RESUMO
Herein we describe the design of a novel series of ATP competitive B-Raf inhibitors via structure-based methods. These 3-N-methylquinazoline-4(3H)-one based inhibitors exhibit both excellent cellular potency and striking B-Raf selectivity. Optimization led to the identification of compound 16, a potent, selective and orally available agent with excellent pharmacokinetic properties and robust tumor growth inhibition in xenograft studies. Our work also demonstrates that by replacing an aryl amide with an aryl sulfonamide, a multikinase inhibitor such as AZ-628, can be converted to a selective B-Raf inhibitor, a finding that should have broad application in kinase drug discovery.
Assuntos
Desenho de Fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Quinazolinas/síntese química , Quinazolinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Cristalografia por Raios X , Ativação Enzimática/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Quinazolinas/química , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Herein we describe a novel series of ATP competitive B-Raf inhibitors based on the pyrazolo[1,5-a]pyrimidine scaffold. These inhibitors exhibit both excellent cellular potency and striking B-Raf selectivity. Optimization led to the identification of compound 17, a potent, selective and orally available agent with improved physicochemical and pharmacokinetic properties.
Assuntos
Inibidores Enzimáticos/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Pirazóis/farmacologia , Pirimidinas/farmacologia , Animais , Físico-Química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Camundongos , Modelos Moleculares , Estrutura Molecular , Proteínas Proto-Oncogênicas B-raf/metabolismo , Pirazóis/síntese química , Pirazóis/química , Pirimidinas/síntese química , Pirimidinas/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Herein we describe the discovery of a novel series of ATP competitive B-Raf inhibitors via structure based drug design (SBDD). These pyridopyrimidin-7-one based inhibitors exhibit both excellent cellular potency and striking B-Raf selectivity. Optimization led to the identification of compound 17, a potent, selective and orally available agent with excellent pharmacokinetic properties and robust tumor growth inhibition in xenograft studies.
Assuntos
Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Pirimidinonas/farmacologia , Administração Oral , Disponibilidade Biológica , Cristalografia por Raios X , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Pirimidinonas/química , Pirimidinonas/farmacocinéticaRESUMO
Recent clinical data provided proof-of-concept for selective B-Raf inhibitors in treatment of B-Raf(V600E) mutant melanoma. Pyrazolopyridine-type B-Raf inhibitors previously described by the authors are potent and selective but exhibit low solubility requiring the use of amorphous dispersion-based formulation for achieving efficacious drug exposures. Through structure-based design, we discovered a new class of highly potent aminopyrimidine-based B-Raf inhibitors with improved solubility and pharmacokinetic profiles. The hinge binding moiety possesses a basic center imparting high solubility at gastric pH, addressing the dissolution limitation observed with our previous series. In our search for an optimal linker-hinge binding moiety system, amide-linked thieno[3,2-d]pyrimidine analogues 32 and 35 (G945), molecules with desirable physicochemical properties, emerged as lead compounds with strong efficacy in a B-Raf(V600E) mutant mouse xenograft model. Synthesis, SAR, lead selection, and evaluation of key compounds in animal studies will be described.
Assuntos
Aminopiridinas/síntese química , Antineoplásicos/síntese química , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Aminopiridinas/farmacocinética , Aminopiridinas/farmacologia , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Camundongos , Modelos Moleculares , Estrutura Molecular , Transplante de Neoplasias , Quinazolinas/síntese química , Quinazolinas/farmacocinética , Quinazolinas/farmacologia , Ratos , Solubilidade , Relação Estrutura-Atividade , Tiofenos/síntese química , Tiofenos/farmacocinética , Tiofenos/farmacologia , Transplante HeterólogoRESUMO
The V600E mutation of B-Raf kinase results in constitutive activation of the MAPK signaling pathway and is present in approximately 7% of all cancers. Using structure-based design, a novel series of pyrazolopyridine inhibitors of B-Raf(V600E) was developed. Optimization led to the identification of 3-methoxy pyrazolopyridines 17 and 19, potent, selective, and orally bioavailable agents that inhibited tumor growth in a mouse xenograft model driven by B-Raf(V600E) with no effect on body weight. On the basis of their in vivo efficacy and preliminary safety profiles, 17 and 19 were selected for further preclinical evaluation.