RESUMO
A search for structurally diversified Tyk2 JH2 ligands from 6 (BMS-986165), a pyridazine carboxamide-derived Tyk2 JH2 ligand as a clinical Tyk2 inhibitor currently in late development for the treatment of psoriasis, began with a survey of six-membered heteroaryl groups in place of the N-methyl triazolyl moiety in 6. The X-ray co-crystal structure of an early lead (12) revealed a potential new binding pocket. Exploration of the new pocket resulted in two frontrunners for a clinical candidate. The potential hydrogen bonding interaction with Thr599 in the pocket was achieved with a tertiary amide moiety, confirmed by the X-ray co-crystal structure of 29. When the diversity search was extended to nicotinamides, a single fluorine atom addition was found to significantly enhance the permeability, which directly led to the discovery of 7 (BMS-986202) as a clinical Tyk2 inhibitor that binds to Tyk2 JH2. The preclinical studies of 7, including efficacy studies in mouse models of IL-23-driven acanthosis, anti-CD40-induced colitis, and spontaneous lupus, will also be presented.
Assuntos
Ciclopropanos/farmacologia , Descoberta de Drogas , Oxazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , TYK2 Quinase/antagonistas & inibidores , Animais , Catálise , Cristalografia por Raios X , Ciclopropanos/química , Humanos , Camundongos , Oxazóis/química , Ligação Proteica , Inibidores de Proteínas Quinases/química , Psoríase/tratamento farmacológico , Relação Estrutura-Atividade , TYK2 Quinase/metabolismoRESUMO
TYK2 is a nonreceptor tyrosine kinase involved in adaptive and innate immune responses. A deactivating coding variant has previously been shown to prevent receptor-stimulated activation of this kinase and provides high protection from several common autoimmune diseases but without immunodeficiency. An agent that recapitulates the phenotype of this deactivating coding variant may therefore represent an important advancement in the treatment of autoimmunity. BMS-986165 is a potent oral agent that similarly blocks receptor-stimulated activation of TYK2 allosterically and with high selectivity and potency afforded through optimized binding to a regulatory domain of the protein. Signaling and functional responses in human TH17, TH1, B cells, and myeloid cells integral to autoimmunity were blocked by BMS-986165, both in vitro and in vivo in a phase 1 clinical trial. BMS-986165 demonstrated robust efficacy, consistent with blockade of multiple autoimmune pathways, in murine models of lupus nephritis and inflammatory bowel disease, supporting its therapeutic potential for multiple immune-mediated diseases.
Assuntos
Autoimunidade/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , TYK2 Quinase/química , Animais , Feminino , Voluntários Saudáveis , Compostos Heterocíclicos/farmacologia , Humanos , Interferon alfa-2/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Inibidores de Proteínas Quinases/farmacologia , TYK2 Quinase/antagonistas & inibidoresRESUMO
As a member of the Janus (JAK) family of nonreceptor tyrosine kinases, TYK2 plays an important role in mediating the signaling of pro-inflammatory cytokines including IL-12, IL-23, and type 1 interferons. The nicotinamide 4, identified by a SPA-based high-throughput screen targeting the TYK2 pseudokinase domain, potently inhibits IL-23 and IFNα signaling in cellular assays. The described work details the optimization of this poorly selective hit (4) to potent and selective molecules such as 47 and 48. The discoveries described herein were critical to the eventual identification of the clinical TYK2 JH2 inhibitor (see following report in this issue). Compound 48 provided robust inhibition in a mouse IL-12-induced IFNγ pharmacodynamic model as well as efficacy in an IL-23 and IL-12-dependent mouse colitis model. These results demonstrate the ability of TYK2 JH2 domain binders to provide a highly selective alternative to conventional TYK2 orthosteric inhibitors.
Assuntos
Niacinamida/análogos & derivados , Ácidos Nicotínicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , TYK2 Quinase/antagonistas & inibidores , Regulação Alostérica , Animais , Humanos , Ligantes , Camundongos , Niacinamida/metabolismo , Niacinamida/farmacologia , Ácidos Nicotínicos/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Relação Estrutura-AtividadeRESUMO
Small molecule JAK inhibitors have emerged as a major therapeutic advancement in treating autoimmune diseases. The discovery of isoform selective JAK inhibitors that traditionally target the catalytically active site of this kinase family has been a formidable challenge. Our strategy to achieve high selectivity for TYK2 relies on targeting the TYK2 pseudokinase (JH2) domain. Herein we report the late stage optimization efforts including a structure-guided design and water displacement strategy that led to the discovery of BMS-986165 (11) as a high affinity JH2 ligand and potent allosteric inhibitor of TYK2. In addition to unprecedented JAK isoform and kinome selectivity, 11 shows excellent pharmacokinetic properties with minimal profiling liabilities and is efficacious in several murine models of autoimmune disease. On the basis of these findings, 11 appears differentiated from all other reported JAK inhibitors and has been advanced as the first pseudokinase-directed therapeutic in clinical development as an oral treatment for autoimmune diseases.
