Zelquistinel acts through a unique binding site on the NMDA receptor, independent of the glycine site, to modulate receptor activity and enhance NMDAR-mediated synaptic plasticity.[4][5] Its mechanism of action is similar to that of rapastinel. However, unlike rapastinel, zelquistinel is orally bioavailable, exhibits increased potency, and has improved drug properties.[2][3][5] The mean half-life of Zelquistinel is reported to be from 1.21 to 2.06 hours, reaching peak plasma concentrations 30 minutes after administration.[6] In preclinical studies, single doses of zelquistinel demonstrated both rapid-acting (24-hours) and sustained (1-week) antidepressant-like effects and enhancement of long-term synaptic plasticity.[6]
On July 23, 2018, the U.S. FDA granted Fast Track designation to the development of zelquistinel as an investigational new treatment for major depressive disorder.[7]
In 2019, Allergan completed an exploratory phase IIaclinical trial of once-weekly oral zelquistinel in major depressive disorder.[1][3][8] As of 2024, zelquistinel is undergoing a phase IIb clinical trial for depression sponsored by Gate Neurosciences.[2]
^Clinical trial number NCT03586427 for "A Double-Blind, Placebo-Controlled, Fixed-Dose Study of AGN-241751 in Adult Participants With Major Depressive Disorder" at ClinicalTrials.gov