63 days after stopping compound treatment in two EZH2-mutant xenograft models. These data confirm the dependency of EZH2-mutant NHL on EZH2 activity and portend the utility of EPZ-6438 as a potential treatment for these genetically defined cancers.
Asunto(s)
Antineoplásicos/farmacología , Benzamidas/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Linfoma no Hodgkin/tratamiento farmacológico , Complejo Represivo Polycomb 2/antagonistas & inhibidores , Complejo Represivo Polycomb 2/genética , Piridonas/farmacología , Animales , Apoptosis/efectos de los fármacos , Compuestos de Bifenilo , Dominio Catalítico/genética , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Femenino , Humanos , Linfoma no Hodgkin/patología , Masculino , Ratones , Ratones SCID , Datos de Secuencia Molecular , Morfolinas , Mutación Puntual , Ratas , Ratas Sprague-Dawley , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
(2R,3R,4S,5R)-2-(6-Amino-9H-purin-9-yl)-5-((((1r,3S)-3-(2-(5-(tert-butyl)-1H-benzo[d]imidazol-2-yl)ethyl)cyclobutyl)(isopropyl)amino)methyl)tetrahydrofuran-3,4-diol (EPZ-5676) is a novel DOT1L histone methyltransferase inhibitor currently in clinical development for the treatment of MLL-rearranged leukemias. This report describes the preclinical pharmacokinetics and metabolism of EPZ-5676, an aminonucleoside analog with exquisite target potency and selectivity that has shown robust and durable tumor growth inhibition in preclinical models. The in vivo pharmacokinetics in mouse, rat and dog were characterized following i.v. and p.o. administration; EPZ-5676 had moderate to high clearance, low oral bioavailability with a steady-state volume of distribution 2-3 fold higher than total body water. EPZ-5676 showed biexponential kinetics following i.v. administration, giving rise to a terminal elimination half-life (t1/2 ) of 1.1, 3.7 and 13.6 h in mouse, rat and dog, respectively. The corresponding in vitro ADME parameters were also studied and utilized for in vitro-in vivo extrapolation purposes. There was good agreement between the microsomal clearance and the in vivo clearance implicating hepatic oxidative metabolism as the predominant elimination route in preclinical species. Furthermore, low renal clearance was observed in mouse, approximating to fu -corrected glomerular filtration rate (GFR) and thus passive glomerular filtration. The metabolic pathways across species were studied in liver microsomes in which EPZ-5676 was metabolized to three monohydroxylated metabolites (M1, M3 and M5), one N-dealkylated product (M4) as well as an N-oxide (M6).
Asunto(s)
Antineoplásicos/farmacocinética , Bencimidazoles/farmacocinética , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Metiltransferasas/antagonistas & inhibidores , Animales , Antineoplásicos/sangre , Bencimidazoles/sangre , Proteínas Sanguíneas/metabolismo , Perros , Hepatocitos/metabolismo , Células de Riñón Canino Madin Darby , Masculino , Ratones , Microsomas Hepáticos/metabolismo , Permeabilidad , Ratas Sprague-DawleyRESUMEN
Rearrangements of the MLL gene define a genetically distinct subset of acute leukemias with poor prognosis. Current treatment options are of limited effectiveness; thus, there is a pressing need for new therapies for this disease. Genetic and small molecule inhibitor studies have demonstrated that the histone methyltransferase DOT1L is required for the development and maintenance of MLL-rearranged leukemia in model systems. Here we describe the characterization of EPZ-5676, a potent and selective aminonucleoside inhibitor of DOT1L histone methyltransferase activity. The compound has an inhibition constant value of 80 pM, and demonstrates 37 000-fold selectivity over all other methyltransferases tested. In cellular studies, EPZ-5676 inhibited H3K79 methylation and MLL-fusion target gene expression and demonstrated potent cell killing that was selective for acute leukemia lines bearing MLL translocations. Continuous IV infusion of EPZ-5676 in a rat xenograft model of MLL-rearranged leukemia caused complete tumor regressions that were sustained well beyond the compound infusion period with no significant weight loss or signs of toxicity. EPZ-5676 is therefore a potential treatment of MLL-rearranged leukemia and is under clinical investigation.
Asunto(s)
Antineoplásicos/farmacología , Bencimidazoles/farmacología , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Leucemia/genética , Leucemia/terapia , Metiltransferasas/antagonistas & inhibidores , Proteína de la Leucemia Mieloide-Linfoide/genética , Animales , Línea Celular Tumoral , Proliferación Celular , Metilación de ADN , Relación Dosis-Respuesta a Droga , Femenino , Histona Metiltransferasas , Histonas/metabolismo , Humanos , Trasplante de Neoplasias , Conformación Proteica , Ratas , Ratas DesnudasRESUMEN
Inactivation of the switch/sucrose nonfermentable complex component SMARCB1 is extremely prevalent in pediatric malignant rhabdoid tumors (MRTs) or atypical teratoid rhabdoid tumors. This alteration is hypothesized to confer oncogenic dependency on EZH2 in these cancers. We report the discovery of a potent, selective, and orally bioavailable small-molecule inhibitor of EZH2 enzymatic activity, (N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-5-(ethyl(tetrahydro-2H-pyran-4-yl)amino)-4-methyl-4'-(morpholinomethyl)-[1,1'-biphenyl]-3-carboxamide). The compound induces apoptosis and differentiation specifically in SMARCB1-deleted MRT cells. Treatment of xenograft-bearing mice with (N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-5-(ethyl(tetrahydro-2H-pyran-4-yl)amino)-4-methyl-4'-(morpholinomethyl)-[1,1'-biphenyl]-3-carboxamide) leads to dose-dependent regression of MRTs with correlative diminution of intratumoral trimethylation levels of lysine 27 on histone H3, and prevention of tumor regrowth after dosing cessation. These data demonstrate the dependency of SMARCB1 mutant MRTs on EZH2 enzymatic activity and portend the utility of EZH2-targeted drugs for the treatment of these genetically defined cancers.
Asunto(s)
Apoptosis , Neoplasias/terapia , Complejo Represivo Polycomb 2/antagonistas & inhibidores , Tumor Rabdoide/enzimología , Tumor Rabdoide/genética , Animales , Antineoplásicos/farmacología , Compuestos de Bifenilo/farmacología , Línea Celular Tumoral , Proliferación Celular , Diseño de Fármacos , Proteína Potenciadora del Homólogo Zeste 2 , Epigénesis Genética , Perfilación de la Expresión Génica , Células HEK293 , Histonas/metabolismo , Humanos , Ratones , Trasplante de Neoplasias , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Piridinas/farmacologíaRESUMEN
EZH2 catalyzes trimethylation of histone H3 lysine 27 (H3K27). Point mutations of EZH2 at Tyr641 and Ala677 occur in subpopulations of non-Hodgkin's lymphoma, where they drive H3K27 hypertrimethylation. Here we report the discovery of EPZ005687, a potent inhibitor of EZH2 (K(i) of 24 nM). EPZ005687 has greater than 500-fold selectivity against 15 other protein methyltransferases and has 50-fold selectivity against the closely related enzyme EZH1. The compound reduces H3K27 methylation in various lymphoma cells; this translates into apoptotic cell killing in heterozygous Tyr641 or Ala677 mutant cells, with minimal effects on the proliferation of wild-type cells. These data suggest that genetic alteration of EZH2 (for example, mutations at Tyr641 or Ala677) results in a critical dependency on enzymatic activity for proliferation (that is, the equivalent of oncogene addiction), thus portending the clinical use of EZH2 inhibitors for cancers in which EZH2 is genetically altered.