Targacept Inc., has announced top-line results from a Phase II trial of TC-5619 as a treatment for inattentive-predominant attention deficit/hyperactivity disorder (ADHDi). In the trial, TC-5619 did not meet the primary outcome measure, change from baseline on the inattention subscale of the Conners' Adult ADHD Rating Scale-Investigator-Rated (CAARS-INV), after four weeks of treatment versus placebo. Across the study measures, patients in the placebo dose group consistently improved more than patients in the TC-5619 dose groups. TC-5619 exhibited a placebo-like safety and tolerability profile in the study. The drug will not be further developed by Targacept.