Efforts at Abbvie Inc. to selectively target voltage-gated sodium channel subunit alpha Nav1.7 to treat pain led to the discovery of quinoline and quinolone agents and, through structure-activity relationship studies, the candidate product ABBV-318. While Nav1.7 potency could be achieved with earlier compounds, efforts were required to improve characteristics including hERG activity, pharmacokinetics and selectivity over Nav1.5, yielding compounds which blocked Nav1.7 as well as another target for treating pain, Nav1.8.