Iclepertin (developmental code name BI 425809) is an investigational nootropic to enhance the cognition and functional capacity in schizophrenia developed by Boehringer Ingelheim.

[1] BI 425809 is an inhibitor of glycine transporter 1 (Gly-T1) that in phase II improved cognition after 12 weeks in patients with schizophrenia.

If these encouraging results are confirmed in phase 3 trials, BI 425809 could provide an effective treatment for cognitive impairment associated with schizophrenia.

[2] Schizophrenia is characterized by abnormalities in glutamatergic pathways related to NMDA receptor hypofunction.

Inhibition of GlyT1 on the presynaptic membrane or astrocytes is hypothesized to increase glycine levels within the synapse.