RESUMO
We have recently disclosed 5-phenyl-N-(pyridin-2-ylmethyl)-2-(pyrimidin-5-yl)quinazolin-4-amine 1 as a potent IKur current blocker with selectivity versus hERG, Na and Ca channels, and an acceptable preclinical PK profile. Upon further characterization in vivo, compound 1 demonstrated an unacceptable level of brain penetration. In an effort to reduce the level of brain penetration while maintaining the overall profile, SAR was developed at the C2' position for a series of close analogues by employing hydrogen bond donors. As a result, 5-[5-phenyl-4-(pyridin-2-ylmethylamino)quinazolin-2-yl]pyridine-3-sulfonamide (25) was identified as the lead compound in this series. Compound 25 showed robust effects in rabbit and canine pharmacodynamic models and an acceptable cross-species pharmacokinetic profile and was advanced as the clinical candidate. Further optimization of 25 to mitigate pH-dependent absorption resulted in identification of the corresponding phosphoramide prodrug (29) with an improved solubility and pharmacokinetic profile.
Assuntos
Fibrilação Atrial/tratamento farmacológico , Bloqueadores dos Canais de Potássio/uso terapêutico , Quinazolinas/uso terapêutico , Bloqueadores dos Canais de Sódio/uso terapêutico , Sulfonamidas/uso terapêutico , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Cães , Espectrometria de Massas , Bloqueadores dos Canais de Potássio/farmacologia , Espectroscopia de Prótons por Ressonância Magnética , Quinazolinas/química , Quinazolinas/farmacologia , Coelhos , Bloqueadores dos Canais de Sódio/farmacologia , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologiaRESUMO
A new series of phenylquinazoline inhibitors of Kv 1.5 is disclosed. The series was optimized for Kv 1.5 potency, selectivity versus hERG, pharmacokinetic exposure, and pharmacodynamic potency. 5-Phenyl-N-(pyridin-2-ylmethyl)-2-(pyrimidin-5-yl)quinazolin-4-amine (13k) was identified as a potent and ion channel selective inhibitor with robust efficacy in the preclinical rat ventricular effective refractory period (VERP) model and the rabbit atrial effective refractory period (AERP) model.