Effect of Ecopipam, a Selective Dopamine-1 Receptor Antagonist, on Tic Characteristics as Assessed by the YGTSS: Results from the Phase IIb (D1AMOND) Randomized, Double-blind, Placebo-controlled Clinical Trial in Tourette Syndrome
Donald Gilbert1, George Karkanias2, Frederick Munschauer2, Stephen Wanaski3, Timothy Cunniff3
1Cincinnati Children's Hospital Med. Ctr., 2Emalex Biosciences, Inc., 3Paragon Biosciences, LLC
Objective:
Assess the effect of ecopipam treatment on motor and phonic/vocal tic characteristics: number, frequency, intensity, complexity, and interference comprising the Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS) in subjects ages 6 to <18 years with Tourette Syndrome (TS).
Background:
Whether features of tics are more or less responsive to treatment is unknown. Ecopipam, a first-in-class selective dopamine-1 receptor antagonist, is in development for TS. In a phase IIb trial, YGTSS-TTS was reduced by 30% (p=0.01) from baseline to week 12 for the ecopipam group. No weight gain, or drug-induced movement disorders were identified. Headache (9.2%), fatigue (6.6%), somnolence (6.6%), insomnia (5.3%), and restlessness (5.3%) were the most common adverse reactions.
Design/Methods:
In the trial, subjects were randomly assigned 1:1 to ecopipam (n =76) or placebo (n = 77). This post-hoc analysis examines YGTSS-TTS characteristics at baseline, weeks 4, 6, 8, and 12, utilizing a mixed model for repeated measures analysis of change from baseline.
Results:
For motor tics, the largest reductions were in intensity scores [ecopipam – placebo LS Means difference of -0.48 (95% confidence interval -0.79 to -0.17); p < 0.01] followed by number, frequency, and interference (ecopipam – placebo differences ranging from -0.34 to -0.43; all p < 0.05). For phonic tics, the largest reduction was in complexity scores [ecopipam – placebo LS Means difference of -0.48 (95% confidence interval -0.91 to -0.06); p = 0.02]. Differences in reduction in motor tic complexity scores and all other phonic tic subscores fell short of statistical significance.
Conclusions:
Ecopipam significantly reduced both motor and phonic tics. Of the 5 motor tic characteristics, only complexity was not significantly reduced. Of phonic tic characteristics, only complexity was significantly reduced. Lower baseline phonic tics scores may limit power to identify statistical differences. The current analysis increases our understanding of ecopipam’s effects on tic characteristics.