A Phase 2, to Evaluating the Safety and Efficacy of Pridopidine Vs Placebo for Symptomatic Treatment in Patients With Huntington's Disease

This is a multicenter, multinational, randomized, parallel-group, double-blind, placebo-controlled, dose range finding study to compare the efficacy and safety of different doses of pridopidine versus placebo in the treatment of motor impairment in Huntington's Disease (HD).

Originally, the study was designed to assess the effect of pridopidine on motor function at 26 weeks. Due to the recognition that the primary target of pridopidine is the Sigma-1 receptor, the trial was extended from 26 to 52 weeks to evaluate the effect of pridopidine on Total Functional Capacity (TFC). A minimum of 52 weeks are needed for the placebo group to decline and allow a window to assess an effect on TFC (a prespecified endpoint). Approximately 20% of patients completed 26 weeks of the study before IRB approvals for this extension, and did not continue into the 2nd treatment period up to 52 weeks.