The STARS phase 2 study: a randomized controlled trial of gaboxadol in Angelman syndrome

Objective: To evaluate safety and tolerability and exploratory efficacy endpoints for gaboxadol (OV101) compared with placebo in individuals with Angelman syndrome (AS). Methods: Gaboxadol is a highly selective orthosteric agonist that activates γ-subunit–containing extrasynaptic γ-aminobutyric acid type A (GABAA) receptors. In a multicenter, double-blind, placebo-controlled, parallel-group trial, adolescent and adult individuals with a molecular diagnosis of AS were randomized (1:1:1) to 1 of 3 dosing regimens for a duration of 12 weeks: placebo morning dose and gaboxadol 15 mg evening dose (qd); gaboxadol 10 mg morning dose and 15 mg evening dose (bid); or placebo morning and evening dose. Safety and tolerability were monitored throughout the study. Prespecified exploratory efficacy endpoints included adapted Clinical Global Impression–Severity (CGI-S) and Clinical Global Impression–Improvement (CGI-I) scales which documented the clinical severity at baseline and change after treat...