d-Amphetamine Transdermal System in Treatment of Children and Adolescents with ADHD: Secondary Endpoint Results from a Phase 2 Trial

Abstract

Background

Amphetamines are a first-line treatment for ADHD. The dextroamphetamine transdermal system (d-ATS) was developed as an alternative to oral amphetamine formulations. A randomized controlled trial of d-ATS in children and adolescents with ADHD was conducted, and its primary and key secondary endpoints were met. Here, we report secondary endpoints of the study, further assessing the efficacy and safety of d-ATS.

Methods

This study comprised a 5-week, open-label dose optimization period (DOP) followed by a 2-week, randomized, cross-over double-blind treatment period (DBP). All eligible patients received d-ATS 5 mg/9 h and were evaluated weekly for a possible dose increase to 10 mg/9 h, 15 mg/9 h, and 20 mg/9 h. Once reached, the optimal dose was maintained for the DOP and utilized during the DBP. Secondary objectives for this study included assessment of efficacy via Permanent Product Measure of Performance-Attempted and -Correct (PERMP-A, PERMP-C), ADHD-RS-IV, Conners Parent Rating Scale Revised Short Form (CPRS-R:S), and Clinical Global Impression (CGI) scores in a laboratory classroom setting. Efficacy was analyzed using a mixed-model repeated-measures (MMRM) approach. Safety assessments included treatment-emergent adverse events (TEAEs) and dermal safety.

Results

In total, 110 patients were enrolled in the DOP, and 106 patients were randomized in the DBP. Patients receiving d-ATS demonstrated significant improvement vs placebo in PERMP-A and -C scores in the DBP consistently from 2 to 12 hours post-dose (P < .001 for all timepoints). ADHD-RS-IV total scores improved during the DOP and improved further during the DBP, with a least-squares mean (95% CI) difference for d-ATS vs placebo of −13.1 (−16.2, −10.0; P < .001). Significant differences between placebo and d-ATS in the DBP were also observed for the CPRS-R:S and CGI scales (P < .001). Most TEAEs were mild or moderate, with 3 TEAEs (abdominal pain, irritated mood, and appetite loss) leading to study discontinuation in the DOP and none in the DBP. No patients were discontinued due to dermal reactions in either phase.

Conclusions

d-ATS was effective in the treatment of ADHD in children and adolescents, meeting its primary endpoint (reported elsewhere) and all secondary endpoints. d-ATS was safe and well-tolerated, with minimal dermal reactions.

Funding

Noven Pharmaceuticals, Inc.