RESUMEN
Gastrointestinal dysfunction as a consequence of the use of opioid analgesics is of significant clinical concern. First generation drugs to treat these opioid-induced side-effects were limited by their negative impact on opioid receptor agonist-induced analgesia. Second generation therapies target a localized, peripherally-restricted, non-CNS penetrant drug distribution of opioid receptor antagonists. Herein we describe the discovery of the N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenol and -phenyl carboxamide series of µ-opioid receptor antagonists. This report highlights the discovery of the key µ-opioid receptor antagonist pharmacophore and the optimization of in vitro metabolic stability through the application of a phenol bioisostere. The compounds 27a and 31a with the most attractive in vitro profile, formed the basis for the application of Theravance Biopharma's multivalent approach to drug discovery to afford the clinical compound axelopran (TD-1211), targeted for the treatment of opioid-induced constipation.
Asunto(s)
Amidas/farmacología , Descubrimiento de Drogas , Fenoles/farmacología , Receptores Opioides mu/antagonistas & inhibidores , Amidas/síntesis química , Amidas/química , Animales , Relación Dosis-Respuesta a Droga , Cobayas , Humanos , Estructura Molecular , Fenoles/síntesis química , Fenoles/química , Receptores Opioides delta/antagonistas & inhibidores , Receptores Opioides delta/metabolismo , Receptores Opioides mu/metabolismo , Relación Estructura-ActividadRESUMEN
The effects of opioids in the central nervous system (CNS) provide significant benefit in the treatment of pain but can also lead to physical dependence and addiction, which has contributed to a growing opioid epidemic in the United States. Gastrointestinal dysfunction is an additional serious consequence of opioid use, and this can be treated with a localized drug distribution of a non-CNS penetrant, peripherally restricted opioid receptor antagonist. Herein, we describe the application of Theravance's multivalent approach to drug discovery coupled with a physicochemical property design strategy by which the N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenyl carboxamide series of µ-opioid receptor antagonists was optimized to afford the orally absorbed, non-CNS penetrant, Phase 3 ready clinical compound axelopran (TD-1211) 19i as a potential treatment for opioid-induced constipation.
RESUMEN
The enantiomeric resolution of a racemic novel cannabinoid receptor ligand conformationally restricted at the southern aliphatic chain was accomplished using a ChiralPak AD column. Both enantiomers were tested for their competitive binding to the rat brain CB1, mouse spleen CB2 and human CB2 receptors. The levorotatory isomer showed exceptionally high affinity for the CB1 receptor with a seven-fold selectivity over CB2.