RESUMO
Transforming growth factor-ß (TGFß) is an important driver of tumor growth via intrinsic and extrinsic mechanisms, and is therefore an attractive target for developing cancer therapeutics. Using preclinical models, we characterized the anti-tumor activity of a small molecule inhibitor of TGFß receptor I (TGFßRI), galunisertib (LY2157299 monohydrate). Galunisertib demonstrated potent and selective inhibition of TGFßRI with corresponding inhibition of downstream signaling via inhibition of SMAD phosphorylation (pSMAD). Galunisertib also inhibited TGFß-induced pSMAD in vivo, which enabled a pharmacokinetic/pharmacodynamic profile in Calu6 and EMT6-LM2 tumors. Galunisertib demonstrated anti-tumor activity including inhibition of tumor cell migration and mesenchymal phenotype, reversal of TGFß-mediated immune-suppression, and tumor growth delay. A concentration-effect relationship was established with a dosing schedule to achieve the optimal level of target modulation. Finally, a rat model demonstrated a correlation between galunisertib-dependent inhibition of pSMAD in tumor tissues and in PBMCs, supporting the use of PBMCs for assessing pharmacodynamic effects. Galunisertib has been tested in several clinical studies with evidence of anti-tumor activity observed in subsets of patients. Here, we demonstrate that galunisertib inhibits a number of TGFß-dependent functions leading to anti-tumor activity. The enhanced understanding of galunisertib provides rationale for further informed clinical development of TGFß pathway inhibitors.
RESUMO
Transforming growth factor-beta (TGF-ß) signaling regulates a wide range of biological processes. TGF-ß plays an important role in tumorigenesis and contributes to the hallmarks of cancer, including tumor proliferation, invasion and metastasis, inflammation, angiogenesis, and escape of immune surveillance. There are several pharmacological approaches to block TGF-ß signaling, such as monoclonal antibodies, vaccines, antisense oligonucleotides, and small molecule inhibitors. Galunisertib (LY2157299 monohydrate) is an oral small molecule inhibitor of the TGF-ß receptor I kinase that specifically downregulates the phosphorylation of SMAD2, abrogating activation of the canonical pathway. Furthermore, galunisertib has antitumor activity in tumor-bearing animal models such as breast, colon, lung cancers, and hepatocellular carcinoma. Continuous long-term exposure to galunisertib caused cardiac toxicities in animals requiring adoption of a pharmacokinetic/pharmacodynamic-based dosing strategy to allow further development. The use of such a pharmacokinetic/pharmacodynamic model defined a therapeutic window with an appropriate safety profile that enabled the clinical investigation of galunisertib. These efforts resulted in an intermittent dosing regimen (14 days on/14 days off, on a 28-day cycle) of galunisertib for all ongoing trials. Galunisertib is being investigated either as monotherapy or in combination with standard antitumor regimens (including nivolumab) in patients with cancer with high unmet medical needs such as glioblastoma, pancreatic cancer, and hepatocellular carcinoma. The present review summarizes the past and current experiences with different pharmacological treatments that enabled galunisertib to be investigated in patients.
Assuntos
Antineoplásicos/uso terapêutico , Descoberta de Drogas , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirazóis/uso terapêutico , Quinolinas/uso terapêutico , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Administração Oral , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/química , Antineoplásicos/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Esquema de Medicação , Cardiopatias/induzido quimicamente , Estrutura Molecular , Terapia de Alvo Molecular , Neoplasias/enzimologia , Neoplasias/patologia , Fosforilação , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Serina-Treonina Quinases/metabolismo , Pirazóis/administração & dosagem , Pirazóis/efeitos adversos , Pirazóis/química , Pirazóis/farmacocinética , Quinolinas/administração & dosagem , Quinolinas/efeitos adversos , Quinolinas/química , Quinolinas/farmacocinética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Resultado do Tratamento , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In our continuing effort to expand the SAR of the quinoline domain of dihydropyrrolopyrazole series, we have discovered compound 15d, which demonstrated the antitumor efficacy with oral bioavailability. This effort also demonstrated that the PK/PD in vivo target inhibition paradigm is an effective approach to assess potential for antitumor efficacy. The dihydropyrrolopyrazole inhibitor 15d (LY2109761) is representative of a novel series of antitumor agents.
Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirazóis/farmacologia , Pirróis/farmacologia , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Administração Oral , Animais , Antineoplásicos/química , Disponibilidade Biológica , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Camundongos , Camundongos Nus , Modelos Moleculares , Conformação Molecular , Inibidores de Proteínas Quinases/química , Pirazóis/síntese química , Pirazóis/química , Pirróis/síntese química , Pirróis/química , Ratos , Receptor do Fator de Crescimento Transformador beta Tipo I , Estereoisomerismo , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A vinyl azide cyclization method was used to synthesize three different carbocyclic[g]indole scaffolds as inhibitors of human nonpancreatic secretory phospholipase A2. Each scaffold demonstrated potent enzyme activity in a chromogenic assay system, with select examples also demonstrating potent activity in a secondary DOC/PC assay. Compound 11, representative of the cyclopent[g]indole series, gave an IC50 of 10 nM for the inhibition of hnps-PLA2 in the chromogenic assay.
Assuntos
Acetatos/síntese química , Ciclopentanos/síntese química , Indóis/síntese química , Fosfolipases A/antagonistas & inibidores , Acetatos/química , Ciclopentanos/química , Humanos , Indóis/química , Fosfolipases A/química , Fosfolipases A2 , Relação Estrutura-AtividadeRESUMO
Transforming growth factor beta (TGF-beta) signaling pathways regulate a wide variety of cellular processes including cell proliferation, differentiation, extracellular matrix deposition, development, and apoptosis. TGF-beta type-I receptor (TbetaRI) is the major receptor that triggers several signaling events by activating downstream targets such as the Smad proteins. The intracellular kinase domain of TbetaRI is essential for its function. In this study, we have identified a short phospho-Smad peptide, pSmad3(-3), KVLTQMGSPSIRCSS(PO4)VS as a substrate of TbetaRI kinase for in vitro kinase assays. This peptide is uniquely phosphorylated by TbetaRI kinase at the C-terminal serine residue, the phosphorylation site of its parent Smad protein in vivo. Specificity analysis demonstrated that the peptide is phosphorylated by only TbetaRI and not TGF-beta type-II receptor kinase, indicating that the peptide is a physiologically relevant substrate suitable for kinetic analysis and screening of TbetaRI kinase inhibitors. Utilizing pSmad3(-3) as a substrate, we have shown that novel pyrazole compounds are potent inhibitors of TbetaRI kinase with K(i) value as low as 15 nM. Kinetic analysis revealed that these pyrazoles act through the ATP-binding site and are typical ATP competitive inhibitors with tight binding kinetics. More importantly, these compounds were shown to inhibit TGF-beta-induced Smad2 phosphorylation in vivo in NMuMg mammary epithelial cells with potency equivalent to the inhibitory activity in the in vitro kinase assay. Cellular selectivity analysis demonstrated that these pyrazoles are capable of inhibiting activin signaling but not bone morphogenic protein or platelet-derived growth factor signal transduction pathways. Further functional analysis revealed that pyrazoles are capable of blocking the TGF-beta-induced epithelial-mesenchymal transition in NMuMg cells, a process involved in the progression of cancer, fibrosis, and other human diseases. These pyrazoles provide a foundation for future development of potent and selective TbetaRI kinase inhibitors to treat human disease.
Assuntos
Células Epiteliais/citologia , Inibidores do Crescimento/química , MAP Quinase Quinase Quinases/antagonistas & inibidores , Mesoderma/citologia , Inibidores de Proteínas Quinases/química , Pirazóis/química , Fator de Crescimento Transformador beta/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Animais , Ligação Competitiva , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/química , Células Epiteliais/efeitos dos fármacos , Inibidores do Crescimento/metabolismo , Células HeLa , Humanos , Cinética , MAP Quinase Quinase Quinases/metabolismo , Espectrometria de Massas , Mesoderma/química , Mesoderma/efeitos dos fármacos , Camundongos , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/metabolismo , Pirazóis/metabolismo , Serina/metabolismo , Proteína Smad2 , Proteína Smad3 , Especificidade por Substrato/efeitos dos fármacos , Transativadores/antagonistas & inibidores , Transativadores/metabolismo , Fator de Crescimento Transformador beta/fisiologiaRESUMO
The transforming growth factor-beta (TGF-beta) superfamily of ligands has a pivotal role in the regulation of a wide variety of physiological processes from development to pathogenesis. Since the discovery of the prototypic member, TGF-beta, almost 20 years ago, there have been tremendous advances in our understanding of the complex biology of this superfamily. Deregulation of TGF-beta has been implicated in the pathogenesis of a variety of diseases, including cancer and fibrosis. Here we present the rationale for evaluating TGF-beta signalling inhibitors as cancer therapeutics, the structures of small-molecule inhibitors that are in development and the targeted drug discovery model that is being applied to their development.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Desenho de Fármacos , Humanos , Neoplasias/metabolismo , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/metabolismoRESUMO
The pathological activation of the transforming growth factor beta (TGFbeta) pathway plays a critical role in the progression of fibrotic diseases and also enhances tumor invasiveness and metastasis. Due to its central role in TGFbeta signaling, the TGFbeta type I receptor (TbetaRI) is emerging as an exciting target for blockade of the TGFbeta pathway. In this review we will discuss how three independent drug discovery strategies, ie, target-hopping, high-throughput screening and virtual screening, have converged in the identification of inhibitors of TalphaRI kinase. Structural studies have provided insight into the potency and selectivity of these inhibitors and form the basis for structure-based design optimization strategies. These efforts have enabled the production of potent, selective inhibitors for dissecting the TGFalpha pathway and assessing the usefulness of TalphaRI blockade in the treatment of fibrotic diseases and cancer.
