Triple-Bead Mixed Amphetamine Salts (SPD465), a Novel, Enhanced Extended-Release Amphetamine Formulation for the Treatment of Adults With ADHD

Abstract

The efficacy and safety of triple-bead mixed amphetamine salts (MAS), an oral, once-daily, enhanced extended-release amphetamine formulation designed for a duration of action up to 16 hours, were evaluated in adults with attention-deficit/hyperactivity disorder (ADHD). In this phase 3, 7-week, randomized, double-blind, multicenter, placebo-controlled, parallel-group, dose-optimization study of 272 adults with ADHD (DSM-IV-TR criteria), subjects (aged 18 to 55 years) were randomly assigned to triple-bead MAS (starting dose 12.5 mg) or placebo. The primary outcome measure was change in ADHD Rating Scale-IV (ADHD-RS-IV). Secondary outcome measures included Clinical Global Impressions (CGI) scale, Time-Sensitive ADHD Symptom Scale (TASS) (measuring extended duration), Brown Attention-Deficit Disorder Scale (BADDS) (measuring executive function), Adult ADHD Impact Module (AIM-A) (measuring quality of life [QOL]), and ADHD-RS-IV hyperactivity-impulsivity and inattentiveness subscales. Adverse events (AEs), vital signs, electrocardiograms (ECGs), and laboratory data were collected. The trial was conducted from January 2005 to June 2005. Triple-bead MAS resulted in significantly greater improvement versus placebo in mean ADHD-RS-IV total score change (p < .0001), CGI-Improvement (p < .0001), TASS total score at 13-16 hours postdose (p = .002), BADDS total score (p < .0001), all AIM-A domains (p < or = .01), and ADHD-RS-IV subscales (p < .01), demonstrating extended duration of efficacy and improvements in executive function and QOL. The most common treatment-emergent AEs included insomnia, dry mouth, decreased appetite and weight, and headache. Most treatment-emergent AEs were mild or moderate in severity. Triple-bead MAS was significantly more effective than placebo in treating adult ADHD. The extended duration of action up to 16 hours and significant improvements in executive function and QOL address unique treatment needs of adults with ADHD. Treatment-emergent AEs with triple-bead MAS were consistent with amphetamine treatment.