Benzoxazolinone aryl sulfonamides as potent, selective Nav1.7 inhibitors with in vivo efficacy in a preclinical pain model.

ABSTRACT

Studies on human genetics have suggested that inhibitors of the Nav1.7 voltage-gated sodium channel hold considerable promise as therapies for the treatment of chronic pain syndromes. Herein, we report novel, peripherally-restricted benzoxazolinone aryl sulfonamides as potent Nav1.7 inhibitors with excellent selectivity against the Nav1.5 isoform, which is expressed in the heart muscle. Elaboration of initial lead compound 3d afforded exemplar 13, which featured attractive physicochemical properties, outstanding lipophilic ligand efficiency and pharmacological selectivity against Nav1.5 exceeding 1000-fold. Key structure-activity relationships associated with oral bioavailability were leveraged to discover compound 17, which exhibited a comparable potency/selectivity profile as well as full efficacy following oral administration in a preclinical model indicative of antinociceptive behavior.