Assuntos
Receptores de Ativinas Tipo I/uso terapêutico , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/uso terapêutico , Fator de Crescimento Transformador beta/metabolismo , Receptores de Ativinas Tipo I/farmacologia , Sequência de Aminoácidos , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Estrutura Molecular , Isoformas de Proteínas , Proteínas Serina-Treonina Quinases , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/antagonistas & inibidores , Fator de Crescimento Transformador beta/uso terapêuticoRESUMO
We have expanded our previously reported series of pyrazole-based inhibitors of the TGF-beta type I receptor kinase domain (TbetaR-I) to now include new 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole analogues. Limited examination of the SAR of this new series in both enzyme and cell based in vitro assays has revealed selectivity differences with respect to p38 MAP kinase (p38 MAPK) depending on the nature of the 'warhead' group on the dihydropyrrolopyrazole ring. As with our original pyrazole series, phenyl substituents tended to show greater selectivity against p38 MAPK than those comprised of the quinoline-4-yl moiety. We have also achieved co-crystallization and X-ray analysis of compounds 3 and 15, two potent examples of this new series, with the TbetaR-I receptor kinase domain.
Assuntos
Receptores de Ativinas Tipo I/antagonistas & inibidores , Inibidores Enzimáticos/síntese química , Pirazóis/síntese química , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Receptores de Ativinas Tipo I/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Células Cultivadas , Cristalografia por Raios X , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Concentração Inibidora 50 , Proteínas Serina-Treonina Quinases , Pirazóis/metabolismo , Pirazóis/farmacologia , Quinolinas/química , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Relação Estrutura-Atividade , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Pyrazole-based inhibitors of the transforming growth factor-beta type I receptor kinase domain (TbetaR-I) are described. Examination of the SAR in both enzyme- and cell-based in vitro assays resulted in the emergence of two subseries featuring differing selectivity versus p38 MAP kinase. A common binding mode at the active site has been established by successful cocrystallization and X-ray analysis of potent inhibitors with the TbetaR-I receptor kinase domain.
Assuntos
Derivados de Benzeno/síntese química , Derivados de Benzeno/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirazóis/síntese química , Pirazóis/farmacologia , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Células 3T3 , Trifosfato de Adenosina/metabolismo , Animais , Derivados de Benzeno/química , Derivados de Benzeno/metabolismo , Sítios de Ligação , Linhagem Celular , Cristalografia por Raios X , Inibidores Enzimáticos/metabolismo , Humanos , Concentração Inibidora 50 , Camundongos , Vison , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Modelos Moleculares , Proteínas Serina-Treonina Quinases/química , Estrutura Terciária de Proteína , Pirazóis/química , Pirazóis/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/química , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Spodoptera , Relação Estrutura-Atividade , Proteínas Quinases p38 Ativadas por MitógenoRESUMO
An efficient alternative to the Ullmann ether synthesis of diaryl ethers, diaryl thioethers, and diarylamines involving the S(N)Ar addition of a phenol, thiophenol, or aniline to an appropriate aryl halide, mediated by potassium-fluoride alumina and 18-crown-6 in acetonitrile or DMSO, is described. Expansion of the reaction conditions to include DMSO as solvent has resulted in a far greater range of substitution patterns permitted on the electrophile. For example, it was found that electronically unfavorable 3-chlorobenzonitrile could be condensed with 3-methoxyphenol to form the corresponding diaryl ether in 66% yield, a combination not normally amenable to Ullmann coupling. Electron-withdrawing groups present on the electrophile may be as diverse as nitro, cyano, formyl, acetyl, ester, amide, and even aryl. The method features a simple reaction procedure that provides products in generally good to excellent purified yields.