Safety and Efficacy of ABT-089 in Pediatric Attention-Deficit/Hyperactivity Disorder: Results from Two Randomized Placebo-Controlled Clinical Trials

Objective: To assess the safety and efficacy of ABT-089, a novel alpha(4)beta(2) neuronal nicotinic receptor partial agonist, vs. placebo in children with attention-deficit/hyperactivity disorder (ADHD). Method: Two multicenter, randomized, double-blind, placebo-controlled, parallel-group studies of children 6 through 12 years of age were conducted. Study 1 (n = 274) assessed six treatment groups over 8 weeks: 4 once-daily (QD) ABT-089 doses (0.085-0.700 mg/kg), QD atomoxetine, and placebo. Study 2 (n = 119) assessed three treatment groups over 6 weeks: 2 QD ABT-089 doses (0.7 mg/kg, 1.4 mg/kg) and placebo. The primary efficacy variable was the investigator-administered Attention-Deficit/Hyperactivity Disorder Rating Scale-IV: Home Version (ADHD-RS-IV [HV]) Total Score. Safety was assessed by adverse event (AE) monitoring, laboratory tests, vital signs, physical examinations, and electrocardiogram measures. Results: There was no statistically significant difference between ABT-089 and placebo in mean change from baseline to final evaluation of ADHD-RS-IV (HV) Total Score or other outcome measures at any dose in either study. In Study 1, atomoxetine showed statistically significant improvement for the primary and most secondary endpoints. ABT-089 was generally safe and well tolerated, with no statistically significant difference between any ABT-089 dose and placebo in the overall incidence of any specific AE, and no clinically significant changes in other safety measures. Conclusions: ABT-089 did not show efficacy on the primary efficacy variable, the ADHD-RS-IV (MV) Total Score, or other measures of ADHD symptomatology in children with ADHD, and had a safety profile similar to placebo. These results contrast with published reports of efficacy of nicotinic modulators in adults with ADHD. J. Am. Acad. Child Adolesc. Psychiatry, 2011;50(1):73-84. Clinical Trial Registry Information- M06-888 (Study 1): A Safety and Efficacy Study of ABT-089 in Children With Attention-Deficit/Hyperactivity Disorder (ADHD), URL: http://clinicaltrials.gov, unique identifier: NCT00528697. M10-345 (Study 2): Safety and Tolerability Study of ABT-089 in Children With Attention-Deficit/Hyperactivity Disorder (ADHD), URL: http://clinicaltrials.gov, unique identifier: NCT00640419.