Background: SPN-812 (extended-release viloxazine) is a structurally distinct, bicyclic, Serotonin Norepinephrine Modulating Agent (SNMA) being developed as a treatment for pediatric attention-deficit/hyperactivity disorder (ADHD). Here we present results of a Phase 3, randomized, double-blind, placebo-controlled study (P303) evaluating efficacy and safety of once-daily SPN-812 dosed at 200 mg or 400 mg in children ages 6-11yrs with ADHD.
Methods: Key inclusion criteria were confirmed DSM-5 ADHD diagnosis, ADHD-Rating Scale-5 (ADHD-RS-5) score ≥28, Clinical Global Impression (CGI)-Severity score ≥4, and free of ADHD medication ≥1 week before randomization. Subjects were randomized 1:1:1, placebo:200 mg:400 mg SPN-812. Treatment included 3 weeks titration and 5 weeks maintenance (intent-to-treat population: N=301; placebo=97, 200 mg=107, 400 mg=97). The primary efficacy endpoint was ADHD-RS-5 total score change from baseline (CFB) at end of study (EOS). Key secondary endpoints included CGI-Improvement (CGI-I) score at EOS among other measures. Safety and tolerability assessments included adverse events (AEs) alongside other parameters.
Results: Compared to placebo, greater improvements in ADHD-RS-5 total score were observed in the 200 mg and 400 mg SPN-812 treatment groups at EOS (p=0.0038, p=0.0063; respectively). A significant improvement in CGI-I score at EOS was also observed for 200 mg and 400 mg SPN-812 compared to placebo (p=0.0028, p<0.0099; respectively). AEs reported (≥5%) in SPN-812 subjects were somnolence, decreased appetite, fatigue, headache, and upper abdominal pain.
Summary: In this study, SPN-812 200 mg and 400 mg met the primary objective with statistical significance. AE-related dropouts were ≤5%, indicating SPN-812 treatment was well tolerated.
This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.