Post Hoc Analyses of Remission From 2 Studies of SHP465 Mixed Amphetamine Salts Extended-Release in Adults With Attention-Deficit/Hyperactivity Disorder

In adults with attention-deficit/hyperactivity disorder (ADHD), reductions in ADHD-Rating Scale-IV total score (ADHD-RS-IV-TS) were significantly greater with SHP465 mixed amphetamine salts (MAS) extended-release than placebo. These post hoc analyses examined SHP465 MAS remission rates from 2 studies of adults diagnosed with ADHD. In a 7-week dose-optimization study, adults with baseline ADHD-RS-IV-TS ≥24 were randomized to SHP465 MAS (12.5–75 mg) or placebo. In a 6-week fixed-dose study, adults with baseline ADHD-RS-IV-TS ≥32 were randomized to SHP465 MAS (25, 50, or 75 mg) or placebo. Remission was defined as ADHD-RS-IV-TS ≤12. Kaplan-Meier analyses assessed time to remission. The intent-to-treat populations in the dose-optimization and fixed-dose studies, respectively, included 132 and 103 placebo and 136 and 302 SHP465 MAS participants. In the dose-optimization study, percentages (95% CI) of participants meeting the remission criterion at endpoint were 27.2% (19.7%, 34.7%) with SHP465 MAS and 9.1% (4.2%, 14.0%) with placebo. In the fixed-dose study, percentages (95% CI) of participants meeting the remission criterion at endpoint were 29.1% (24.0%, 34.3%) across all SHP465 MAS doses (25.2% [16.9%, 33.6%] for 25 mg, 30.7% [21.7%, 39.7%] for 50 mg, and 31.6% [22.4%, 40.8%] for 75 mg) and 4.9% (0.7%, 9.0%) with placebo. In both studies, time to remission favored SHP465 MAS over placebo (all nominal log-rank P < 0.0001). In conclusion, SHP465 MAS was associated with remission rates that were more than twice the magnitude of placebo in 2 clinical studies of adults with ADHD. Approximately 25% of SHP465 MAS treated participants met the remission criterion.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.