Targacept has announced that TC-5619 has failed to meet the primary efficacy outcome measure of a Phase II proof-of-concept trial to evaluate it as a treatment for attention deficit/hyperactivity disorder (ADHD) in adults.

The primary endpoint of the trial was defined as change from baseline on the Conners’ Adult ADHD Rating Scale-Investigator Rated Total ADHD Symptoms score after four, eight and 12 weeks of dosing, compared to a placebo.

The trial also included a number of assessments as secondary efficacy outcome measures, and results across all of these assessments indicated that TC-5619 had activity in the patient population.

TC-5619 was generally well-tolerated in the trial, without any serious adverse events.

The double-blind, placebo-controlled and forced-titration trial was conducted at 17 sites in the US.

The trial involved 135 non-tobacco using patients, age 18 to 65, meeting DSM-IV criteria for ADHD, who were randomised to receive either TC-5619 or placebo for 12 weeks.

TC-5619, a highly selective alpha7 neuronal nicotinic receptor modulator, is subject to licence by Targacept’s strategic partner, AstraZeneca.

ADHD is a condition that develops during childhood, and is characterised by inattention, hyperactivity and impulsivity.