EPA-0672 – Efficacy outcomes in age and sex subgroups from two clinical trials of lisdexamfetamine dimesylate in the treatment of adults with attention-deficit/hyperactivity disorder

Abstract

Symptoms of attention-deficit/hyperactivity disorder (ADHD) persist into adulthood in many patients. Analyse post hoc the impact of sex and age on the efficacy of lisdexamfetamine dimesylate (LDX) in the treatment of adult ADHD. In NRP104.303, a 4-week, double-blind, forced-dose study, adults with ADHD were randomized (2:2:2:1) to receive LDX 30, 50 or 70 mg/day, or placebo. NRP104.304 was a 12-month, open-label, dose-optimized, extension to NRP104.303. In both studies, the primary efficacy outcome was the change from baseline in ADHD Rating Scale (ADHD-RS) total score. In NRP104.303 (N=420), least-squares mean changes from baseline to endpoint in ADHD-RS total score (standard error) were significantly greater for LDX (range across doses, −16.2 [1.06] to −18.6 [1.03]) than placebo (−8.2 [1.43]). Post hoc analyses revealed similar improvements with LDX in sex (male, LDX −16.7 [1.50] to −18.6 [1.53], placebo, −8.9 [2.12]; female, LDX −15.5 [1.56] to −19.3 [1.46], placebo −8.0 [2.02]) and age (18−39 years, LDX −15.3 [1.34] to −18.9 [1.31], placebo −5.6 [1.87]; 40−55 years, LDX −16.1 [1.81] to −17.1 [1.87], placebo −12.8 [2.52]) subgroups. In study NRP104.304 (N=349), improvements from baseline to endpoint in mean (standard deviation) ADHD-RS total score were similar between the overall population (−24.8 [11.7]) and sex and age subgroups (male −24.5 [11.5]; female −25.2 [12.0]; 18−39 years −25.3 [11.4]; 40–55 years −24.1 [12.2]). In short- and long-term adult studies, LDX was associated with improvements in ADHD symptoms in sex and age-related subgroups. Supported by funding from Shire.