Dopamine D2/D3 and serotonin 5-HT1A/5-HT2A receptors (multi-target)

Class

Oral multi-target antipsychotic (Hansoh Pharma, Class 1 innovative drug): agonist at dopamine D2 and D3 receptors and at the serotonin 5-HT1A receptor (partial), with antagonist activity at the serotonin 5-HT2A receptor. First cleared by NMPA for schizophrenia (March 2022); a separate clinical application for bipolar I manic episodes was later approved.

This mechanism describes a multi-target antipsychotic acting on both the dopamine and serotonin systems, two neurotransmitter networks implicated in psychotic and mood disorders. The compound acts as a partial agonist at dopamine D2 and D3 receptors, meaning it activates these receptors weakly rather than fully blocking or fully stimulating them, which can dampen excess dopamine signaling in overactive brain circuits while providing a baseline of activity in circuits where dopamine tone is low. It also partially activates serotonin 5-HT1A receptors, a mechanism associated with mood stabilization and reduced motor side effects, and blocks 5-HT2A receptors, which further modulates dopamine release in specific brain regions and is linked to antipsychotic efficacy and improved tolerability. Combining these four activities in one molecule aims to treat the hallucinations, delusions, and disorganized thinking of psychotic illness while minimizing movement-related side effects and mood disturbance that can accompany therapies acting on a single receptor type. This class of multi-target agents is used broadly in psychiatric conditions marked by dysregulated dopamine and serotonin signaling, including schizophrenia and manic states associated with bipolar disorder, where balancing rather than simply suppressing neurotransmission is thought to produce a more favorable clinical profile.