PG203

PG203 (also known as CPL500036) is a small molecule agonist of the G protein-coupled receptor 52 (GPR52), currently under development by Celon Pharma S.A. for the treatment of schizophrenia, psychotic disorders, and levodopa-induced dyskinesia (LID) in Parkinson's disease. GPR52 is an orphan G protein-coupled receptor primarily expressed in the striatum and prefrontal cortex. Its activation is hypothesized to provide antipsychotic and pro-cognitive effects by modulating dopaminergic and glutamatergic neurotransmission without the metabolic or extrapyramidal side effects typically associated with D2 receptor antagonists. PG203 has completed Phase 1 studies and has been evaluated in Phase 2 trials for schizophrenia. It also serves as a reference compound for Celon Pharma's next-generation GPR52 agonists, including PG511, PG521, and PG531, which are being compared to PG203 in clinical safety and pharmacokinetic studies.