What is "apimostinel"

Apimostinel ( INN) (developmental code names NRX-1074, AGN-241660) is a novel antidepressant, acting as a selective partial agonist of an allosteric site of the glycine site of the NMDA receptor complex, which is under investigation by Naurex (recently acquired by Allergan) for the treatment of major depressive disorder. Its mechanism of action and effects are similar to those of rapastinel (GLYX-13), which is under development as an adjunctive therapy for treatment-resistant depression also by Naurex; however, apimostinel is 100-fold more potent by weight and, unlike GLYX-13 (which must be administered via intravenous injection), is orally-active. Apimostinel is intended by Naurex as an improved, follow-up drug to GLYX-13. The drug has shown rapid antidepressant effects in pre-clinical models of depression. In addition, similarly to GLYX-13, it is well-tolerated and lacks the schizophrenia-like psychotomimetic effects of other NMDA receptor antagonists such as ketamine. As of 2015, an intravenous formulation of apimostinel is in a phase II clinical trial for MDD, and an oral formulation is concurrently in phase I trials for MDD.