ABSTRACT
A novel alpha7 nAChR agonist, N-[(3R,5R)-1-azabicyclo[3.2.1]oct-3-yl]furo[2,3-c]pyridine-5-carboxamide (3a, PHA-709829), has been identified for the potential treatment of cognitive deficits in schizophrenia. The compound shows potent and selective alpha7 in vitro activity, excellent brain penetration, good rat oral bioavailability and robust in vivo efficacy in a rat auditory sensory gating model.
Subject(s)
Azabicyclo Compounds/pharmacology , Nicotinic Agonists/pharmacology , Pyridines/pharmacology , Receptors, Nicotinic/drug effects , Animals , Azabicyclo Compounds/chemical synthesis , Azabicyclo Compounds/chemistry , Benzamides/pharmacology , Blood Proteins/drug effects , Bridged Bicyclo Compounds/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Dogs , Dose-Response Relationship, Drug , Humans , Mice , Microsomes, Liver/drug effects , Molecular Conformation , Nicotinic Agonists/chemical synthesis , Nicotinic Agonists/chemistry , Pyridines/chemical synthesis , Pyridines/chemistry , Quinuclidines/pharmacology , Rats , Receptors, Muscarinic/drug effects , Stereoisomerism , Structure-Activity Relationship , alpha7 Nicotinic Acetylcholine ReceptorABSTRACT
A novel set of azabicyclic aryl amides have been identified as potent and selective agonists of the alpha7 nAChR. A two-pronged approach was taken to improve the potential hERG liability of previously disclosed alpha7 nAChR agonist, PNU-282,987, while maintaining the compound's other desirable pharmacological properties. The first approach involved further exploration of the aryl carboxylic acid fragment of PNU-282,987, while the second approach focused on modification of the azabicyclic amine portion of PNU-282,987. The best compounds from each series are characterized by rapid brain penetration, good oral bioavailability in rat, and demonstrate in vivo efficacy in a rat P50 auditory sensory gating assay. At least one analog from each series (1h, 1o, 2a, 9a, and 18a) shows an improved hERG safety profile over PNU-282,987.