Assuntos
Doenças Autoimunes/tratamento farmacológico , Descoberta de Drogas , Compostos Heterocíclicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , TYK2 Quinase/antagonistas & inibidores , Regulação Alostérica/efeitos dos fármacos , Animais , Cristalografia por Raios X , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacocinética , Compostos Heterocíclicos/uso terapêutico , Humanos , Camundongos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêuticoRESUMO
In sharp contrast to a previously reported series of 6-anilino imidazopyridazine based Tyk2 JH2 ligands, 6-((2-oxo-N1-substituted-1,2-dihydropyridin-3-yl)amino)imidazo[1,2-b]pyridazine analogs were found to display dramatically improved metabolic stability. The N1-substituent on 2-oxo-1,2-dihydropyridine ring can be a variety of alkyl, aryl, and heteroaryl groups, but among them, 2-pyridyl provided much enhanced Caco-2 permeability, attributed to its ability to form intramolecular hydrogen bonds. Further structure-activity relationship studies at the C3 position led to the identification of highly potent and selective Tyk2 JH2 inhibitor 6, which proved to be highly effective in inhibiting IFNγ production in a rat pharmacodynamics model and fully efficacious in a rat adjuvant arthritis model.
RESUMO
Inhibition of signal transduction downstream of the IL-23 receptor represents an intriguing approach to the treatment of autoimmunity. Using a chemogenomics approach marrying kinome-wide inhibitory profiles of a compound library with the cellular activity against an IL-23-stimulated transcriptional response in T lymphocytes, a class of inhibitors was identified that bind to and stabilize the pseudokinase domain of the Janus kinase tyrosine kinase 2 (Tyk2), resulting in blockade of receptor-mediated activation of the adjacent catalytic domain. These Tyk2 pseudokinase domain stabilizers were also shown to inhibit Tyk2-dependent signaling through the Type I interferon receptor but not Tyk2-independent signaling and transcriptional cellular assays, including stimulation through the receptors for IL-2 (JAK1- and JAK3-dependent) and thrombopoietin (JAK2-dependent), demonstrating the high functional selectivity of this approach. A crystal structure of the pseudokinase domain liganded with a representative example showed the compound bound to a site analogous to the ATP-binding site in catalytic kinases with features consistent with high ligand selectivity. The results support a model where the pseudokinase domain regulates activation of the catalytic domain by forming receptor-regulated inhibitory interactions. Tyk2 pseudokinase stabilizers, therefore, represent a novel approach to the design of potent and selective agents for the treatment of autoimmunity.
Assuntos
Modelos Moleculares , Transdução de Sinais , Linfócitos T/enzimologia , TYK2 Quinase/química , Cristalografia por Raios X , Estabilidade Enzimática , Humanos , Janus Quinase 1/genética , Janus Quinase 1/metabolismo , Janus Quinase 3/genética , Janus Quinase 3/metabolismo , Estrutura Terciária de Proteína , Receptores de Interleucina-2/genética , Receptores de Interleucina-2/metabolismo , Receptores de Trombopoetina/genética , Receptores de Trombopoetina/metabolismo , TYK2 Quinase/genéticaRESUMO
Transgenic mouse models of Alzheimer's disease (AD) are being utilized as models for elucidating AD etiology and potential therapeutic approaches. However, two major drawbacks of these models are: (1) transgenic animals often over-express amyloid beta (Abeta) to high levels compared to that seen in sporadic human AD and (2) the current intellectual property issues surrounding a number of these models make them difficult to utilize in a commercial setting. Our goal was to identify an appropriate non-transgenic mouse strain, devoid of these patent restrictions and test whether amyloid-modulating compounds will lower total brain and plasma Abeta. Plasma and brain samples were collected from eight commonly used mouse strains (C57BL/6, SJL, CF-1, DBA/2, CD-1, 129, FVB and B6D2F1; Charles River Labs) and total Abetalevels were validated and quantified with a rodent-specific monoclonal Abetaantibody. Plasma Abeta in SJL mice was the highest of the eight strains tested (213 pM +/- 21 pM), but was not significantly different than the seven other strains. Total brain Abeta in SJL mice was also the greatest of the mouse strains tested (356 pM +/- 73 pM). SJL, C57BL/6 and CF-1 mice had total brain Abeta levels that were significantly greater than Abeta levels in B6D2F1 mice (242 +/- 20 pM). In vivo efficacy of an Abeta lowering agent was observed in CF-1 mice upon oral administration of the gamma-secretase inhibitors, DAPT and LY-411575. The absolute levels of rodent brain Abeta detected and the efficacy of the gamma-secretase treatment were dependent upon the antibodies used, as well as the extraction methodology. The measurement of total brain Abeta lowering in a common mouse strain could help accelerate drug discovery programs for Alzheimer's disease without relying on costly transgenic animals that overexpress APP in a manner that may not be predictive of the effects of these compounds in human AD.
Assuntos
Peptídeos beta-Amiloides/análise , Peptídeos beta-Amiloides/sangue , Química Encefálica , Encéfalo/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , Camundongos , Reprodutibilidade dos Testes , Especificidade da EspécieRESUMO
We report a woman with anti-Yo-associated cerebellar degeneration, severe eye movement abnormalities, and no evidence of malignancy after 3 years of extensive evaluation. The prominent neuro-ophthalmologic findings suggest brainstem involvement, which may be a novel manifestation of anti-Yo associated paraneoplastic syndrome.