WAY-181187 is a high affinity and selective 5-HT6 agonist. It displays 60-fold selectivity over other 5-HT and monoamine receptors. WAY-181187 stimulates cAMP, ERK1/2 and Fyn kinase signaling pathway through serotonin receptor activation. WAY-181187 produced both antidepressant-like and anxiolytic-like effects in the animal model. It had been in phase I clinical trial for the treatment of anxiety disorders but this research has been discontinued.

The investigational psychopharmacologic drug candidate CP 615003 (NGD 91-3) is a potent subtype-selective partial agonist at the GABA-A receptor complex. It was designed to be fast acting without causing the sedation, memory impairment, addiction or potentiation of effects of alcohol associated with conventional anti-anxiety medication. Tissue distribution studies conducted during early clinical development of CP 615003 suggested limited brain penetration. In the Phase II clinical study, subjects tested at the high dose of NGD 91-3 showed a trend toward efficacy that did not achieve statistical significance.