Pardoprunox
Pardoprunox is an antiparkinsonian drug developed by Solvay for the treatment of Parkinson's disease that reached phase III clinical trials before being discontinued. It was also being investigated for the treatment of depression and anxiety but these indications appear to have been abandoned as well.
Pardoprunox acts as a D2 and D3 receptor partial agonist and 5-HT1A receptor full agonist. It also binds to D4, α1-adrenergic, α2-adrenergic, and 5-HT7 receptors with lower affinity. Relative to other dopaminergic antiparkinsonian agents, pardoprunox is thought to have significantly less of a propensity for inducing certain side effects like dyskinesia and psychosis.