To evaluate the efficacy of Vyvanse for maintenance treatment in children and adolescents with ADHD, Shire elected to conduct a double-blind, placebo-controlled, randomized withdrawal clinical trial. In this design, patients who respond to a treatment are randomized to continue receiving that treatment or placebo. Using the proportion of patients experiencing symptom relapse as a primary outcome, this type of study in patients with ADHD can be used to demonstrate long-term efficacy in lieu of conducting a long-term, placebo-controlled, parallel-group study. The utility of this design is that the period of placebo exposure, with the potential for worsening of ADHD symptoms, is relatively short.The double-blind, placebo-controlled, randomized withdrawal study was conducted in 276 children and adolescents aged 6 to 17 with ADHD. Of these patients, 236 participated in a preceding study and 40 directly enrolled. The study consisted of 4 phases:
- 4-week, open-label, dose-optimization phase in which patients received Vyvanse 30 mg/day, 50 mg/day, or 70 mg/day. Eligible subjects started on Vyvanse 30 mg/day and could be titrated in weekly increments of 20 mg until an optimal dose was reached (up to a maximum of 70 mg/day)
- 20-week, open-label, maintenance phase
- 2-week, open-label, fixed-dose phase in which patients were discontinued if they required further dose adjustments, experienced unacceptable tolerability, or had an Attention-Deficit/Hyperactivity Disorder Rating Scale, Version IV (ADHD-RS-IV) total score >22 or Clinical Global Impression Severity (CGI-S) score ≥3. Patients who maintained treatment response entered the randomized withdrawal phase.
- 6-week, double-blind, randomized withdrawal phase in which patients either received ongoing treatment with the same dose of Vyvanse (N=78) or were switched to placebo (N=79).