Is Ecopipam an effective treatment for Tourette syndrome? A systematic review and meta-analysis with GRADE assessment

Abstract Background and aim Tourette syndrome is a neurodevelopmental disorder characterized by the presence of motor and vocal tics, typically emerging in childhood. Ecopipam is a selective antagonist of the D1 dopamine receptor that has been evaluated in several trials for treating Tourette syndrome (TS). Our objective was to assess the efficacy and safety of Ecopipam to reduce motor and vocal tics of TS in terms of the Yale Global Tic Severity Scale (YGTSS), the Clinical Global Impression of Improvement (CGI-Improvement), and the CGI-Severity scales. Besides, we provided insights into the drug's safety profile and tolerability. Methods All clinical trials conducted on human subjects, focusing on patients diagnosed with Tourette syndrome, were included. PubMed, Scopus, Cochrane Central Register of Controlled Studies (CENTRAL), and Web of Science were searched for studies published up until December 2024. Results A total of 76 records were assessed for eligibility after our search strategy. Eventually, two randomized controlled trials and one single-arm trial were included in our study. Ecopipam showed a statistically non-significant reduction in terms of YGTSS total tic score compared to placebo at week 4 (mean difference (MD) − 1.73, 95% confidence interval (CI) [− 4 to 0.54], P = 0.14). It also exhibited statistically significant reductions in terms of CGI-severity and CGI-improvement, P = 0.03 and P = 0.009, respectively. Conclusion Ecopipam was effective in reducing tics in TS patients and also had a good safety profile. However, further follow-up studies are warranted due to the limited number of included studies and the small sample size.