Ecopipam Treatment of Self-Injurious Behavior in Subjects With Lesch-Nyhan Disease

This study will be done in approximately 6 centers in approximately 4 countries, and approximately 24 subjects will be included. This study is divided into two parts. The first is a double-blinded portion lasting up to 18 weeks in total. The second portion is an optional open-label extension and lasts up to 54 weeks total. The total duration of the study, if you choose to participate in both portions, is anticipated to be up to approximately 78 weeks. The first portion of this study is double-blind and assignment to a treatment group is done randomly. In this study, there are two treatment groups. One group will receive Ecopipam for one 6-week period and placebo for two 6-week periods, and the other group will receive Ecopipam for two 6-week periods and placebo for one 6-week period. Subjects who did not experience any clinically significant side effects during the blinded portion of the study may be eligible to participate in an open-label extension that may last up to 54 weeks.