RESUMO
MALT1 plays a central role in immune cell activation by transducing NF-κB signaling, and its proteolytic activity represents a key node for therapeutic intervention. Two cycles of scaffold morphing of a high-throughput biochemical screening hit resulted in the discovery of MLT-231, which enabled the successful pharmacological validation of MALT1 allosteric inhibition in preclinical models of humoral immune responses and B-cell lymphomas. Herein, we report the structural activity relationships (SARs) and analysis of the physicochemical properties of a pyrazolopyrimidine-derived compound series. In human T-cells and B-cell lymphoma lines, MLT-231 potently and selectively inhibits the proteolytic activity of MALT1 in NF-κB-dependent assays. Both in vitro and in vivo profiling of MLT-231 support further optimization of this in vivo tool compound toward preclinical characterization.
Assuntos
Inibidores de Caspase/uso terapêutico , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Ureia/análogos & derivados , Ureia/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Inibidores de Caspase/síntese química , Inibidores de Caspase/farmacologia , Descoberta de Drogas , Feminino , Humanos , Imunidade Humoral/efeitos dos fármacos , Masculino , Camundongos Endogâmicos BALB C , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Pirimidinas/síntese química , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Ureia/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The paracaspase MALT1 has gained increasing interest as a target for the treatment of subsets of lymphomas as well as autoimmune diseases, and there is a need for suitable compounds to explore the therapeutic potential of this target. Here, we report the optimization of the in vivo potency of pyrazolopyrimidines, a class of highly selective allosteric MALT1 inhibitors. High doses of the initial lead compound led to tumor stasis in an activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) xenograft model, but this compound suffered from a short in vivo half-life and suboptimal potency in whole blood. Guided by metabolism studies, we identified compounds with reduced metabolic clearance and increased in vivo half-life. In the second optimization step, masking one of the hydrogen-bond donors of the central urea moiety through an intramolecular interaction led to improved potency in whole blood. This was associated with improved in vivo potency in a mechanistic model of B cell activation. The optimized compound led to tumor regression in a CARD11 mutant ABC-DLBCL lymphoma xenograft model.
Assuntos
Sangue/metabolismo , Inibidores de Caspase/uso terapêutico , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/antagonistas & inibidores , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Ureia/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Inibidores de Caspase/síntese química , Inibidores de Caspase/metabolismo , Inibidores de Caspase/farmacocinética , Linhagem Celular Tumoral , Feminino , Meia-Vida , Humanos , Camundongos Endogâmicos BALB C , Camundongos SCID , Microssomos Hepáticos/metabolismo , Neoplasias/tratamento farmacológico , Pirazóis/síntese química , Pirazóis/metabolismo , Pirazóis/farmacocinética , Pirimidinas/síntese química , Pirimidinas/metabolismo , Pirimidinas/farmacocinética , Ratos Sprague-Dawley , Ovinos , Ureia/síntese química , Ureia/metabolismo , Ureia/farmacocinética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Starting from a weak screening hit, potent and selective inhibitors of the MALT1 protease function were elaborated. Advanced compounds displayed high potency in biochemical and cellular assays. Compounds showed activity in a mechanistic Jurkat T cell activation assay as well as in the B-cell lymphoma line OCI-Ly3, which suggests potential use of MALT1 inhibitors in the treatment of autoimmune diseases as well as B-cell lymphomas with a dysregulated NF-κB pathway. Initially, rat pharmacokinetic properties of this compound series were dominated by very high clearance which could be linked to amide cleavage. Using a rat hepatocyte assay a good in vitro-in vivo correlation could be established which led to the identification of compounds with improved PK properties.
Assuntos
Antineoplásicos/farmacologia , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/antagonistas & inibidores , Piperidinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Hepatócitos/efeitos dos fármacos , Humanos , Células Jurkat , Microssomos/efeitos dos fármacos , Estrutura Molecular , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/metabolismo , Piperidinas/síntese química , Piperidinas/química , Proteólise/efeitos dos fármacos , Ratos , Relação Estrutura-AtividadeRESUMO
Oxysterols have recently been identified as natural ligands for a G protein-coupled receptor called EBI2 (aka GPR183) ( Nature 2011 , 475 , 524 ; 519 ). EBI2 is highly expressed in immune cells ( J. Biol. Chem. 2006 , 281 , 13199 ), and its activation has been shown to be critical for the adaptive immune response and has been genetically linked to autoimmune diseases such as type I diabetes ( Nature 2010 , 467 , 460 ). Here we describe the isolation of a potent small molecule antagonist for the EBI2 receptor. First, we identified a small molecule agonist NIBR51 (1), which enabled identification of inhibitors of receptor activation. One antagonist called NIBR127 (2) was used as a starting point for a medicinal chemistry campaign, which yielded NIBR189 (4m). This compound was extensively characterized in binding and various functional signaling assays. Furthermore, we have used 4m to block migration of a monocyte cell line called U937, suggesting a functional role of the oxysterol/EBI2 pathway in these immune cells.
Assuntos
Herpesvirus Humano 4 , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Animais , Células CHO , Cálcio/metabolismo , Cricetulus , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células U937RESUMO
A series of novel benzimidazole derivatives has been designed via a scaffold morphing approach based on known calcilytics chemotypes. Subsequent lead optimisation led to the discovery of penta-substituted benzimidazoles that exhibit attractive in vitro and in vivo calcium-sensing receptor (CaSR) inhibitory profiles. In addition, synthesis and structure-activity relationship data are provided.
Assuntos
Benzimidazóis/farmacologia , Receptores de Detecção de Cálcio/antagonistas & inibidores , Benzimidazóis/química , Benzimidazóis/farmacocinética , Modelos Moleculares , Relação Estrutura-AtividadeRESUMO
A series of novel benzoxazole derivatives has been designed and shown to exhibit attractive JAK2 inhibitory profiles in biochemical and cellular assays, capable of delivering compounds with favorable PK properties in rats. Synthesis and structure-activity relationship data are also provided.