Supernus Announces Positive Results from Phase III Study for SPN-812 in Adults with ADHD - Seite 2

About the P306 Study

The study was a randomized, double-blind, placebo controlled, multicenter, parallel group clinical trial in adult patients diagnosed with ADHD. The study had a two-arm flexible dose design where treatment was administered orally once a day over six weeks, including the titration phase up to a total daily dose of 600mg SPN-812 or matched placebo.

A total of 374 adult patients were randomized across placebo and a daily dose of SPN-812 starting with 200mg with flexible dose administration up to 600mg. The primary objective was to assess the effect of SPN-812 in reducing the symptoms of ADHD. The primary outcome measure was the change from baseline to the end of the study in the AISRS. Safety and tolerability of SPN-812 were assessed by the monitoring of adverse events (AEs), clinical laboratory tests, vital signs, ECGs, suicidality and physical examinations. Patients who completed the study were offered the opportunity to continue into an ongoing open-label safety extension study.

Topline Results

At the end of the study, SPN-812 reached statistical significance compared to placebo in the primary endpoint. Patients receiving SPN-812 had a -15.5 point change from baseline in the primary endpoint compared to -11.7 for placebo at week 6 (p=0.0040).

This primary result, based on a Mixed Model Repeated Measures (MMRM) analysis using the Full Analysis Set (FAS) population, was confirmed by sensitivity analysis with a p-value of 0.0085.

The study demonstrated fast onset of action, reaching statistical significance as early as week 2 with a p-value of 0.0397, and maintaining statistical significance through the end of the trial at week 6.

Similar to the previously reported studies in pediatric patients 6 to 17 years of age, at the end of the P306 study, SPN-812 reached statistical significance compared to placebo on the hyperactivity/impulsivity and inattention subscales of the AISRS with p-values of 0.0380 and 0.0015, respectively.

In addition, SPN-812 met the CGI-S secondary endpoint with a p-value of 0.0023 compared to placebo at week 6 and showed significant improvement as early as week 2 with a p-value of 0.0203.

Safety and tolerability

Overall, the trial exhibited a good safety and tolerability profile. Adverse events (AEs) were primarily mild to moderate leading to a low placebo-adjusted discontinuation rate due to AEs in the SPN-812 group of 4.1% (9.0% for SPN-812 compared to 4.9% in the placebo group). Treatment related AEs that reported at more than or equal to 5% for SPN-812 were insomnia, fatigue, decreased appetite, nausea, headache, and dry mouth.